NEHRP Extramural Research

<!DOCTYPE html> <html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# "> <head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("https://www.nist.gov/programs-projects/nehrp-extramural-research","20240305041050","https://web.archive.org/","web","/_static/", "1709611850"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" />  <meta charset="utf-8"/><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;/*! For license information please see nr-loader-rum-1.252.0.min.js.LICENSE.txt */ (()=>{var e,t,r={234:(e,t,r)=>{"use strict";r.d(t,{P_:()=>v,Mt:()=>b,C5:()=>s,DL:()=>w,OP:()=>S,lF:()=>T,Yu:()=>x,Dg:()=>m,CX:()=>c,GE:()=>_,sU:()=>R});var n=r(8632),i=r(9567);const o={beacon:n.ce.beacon,errorBeacon:n.ce.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},a={};function s(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!a[e])throw new Error("Info for ".concat(e," was never set"));return a[e]}function c(e,t){if(!e)throw new Error("All info objects require an agent identifier!");a[e]=(0,i.D)(t,o);const r=(0,n.ek)(e);r&&(r.info=a[e])}const u=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var d=r(7056),l=r(50);const f="[data-nr-mask]",g=()=>{const e={mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{feature_flags:[],proxy:{assets:void 0,beacon:void 0},privacy:{cookies_enabled:!0},ajax:{deny_list:void 0,block_internal:!0,enabled:!0,harvestTimeSeconds:10,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},session:{domain:void 0,expiresMs:d.oD,inactiveMs:d.Hb},ssl:void 0,obfuscate:void 0,jserrors:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},metrics:{enabled:!0,autoStart:!0},page_action:{enabled:!0,harvestTimeSeconds:30,autoStart:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,harvestTimeSeconds:30,long_task:!1,autoStart:!0},session_trace:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},harvest:{tooManyRequestsDelay:60},session_replay:{autoStart:!0,enabled:!1,harvestTimeSeconds:60,sampling_rate:10,error_sampling_rate:100,collect_fonts:!1,inline_images:!1,inline_stylesheet:!0,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){u(t)?e.mask_selector="".concat(t,",").concat(f):""===t||null===t?e.mask_selector=f:(0,l.Z)("An invalid session_replay.mask_selector was provided. '*' will be used.",t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){u(t)?e.block_selector+=",".concat(t):""!==t&&(0,l.Z)("An invalid session_replay.block_selector was provided and will not be used",t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,l.Z)("An invalid session_replay.mask_input_option was provided and will not be used",t)}},spa:{enabled:!0,harvestTimeSeconds:10,autoStart:!0}}},p={},h="All configuration objects require an agent identifier!";function v(e){if(!e)throw new Error(h);if(!p[e])throw new Error("Configuration for ".concat(e," was never set"));return p[e]}function m(e,t){if(!e)throw new Error(h);p[e]=(0,i.D)(t,g());const r=(0,n.ek)(e);r&&(r.init=p[e])}function b(e,t){if(!e)throw new Error(h);var r=v(e);if(r){for(var n=t.split("."),i=0;i<n.length-1;i++)if("object"!=typeof(r=r[n[i]]))return;r=r[n[n.length-1]]}return r}const y={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},A={};function w(e){if(!e)throw new Error("All loader-config objects require an agent identifier!");if(!A[e])throw new Error("LoaderConfig for ".concat(e," was never set"));return A[e]}function _(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");A[e]=(0,i.D)(t,y);const r=(0,n.ek)(e);r&&(r.loader_config=A[e])}const x=(0,n.mF)().o;var E=r(385),D=r(6818);const k={buildEnv:D.Re,customTransaction:void 0,disabled:!1,distMethod:D.gF,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,offset:Math.floor(E._A?.performance?.timeOrigin||E._A?.performance?.timing?.navigationStart||Date.now()),onerror:void 0,origin:""+E._A.location,ptid:void 0,releaseIds:{},session:void 0,xhrWrappable:"function"==typeof E._A.XMLHttpRequest?.prototype?.addEventListener,version:D.q4,denyList:void 0},j={};function S(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!j[e])throw new Error("Runtime for ".concat(e," was never set"));return j[e]}function R(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");j[e]=(0,i.D)(t,k);const r=(0,n.ek)(e);r&&(r.runtime=j[e])}function T(e){return function(e){try{const t=s(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}(e)}},9567:(e,t,r)=>{"use strict";r.d(t,{D:()=>i});var n=r(50);function i(e,t){try{if(!e||"object"!=typeof e)return(0,n.Z)("Setting a Configurable requires an object as input");if(!t||"object"!=typeof t)return(0,n.Z)("Setting a Configurable requires a model to set its initial properties");const r=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),o=0===Object.keys(r).length?e:r;for(let a in o)if(void 0!==e[a])try{Array.isArray(e[a])&&Array.isArray(t[a])?r[a]=Array.from(new Set([...e[a],...t[a]])):"object"==typeof e[a]&&"object"==typeof t[a]?r[a]=i(e[a],t[a]):r[a]=e[a]}catch(e){(0,n.Z)("An error occurred while setting a property of a Configurable",e)}return r}catch(e){(0,n.Z)("An error occured while setting a Configurable",e)}}},6818:(e,t,r)=>{"use strict";r.d(t,{Re:()=>i,gF:()=>o,q4:()=>n});const n="1.252.0",i="PROD",o="CDN"},385:(e,t,r)=>{"use strict";r.d(t,{Nk:()=>d,Tt:()=>s,_A:()=>o,cv:()=>l,iS:()=>a,il:()=>n,ux:()=>c,v6:()=>i,w1:()=>u});const n="undefined"!=typeof window&&!!window.document,i="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),o=n?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),a=Boolean("hidden"===o?.document?.visibilityState),s=/iPad|iPhone|iPod/.test(o.navigator?.userAgent),c=s&&"undefined"==typeof SharedWorker,u=((()=>{const e=o.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Boolean(n&&window.document.documentMode)),d=!!o.navigator?.sendBeacon,l=Math.floor(o?.performance?.timeOrigin||o?.performance?.timing?.navigationStart||Date.now())},1117:(e,t,r)=>{"use strict";r.d(t,{w:()=>o});var n=r(50);const i={agentIdentifier:"",ee:void 0};class o{constructor(e){try{if("object"!=typeof e)return(0,n.Z)("shared context requires an object as input");this.sharedContext={},Object.assign(this.sharedContext,i),Object.entries(e).forEach((e=>{let[t,r]=e;Object.keys(i).includes(t)&&(this.sharedContext[t]=r)}))}catch(e){(0,n.Z)("An error occured while setting SharedContext",e)}}}},8e3:(e,t,r)=>{"use strict";r.d(t,{L:()=>d,R:()=>c});var n=r(8325),i=r(1284),o=r(4322),a=r(3325);const s={};function c(e,t){const r={staged:!1,priority:a.p[t]||0};u(e),s[e].get(t)||s[e].set(t,r)}function u(e){e&&(s[e]||(s[e]=new Map))}function d(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:"",t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:"feature",r=arguments.length>2&&void 0!==arguments[2]&&arguments[2];if(u(e),!e||!s[e].get(t)||r)return c(t);s[e].get(t).staged=!0;const a=[...s[e]];function c(t){const r=e?n.ee.get(e):n.ee,a=o.X.handlers;if(r.backlog&&a){var s=r.backlog[t],c=a[t];if(c){for(var u=0;s&&u<s.length;++u)l(s[u],c);(0,i.D)(c,(function(e,t){(0,i.D)(t,(function(t,r){r[0].on(e,r[1])}))}))}delete a[t],r.backlog[t]=null,r.emit("drain-"+t,[])}}a.every((e=>{let[t,r]=e;return r.staged}))&&(a.sort(((e,t)=>e[1].priority-t[1].priority)),a.forEach((t=>{let[r]=t;s[e].delete(r),c(r)})))}function l(e,t){var r=e[1];(0,i.D)(t[r],(function(t,r){var n=e[0];if(r[0]===n){var i=r[1],o=e[3],a=e[2];i.apply(o,a)}}))}},8325:(e,t,r)=>{"use strict";r.d(t,{A:()=>c,ee:()=>u});var n=r(8632),i=r(2210),o=r(234);class a{constructor(e){this.contextId=e}}var s=r(3117);const c="nr@context:".concat(s.a),u=function e(t,r){var n={},s={},d={},f=!1;try{f=16===r.length&&(0,o.OP)(r).isolatedBacklog}catch(e){}var g={on:h,addEventListener:h,removeEventListener:function(e,t){var r=n[e];if(!r)return;for(var i=0;i<r.length;i++)r[i]===t&&r.splice(i,1)},emit:function(e,r,n,i,o){!1!==o&&(o=!0);if(u.aborted&&!i)return;t&&o&&t.emit(e,r,n);for(var a=p(n),c=v(e),d=c.length,l=0;l<d;l++)c[l].apply(a,r);var f=b()[s[e]];f&&f.push([g,e,r,a]);return a},get:m,listeners:v,context:p,buffer:function(e,t){const r=b();if(t=t||"feature",g.aborted)return;Object.entries(e||{}).forEach((e=>{let[n,i]=e;s[i]=t,t in r||(r[t]=[])}))},abort:l,aborted:!1,isBuffering:function(e){return!!b()[s[e]]},debugId:r,backlog:f?{}:t&&"object"==typeof t.backlog?t.backlog:{}};return g;function p(e){return e&&e instanceof a?e:e?(0,i.X)(e,c,(()=>new a(c))):new a(c)}function h(e,t){n[e]=v(e).concat(t)}function v(e){return n[e]||[]}function m(t){return d[t]=d[t]||e(g,t)}function b(){return g.backlog}}(void 0,"globalEE"),d=(0,n.fP)();function l(){u.aborted=!0,Object.keys(u.backlog).forEach((e=>{delete u.backlog[e]}))}d.ee||(d.ee=u)},5546:(e,t,r)=>{"use strict";r.d(t,{E:()=>n,p:()=>i});var n=r(8325).ee.get("handle");function i(e,t,r,i,o){o?(o.buffer([e],i),o.emit(e,t,r)):(n.buffer([e],i),n.emit(e,t,r))}},4322:(e,t,r)=>{"use strict";r.d(t,{X:()=>o});var n=r(5546);o.on=a;var i=o.handlers={};function o(e,t,r,o){a(o||n.E,i,e,t,r)}function a(e,t,r,i,o){o||(o="feature"),e||(e=n.E);var a=t[o]=t[o]||{};(a[r]=a[r]||[]).push([e,i])}},3239:(e,t,r)=>{"use strict";r.d(t,{bP:()=>s,iz:()=>c,m$:()=>a});var n=r(385);let i=!1,o=!1;try{const e={get passive(){return i=!0,!1},get signal(){return o=!0,!1}};n._A.addEventListener("test",null,e),n._A.removeEventListener("test",null,e)}catch(e){}function a(e,t){return i||o?{capture:!!e,passive:i,signal:t}:!!e}function s(e,t){let r=arguments.length>2&&void 0!==arguments[2]&&arguments[2],n=arguments.length>3?arguments[3]:void 0;window.addEventListener(e,t,a(r,n))}function c(e,t){let r=arguments.length>2&&void 0!==arguments[2]&&arguments[2],n=arguments.length>3?arguments[3]:void 0;document.addEventListener(e,t,a(r,n))}},3117:(e,t,r)=>{"use strict";r.d(t,{a:()=>n});const n=(0,r(4402).Rl)()},4402:(e,t,r)=>{"use strict";r.d(t,{Rl:()=>a,ky:()=>s});var n=r(385);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function o(e,t){return e?15&e[t]:16*Math.random()|0}function a(){const e=n._A?.crypto||n._A?.msCrypto;let t,r=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(30))),i.split("").map((e=>"x"===e?o(t,r++).toString(16):"y"===e?(3&o()|8).toString(16):e)).join("")}function s(e){const t=n._A?.crypto||n._A?.msCrypto;let r,i=0;t&&t.getRandomValues&&(r=t.getRandomValues(new Uint8Array(e)));const a=[];for(var s=0;s<e;s++)a.push(o(r,i++).toString(16));return a.join("")}},7056:(e,t,r)=>{"use strict";r.d(t,{Bq:()=>n,Hb:()=>o,IK:()=>c,oD:()=>i,uT:()=>s,wO:()=>a});const n="NRBA",i=144e5,o=18e5,a={PAUSE:"session-pause",RESET:"session-reset",RESUME:"session-resume",UPDATE:"session-update"},s={SAME_TAB:"same-tab",CROSS_TAB:"cross-tab"},c={OFF:0,FULL:1,ERROR:2}},7894:(e,t,r)=>{"use strict";function n(){return Math.round(performance.now())}r.d(t,{z:()=>n})},50:(e,t,r)=>{"use strict";function n(e,t){"function"==typeof console.warn&&(console.warn("New Relic: ".concat(e)),t&&console.warn(t))}r.d(t,{Z:()=>n})},2825:(e,t,r)=>{"use strict";r.d(t,{N:()=>d,T:()=>l});var n=r(8325),i=r(5546),o=r(3325),a=r(385);const s="newrelic";const c={stn:[o.D.sessionTrace],err:[o.D.jserrors,o.D.metrics],ins:[o.D.pageAction],spa:[o.D.spa],sr:[o.D.sessionReplay,o.D.sessionTrace]},u=new Set;function d(e,t){const r=n.ee.get(t);e&&"object"==typeof e&&(u.has(t)||(Object.entries(e).forEach((e=>{let[t,n]=e;c[t]?c[t].forEach((e=>{n?(0,i.p)("feat-"+t,[],void 0,e,r):(0,i.p)("block-"+t,[],void 0,e,r),(0,i.p)("rumresp-"+t,[Boolean(n)],void 0,e,r)})):n&&(0,i.p)("feat-"+t,[],void 0,void 0,r),l[t]=Boolean(n)})),Object.keys(c).forEach((e=>{void 0===l[e]&&(c[e]?.forEach((t=>(0,i.p)("rumresp-"+e,[!1],void 0,t,r))),l[e]=!1)})),u.add(t),function(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:{};try{a._A.dispatchEvent(new CustomEvent(s,{detail:e}))}catch(e){}}({loaded:!0})))}const l={}},2210:(e,t,r)=>{"use strict";r.d(t,{X:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t,r){if(n.call(e,t))return e[t];var i=r();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},1284:(e,t,r)=>{"use strict";r.d(t,{D:()=>n});const n=(e,t)=>Object.entries(e||{}).map((e=>{let[r,n]=e;return t(r,n)}))},4351:(e,t,r)=>{"use strict";r.d(t,{P:()=>o});var n=r(8325);const i=()=>{const e=new WeakSet;return(t,r)=>{if("object"==typeof r&&null!==r){if(e.has(r))return;e.add(r)}return r}};function o(e){try{return JSON.stringify(e,i())}catch(e){try{n.ee.emit("internal-error",[e])}catch(e){}}}},3960:(e,t,r)=>{"use strict";r.d(t,{KB:()=>a,b2:()=>o});var n=r(3239);function i(){return"undefined"==typeof document||"complete"===document.readyState}function o(e,t){if(i())return e();(0,n.bP)("load",e,t)}function a(e){if(i())return e();(0,n.iz)("DOMContentLoaded",e)}},8632:(e,t,r)=>{"use strict";r.d(t,{EZ:()=>d,ce:()=>o,ek:()=>u,fP:()=>a,gG:()=>l,h5:()=>c,mF:()=>s});var n=r(7894),i=r(385);const o={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function a(){return i._A.NREUM||(i._A.NREUM={}),void 0===i._A.newrelic&&(i._A.newrelic=i._A.NREUM),i._A.NREUM}function s(){let e=a();return e.o||(e.o={ST:i._A.setTimeout,SI:i._A.setImmediate,CT:i._A.clearTimeout,XHR:i._A.XMLHttpRequest,REQ:i._A.Request,EV:i._A.Event,PR:i._A.Promise,MO:i._A.MutationObserver,FETCH:i._A.fetch}),e}function c(e,t){let r=a();r.initializedAgents??={},t.initializedAt={ms:(0,n.z)(),date:new Date},r.initializedAgents[e]=t}function u(e){let t=a();return t.initializedAgents?.[e]}function d(e,t){a()[e]=t}function l(){return function(){let e=a();const t=e.info||{};e.info={beacon:o.beacon,errorBeacon:o.errorBeacon,...t}}(),function(){let e=a();const t=e.init||{};e.init={...t}}(),s(),function(){let e=a();const t=e.loader_config||{};e.loader_config={...t}}(),a()}},7956:(e,t,r)=>{"use strict";r.d(t,{N:()=>i});var n=r(3239);function i(e){let t=arguments.length>1&&void 0!==arguments[1]&&arguments[1],r=arguments.length>2?arguments[2]:void 0,i=arguments.length>3?arguments[3]:void 0;(0,n.iz)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),r,i)}},3081:(e,t,r)=>{"use strict";r.d(t,{gF:()=>o,mY:()=>i,t9:()=>n,vz:()=>s,xS:()=>a});const n=r(3325).D.metrics,i="sm",o="cm",a="storeSupportabilityMetrics",s="storeEventMetrics"},7633:(e,t,r)=>{"use strict";r.d(t,{t:()=>n});const n=r(3325).D.pageViewEvent},9251:(e,t,r)=>{"use strict";r.d(t,{t:()=>n});const n=r(3325).D.pageViewTiming},5938:(e,t,r)=>{"use strict";r.d(t,{W:()=>i});var n=r(8325);class i{constructor(e,t,r){this.agentIdentifier=e,this.aggregator=t,this.ee=n.ee.get(e),this.featureName=r,this.blocked=!1}}},7530:(e,t,r)=>{"use strict";r.d(t,{j:()=>b});var n=r(3325),i=r(234),o=r(5546),a=r(8325),s=r(7894),c=r(8e3),u=r(3960),d=r(385),l=r(50),f=r(3081),g=r(8632);function p(){const e=(0,g.gG)();["setErrorHandler","finished","addToTrace","addRelease","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start","recordReplay","pauseReplay"].forEach((t=>{e[t]=function(){for(var r=arguments.length,n=new Array(r),i=0;i<r;i++)n[i]=arguments[i];return function(t){for(var r=arguments.length,n=new Array(r>1?r-1:0),i=1;i<r;i++)n[i-1]=arguments[i];let o=[];return Object.values(e.initializedAgents).forEach((e=>{e.exposed&&e.api[t]&&o.push(e.api[t](...n))})),o.length>1?o:o[0]}(t,...n)}}))}var h=r(2825);const v=e=>{const t=e.startsWith("http");e+="/",r.p=t?e:"https://"+e};let m=!1;function b(e){let t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:{},b=arguments.length>2?arguments[2]:void 0,y=arguments.length>3?arguments[3]:void 0,{init:A,info:w,loader_config:_,runtime:x={loaderType:b},exposed:E=!0}=t;const D=(0,g.gG)();w||(A=D.init,w=D.info,_=D.loader_config),(0,i.Dg)(e.agentIdentifier,A||{}),(0,i.GE)(e.agentIdentifier,_||{}),w.jsAttributes??={},d.v6&&(w.jsAttributes.isWorker=!0),(0,i.CX)(e.agentIdentifier,w);const k=(0,i.P_)(e.agentIdentifier),j=[w.beacon,w.errorBeacon];m||(k.proxy.assets&&(v(k.proxy.assets),j.push(k.proxy.assets)),k.proxy.beacon&&j.push(k.proxy.beacon),p(),(0,g.EZ)("activatedFeatures",h.T)),x.denyList=[...k.ajax.deny_list||[],...k.ajax.block_internal?j:[]],(0,i.sU)(e.agentIdentifier,x),void 0===e.api&&(e.api=function(e,t){t||(0,c.R)(e,"api");const g={};var p=a.ee.get(e),h=p.get("tracer"),v="api-",m=v+"ixn-";function b(t,r,n,o){const a=(0,i.C5)(e);return null===r?delete a.jsAttributes[t]:(0,i.CX)(e,{...a,jsAttributes:{...a.jsAttributes,[t]:r}}),w(v,n,!0,o||null===r?"session":void 0)(t,r)}function y(){}["setErrorHandler","finished","addToTrace","addRelease"].forEach((e=>{g[e]=w(v,e,!0,"api")})),g.addPageAction=w(v,"addPageAction",!0,n.D.pageAction),g.setCurrentRouteName=w(v,"routeName",!0,n.D.spa),g.setPageViewName=function(t,r){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,i.OP)(e).customTransaction=(r||"https://web.archive.org/web/20240305041050/http://custom.transaction")+t,w(v,"setPageViewName",!0)()},g.setCustomAttribute=function(e,t){let r=arguments.length>2&&void 0!==arguments[2]&&arguments[2];if("string"==typeof e){if(["string","number","boolean"].includes(typeof t)||null===t)return b(e,t,"setCustomAttribute",r);(0,l.Z)("Failed to execute setCustomAttribute.\nNon-null value must be a string, number or boolean type, but a type of <".concat(typeof t,"> was provided."))}else(0,l.Z)("Failed to execute setCustomAttribute.\nName must be a string type, but a type of <".concat(typeof e,"> was provided."))},g.setUserId=function(e){if("string"==typeof e||null===e)return b("enduser.id",e,"setUserId",!0);(0,l.Z)("Failed to execute setUserId.\nNon-null value must be a string type, but a type of <".concat(typeof e,"> was provided."))},g.setApplicationVersion=function(e){if("string"==typeof e||null===e)return b("application.version",e,"setApplicationVersion",!1);(0,l.Z)("Failed to execute setApplicationVersion. Expected <String | null>, but got <".concat(typeof e,">."))},g.start=e=>{try{const t=e?"defined":"undefined";(0,o.p)(f.xS,["API/start/".concat(t,"/called")],void 0,n.D.metrics,p);const r=Object.values(n.D);if(void 0===e)e=r;else{if((e=Array.isArray(e)&&e.length?e:[e]).some((e=>!r.includes(e))))return(0,l.Z)("Invalid feature name supplied. Acceptable feature names are: ".concat(r));e.includes(n.D.pageViewEvent)||e.push(n.D.pageViewEvent)}e.forEach((e=>{p.emit("".concat(e,"-opt-in"))}))}catch(e){(0,l.Z)("An unexpected issue occurred",e)}},g.recordReplay=function(){(0,o.p)(f.xS,["API/recordReplay/called"],void 0,n.D.metrics,p),(0,o.p)("recordReplay",[],void 0,n.D.sessionReplay,p)},g.pauseReplay=function(){(0,o.p)(f.xS,["API/pauseReplay/called"],void 0,n.D.metrics,p),(0,o.p)("pauseReplay",[],void 0,n.D.sessionReplay,p)},g.interaction=function(){return(new y).get()};var A=y.prototype={createTracer:function(e,t){var r={},i=this,a="function"==typeof t;return(0,o.p)(f.xS,["API/createTracer/called"],void 0,n.D.metrics,p),(0,o.p)(m+"tracer",[(0,s.z)(),e,r],i,n.D.spa,p),function(){if(h.emit((a?"":"no-")+"fn-start",[(0,s.z)(),i,a],r),a)try{return t.apply(this,arguments)}catch(e){throw h.emit("fn-err",[arguments,this,e],r),e}finally{h.emit("fn-end",[(0,s.z)()],r)}}}};function w(e,t,r,i){return function(){return(0,o.p)(f.xS,["API/"+t+"/called"],void 0,n.D.metrics,p),i&&(0,o.p)(e+t,[(0,s.z)(),...arguments],r?null:this,i,p),r?void 0:this}}function _(){r.e(75).then(r.bind(r,7438)).then((t=>{let{setAPI:r}=t;r(e),(0,c.L)(e,"api")})).catch((()=>{(0,l.Z)("Downloading runtime APIs failed..."),(0,c.L)(e,"api",!0)}))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{A[e]=w(m,e,void 0,n.D.spa)})),g.noticeError=function(e,t){"string"==typeof e&&(e=new Error(e)),(0,o.p)(f.xS,["API/noticeError/called"],void 0,n.D.metrics,p),(0,o.p)("err",[e,(0,s.z)(),!1,t],void 0,n.D.jserrors,p)},d.il?(0,u.b2)((()=>_()),!0):_(),g}(e.agentIdentifier,y)),void 0===e.exposed&&(e.exposed=E),m=!0}},1926:(e,t,r)=>{r.nc=(()=>{try{return document?.currentScript?.nonce}catch(e){}return""})()},3325:(e,t,r)=>{"use strict";r.d(t,{D:()=>n,p:()=>i});const n={ajax:"ajax",jserrors:"jserrors",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",spa:"spa"},i={[n.pageViewEvent]:1,[n.pageViewTiming]:2,[n.metrics]:3,[n.jserrors]:4,[n.ajax]:5,[n.sessionTrace]:6,[n.pageAction]:7,[n.spa]:8,[n.sessionReplay]:9}}},n={};function i(e){var t=n[e];if(void 0!==t)return t.exports;var o=n[e]={exports:{}};return r[e](o,o.exports,i),o.exports}i.m=r,i.d=(e,t)=>{for(var r in t)i.o(t,r)&&!i.o(e,r)&&Object.defineProperty(e,r,{enumerable:!0,get:t[r]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,r)=>(i.f[r](e,t),t)),[])),i.u=e=>"nr-rum-1.252.0.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.252.0.PROD:",i.l=(r,n,o,a)=>{if(e[r])e[r].push(n);else{var s,c;if(void 0!==o)for(var u=document.getElementsByTagName("script"),d=0;d<u.length;d++){var l=u[d];if(l.getAttribute("src")==r||l.getAttribute("data-webpack")==t+o){s=l;break}}if(!s){c=!0;var f={75:"sha512-85KXSsv643MTRPulZfmcwj8IKIbJeT9JfNpsSBckCZNUr+o/ILbmpOISx04Ol69WzHRZplUy/y2FaJ3KUChaTw=="};(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+o),s.src=r,0!==s.src.indexOf(window.location.origin+"/")&&(s.crossOrigin="anonymous"),f[a]&&(s.integrity=f[a])}e[r]=[n];var g=(t,n)=>{s.onerror=s.onload=null,clearTimeout(p);var i=e[r];if(delete e[r],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(n))),t)return t(n)},p=setTimeout(g.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=g.bind(null,s.onerror),s.onload=g.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://web.archive.org/web/20240305041050/https://js-agent.newrelic.com/",(()=>{var e={50:0,832:0};i.f.j=(t,r)=>{var n=i.o(e,t)?e[t]:void 0;if(0!==n)if(n)r.push(n[2]);else{var o=new Promise(((r,i)=>n=e[t]=[r,i]));r.push(n[2]=o);var a=i.p+i.u(t),s=new Error;i.l(a,(r=>{if(i.o(e,t)&&(0!==(n=e[t])&&(e[t]=void 0),n)){var o=r&&("load"===r.type?"missing":r.type),a=r&&r.target&&r.target.src;s.message="Loading chunk "+t+" failed.\n("+o+": "+a+")",s.name="ChunkLoadError",s.type=o,s.request=a,n[1](s)}}),"chunk-"+t,t)}};var t=(t,r)=>{var n,o,[a,s,c]=r,u=0;if(a.some((t=>0!==e[t]))){for(n in s)i.o(s,n)&&(i.m[n]=s[n]);if(c)c(i)}for(t&&t(r);u<a.length;u++)o=a[u],i.o(e,o)&&e[o]&&e[o][0](),e[o]=0},r=self["webpackChunk:NRBA-1.252.0.PROD"]=self["webpackChunk:NRBA-1.252.0.PROD"]||[];r.forEach(t.bind(null,0)),r.push=t.bind(null,r.push.bind(r))})(),(()=>{"use strict";i(1926);var e=i(50);class t{#e(t){for(var r=arguments.length,n=new Array(r>1?r-1:0),i=1;i<r;i++)n[i-1]=arguments[i];if("function"==typeof this.api?.[t])return this.api[t](...n);(0,e.Z)("Call to agent api ".concat(t," failed. The API is not currently initialized."))}addPageAction(e,t){return this.#e("addPageAction",e,t)}setPageViewName(e,t){return this.#e("setPageViewName",e,t)}setCustomAttribute(e,t,r){return this.#e("setCustomAttribute",e,t,r)}noticeError(e,t){return this.#e("noticeError",e,t)}setUserId(e){return this.#e("setUserId",e)}setApplicationVersion(e){return this.#e("setApplicationVersion",e)}setErrorHandler(e){return this.#e("setErrorHandler",e)}finished(e){return this.#e("finished",e)}addRelease(e,t){return this.#e("addRelease",e,t)}start(e){return this.#e("start",e)}recordReplay(){return this.#e("recordReplay")}pauseReplay(){return this.#e("pauseReplay")}addToTrace(e){return this.#e("addToTrace",e)}setCurrentRouteName(e){return this.#e("setCurrentRouteName",e)}interaction(){return this.#e("interaction")}}var r=i(3325),n=i(234);const o=Object.values(r.D);function a(e){const t={};return o.forEach((r=>{t[r]=function(e,t){return!1!==(0,n.Mt)(t,"".concat(e,".enabled"))}(r,e)})),t}var s=i(7530);var c=i(8e3),u=i(5938),d=i(3960),l=i(385);class f extends u.W{constructor(e,t,r){let i=!(arguments.length>3&&void 0!==arguments[3])||arguments[3];super(e,t,r),this.auto=i,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===(0,n.Mt)(this.agentIdentifier,"".concat(this.featureName,".autoStart"))&&(this.auto=!1),this.auto&&(0,c.R)(e,r)}importAggregator(){let t=arguments.length>0&&void 0!==arguments[0]?arguments[0]:{};if(this.featAggregate)return;if(!this.auto)return void this.ee.on("".concat(this.featureName,"-opt-in"),(()=>{(0,c.R)(this.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator()}));const r=l.il&&!0===(0,n.Mt)(this.agentIdentifier,"privacy.cookies_enabled");let o;this.onAggregateImported=new Promise((e=>{o=e}));const a=async()=>{let n;try{if(r){const{setupAgentSession:e}=await i.e(75).then(i.bind(i,957));n=e(this.agentIdentifier)}}catch(t){(0,e.Z)("A problem occurred when starting up session manager. This page will not start or extend any session.",t)}try{if(!this.shouldImportAgg(this.featureName,n))return(0,c.L)(this.agentIdentifier,this.featureName),void o(!1);const{lazyFeatureLoader:e}=await i.e(75).then(i.bind(i,8582)),{Aggregate:r}=await e(this.featureName,"aggregate");this.featAggregate=new r(this.agentIdentifier,this.aggregator,t),o(!0)}catch(t){(0,e.Z)("Downloading and initializing ".concat(this.featureName," failed..."),t),this.abortHandler?.(),(0,c.L)(this.agentIdentifier,this.featureName,!0),o(!1)}};l.il?(0,d.b2)((()=>a()),!0):a()}shouldImportAgg(e,t){return e!==r.D.sessionReplay||!!n.Yu.MO&&(!1!==(0,n.Mt)(this.agentIdentifier,"session_trace.enabled")&&(!!t?.isNew||!!t?.state.sessionReplayMode))}}var g=i(7633);class p extends f{static featureName=g.t;constructor(e,t){let r=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,g.t,r),this.importAggregator()}}var h=i(1117),v=i(1284);class m extends h.w{constructor(e){super(e),this.aggregatedData={}}store(e,t,r,n,i){var o=this.getBucket(e,t,r,i);return o.metrics=function(e,t){t||(t={count:0});return t.count+=1,(0,v.D)(e,(function(e,r){t[e]=b(r,t[e])})),t}(n,o.metrics),o}merge(e,t,r,n,i){var o=this.getBucket(e,t,n,i);if(o.metrics){var a=o.metrics;a.count+=r.count,(0,v.D)(r,(function(e,t){if("count"!==e){var n=a[e],i=r[e];i&&!i.c?a[e]=b(i.t,n):a[e]=function(e,t){if(!t)return e;t.c||(t=y(t.t));return t.min=Math.min(e.min,t.min),t.max=Math.max(e.max,t.max),t.t+=e.t,t.sos+=e.sos,t.c+=e.c,t}(i,a[e])}}))}else o.metrics=r}storeMetric(e,t,r,n){var i=this.getBucket(e,t,r);return i.stats=b(n,i.stats),i}getBucket(e,t,r,n){this.aggregatedData[e]||(this.aggregatedData[e]={});var i=this.aggregatedData[e][t];return i||(i=this.aggregatedData[e][t]={params:r||{}},n&&(i.custom=n)),i}get(e,t){return t?this.aggregatedData[e]&&this.aggregatedData[e][t]:this.aggregatedData[e]}take(e){for(var t={},r="",n=!1,i=0;i<e.length;i++)t[r=e[i]]=A(this.aggregatedData[r]),t[r].length&&(n=!0),delete this.aggregatedData[r];return n?t:null}}function b(e,t){return null==e?function(e){e?e.c++:e={c:1};return e}(t):t?(t.c||(t=y(t.t)),t.c+=1,t.t+=e,t.sos+=e*e,e>t.max&&(t.max=e),e<t.min&&(t.min=e),t):{t:e}}function y(e){return{t:e,min:e,max:e,sos:e*e,c:1}}function A(e){return"object"!=typeof e?[]:(0,v.D)(e,w)}function w(e,t){return t}var _=i(8632),x=i(4402),E=i(4351);var D=i(5546),k=i(7956),j=i(3239),S=i(7894),R=i(9251);class T extends f{static featureName=R.t;constructor(e,t){let r=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,R.t,r),l.il&&((0,k.N)((()=>(0,D.p)("docHidden",[(0,S.z)()],void 0,R.t,this.ee)),!0),(0,j.bP)("pagehide",(()=>(0,D.p)("winPagehide",[(0,S.z)()],void 0,R.t,this.ee))),this.importAggregator())}}var I=i(3081);class P extends f{static featureName=I.t9;constructor(e,t){let r=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,I.t9,r),this.importAggregator()}}new class extends t{constructor(t){let r=arguments.length>1&&void 0!==arguments[1]?arguments[1]:(0,x.ky)(16);super(),l._A?(this.agentIdentifier=r,this.sharedAggregator=new m({agentIdentifier:this.agentIdentifier}),this.features={},(0,_.h5)(r,this),this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(p),(0,s.j)(this,t,t.loaderType||"agent"),this.run()):(0,e.Z)("Failed to initial the agent. Could not determine the runtime environment.")}get config(){return{info:(0,n.C5)(this.agentIdentifier),init:(0,n.P_)(this.agentIdentifier),loader_config:(0,n.DL)(this.agentIdentifier),runtime:(0,n.OP)(this.agentIdentifier)}}run(){try{const t=a(this.agentIdentifier),n=[...this.desiredFeatures];n.sort(((e,t)=>r.p[e.featureName]-r.p[t.featureName])),n.forEach((n=>{if(t[n.featureName]||n.featureName===r.D.pageViewEvent){const i=function(e){switch(e){case r.D.ajax:return[r.D.jserrors];case r.D.sessionTrace:return[r.D.ajax,r.D.pageViewEvent];case r.D.sessionReplay:return[r.D.sessionTrace];case r.D.pageViewTiming:return[r.D.pageViewEvent];default:return[]}}(n.featureName);i.every((e=>t[e]))||(0,e.Z)("".concat(n.featureName," is enabled but one or more dependent features has been disabled (").concat((0,E.P)(i),"). This may cause unintended consequences or missing data...")),this.features[n.featureName]=new n(this.agentIdentifier,this.sharedAggregator)}}))}catch(t){(0,e.Z)("Failed to initialize all enabled instrument classes (agent aborted) -",t);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,_.fP)();return delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.features,delete this.sharedAggregator,r.ee?.abort(),delete r.ee?.get(this.agentIdentifier),!1}}}({features:[p,T,P],loaderType:"lite"})})()})();</script> <noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style> </noscript><script async src="https://web.archive.org/web/20240305041050js_/https://www.googletagmanager.com/gtag/js?id=G-HEQ0YF2VYL"></script> <script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {'cookie_flags': 'SameSite=None;Secure', 'cookie_domain': 'www.nist.gov'});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("config", "UA-33523145-1", {"groups":"default","anonymize_ip":true,"page_placeholder":"PLACEHOLDER_page_path","link_attribution":true,"allow_ad_personalization_signals":false,"custom_map":{"dimension2":"node_title","dimension3":"node_id","dimension7":"content_type"}});gtag("config", "G-CSLL4ZEK4L", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("event", "custom", {"node_title":"NEHRP Extramural Research","node_id":"417716","content_type":"Project\/Program"});</script> <meta name="description" content="Research performed by the EL Earthquake Engineering Group (2EG) consists of a combination of in-house and extramural research. Policy related work is awarded to the Science Technology Policy Institute. Traditional technical extramural research is performed by an outside contractor via a series of an"/> <link rel="canonical" href="https://web.archive.org/web/20240305041050/https://www.nist.gov/programs-projects/nehrp-extramural-research"/> <link rel="shortlink" href="https://web.archive.org/web/20240305041050/https://www.nist.gov/node/417716"/> <meta name="citation_title" content="NEHRP Extramural Research | NIST"/> <meta property="og:site_name" content="NIST"/> <meta property="og:type" content="Article"/> <meta property="og:url" content="https://web.archive.org/web/20240305041050/https://www.nist.gov/programs-projects/nehrp-extramural-research"/> <meta property="og:title" content="NEHRP Extramural Research"/> <meta property="og:description" content="Research performed by the EL Earthquake Engineering Group (2EG) consists of a combination of in-house and extramural research. Policy related work is awarded to the Science Technology Policy Institute. Traditional technical extramural research is performed by an outside contractor via a series of an"/> <meta property="article:modified_time" content="2023-01-06T12:00-05:00"/> <meta name="dcterms.title" content="NEHRP Extramural Research"/> <meta name="dcterms.description" content="Research performed by the EL Earthquake Engineering Group (2EG) consists of a combination of in-house and extramural research. Policy related work is awarded to the Science Technology Policy Institute. Traditional technical extramural research is performed by an outside contractor via a series of an"/> <meta name="dcterms.type" content="text"/> <meta name="dcterms.format" content="text/html"/> <meta name="dcterms.identifier" content="https://www.nist.gov/programs-projects/nehrp-extramural-research"/> <meta name="dcterms.source" content="NIST"/> <meta name="dcterms.modified" content="2023-01-06T12:00-05:00"/> <meta name="twitter:card" content="summary_large_image"/> <meta name="twitter:description" content="Research performed by the EL Earthquake Engineering Group (2EG) consists of a combination of in-house and extramural research. Policy related work is awarded to the Science Technology Policy Institute. Traditional technical extramural research is performed by an outside contractor via a series of an"/> <meta name="twitter:site" content="NIST"/> <meta name="twitter:title" content="NEHRP Extramural Research"/> <meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA"/> <meta name="Generator" content="Drupal 10 (https://www.drupal.org)"/> <meta name="MobileOptimized" content="width"/> <meta name="HandheldFriendly" content="true"/> <meta name="viewport" content="width=device-width, initial-scale=1.0"/> <meta name="nist_search_modified" class="elastic" content="2023-01-06T12:00:00-05:00"/> <script type="application/ld+json">{ "@context": "https://web.archive.org/web/20240305041050/https://schema.org", "@graph": [ { "@type": "Article", "headline": "NEHRP Extramural Research | NIST", "description": "Research performed by the EL Earthquake Engineering Group (2EG) consists of a combination of in-house and extramural research. Policy related work is awarded to the Science Technology Policy Institute. Traditional technical extramural research is performed by an outside contractor via a series of annually awarded Indefinite Delivery Indefinite Quantity (IDIQ) task orders. The extramural research provides a breadth and depth of multi-disciplinary research capabilities that strongly supplements the in-house work force.聽\r\n\r\nOne task order (Project 1) will be issued to a policy contractor to assist in updating the NEHRP Strategic Plan. Two perhaps three task orders will be awarded to a new support contractor to be identified. The existing IDIQ contract expired earlier in FY2019 and a new contract will be competed in FY2020. Once that is in place the task orders will be issued against this new IDIQ contract. These technical task orders will (Project 2) assist NIST in updating RP-8, Standards of Seismic Safety for Existing Federally Owned and Leased Buildings, (Project 3) evaluation of the design rules in ASCE/SEI 7 and the NEHRP Provisions concerning how vertical accelerations are handled, and (Project 4) Development of a research plan to study mitigation approaches to improve the performance of pre-1980 non-ductile steel column splices and weak panel zones.聽\r\n\r\nProjects 1 \u0026 2 are priorities for funding; Projects 3 \u0026 4 are subject to availability of funds.聽", "dateModified": "2023-01-06T12:00-05:00" } ] }</script> <meta name="nist_search_bundle" class="elastic" content="project_program"/> <link rel="icon" href="/web/20240305041050im_/https://www.nist.gov/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon"/> <title>NEHRP Extramural Research | NIST</title> <link rel="stylesheet" media="all" href="/web/20240305041050cs_/https://www.nist.gov/sites/default/files/css/css_fQdJ4BM0kKSqHclMXIbrmq6NSFQk5aVSO8SGerC2clI.css?delta=0&language=en&theme=nist_www&include=eJx1UAFuAyEM-xArT4oCpDRrICdCy_r7wbXTTtUmIRQ7lm0lYLxC1_k2H35n-DQX_llx1OqyahYCrCiPztH8O-EqW4czTy7pqKKYoLdpwzX7jM-1cScuW9M7-XdiVdi5fqFCM1klYIOiySc2DNNYuF6dPaxTmQ2Ndr3PogHlOH-8rPyFMFH7gTDGOKoPeEnoq68An9ptQzm9oDONjAKFEuNK5ejuTMP8_p9mv5uQ69QKNDpToxpn-0bk_-Ag2qFL4dh0neAbz3OgYA"/> <link rel="stylesheet" media="all" href="/web/20240305041050cs_/https://www.nist.gov/sites/default/files/css/css_6prwlieMvitJqVLptJ59w_NxX2prM0abXhYVoH12prk.css?delta=1&language=en&theme=nist_www&include=eJx1UAFuAyEM-xArT4oCpDRrICdCy_r7wbXTTtUmIRQ7lm0lYLxC1_k2H35n-DQX_llx1OqyahYCrCiPztH8O-EqW4czTy7pqKKYoLdpwzX7jM-1cScuW9M7-XdiVdi5fqFCM1klYIOiySc2DNNYuF6dPaxTmQ2Ndr3PogHlOH-8rPyFMFH7gTDGOKoPeEnoq68An9ptQzm9oDONjAKFEuNK5ejuTMP8_p9mv5uQ69QKNDpToxpn-0bk_-Ag2qFL4dh0neAbz3OgYA"/> <link rel="stylesheet" media="print" href="/web/20240305041050cs_/https://www.nist.gov/sites/default/files/css/css_6MuKXqcH69mMwmOSjiD2G_c6UXIqUTZ1TRnur95k7Qk.css?delta=2&language=en&theme=nist_www&include=eJx1UAFuAyEM-xArT4oCpDRrICdCy_r7wbXTTtUmIRQ7lm0lYLxC1_k2H35n-DQX_llx1OqyahYCrCiPztH8O-EqW4czTy7pqKKYoLdpwzX7jM-1cScuW9M7-XdiVdi5fqFCM1klYIOiySc2DNNYuF6dPaxTmQ2Ndr3PogHlOH-8rPyFMFH7gTDGOKoPeEnoq68An9ptQzm9oDONjAKFEuNK5ejuTMP8_p9mv5uQ69QKNDpToxpn-0bk_-Ag2qFL4dh0neAbz3OgYA"/> <link rel="stylesheet" media="all" href="/web/20240305041050cs_/https://www.nist.gov/sites/default/files/css/css_Vlb5tKBrTnXBpCoEIEyOWSUGgmDWOgkDFIgemxZcHGg.css?delta=3&language=en&theme=nist_www&include=eJx1UAFuAyEM-xArT4oCpDRrICdCy_r7wbXTTtUmIRQ7lm0lYLxC1_k2H35n-DQX_llx1OqyahYCrCiPztH8O-EqW4czTy7pqKKYoLdpwzX7jM-1cScuW9M7-XdiVdi5fqFCM1klYIOiySc2DNNYuF6dPaxTmQ2Ndr3PogHlOH-8rPyFMFH7gTDGOKoPeEnoq68An9ptQzm9oDONjAKFEuNK5ejuTMP8_p9mv5uQ69QKNDpToxpn-0bk_-Ag2qFL4dh0neAbz3OgYA"/> <script src="/web/20240305041050js_/https://www.nist.gov/sites/default/files/js/js_3ssAdmvsW-btol8ydZT2eloQN8l11yuGacOobfI1-_0.js?scope=header&delta=0&language=en&theme=nist_www&include=eJx1UAFuAyEM-xArT4oCpDRrICdCy_r7wbXTTtUmIRQ7lm0lYLxC1_k2H35n-DQX_llx1OqyahYCrCiPztH8O-EqW4czTy7pqKKYoLdpwzX7jM-1cScuW9M7-XdiVdi5fqFCM1klYIOiySc2DNNYuF6dPaxTmQ2Ndr3PogHlOH-8rPyFMFH7gTDGOKoPeEnoq68An9ptQzm9oDONjAKFEuNK5ejuTMP8_p9mv5uQ69QKNDpToxpn-0bk_-Ag2qFL4dh0neAbz3OgYA"></script> </head> <body class="node-417716"> <a href="#main-content" class="visually-hidden focusable" data-elastic-exclude> Skip to main content </a> <div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas>  <section data-elastic-exclude class="usa-banner" aria-label="Official government website"> <div class="usa-accordion"> <header class="usa-banner__header"> <div class="usa-banner__inner"> <div class="grid-col-auto"> <img class="usa-banner__header-flag" src="/web/20240305041050im_/https://www.nist.gov/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag"> </div> <div class="grid-col-fill tablet:grid-col-auto"> <p class="usa-banner__header-text">An official website of the United States government</p> <p class="usa-banner__header-action" aria-hidden="true">Here鈥檚 how you know</p> </div> <button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default"> <span class="usa-banner__button-text">Here鈥檚 how you know</span> </button> </div> </header> <div class="usa-banner__content usa-accordion__content" id="gov-banner-default"> <div class="grid-row grid-gap-lg"> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20240305041050im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Official websites use .gov</strong> <br/> A <strong>.gov</strong> website belongs to an official government organization in the United States. </p> </div> </div> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20240305041050im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Secure .gov websites use HTTPS</strong> <br/> A <strong>lock</strong> ( <span class="icon-lock"> <svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false"> <title id="banner-lock-title">Lock</title> <desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg> </span> ) or <strong>https://</strong> means you鈥檝e safely connected to the .gov website. Share sensitive information only on official, secure websites. </p> </div> </div> </div> </div> </div> </section>  <div data-elastic-exclude>  <div class="nist-print-header" style="display:none;"> <p class="nist-print-header__url">https://www.nist.gov/programs-projects/nehrp-extramural-research</p> <img class="nist-print-header__logo" width="289" height="38" src="/web/20240305041050im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology"/> </div> <div class="usa-overlay"></div> <header class="usa-header nist-header--www nist-header--minimal" role="banner"> <div class="usa-navbar"> <div class="usa-logo flex-fill"> <a href="/web/20240305041050/https://www.nist.gov/" title="National Institute of Standards and Technology" aria-label="Home"> <img src="/web/20240305041050im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px"/> </a> </div> <div class="usa-header__right grid-row flex-auto"> <div class="grid-col-fill nist-header__search-group"> <form class="usa-search usa-search--small" accept-charset="UTF-8" action="/web/20240305041050/https://www.nist.gov/search" id="search_form" method="get"> <div role="search"> <label class="usa-sr-only" for="search-form">Search NIST</label> <input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128"> <button class="usa-button" type="submit"><img src="/web/20240305041050im_/https://www.nist.gov/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button> </div> </form> </div> <div class="grid-col-auto padding-left-1"> <button class="usa-menu-btn">Menu</button> </div> </div> </div> <nav aria-label="Primary navigation" class="usa-nav"> <div class="usa-nav__inner"> <button class="usa-nav__close">Close</button> <ul class="usa-nav__primary usa-accordion"> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-1"><span>Topics</span></button> <div id="primary_menu-1" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/topics" class="usa-nav__link">All Topics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/advanced-communications" class="usa-nav__link">Advanced communications</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/bioscience" class="usa-nav__link">Bioscience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/buildings-construction" class="usa-nav__link">Buildings and construction</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/chemistry" class="usa-nav__link">Chemistry</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/climate" class="usa-nav__link">Climate</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/cybersecurity" class="usa-nav__link">Cybersecurity</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/electronics" class="usa-nav__link">Electronics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/energy" class="usa-nav__link">Energy</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/environment" class="usa-nav__link">Environment</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/fire" class="usa-nav__link">Fire</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/forensic-science" class="usa-nav__link">Forensic science</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/health" class="usa-nav__link">Health</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/information-technology" class="usa-nav__link">Information technology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/infrastructure" class="usa-nav__link">Infrastructure</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/manufacturing" class="usa-nav__link">Manufacturing</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/materials" class="usa-nav__link">Materials</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/metrology" class="usa-nav__link">Metrology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/nanotechnology" class="usa-nav__link">Nanotechnology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/neutron-research" class="usa-nav__link">Neutron research</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/performance-excellence" class="usa-nav__link">Performance excellence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/physics" class="usa-nav__link">Physics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/public-safety" class="usa-nav__link">Public safety</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/resilience" class="usa-nav__link">Resilience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/standards" class="usa-nav__link">Standards</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/transportation" class="usa-nav__link">Transportation</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <a class="usa-nav__link" href="/web/20240305041050/https://www.nist.gov/publications">Publications</a> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs & Major Programs</span></button> <div id="primary_menu-3" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/laboratories" class="usa-nav__link">Laboratories</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20240305041050/https://www.nist.gov/ctl" class="usa-nav__link">Communications Technology Laboratory</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/el" class="usa-nav__link">Engineering Laboratory</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/itl" class="usa-nav__link">Information Technology Laboratory</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/mml" class="usa-nav__link">Material Measurement Laboratory</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/pml" class="usa-nav__link">Physical Measurement Laboratory</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/user-facilities" class="usa-nav__link">User Facilities</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20240305041050/https://www.nist.gov/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/cnst" class="usa-nav__link">CNST NanoFab</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/laboratories/projects-programs" class="usa-nav__link">Research Projects</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/laboratories/tools-instruments" class="usa-nav__link">Tools & Instruments</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/major-programs" class="usa-nav__link">Major Programs</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20240305041050/https://www.nist.gov/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/chips" class="usa-nav__link">CHIPS for America Initiative</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/oam" class="usa-nav__link">Office of Advanced Manufacturing</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/spo" class="usa-nav__link">Special Programs Office</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/tpo" class="usa-nav__link">Technology Partnerships Office</a> </li> </ul> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-4"><span>Services & Resources</span></button> <div id="primary_menu-4" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/services-resources/standards-and-measurements" class="usa-nav__link">Standards and Measurements</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20240305041050/https://www.nist.gov/calibrations" class="usa-nav__link">Calibration Services</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/nist-quality-system" class="usa-nav__link">Quality System</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/standardsgov" class="usa-nav__link">Standards.gov</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/pml/owm" class="usa-nav__link">Office of Weights and Measures</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/services-resources/software" class="usa-nav__link">Software</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/data" class="usa-nav__link">Data</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20240305041050/https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a> </li> <li> <a href="https://web.archive.org/web/20240305041050/https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/srd" class="usa-nav__link">Standard Reference Data (SRD)</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/shop" class="usa-nav__link">Storefront</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/tpo" class="usa-nav__link">License & Patents</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20240305041050/https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/nist-research-library" class="usa-nav__link">NIST Research Library</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News & Events</span></button> <div id="primary_menu-5" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/news-events/news" class="usa-nav__link">News</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/news-events/events" class="usa-nav__link">Events</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/blogs" class="usa-nav__link">Blogs</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/feature-stories" class="usa-nav__link">Feature Stories</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/awards" class="usa-nav__link">Awards</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/video-gallery" class="usa-nav__link">Video Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/image-gallery" class="usa-nav__link">Image Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/pao/media-contacts" class="usa-nav__link">Media Contacts</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button> <div id="primary_menu-6" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/about-nist" class="usa-nav__link">About Us</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20240305041050/https://www.nist.gov/director/leadership" class="usa-nav__link">Leadership</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/director/nist-organization-structure" class="usa-nav__link">Organization Structure</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/about-nist/budget-planning" class="usa-nav__link">Budget & Planning</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/about-nist/contact-us" class="usa-nav__link">Contact Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/about-nist/visit" class="usa-nav__link">Visit</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/careers" class="usa-nav__link">Careers</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20240305041050/https://www.nist.gov/iaao/academic-affairs-office" class="usa-nav__link">Student programs</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/about-nist/work-nist" class="usa-nav__link">Work with NIST</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/history" class="usa-nav__link">History</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20240305041050/http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/nist-museum" class="usa-nav__link">NIST Museum</a> </li> <li> <a href="/web/20240305041050/https://www.nist.gov/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20240305041050/https://www.nist.gov/education" class="usa-nav__link">Educational Resources</a> </li> </ul> </div> </div> </div> </li> </ul> </div> </nav> </header>  </div> <div class="grid-container"> <div data-drupal-messages-fallback class="hidden"></div> </div> <div id="block-nist-www-content" class="nist-block"> <section class="nist-page__content usa-section clearfix"> <a id="main-content" tabindex="-1"></a> <div class="grid-container margin-top-4"> <div class="nist-page__region nist-page__region--content-top"> <div class="nist-block"> <a class="usa-button usa-button--accent-cool" href="/web/20240305041050/https://www.nist.gov/laboratories/projects-programs">PROJECTS/PROGRAMS</a> </div> <div class="nist-block"> <h1 class="nist-page__title">NEHRP Extramural Research</h1> </div> <div class="nist-block">  <div data-elastic-exclude class="nist-block nist-social__wrapper"> <h2 class="nist-social__title">Share</h2> <div class="social-media-sharing"> <div class="nist-social__wrapper--share"> <div> <a target="_blank" rel="noopener" href="https://web.archive.org/web/20240305041050/https://www.facebook.com/share.php?u=https://www.nist.gov/programs-projects/nehrp-extramural-research" title="Facebook" class="nist-social nist-social--facebook-gray"> <span>Facebook</span> </a> </div> <div> <a target="_blank" rel="noopener" href="https://web.archive.org/web/20240305041050/https://www.linkedin.com/shareArticle?mini=true&url=https://www.nist.gov/programs-projects/nehrp-extramural-research&source=https://www.nist.gov/programs-projects/nehrp-extramural-research" title="Linkedin" class="nist-social nist-social--linkedin-gray"> <span>Linkedin</span> </a> </div> <div> <a target="_blank" rel="noopener" href="https://web.archive.org/web/20240305041050/https://twitter.com/intent/tweet?url=https://www.nist.gov/programs-projects/nehrp-extramural-research&status=https://www.nist.gov/programs-projects/nehrp-extramural-research" title="Twitter" class="nist-social nist-social--twitter-gray"> <span>Twitter</span> </a> </div> <div> <a href="https://web.archive.org/web/20240305041050/mailto:/?subject=NIST.gov&body=Check out this site https://www.nist.gov/programs-projects/nehrp-extramural-research" title="Email" class="nist-social nist-social--envelope-gray"> <span>Email</span> </a> </div> </div> </div> </div>  </div> </div> </div> <div class="grid-container margin-top-4"> <div class="grid-row grid-gap-6"> <div class="nist-page__region nist-page__region--content tablet-lg:grid-col-8"> <div class="nist-block gray-box"> <div class="text-long"> <h2>Summary</h2> <p>Research performed by the EL Earthquake Engineering Group (2EG) consists of a combination of in-house and extramural research. Policy related work is awarded to the Science Technology Policy Institute. Traditional technical extramural research is performed by an outside contractor via a series of annually awarded Indefinite Delivery Indefinite Quantity (IDIQ) task orders. The extramural research provides a breadth and depth of multi-disciplinary research capabilities that strongly supplements the in-house work force.聽</p> <p>One task order (Project 1) will be issued to a policy contractor to assist in updating the NEHRP Strategic Plan. Two perhaps three task orders will be awarded to a new support contractor to be identified. The existing IDIQ contract expired earlier in FY2019 and a new contract will be competed in FY2020. Once that is in place the task orders will be issued against this new IDIQ contract. These technical task orders will (Project 2) assist NIST in updating RP-8, Standards of Seismic Safety for Existing Federally Owned and Leased Buildings, (Project 3) evaluation of the design rules in ASCE/SEI 7 and the NEHRP Provisions concerning how vertical accelerations are handled, and (Project 4) Development of a research plan to study mitigation approaches to improve the performance of pre-1980 non-ductile steel column splices and weak panel zones.聽</p> <p>Projects 1 & 2 are priorities for funding; Projects 3 & 4 are subject to availability of funds.聽</p> </div> </div> <div class="nist-block"> <h2 class="nist-block__title">Description</h2> <div class="text-with-summary"> <p><strong>Objective聽-</strong>聽 A task order to assist NIST and the NEHRP agencies in updating the NEHRP Strategic Plan will be awarded to a policy contractor. In addition, other planned FY 2020 extramural research will be assigned by task order to the new IDIQ contractor once that award is made. It is anticipated that two or three technical task orders will be awarded, subject to availability of funds. These task orders concern specific efforts to support the Earthquake Engineering Group (2EG) research portfolio in support of the NEHRP mission; all will be managed by the PI, supported by co-PI Sattar (with Jay Harris of 2EG as the COR). The task orders include:聽</p> <ol><li>聽A task order will be issued to the Science and Technology Policy Institute (STPI) to assist NIST and the NEHRP agencies in updating the 2008 NEHRP Strategic Plan. The Plan was published in 2008 and needs to be updated to reflect progress in earthquake hazard mitigation over the past decade. Moreover, earthquake engineering has evolved to be more than mitigation to now aimed at providing resilient communities. The role of buildings and their interconnecting lifelines are part of the community system that must be sufficiently robust to perform under strong shaking. Moreover, the traditional life safety design approach is being replaced with a goal of functional recovery with a faster return to service. The Strategic Plan needs to reflect this new thinking and to identify 聽issues that the Plan must address over the next decade of NEHRP operation, and the removal of items that are completed or no longer need study. <a href="https://web.archive.org/web/20240305041050/https://www.nehrp.gov/pdf/strategic_plan_2008.pdf">https://www.nehrp.gov/pdf/strategic_plan_2008.pdf</a></li> <li>A task order will be issued to the new IDIQ Contractor to assist NIST in completing the updating of RP-8, Standards of Seismic Safety for Existing Federally Owned and Leased Buildings. RP-8 is published by the Interagency Committee on Seismic Safety in Construction (ICSSC) and provides the consensus approaches to determine if seismic strengthening is required in existing Federally owned or leased buildings. A draft update of RP-8 was completed by the Applied Technology Council in 2016. Now that the 2017 edition of ASCE/SEI 41 has been published, the update can be completed.聽</li> <li>A task order will be issued to the new IDIQ contractor to assess the current approaches in ASCE/SEI 7 and the NEHRP Provisions to address vertical accelerations in design. Current provisions date back to the original NEHRP Provisions (ATC-3) that were published in 1979. The efficacy of these provisions has not been studied. The Building Seismic Safety Council Provisions Update Committee has requested that NIST conduct a study of this question to determine if modifications to the provisions are required and to suggest what the language should be.聽</li> <li>A fourth task order will be considered, depending on available funds, to develop a research plan to address two specific issues found in pre-1980, non-ductile structural steel buildings. These issues include (1) the performance of weak panel zones, the areas formed by the intersection of beams and columns and (2) the performance of column splices utilizing partial penetration welds, as was typical in these older buildings. These two issues are related and are a function of design and detailing decisions made prior to 1980 that can result in poor performance in these steel buildings. The development of the research plan also will identify the resources that are available concerning panel zones and non-ductile column splices. The goal will be to determine the problem statement, the approach to be utilized to determine solutions and the available information published in the literature.聽</li> </ol><p><strong>What is the technical idea?</strong> 聽A total of four task orders are proposed to be completed by outside contractors. The following task orders are part of this overall extramural research project:<br/> 聽</p> <ol><li>Assist NIST and the NEHRP agencies in developing an updated Strategic Plan. The existing plan dates from 2008 and needs to be updated and revised to reflect current Program needs and anticipated issues going forward. Priority task order.聽</li> <li>Assist NIST in updating the RP-8 Standards of Seismic Safety for Existing Federally Owned and Leased Buildings which is required to be used by Federal agencies in examining their buildings to determine which buildings must be assessed in detail. Priority task order.</li> <li>Assist NIST in evaluating the current provisions found in ASCE/SEI 7 and the NEHRP Provisions concerning how to incorporated the effects of vertical accelerations in design. The goal will be to determine what changes are needed and to propose revised language for consideration by the BSSC PUC. Depending on funds availability.聽</li> <li>Assist NIST in examining the question of non-ductile partial penetration welds found in pre-1980 structural steel panel zones, the intersection of columns and beams, as well as column splices. Modern design requirements and materials produce ductile welds that perform significantly better than these older connections. The question is how widespread is this problem and what information is needed to provide solutions? Depending on funds availability.<br/> 聽</li> </ol><p><strong>What is the research plan?</strong></p> <p>NIST will award three task orders, depending on funds to the new IDIQ Contractor once the award is made in FY2020, and one task order to the Science and Technology Policy Institute (STPI). 聽</p> <ol><li>The NEHRP Strategic Plan was published in 2008 reflecting the then Program priorities. There is an urgent need to review the Plan, to identify topics that have been addressed, to identify topics that remain to be addressed as well as new issues to add to the Plan. Earthquake engineering has evolved since 2008 and has become oriented towards providing a resilient nation as opposed to a concentration on mitigation. Additional considerations concerning lifelines and faster return to service of shaken buildings also need to be addressed. The updating process will involve all four NEHRP agencies and will be supported by a task order planned to be awarded to STPI, a contractor that specializes in policy-related studies. The updating will require a number of community workshops to reach out to specific stakeholder groups and other forms of contact with communities, building owners, building residents, local building departments, engineers, urban planners and social scientists. A key theme is that of moving from classic mitigation-focused work to that of resilience.聽<br/><br/> The task order is anticipated to require 30 months of effort to complete the study.聽</li> <li>A task order will be awarded to the new IDIQ contractor to assist NIST in completing the updating of RP-8, Standards of Seismic Safety for Existing Federally Owned and Leased Buildings, published by the ICSSC, which is chaired by NIST. RP-8 is required to be used by Federal agencies who own or lease buildings. The document provides the approach to determine if a building鈥檚 seismic performance has to be evaluated. A draft update of RP-8 was completed by the Applied Technology Council in 2016; the 2017 edition of ASCE/SEI 41 has been published and the final update document can be completed and published. The International Existing Building Code also will be included in this updating.聽聽It must be noted that Executive Order 13717 that established the requirements for Federal building seismic safety requires that NIST update the RP series periodically.聽<br/><br/> It is anticipated that this will require a modest effect of approximately 18 months. The work will include holding of at least one workshop in the DC area to get review input from ICSSC agencies concerning the proposed changes in the RP document.聽</li> <li>A task order will be awarded to the new IDIQ contractor to assist NIST in evaluating the existing provisions found in ASCE/SEI 7 and the NEHRP Provisions concerning vertical accelerations. The present provisions date back to 1979 and the first NEHRP Provisions document; no changes in the provisions have been made. The effectiveness of the existing language needs to be assessed in light of the knowledge gained over the past 40 years from research and from observations from actual earthquakes.聽<br/><br/> This study is anticipated to require 18 months to complete.聽</li> <li>Pre-1980 structural steel moment frames favored panel zones that would yield before the adjacent beams and columns. Panel zones as well as column splices used partial joint penetration (PJP) welds that are less expensive than full penetration welds that are now required. The welding requirements used during this era were not as stringent as modern requirements. Weld fracture in structural components can result in undesirable behavior of the moment frame during a seismic event. A weak panel zone mechanism may result in excessive shear deformations within the panel zone and significant column flange bending at the corners of the panel zone resulting in fracture of the welds connecting the bottom beam flange to the column flange. 聽Similar issues with welds in beam-to-column connections identified during the Northridge earthquake also put welded column splices at risk of fracture.聽<br/><br/> In this era column splices also were accomplished by welding splice plates to the column flanges using partial penetration welds. The resulting splices are not as ductile as modern splices produced using full penetration welds and improved welding methods and materials. Work being conducted on the west coast has indicated that perhaps many buildings were constructed using this approach, resulting in non-ductile columns splices and building performance that will not meet modern requirements.聽<br/><br/> A task order will be awarded to the new IDIQ contractor to determine the scope of the problem and what approaches should be taken to research potential solutions to this issue. A combination of analytical and testing work will no doubt be required to do the actual research. It is estimated that this task order will require 18 months to complete. The award will be made to the new IDIQ contractor subject to availability of funds in FY2020.</li> </ol> </div> </div> <div class="nist-block"> <h2 class="nist-block__title">Major Accomplishments</h2> <div class="text-long"><p><strong>Results:</strong></p> <p>These new TechBriefs will be the tenth and eleventh in a series of documents that have addressed the following seismic analysis and design issues:</p> <ul><li>TechBrief No. 1: <em><a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/publications/nehrp-seismic-design-technical-brief-no-1-seismic-design-reinforced-concrete-special">Seismic Design of Reinforced Concrete Special Moment Frames: A Guide for Practicing Engineers</a>.</em> NIST GCR 8-917-1,</li> <li>TechBrief No. 2: <em><a href="https://web.archive.org/web/20240305041050/http://www.nehrp.gov/pdf/nistgcr9-917-3.pdf">Seismic Design of Steel Special Moment Frames: A Guide for Practicing Engineers</a>,</em> NIST GCR 9-917-3</li> <li>TechBrief No. 3: <em><a href="https://web.archive.org/web/20240305041050/http://www.nehrp.gov/pdf/nistgcr10-917-4.pdf">Seismic Design of Cast-in-Place Concrete Diaphragms, Chords, and Collectors: A Guide for Practicing Engineers</a>,</em> NIST GCR 10-917-4</li> <li>TechBrief No. 4 <em><a href="https://web.archive.org/web/20240305041050/http://www.nehrp.gov/pdf/nistgcr10-917-5.pdf">Nonlinear Structural Analysis For Seismic Design: A Guide for Practicing Engineers</a>,</em> NIST GCR 10-917-5</li> <li>TechBrief No. 5: <em><a href="https://web.archive.org/web/20240305041050/http://www.nehrp.gov/pdf/nistgcr11-917-10.pdf">Seismic Design of Composite Steel Deck and Concrete-filled Diaphragms: A Guide for Practicing Engineers</a>,</em> NIST GCR 11-917-10</li> <li>TechBrief No. 6: <a href="https://web.archive.org/web/20240305041050/http://www.nehrp.gov/pdf/nistgcr11-917-11.pdf"><em>Seismic Design of Cast-in-Place Concrete Special Structural Walls and Coupling Beams: A Guide for Practicing Engineers</em></a><em>,</em> NIST GCR 11-917-11REV-1</li> <li>TechBrief No. 7: <em><a href="https://web.archive.org/web/20240305041050/http://www.nehrp.gov/pdf/nistgcr12-917-22.pdf">Seismic Design of Reinforced Concrete Mat Foundations: A Guide for Practicing Engineers</a>,</em> GCR 12-917-22</li> <li>TechBrief No. 8: <em>Seismic Design of Steel Special Concentric Braced Frame Systems: A Guide for Practicing Engineers,</em> in process</li> <li>TechBrief No. 9: <em>Seismic Design of Structural Wood Diaphragm Systems: A Guide for Practicing Engineers,</em> in process</li> </ul><p>The TechBrief series has had significant impact on the structural engineering community. The National Council of Structural Engineers Associations (NCSEA) provided webinars on TechBriefs 1 through 4 in 2011. In addition, TechBrief No. 2 was the subject of a presentation at the 2009 SEAOC Annual Conference, the subject of an article in <em>Structure Magazine</em> and won the SEAONC Award of Merit in 2010 for Excellence in Structural Engineering. TechBrief 4 was also cited in FEMA P-58. The TechBrief series has received high praise from practicing engineers and the university community as a source of concise information from subject matter experts on important structural engineering topics related to seismic design.</p> <p><strong>Standards and Codes:</strong></p> <p>Each <em>TechBrief</em> will be a concise synthesis of recent research results, model building code provisions and recommended design practices as developed by recognized experts in structural steel and reinforced masonry, as appropriate. The document will be completely compatible with existing and developing model building code provisions. The braced frame TechBrief will assist designers in their application of AISC 341 (see endnote i) and ASCE 7. The masonry TechBrief will assist designers in their application of MSJC and ASCE 7.</p></div> </div> <div class="nist-block">  <div data-elastic-exclude="" class="nist-tags"> <a href="/web/20240305041050/https://www.nist.gov/topic-terms/buildings-and-construction" hreflang="en">Buildings and Construction</a>, <a href="/web/20240305041050/https://www.nist.gov/topic-terms/building-codes-and-standards" hreflang="en">Building codes and standards</a>, <a href="/web/20240305041050/https://www.nist.gov/topic-terms/structural-engineering" hreflang="en">Structural engineering</a>, <a href="/web/20240305041050/https://www.nist.gov/topic-terms/resilience" hreflang="en">Resilience</a> and <a href="/web/20240305041050/https://www.nist.gov/topic-terms/disaster-and-failure-studies" hreflang="en">Disaster and failure studies</a></div>  </div> </div> <aside class="nist-page__region nist-page__region--sidebar-second tablet-lg:grid-col-4"> <div>  <div class="views-element-container nist-block nist-block--org" data-elastic-exclude=""> <h2 class="nist-block__title">Organizations</h2> <div><div class="js-view-dom-id-6e526302236c9773f8ea0f44473976a00f7abb4f2e3cece9c46b70cb4c14c765"> <div class="nist-related-orgs"><div class="term-tree-list"> <ul class="term"><li><a href="/web/20240305041050/https://www.nist.gov/nist-organizations/nist-headquarters" class="selected" hreflang="en">NIST Headquarters</a></li><li><ul class="term"><li><a href="/web/20240305041050/https://www.nist.gov/nist-organizations/nist-headquarters/laboratory-programs" class="selected" hreflang="en">Laboratory Programs</a></li><li><ul class="term"><li><a href="/web/20240305041050/https://www.nist.gov/nist-organizations/nist-headquarters/laboratory-programs/engineering-laboratory" class="selected" hreflang="en">Engineering Laboratory</a></li><li><ul class="term"><li><a href="/web/20240305041050/https://www.nist.gov/nist-organizations/nist-headquarters/laboratory-programs/engineering-laboratory/materials-and" class="selected" hreflang="en">Materials and Structural Systems Division</a></li><li><ul class="term"><li><a href="/web/20240305041050/https://www.nist.gov/nist-organizations/nist-headquarters/laboratory-programs/engineering-laboratory/materials-and-2" class="selected" hreflang="en">Earthquake Engineering Group</a></li></ul></li></ul></li></ul></li></ul></li></ul> </div> </div> <div class="nist-related-orgs"></div> <div class="nist-related-orgs"></div> <div class="nist-related-orgs"></div> <div class="nist-related-orgs"></div> </div> </div> </div>  <div class="nist-block nist-block--contact"> <h2 class="nist-block__title">Contact</h2> <div class="nist-contact"> <ul class="nist-contact__items"> </ul> </div> </div> <div class="nist-block"> <h2 class="nist-block__title">Project Status</h2> <div class="nist-badge display-inline-block margin-y-1 nist-badge--green boolean">Completed</div> </div> <div class="nist-block"> <h2 class="nist-block__title">Related NIST Projects</h2> <div class="nist-field nist-field--label-hidden nist-field--link-list entity-reference"> <div class="nist-field__items"> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/earthquake-risk-reduction-buildings-and-infrastructure-program" hreflang="en">Earthquake Risk Reduction in Buildings and Infrastructure Program</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/collapse-assessment-buildings-under-seismic-loading" hreflang="en">Collapse Assessment of Buildings under Seismic Loading</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/collapse-performance-modeling-nonductile-reinforced-concrete-columns-under" hreflang="en">Collapse Performance Modeling of Nonductile Reinforced Concrete Columns under Combined Axial and Seismic Loading</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/developing-cost-effective-relationships-between-federal-building-profiles-and" hreflang="en">Developing Cost-Effective Relationships Between Federal Building Profiles and Seismic Retrofit Cost</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/national-earthquake-hazards-reduction-program-nehrp-coordination" hreflang="en">National Earthquake Hazards Reduction Program (NEHRP) Coordination</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/quantification-material-loading-and-modeling-uncertainties-reinforced-concrete" hreflang="en">Quantification of Material, Loading, and Modeling Uncertainties of Reinforced Concrete Column Components and Frame Systems under Seismic and Gravity Loads for Use in PBSE</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/seismic-performance-steel-buildings-central-and-eastern-united-states" hreflang="en">Seismic Performance of Steel Buildings in the Central and Eastern United States</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/reliability-fiber-reinforced-composite-systems-resilient-infrastructure" hreflang="en">Reliability of Fiber Reinforced Composite Systems in Resilient Infrastructure</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/advancing-seismic-implementation-high-strength-reinforcement-bars-reinforced" hreflang="en">Advancing the Seismic Implementation of High Strength Reinforcement Bars in Reinforced Concrete Structural Wall Systems</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/improved-assessment-criteria-performance-based-seismic-design" hreflang="en">Improved Assessment Criteria for Performance-Based Seismic Design</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/seismic-assessment-and-retrofit-pre-northridge-earthquake-panel-zones-steel-moment" hreflang="en">Seismic Assessment and Retrofit of Pre-Northridge Earthquake Panel Zones in Steel Moment Frames</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/energy-based-collapse-assessment-framed-structures-performance-based-seismic" hreflang="en">Energy-based collapse assessment of framed structures for performance-based seismic engineering</a></div> <div class="nist-field__item"><a href="/web/20240305041050/https://www.nist.gov/programs-projects/options-improving-post-earthquake-re-occupancy-and-functional-recovery-time" hreflang="en">Options for Improving Post-Earthquake Re-Occupancy and Functional Recovery Time</a></div> </div> </div> </div> </div> </aside> </div> </div> <div class="grid-container"> <div class="nist-page__region nist-page__region--content-bottom"> <div class="nist-block"> <div class="text-italic font-sans-2xs"> Created November 1, 2011, Updated January 6, 2023 </div> </div> </div> </div> </section> </div> <div data-elastic-exclude>  <footer class="nist-footer padding-bottom-4"> <div class="grid-container nist-footer__info"> <div class="grid-row"> <div class="tablet:grid-col-6"> <div class="nist-footer__logo"> <a href="/web/20240305041050/https://www.nist.gov/" title="National Institute of Standards and Technology" rel="home"> <img class="nist-footer__logo-img" src="/web/20240305041050im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px"/> </a> </div> <div class="nist-footer__contact"> <h3 class="nist-footer__contact-heading">HEADQUARTERS</h3> <address> 100 Bureau Drive<br> Gaithersburg, MD 20899<br> <a href="https://web.archive.org/web/20240305041050/tel:301-975-2000">301-975-2000</a> </address> <p> <a href="https://web.archive.org/web/20240305041050/mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/visit">Our Other Offices</a> </p> </div> </div> <div class="tablet:grid-col-6"> <div class="nist-footer__social-links"> <a class="nist-social nist-social--twitter-white" href="https://web.archive.org/web/20240305041050/https://twitter.com/NIST"> <span>Twitter</span> </a> <a class="nist-social nist-social--facebook-white" href="https://web.archive.org/web/20240305041050/https://www.facebook.com/NIST"> <span>Facebook</span> </a> <a class="nist-social nist-social--linkedin-white" href="https://web.archive.org/web/20240305041050/https://www.linkedin.com/company/nist"> <span>LinkedIn</span> </a> <a class="nist-social nist-social--instagram-white" href="https://web.archive.org/web/20240305041050/https://www.instagram.com/nist/"> <span>Instagram</span> </a> <a class="nist-social nist-social--youtube-white" href="https://web.archive.org/web/20240305041050/https://www.youtube.com/NIST"> <span>YouTube</span> </a> <a class="nist-social nist-social--giphy-white" href="https://web.archive.org/web/20240305041050/https://giphy.com/nist"> <span>Giphy</span> </a> <a class="nist-social nist-social--rss-white" href="https://web.archive.org/web/20240305041050/https://www.nist.gov/news-events/nist-rss-feeds"> <span>RSS Feed</span> </a> <a class="nist-social nist-social--envelope-white" href="https://web.archive.org/web/20240305041050/https://public.govdelivery.com/accounts/USNIST/subscriber/new"> <span>Mailing List</span> </a> </div> <div class="nist-footer__feedback"> How are we doing? <a class="usa-button" rel="nofollow" href="/web/20240305041050/https://www.nist.gov/form/nist-gov-feedback?destination=/programs-projects/nehrp-extramural-research" title="Provide feedback">Feedback</a> </div> </div> </div> </div> <div class="grid-container"> <div class="nist-footer__nav" role="navigation"> <ul> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/privacy-policy">Site Privacy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/oism/accessibility">Accessibility</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/privacy">Privacy Program</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/oism/copyrights">Copyrights</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/office-director/freedom-information-act">FOIA</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/environmental-policy-statement">Environmental Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://www.commerce.gov/">Commerce.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/http://www.science.gov/">Science.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/http://www.usa.gov/">USA.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20240305041050/https://vote.gov/">Vote.gov</a> </li> </ul> </div> </div> </footer>  </div> </div> <script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","scriptPath":null,"pathPrefix":"","currentPath":"node\/417716","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"G-HEQ0YF2VYL","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip"},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":".ck-editor, .nist-social, .nist-video-thumbnail__lightbox-trigger, a.nist-icon--mail-blue","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"after","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"user":{"uid":0,"permissionsHash":"2f77e4dcfce20728ac491170886da836c10b580f9bdfeb9c9e729fe4958834d5"}}</script> <script src="/web/20240305041050js_/https://www.nist.gov/sites/default/files/js/js_L4s-xoxkQ67XMK98eQiz0h1j1ibNkR1AmjhYszY77y0.js?scope=footer&delta=0&language=en&theme=nist_www&include=eJx1UAFuAyEM-xArT4oCpDRrICdCy_r7wbXTTtUmIRQ7lm0lYLxC1_k2H35n-DQX_llx1OqyahYCrCiPztH8O-EqW4czTy7pqKKYoLdpwzX7jM-1cScuW9M7-XdiVdi5fqFCM1klYIOiySc2DNNYuF6dPaxTmQ2Ndr3PogHlOH-8rPyFMFH7gTDGOKoPeEnoq68An9ptQzm9oDONjAKFEuNK5ejuTMP8_p9mv5uQ69QKNDpToxpn-0bk_-Ag2qFL4dh0neAbz3OgYA"></script> <script src="https://web.archive.org/web/20240305041050js_/https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script> <script src="/web/20240305041050js_/https://www.nist.gov/sites/default/files/js/js_3eRXHrPpksrnWG1E8OJzoaq-9enhLNMMVm0GPoHbKRs.js?scope=footer&delta=2&language=en&theme=nist_www&include=eJx1UAFuAyEM-xArT4oCpDRrICdCy_r7wbXTTtUmIRQ7lm0lYLxC1_k2H35n-DQX_llx1OqyahYCrCiPztH8O-EqW4czTy7pqKKYoLdpwzX7jM-1cScuW9M7-XdiVdi5fqFCM1klYIOiySc2DNNYuF6dPaxTmQ2Ndr3PogHlOH-8rPyFMFH7gTDGOKoPeEnoq68An9ptQzm9oDONjAKFEuNK5ejuTMP8_p9mv5uQ69QKNDpToxpn-0bk_-Ag2qFL4dh0neAbz3OgYA"></script> <script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFnFGRhVWVWoNVgUHaHpaWkcXWFVaBks9LFtdUGJaAEB6WQ1NEw1YVVBGHltBUFMU","queueTime":4,"applicationTime":554,"atts":"TBtXQQMaH0k=","errorBeacon":"bam.nr-data.net","agent":""}</script></body> </html>

CINXE.COM

NEHRP Extramural Research | NIST