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Search results for: dynamic headspace sampling
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6852</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: dynamic headspace sampling</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6852</span> Investigation of Deep Eutectic Solvents for Microwave Assisted Extraction and Headspace Gas Chromatographic Determination of Hexanal in Fat-Rich Food</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Birute%20Bugelyte">Birute Bugelyte</a>, <a href="https://publications.waset.org/abstracts/search?q=Ingrida%20Jurkute"> Ingrida Jurkute</a>, <a href="https://publications.waset.org/abstracts/search?q=Vida%20Vickackaite"> Vida Vickackaite</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The most complicated step of the determination of volatile compounds in complex matrices is the separation of analytes from the matrix. Traditional analyte separation methods (liquid extraction, Soxhlet extraction) require a lot of time and labour; moreover, there is a risk to lose the volatile analytes. In recent years, headspace gas chromatography has been used to determine volatile compounds. To date, traditional extraction solvents have been used in headspace gas chromatography. As a rule, such solvents are rather volatile; therefore, a large amount of solvent vapour enters into the headspace together with the analyte. Because of that, the determination sensitivity of the analyte is reduced, a huge solvent peak in the chromatogram can overlap with the peaks of the analyts. The sensitivity is also limited by the fact that the sample can’t be heated at a higher temperature than the solvent boiling point. In 2018 it was suggested to replace traditional headspace gas chromatographic solvents with non-volatile, eco-friendly, biodegradable, inexpensive, and easy to prepare deep eutectic solvents (DESs). Generally, deep eutectic solvents have low vapour pressure, a relatively wide liquid range, much lower melting point than that of any of their individual components. Those features make DESs very attractive as matrix media for application in headspace gas chromatography. Also, DESs are polar compounds, so they can be applied for microwave assisted extraction. The aim of this work was to investigate the possibility of applying deep eutectic solvents for microwave assisted extraction and headspace gas chromatographic determination of hexanal in fat-rich food. Hexanal is considered one of the most suitable indicators of lipid oxidation degree as it is the main secondary oxidation product of linoleic acid, which is one of the principal fatty acids of many edible oils. Eight hydrophilic and hydrophobic deep eutectic solvents have been synthesized, and the influence of the temperature and microwaves on their headspace gas chromatographic behaviour has been investigated. Using the most suitable DES, microwave assisted extraction conditions and headspace gas chromatographic conditions have been optimized for the determination of hexanal in potato chips. Under optimized conditions, the quality parameters of the prepared technique have been determined. The suggested technique was applied for the determination of hexanal in potato chips and other fat-rich food. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=deep%20eutectic%20solvents" title="deep eutectic solvents">deep eutectic solvents</a>, <a href="https://publications.waset.org/abstracts/search?q=headspace%20gas%20chromatography" title=" headspace gas chromatography"> headspace gas chromatography</a>, <a href="https://publications.waset.org/abstracts/search?q=hexanal" title=" hexanal"> hexanal</a>, <a href="https://publications.waset.org/abstracts/search?q=microwave%20assisted%20extraction" title=" microwave assisted extraction"> microwave assisted extraction</a> </p> <a href="https://publications.waset.org/abstracts/130578/investigation-of-deep-eutectic-solvents-for-microwave-assisted-extraction-and-headspace-gas-chromatographic-determination-of-hexanal-in-fat-rich-food" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/130578.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">195</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6851</span> Development and Validation of a Carbon Dioxide TDLAS Sensor for Studies on Fermented Dairy Products</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Lorenzo%20Cocola">Lorenzo Cocola</a>, <a href="https://publications.waset.org/abstracts/search?q=Massimo%20Fedel"> Massimo Fedel</a>, <a href="https://publications.waset.org/abstracts/search?q=Dragi%C5%A1a%20Savi%C4%87"> Dragiša Savić</a>, <a href="https://publications.waset.org/abstracts/search?q=Bojana%20Danilovi%C4%87"> Bojana Danilović</a>, <a href="https://publications.waset.org/abstracts/search?q=Luca%20Poletto"> Luca Poletto</a> </p> <p class="card-text"><strong>Abstract:</strong></p> An instrument for the detection and evaluation of gaseous carbon dioxide in the headspace of closed containers has been developed in the context of Packsensor Italian-Serbian joint project. The device is based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) with a Wavelength Modulation Spectroscopy (WMS) technique in order to accomplish a non-invasive measurement inside closed containers of fermented dairy products (yogurts and fermented cheese in cups and bottles). The purpose of this instrument is the continuous monitoring of carbon dioxide concentration during incubation and storage of products over a time span of the whole shelf life of the product, in the presence of different microorganisms. The instrument’s optical front end has been designed to be integrated in a thermally stabilized incubator. An embedded computer provides processing of spectral artifacts and storage of an arbitrary set of calibration data allowing a properly calibrated measurement on many samples (cups and bottles) of different shapes and sizes commonly found in the retail distribution. A calibration protocol has been developed in order to be able to calibrate the instrument on the field also on containers which are notoriously difficult to seal properly. This calibration protocol is described and evaluated against reference measurements obtained through an industry standard (sampling) carbon dioxide metering technique. Some sets of validation test measurements on different containers are reported. Two test recordings of carbon dioxide concentration evolution are shown as an example of instrument operation. The first demonstrates the ability to monitor a rapid yeast growth in a contaminated sample through the increase of headspace carbon dioxide. Another experiment shows the dissolution transient with a non-saturated liquid medium in presence of a carbon dioxide rich headspace atmosphere. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=TDLAS" title="TDLAS">TDLAS</a>, <a href="https://publications.waset.org/abstracts/search?q=carbon%20dioxide" title=" carbon dioxide"> carbon dioxide</a>, <a href="https://publications.waset.org/abstracts/search?q=cups" title=" cups"> cups</a>, <a href="https://publications.waset.org/abstracts/search?q=headspace" title=" headspace"> headspace</a>, <a href="https://publications.waset.org/abstracts/search?q=measurement" title=" measurement"> measurement</a> </p> <a href="https://publications.waset.org/abstracts/41645/development-and-validation-of-a-carbon-dioxide-tdlas-sensor-for-studies-on-fermented-dairy-products" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/41645.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">324</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6850</span> Managing Shallow Gas for Offshore Platforms via Fit-For-Purpose Solutions: Case Study for Offshore Malaysia</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Noorizal%20Huang">Noorizal Huang</a>, <a href="https://publications.waset.org/abstracts/search?q=Christian%20Girsang"> Christian Girsang</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohamad%20Razi%20Mansoor"> Mohamad Razi Mansoor</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Shallow gas seepage was first spotted at a central processing platform offshore Malaysia in 2010, acknowledged as Platform T in this paper. Frequent monitoring of the gas seepage was performed through remotely operated vehicle (ROV) baseline survey and a comprehensive geophysical survey was conducted to understand the characteristics of the gas seepage and to ensure that the integrity of the foundation at Platform T was not compromised. The origin of the gas back then was unknown. A soil investigation campaign was performed in 2016 to study the origin of the gas seepage. Two boreholes were drilled; a composite borehole to 150m below seabed for the purpose of soil sampling and in-situ testing and a pilot hole to 155m below the seabed, which was later converted to a fit-for-purpose relief well as an alternate migration path for the gas. During the soil investigation campaign, dissipation tests were performed at several layers which were potentially the source or migration path for the gas. Five (5) soil samples were segregated for headspace test, to identify the gas type which subsequently can be used to identify the origin of the gas. Dissipation tests performed at four depth intervals indicates pore water pressure less than 20 % of the effective vertical stress and appear to continue decreasing if the test had not been stopped. It was concluded that a low to a negligible amount of excess pore pressure exist in clayey silt layers. Results from headspace test show presence of methane corresponding to the clayey silt layers as reported in the boring logs. The gas most likely comes from biogenic sources, feeding on organic matter in situ over a large depth range. It is unlikely that there are large pockets of gas in the soil due to its homogeneous clayey nature and the lack of excess pore pressure in other permeable clayey silt layers encountered. Instead, it is more likely that when pore water at certain depth encounters a more permeable path, such as a borehole, it rises up through this path due to the temperature gradient in the soil. As the water rises the pressure decreases, which could cause gases dissolved in the water to come out of solution and form bubbles. As a result, the gas will have no impact on the integrity of the foundation at Platform T. The fit-for-purpose relief well design as well as adopting headspace testing can be used to address the shallow gas issue at Platform T in a cost effective and efficient manners. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dissipation%20test" title="dissipation test">dissipation test</a>, <a href="https://publications.waset.org/abstracts/search?q=headspace%20test" title=" headspace test"> headspace test</a>, <a href="https://publications.waset.org/abstracts/search?q=excess%20pore%20pressure" title=" excess pore pressure"> excess pore pressure</a>, <a href="https://publications.waset.org/abstracts/search?q=relief%20well" title=" relief well"> relief well</a>, <a href="https://publications.waset.org/abstracts/search?q=shallow%20gas" title=" shallow gas"> shallow gas</a> </p> <a href="https://publications.waset.org/abstracts/76798/managing-shallow-gas-for-offshore-platforms-via-fit-for-purpose-solutions-case-study-for-offshore-malaysia" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/76798.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">273</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6849</span> Evaluation of Oxidative Changes in Soybean Oil During Shelf-Life by Physico-Chemical Methods and Headspace-Liquid Phase Microextraction (HS-LPME) Technique</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Maryam%20Enteshari">Maryam Enteshari</a>, <a href="https://publications.waset.org/abstracts/search?q=Kooshan%20Nayebzadeh"> Kooshan Nayebzadeh</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdorreza%20Mohammadi"> Abdorreza Mohammadi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study, the oxidative stability of soybean oil under different storage temperatures (4 and 25˚C) and during 6-month shelf-life was investigated by various analytical methods and headspace-liquid phase microextraction (HS-LPME) coupled to gas chromatography-mass spectrometry (GC-MS). Oxidation changes were monitored by analytical parameters consisted of acid value (AV), peroxide value (PV), p-Anisidine value (p-AV), thiobarbituric acid value (TBA), fatty acids profile, iodine value (IV), and oxidative stability index (OSI). In addition, concentrations of hexanal and heptanal as secondary volatile oxidation compounds were determined by HS-LPME/GC-MS technique. Rate of oxidation in soybean oil which stored at 25˚C was so higher. The AV, p-AV, and TBA were gradually increased during 6 months while the amount of unsaturated fatty acids, IV, and OSI decreased. Other parameters included concentrations of both hexanal and heptanal, and PV exhibited increasing trend during primitive months of storage; then, at the end of third and fourth months a sudden decrement was understood for the concentrations of hexanal and heptanal and the amount of PV, simultaneously. The latter parameters increased again until the end of shelf-time. As a result, the temperature and time were effective factors in oxidative stability of soybean oil. Also intensive correlations were found for soybean oil at 4 ˚C between AV and TBA (r2=0.96), PV and p-AV (r2=0.9), IV and TBA (-r2=0.9), and for soybean oil stored at 4˚C between p-AV and TBA (r2=0.99). <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=headspace-liquid%20phase%20microextraction" title="headspace-liquid phase microextraction">headspace-liquid phase microextraction</a>, <a href="https://publications.waset.org/abstracts/search?q=oxidation" title=" oxidation"> oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=shelf-life" title=" shelf-life"> shelf-life</a>, <a href="https://publications.waset.org/abstracts/search?q=soybean%20oil" title=" soybean oil"> soybean oil</a> </p> <a href="https://publications.waset.org/abstracts/33686/evaluation-of-oxidative-changes-in-soybean-oil-during-shelf-life-by-physico-chemical-methods-and-headspace-liquid-phase-microextraction-hs-lpme-technique" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/33686.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">404</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6848</span> Smelling Our Way through Names: Understanding the Potential of Floral Volatiles as Taxonomic Traits in the Fragrant Ginger Genus Hedychium</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Anupama%20Sekhar">Anupama Sekhar</a>, <a href="https://publications.waset.org/abstracts/search?q=Preeti%20Saryan"> Preeti Saryan</a>, <a href="https://publications.waset.org/abstracts/search?q=Vinita%20Gowda"> Vinita Gowda</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Plants, due to their sedentary lifestyle, have evolved mechanisms to synthesize a huge diversity of complex, specialized chemical metabolites, a majority of them being volatile organic compounds (VOCs). These VOCs are heavily involved in their biotic and abiotic interactions. Since chemical composition could be under the same selection processes as other morphological characters, we test if VOCs can be used to taxonomically distinguish species in the well-studied, fragrant ginger genus -Hedychium (Zingiberaceae). We propose that variations in the volatile profiles are suggestive of adaptation to divergent environments, and their presence could be explained by either phylogenetic conservatism or ecological factors. In this study, we investigate the volatile chemistry within Hedychium, which is endemic to Asian palaeotropics. We used an unsupervised clustering approach which clearly distinguished most taxa, and we used ancestral state reconstruction to estimate phylogenetic signals and chemical trait evolution in the genus. We propose that taxonomically, the chemical composition could aid in species identification, especially in species complexes where taxa are not morphologically distinguishable, and extensive, targeted chemical libraries will help in this effort. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=chemotaxonomy" title="chemotaxonomy">chemotaxonomy</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20headspace%20sampling" title=" dynamic headspace sampling"> dynamic headspace sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=floral%20fragrance" title=" floral fragrance"> floral fragrance</a>, <a href="https://publications.waset.org/abstracts/search?q=floral%20volatile%20evolution" title=" floral volatile evolution"> floral volatile evolution</a>, <a href="https://publications.waset.org/abstracts/search?q=gingers" title=" gingers"> gingers</a>, <a href="https://publications.waset.org/abstracts/search?q=Hedychium" title=" Hedychium"> Hedychium</a> </p> <a href="https://publications.waset.org/abstracts/161617/smelling-our-way-through-names-understanding-the-potential-of-floral-volatiles-as-taxonomic-traits-in-the-fragrant-ginger-genus-hedychium" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/161617.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">95</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6847</span> Oxidation Assessment of Mayonnaise with Headspace Single-Drop Microextarction (HS-SDME) Coupled with Gas Chromatography-Mass Spectrometry (GC-MS) during Shelf-Life </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kooshan%20Nayebzadeh">Kooshan Nayebzadeh</a>, <a href="https://publications.waset.org/abstracts/search?q=Maryam%20Enteshari"> Maryam Enteshari</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdorreza%20Mohammadi"> Abdorreza Mohammadi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The oxidative stability of mayonnaise under different storage temperatures (4 and 25˚C) during 6-month shelf-life was investigated by different analytical methods. In this study, headspace single-drop microextarction (HS-SDME) combined with gas chromatography-mass spectrometry (GC-MS) as a green, sensitive and rapid technique was applied to evaluate oxidative state in mayonnaise. Oxidation changes of extracted oil from mayonnaise were monitored by analytical parameters including peroxide value (PV), p-Anisidine value (p-An V), thiobarbituric acid value (TBA), and oxidative stability index (OSI). Hexanal and heptanal as secondary volatile oxidation compounds were determined by HS-SDME/GC-MS method in mayonnaise matrix. The rate of oxidation in mayonnaises increased during storage and it was determined greater at 25 ˚C. The values of Anisidine and TBA were gradually enhanced during 6 months, while the amount of OSI decreased. At both temperatures, the content of hexanal was higher than heptanal during all storage periods. Also significant increments in hexanal and heptanal concentrations in the second and sixth month of storage have been observed. Hexanal concentrations in mayonnaises which were stored at 25 ˚C and during storage time showed the highest values. It can be concluded that the temperature and duration of storage time are definitive parameters which affect on quality and oxidative stability of mayonnaise. Additionally, hexanal content in comparison to heptanal is a more reliable oxidative indicator and HS-SDME/GC-MS can be applied in a quick and simple manner. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=oxidative%20stability" title="oxidative stability">oxidative stability</a>, <a href="https://publications.waset.org/abstracts/search?q=mayonnaise" title=" mayonnaise"> mayonnaise</a>, <a href="https://publications.waset.org/abstracts/search?q=headspace%20single-drop%20microextarction%20%28HS-SDME%29" title=" headspace single-drop microextarction (HS-SDME)"> headspace single-drop microextarction (HS-SDME)</a>, <a href="https://publications.waset.org/abstracts/search?q=shelf-life" title=" shelf-life"> shelf-life</a> </p> <a href="https://publications.waset.org/abstracts/18043/oxidation-assessment-of-mayonnaise-with-headspace-single-drop-microextarction-hs-sdme-coupled-with-gas-chromatography-mass-spectrometry-gc-ms-during-shelf-life" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/18043.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">419</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6846</span> Analysis of the Volatile Organic Compounds of Tillandsia Flowers by HS-SPME/GC-MS</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Alexandre%20Gonzalez">Alexandre Gonzalez</a>, <a href="https://publications.waset.org/abstracts/search?q=Zohra%20Benfodda"> Zohra Benfodda</a>, <a href="https://publications.waset.org/abstracts/search?q=David%20B%C3%A9nim%C3%A9lis"> David Bénimélis</a>, <a href="https://publications.waset.org/abstracts/search?q=Jean-Xavier%20Fontaine"> Jean-Xavier Fontaine</a>, <a href="https://publications.waset.org/abstracts/search?q=Roland%20Molini%C3%A9"> Roland Molinié</a>, <a href="https://publications.waset.org/abstracts/search?q=Patrick%20Meffre"> Patrick Meffre</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Volatile organic compounds (VOCs) emitted by flowers play an important role in plant ecology. However, the Tillandsia genus has been scarcely studied according to the VOCs emitted by flowers. Tillandsia are epiphytic flowering plants belonging to the Bromeliaceae family. The VOCs composition of twelve unscented and two faint-scented Tillandsia species was studied. The headspace solid phase microextraction coupled with gas chromatography combined with mass spectrometry method was used to explore the chemical diversity of the VOCs. This study allowed the identification of 65 VOCs among the fourteen species, and between six to twenty-five compounds were identified in each of the species. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=tillandsia" title="tillandsia">tillandsia</a>, <a href="https://publications.waset.org/abstracts/search?q=headspace%20solid%20phase%20microextraction%20%28HS-SPME%29" title=" headspace solid phase microextraction (HS-SPME)"> headspace solid phase microextraction (HS-SPME)</a>, <a href="https://publications.waset.org/abstracts/search?q=gas%20chromatography-mass%20spectrometry%20%28GC-MS%29" title=" gas chromatography-mass spectrometry (GC-MS)"> gas chromatography-mass spectrometry (GC-MS)</a>, <a href="https://publications.waset.org/abstracts/search?q=scentless%20flowers" title=" scentless flowers"> scentless flowers</a>, <a href="https://publications.waset.org/abstracts/search?q=volatile%20organic%20compounds%20%28VOCs%29" title=" volatile organic compounds (VOCs)"> volatile organic compounds (VOCs)</a>, <a href="https://publications.waset.org/abstracts/search?q=PCA%20analysis" title=" PCA analysis"> PCA analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=heatmap" title=" heatmap"> heatmap</a> </p> <a href="https://publications.waset.org/abstracts/152016/analysis-of-the-volatile-organic-compounds-of-tillandsia-flowers-by-hs-spmegc-ms" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/152016.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">124</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6845</span> Estimating The Population Mean by Using Stratified Double Extreme Ranked Set Sample</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mahmoud%20I.%20Syam">Mahmoud I. Syam</a>, <a href="https://publications.waset.org/abstracts/search?q=Kamarulzaman%20Ibrahim"> Kamarulzaman Ibrahim</a>, <a href="https://publications.waset.org/abstracts/search?q=Amer%20I.%20Al-Omari"> Amer I. Al-Omari </a> </p> <p class="card-text"><strong>Abstract:</strong></p> Stratified double extreme ranked set sampling (SDERSS) method is introduced and considered for estimating the population mean. The SDERSS is compared with the simple random sampling (SRS), stratified ranked set sampling (SRSS) and stratified simple set sampling (SSRS). It is shown that the SDERSS estimator is an unbiased of the population mean and more efficient than the estimators using SRS, SRSS and SSRS when the underlying distribution of the variable of interest is symmetric or asymmetric. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=double%20extreme%20ranked%20set%20sampling" title="double extreme ranked set sampling">double extreme ranked set sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=extreme%20ranked%20set%20sampling" title=" extreme ranked set sampling"> extreme ranked set sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=ranked%20set%20sampling" title=" ranked set sampling"> ranked set sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=stratified%20double%20extreme%20ranked%20set%20sampling" title=" stratified double extreme ranked set sampling"> stratified double extreme ranked set sampling</a> </p> <a href="https://publications.waset.org/abstracts/25207/estimating-the-population-mean-by-using-stratified-double-extreme-ranked-set-sample" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/25207.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">456</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6844</span> Optimal ECG Sampling Frequency for Multiscale Entropy-Based HRV</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Manjit%20Singh">Manjit Singh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Multiscale entropy (MSE) is an extensively used index to provide a general understanding of multiple complexity of physiologic mechanism of heart rate variability (HRV) that operates on a wide range of time scales. Accurate selection of electrocardiogram (ECG) sampling frequency is an essential concern for clinically significant HRV quantification; high ECG sampling rate increase memory requirements and processing time, whereas low sampling rate degrade signal quality and results in clinically misinterpreted HRV. In this work, the impact of ECG sampling frequency on MSE based HRV have been quantified. MSE measures are found to be sensitive to ECG sampling frequency and effect of sampling frequency will be a function of time scale. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ECG%20%28electrocardiogram%29" title="ECG (electrocardiogram)">ECG (electrocardiogram)</a>, <a href="https://publications.waset.org/abstracts/search?q=heart%20rate%20variability%20%28HRV%29" title=" heart rate variability (HRV)"> heart rate variability (HRV)</a>, <a href="https://publications.waset.org/abstracts/search?q=multiscale%20entropy" title=" multiscale entropy"> multiscale entropy</a>, <a href="https://publications.waset.org/abstracts/search?q=sampling%20frequency" title=" sampling frequency"> sampling frequency</a> </p> <a href="https://publications.waset.org/abstracts/78603/optimal-ecg-sampling-frequency-for-multiscale-entropy-based-hrv" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/78603.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">271</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6843</span> Bayesian Approach for Moving Extremes Ranked Set Sampling</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Said%20Ali%20Al-Hadhrami">Said Ali Al-Hadhrami</a>, <a href="https://publications.waset.org/abstracts/search?q=Amer%20Ibrahim%20Al-Omari"> Amer Ibrahim Al-Omari</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, Bayesian estimation for the mean of exponential distribution is considered using Moving Extremes Ranked Set Sampling (MERSS). Three priors are used; Jeffery, conjugate and constant using MERSS and Simple Random Sampling (SRS). Some properties of the proposed estimators are investigated. It is found that the suggested estimators using MERSS are more efficient than its counterparts based on SRS. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bayesian" title="Bayesian">Bayesian</a>, <a href="https://publications.waset.org/abstracts/search?q=efficiency" title=" efficiency"> efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=moving%20extreme%20ranked%20set%20sampling" title=" moving extreme ranked set sampling"> moving extreme ranked set sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=ranked%20set%20sampling" title=" ranked set sampling"> ranked set sampling</a> </p> <a href="https://publications.waset.org/abstracts/30733/bayesian-approach-for-moving-extremes-ranked-set-sampling" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/30733.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">514</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6842</span> Stripping of Flavour-Active Compounds from Aqueous Food Streams: Effect of Liquid Matrix on Vapour-Liquid Equilibrium in a Beer-Like Solution</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ali%20Ammari">Ali Ammari</a>, <a href="https://publications.waset.org/abstracts/search?q=Karin%20Schroen"> Karin Schroen</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In brewing industries, stripping is a downstream process to separate volatiles from beer. Due to physiochemical similarities between flavour components, the selectivity of this method is not favourable. Besides, the presence of non-volatile compounds such as proteins and carbohydrates may affect the separation of flavours due to their retaining properties. By using a stripping column with structured packing coupled with a gas chromatography, in this work, the overall mass transfer coefficient along with their corresponding equilibrium data was investigated for a model solution consist of water, ethanol, ethyl acetate and isoamyl acetate. Static headspace analysis also was employed to derive equilibrium data for flavours in the presence of beer dry matter. As it was expected ethanol and dry matter showed retention properties; however, the effect of viscosity in mass transfer coefficient was discarded due to the fact that the viscosity of solution decreased during stripping. The effect of ethanol and beer dry matter were mapped to be used for designing stripping could. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=flavour" title="flavour">flavour</a>, <a href="https://publications.waset.org/abstracts/search?q=headspace" title=" headspace"> headspace</a>, <a href="https://publications.waset.org/abstracts/search?q=Henry%E2%80%99s%20coefficient" title=" Henry’s coefficient"> Henry’s coefficient</a>, <a href="https://publications.waset.org/abstracts/search?q=mass%20transfer%20coefficient" title=" mass transfer coefficient"> mass transfer coefficient</a>, <a href="https://publications.waset.org/abstracts/search?q=stripping" title=" stripping"> stripping</a> </p> <a href="https://publications.waset.org/abstracts/80348/stripping-of-flavour-active-compounds-from-aqueous-food-streams-effect-of-liquid-matrix-on-vapour-liquid-equilibrium-in-a-beer-like-solution" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/80348.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">194</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6841</span> Efficient Alias-Free Level Crossing Sampling</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Negar%20Riazifar">Negar Riazifar</a>, <a href="https://publications.waset.org/abstracts/search?q=Nigel%20G.%20Stocks"> Nigel G. Stocks</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper proposes strategies in level crossing (LC) sampling and reconstruction that provide alias-free high-fidelity signal reconstruction for speech signals without exponentially increasing sample number with increasing bit-depth. We introduce methods in LC sampling that reduce the sampling rate close to the Nyquist frequency even for large bit-depth. The results indicate that larger variation in the sampling intervals leads to an alias-free sampling scheme; this is achieved by either reducing the bit-depth or adding jitter to the system for high bit-depths. In conjunction with windowing, the signal is reconstructed from the LC samples using an efficient Toeplitz reconstruction algorithm. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=alias-free" title="alias-free">alias-free</a>, <a href="https://publications.waset.org/abstracts/search?q=level%20crossing%20sampling" title=" level crossing sampling"> level crossing sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=spectrum" title=" spectrum"> spectrum</a>, <a href="https://publications.waset.org/abstracts/search?q=trigonometric%20polynomial" title=" trigonometric polynomial"> trigonometric polynomial</a> </p> <a href="https://publications.waset.org/abstracts/136144/efficient-alias-free-level-crossing-sampling" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/136144.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">209</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6840</span> Design of Bayesian MDS Sampling Plan Based on the Process Capability Index</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Davood%20Shishebori">Davood Shishebori</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Saber%20Fallah%20Nezhad"> Mohammad Saber Fallah Nezhad</a>, <a href="https://publications.waset.org/abstracts/search?q=Sina%20Seifi"> Sina Seifi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, a variable multiple dependent state (MDS) sampling plan is developed based on the process capability index using Bayesian approach. The optimal parameters of the developed sampling plan with respect to constraints related to the risk of consumer and producer are presented. Two comparison studies have been done. First, the methods of double sampling model, sampling plan for resubmitted lots and repetitive group sampling (RGS) plan are elaborated and average sample numbers of the developed MDS plan and other classical methods are compared. A comparison study between the developed MDS plan based on Bayesian approach and the exact probability distribution is carried out. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=MDS%20sampling%20plan" title="MDS sampling plan">MDS sampling plan</a>, <a href="https://publications.waset.org/abstracts/search?q=RGS%20plan" title=" RGS plan"> RGS plan</a>, <a href="https://publications.waset.org/abstracts/search?q=sampling%20plan%20for%20resubmitted%20lots" title=" sampling plan for resubmitted lots"> sampling plan for resubmitted lots</a>, <a href="https://publications.waset.org/abstracts/search?q=process%20capability%20index%20%28PCI%29" title=" process capability index (PCI)"> process capability index (PCI)</a>, <a href="https://publications.waset.org/abstracts/search?q=average%20sample%20number%20%28ASN%29" title=" average sample number (ASN)"> average sample number (ASN)</a>, <a href="https://publications.waset.org/abstracts/search?q=Bayesian%20approach" title=" Bayesian approach"> Bayesian approach</a> </p> <a href="https://publications.waset.org/abstracts/74571/design-of-bayesian-mds-sampling-plan-based-on-the-process-capability-index" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/74571.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">301</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6839</span> Static Headspace GC Method for Aldehydes Determination in Different Food Matrices</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=A.%20Mandi%C4%87">A. Mandić</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Saka%C4%8D"> M. Sakač</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Mi%C5%A1an"> A. Mišan</a>, <a href="https://publications.waset.org/abstracts/search?q=B.%20%C5%A0oji%C4%87"> B. Šojić</a>, <a href="https://publications.waset.org/abstracts/search?q=L.%20Petrovi%C4%87"> L. Petrović</a>, <a href="https://publications.waset.org/abstracts/search?q=I.%20Lon%C4%8Darevi%C4%87"> I. Lončarević</a>, <a href="https://publications.waset.org/abstracts/search?q=B.%20Pajin"> B. Pajin</a>, <a href="https://publications.waset.org/abstracts/search?q=I.%20Sedej"> I. Sedej</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Aldehydes as secondary lipid oxidation products are highly specific to the oxidative degradation of particular polyunsaturated fatty acids present in foods. Gas chromatographic analysis of those volatile compounds has been widely used for monitoring of the deterioration of food products. Developed static headspace gas chromatography method using flame ionization detector (SHS GC FID) was applied to monitor the aldehydes present in processed foods such as bakery, meat and confectionary products. Five selected aldehydes were determined in samples without any sample preparation, except grinding for bakery and meat products. SHS–GC analysis allows the separation of propanal, pentanal, hexanal, heptanal and octanal, within 15min. Aldehydes were quantified in fresh and stored samples, and the obtained range of aldehydes in crackers was 1.62±0.05-9.95±0.05mg/kg, in sausages 6.62±0.46-39.16±0.39mg/kg; and in cocoa spread cream 0.48±0.01-1.13±0.02mg/kg. Referring to the obtained results, the following can be concluded, proposed method is suitable for different types of samples, content of aldehydes varies depending on the type of a sample, and differs in fresh and stored samples of the same type. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=lipid%20oxidation" title="lipid oxidation">lipid oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=aldehydes" title=" aldehydes"> aldehydes</a>, <a href="https://publications.waset.org/abstracts/search?q=crackers" title=" crackers"> crackers</a>, <a href="https://publications.waset.org/abstracts/search?q=sausage" title=" sausage"> sausage</a>, <a href="https://publications.waset.org/abstracts/search?q=cocoa%20cream%20spread" title=" cocoa cream spread"> cocoa cream spread</a> </p> <a href="https://publications.waset.org/abstracts/7771/static-headspace-gc-method-for-aldehydes-determination-in-different-food-matrices" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/7771.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">429</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6838</span> Methods of Variance Estimation in Two-Phase Sampling</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Raghunath%20Arnab">Raghunath Arnab</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The two-phase sampling which is also known as double sampling was introduced in 1938. In two-phase sampling, samples are selected in phases. In the first phase, a relatively large sample of size is selected by some suitable sampling design and only information on the auxiliary variable is collected. During the second phase, a sample of size is selected either from, the sample selected in the first phase or from the entire population by using a suitable sampling design and information regarding the study and auxiliary variable is collected. Evidently, two phase sampling is useful if the auxiliary information is relatively easy and cheaper to collect than the study variable as well as if the strength of the relationship between the variables and is high. If the sample is selected in more than two phases, the resulting sampling design is called a multi-phase sampling. In this article we will consider how one can use data collected at the first phase sampling at the stages of estimation of the parameter, stratification, selection of sample and their combinations in the second phase in a unified setup applicable to any sampling design and wider classes of estimators. The problem of the estimation of variance will also be considered. The variance of estimator is essential for estimating precision of the survey estimates, calculation of confidence intervals, determination of the optimal sample sizes and for testing of hypotheses amongst others. Although, the variance is a non-negative quantity but its estimators may not be non-negative. If the estimator of variance is negative, then it cannot be used for estimation of confidence intervals, testing of hypothesis or measure of sampling error. The non-negativity properties of the variance estimators will also be studied in details. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=auxiliary%20information" title="auxiliary information">auxiliary information</a>, <a href="https://publications.waset.org/abstracts/search?q=two-phase%20sampling" title=" two-phase sampling"> two-phase sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=varying%20probability%20sampling" title=" varying probability sampling"> varying probability sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=unbiased%20estimators" title=" unbiased estimators"> unbiased estimators</a> </p> <a href="https://publications.waset.org/abstracts/36087/methods-of-variance-estimation-in-two-phase-sampling" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/36087.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">588</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6837</span> Investigating the Efficiency of Stratified Double Median Ranked Set Sample for Estimating the Population Mean</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mahmoud%20I.%20Syam">Mahmoud I. Syam</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Stratified double median ranked set sampling (SDMRSS) method is suggested for estimating the population mean. The SDMRSS is compared with the simple random sampling (SRS), stratified simple random sampling (SSRS), and stratified ranked set sampling (SRSS). It is shown that SDMRSS estimator is an unbiased of the population mean and more efficient than SRS, SSRS, and SRSS. Also, by SDMRSS, we can increase the efficiency of mean estimator for specific value of the sample size. SDMRSS is applied on real life examples, and the results of the example agreed the theoretical results. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=efficiency" title="efficiency">efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=double%20ranked%20set%20sampling" title=" double ranked set sampling"> double ranked set sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=median%20ranked%20set%20sampling" title=" median ranked set sampling"> median ranked set sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=ranked%20set%20sampling" title=" ranked set sampling"> ranked set sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=stratified" title=" stratified"> stratified</a> </p> <a href="https://publications.waset.org/abstracts/56985/investigating-the-efficiency-of-stratified-double-median-ranked-set-sample-for-estimating-the-population-mean" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/56985.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">247</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6836</span> Oxidative Stability of an Iranian Ghee (Butter Fat) Versus Soybean Oil During Storage at Different Temperatures</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kooshan%20Nayebzadeh">Kooshan Nayebzadeh</a>, <a href="https://publications.waset.org/abstracts/search?q=Maryam%20Enteshari"> Maryam Enteshari</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study, the oxidative stability of soybean oil under different storage temperatures (4 and 25 ˚C) and during 6-month shelf-life was investigated by various analytical methods and headspace-liquid phase microextraction (HS-LPME) coupled to gas chromatography-mass spectrometry (GC-MS). Oxidation changes were monitored by analytical parameters consisted of acid value (AV), peroxide value (PV), p-Anisidine value (p-AV), thiobarbituric acid value (TBA), fatty acids profile, iodine value (IV) and oxidative stability index (OSI). In addition, concentrations of hexanal and heptanal as secondary volatile oxidation compounds were determined by HS-LPME/GC-MS technique. Rate of oxidation in soybean oil which stored at 25 ˚C was so higher. The AV, p-AV, and TBA were gradually increased during 6 months, while the amount of unsaturated fatty acids, IV, and OSI decreased. Other parameters included concentrations of both hexanal and heptanal, and PV exhibited increasing trend during primitive months of storage; then, at the end of third and fourth months a sudden decrement was understood for the concentrations of hexanal and heptanal and the amount of PV, simultaneously. The latter parameters increased again until the end of shelf-time. As a result, the temperature and time were effective factors in oxidative stability of soybean oil. Also intensive correlations were found for soybean oil at 4 ˚C between AV and TBA (r2=0.96), PV and p-AV (r2=0.9), IV and TBA (-r2=0.9), and for soybean oil stored at 4 ˚C between p-AV and TBA (r2=0.99). <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=headspace-liquid%20phase%20microextraction" title="headspace-liquid phase microextraction">headspace-liquid phase microextraction</a>, <a href="https://publications.waset.org/abstracts/search?q=oxidation" title=" oxidation"> oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=shelf-life" title=" shelf-life"> shelf-life</a>, <a href="https://publications.waset.org/abstracts/search?q=soybean%20oil" title=" soybean oil"> soybean oil</a> </p> <a href="https://publications.waset.org/abstracts/33685/oxidative-stability-of-an-iranian-ghee-butter-fat-versus-soybean-oil-during-storage-at-different-temperatures" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/33685.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">398</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6835</span> Investigation of the Effects of Sampling Frequency on the THD of 3-Phase Inverters Using Space Vector Modulation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Khattab%20Al%20Qaisi">Khattab Al Qaisi</a>, <a href="https://publications.waset.org/abstracts/search?q=Nicholas%20Bowring"> Nicholas Bowring</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the simulation results of the effects of sampling frequency on the total harmonic distortion (THD) of three-phase inverters using the space vector pulse width modulation (SVPWM) and space vector control (SVC) algorithms. The relationship between the variables was studied using curve fitting techniques, and it has been shown that, for 50 Hz inverters, there is an exponential relation between the sampling frequency and THD up to around 8500 Hz, beyond which the performance of the model becomes irregular, and there is an negative exponential relation between the sampling frequency and the marginal improvement to the THD. It has also been found that the performance of SVPWM is better than that of SVC with the same sampling frequency in most frequency range, including the range where the performance of the former is irregular. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=DSI" title="DSI">DSI</a>, <a href="https://publications.waset.org/abstracts/search?q=SVPWM" title=" SVPWM"> SVPWM</a>, <a href="https://publications.waset.org/abstracts/search?q=THD" title=" THD"> THD</a>, <a href="https://publications.waset.org/abstracts/search?q=DC-AC%20converter" title=" DC-AC converter"> DC-AC converter</a>, <a href="https://publications.waset.org/abstracts/search?q=sampling%20frequency" title=" sampling frequency"> sampling frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=performance" title=" performance"> performance</a> </p> <a href="https://publications.waset.org/abstracts/17856/investigation-of-the-effects-of-sampling-frequency-on-the-thd-of-3-phase-inverters-using-space-vector-modulation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/17856.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">485</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6834</span> Effects of Reclamation on Seasonal Dynamic of Carbon, Nitrogen and Phosphorus Stoichiometry in Suaeda salsa</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yajun%20Qiao">Yajun Qiao</a>, <a href="https://publications.waset.org/abstracts/search?q=Yaner%20Yan"> Yaner Yan</a>, <a href="https://publications.waset.org/abstracts/search?q=Ning%20Li"> Ning Li</a>, <a href="https://publications.waset.org/abstracts/search?q=Shuqing%20An"> Shuqing An</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In order to relieve the pressure on a land resource from a huge population, reclamation has occurred in many coastal wetlands. Plants can maintain their elemental composition within normal limits despite the variations of external conditions. Reclamation may affect carbon (C), nitrogen (N) and phosphorus (P) stoichiometry in the plant to some extent by altering physical and chemical properties of soil in a coastal wetland. We reported the seasonal dynamic of C, N and P stoichiometry in root, stem and leaf of Suaeda salsa (L.) Pall. and in soil between reclamation plots and natural plots. Our results of three-way ANOVA indicated that sampling season always had significant effect on C, N, P concentrations and their ratios; organ had no significant effect on N, P concentration and N:P; plot type had no significant effect on N concentration and C:N. Sampling season explained the most variability of tissue N and P contents, C:N, C:P and N:P, while it’s organ for C using the restricted maximum likelihood (REML) method. By independent sample T-test, we found that reclamation affect more on C, N and P stoichiometry of stem than that of root or leaf on the whole. While there was no difference between reclamation plots and natural plots for soil in four seasons. For three organs, C concentration had peak values in autumn and minimum values in spring while N concentration had peak values in spring and minimum values in autumn. For P concentration, three organs all had peak values in spring; however, the root had minimum value in winter, the stem had that in autumn, and leaf had that in summer. The seasonal dynamic of C, N and P stoichiometry in a leaf of Suaeda salsa were much steadier than that in root or stem under the drive of reclamation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=nitrogen" title="nitrogen">nitrogen</a>, <a href="https://publications.waset.org/abstracts/search?q=phosphorus" title=" phosphorus"> phosphorus</a>, <a href="https://publications.waset.org/abstracts/search?q=reclamation" title=" reclamation"> reclamation</a>, <a href="https://publications.waset.org/abstracts/search?q=seasonal%20dynamic" title=" seasonal dynamic"> seasonal dynamic</a>, <a href="https://publications.waset.org/abstracts/search?q=Suaeda%20salsa" title=" Suaeda salsa"> Suaeda salsa</a> </p> <a href="https://publications.waset.org/abstracts/29581/effects-of-reclamation-on-seasonal-dynamic-of-carbon-nitrogen-and-phosphorus-stoichiometry-in-suaeda-salsa" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/29581.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">353</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6833</span> Different Sampling Schemes for Semi-Parametric Frailty Model</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Nursel%20Koyuncu">Nursel Koyuncu</a>, <a href="https://publications.waset.org/abstracts/search?q=Nihal%20Ata%20Tutkun"> Nihal Ata Tutkun</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Frailty model is a survival model that takes into account the unobserved heterogeneity for exploring the relationship between the survival of an individual and several covariates. In the recent years, proposed survival models become more complex and this feature causes convergence problems especially in large data sets. Therefore selection of sample from these big data sets is very important for estimation of parameters. In sampling literature, some authors have defined new sampling schemes to predict the parameters correctly. For this aim, we try to see the effect of sampling design in semi-parametric frailty model. We conducted a simulation study in R programme to estimate the parameters of semi-parametric frailty model for different sample sizes, censoring rates under classical simple random sampling and ranked set sampling schemes. In the simulation study, we used data set recording 17260 male Civil Servants aged 40–64 years with complete 10-year follow-up as population. Time to death from coronary heart disease is treated as a survival-time and age, systolic blood pressure are used as covariates. We select the 1000 samples from population using different sampling schemes and estimate the parameters. From the simulation study, we concluded that ranked set sampling design performs better than simple random sampling for each scenario. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=frailty%20model" title="frailty model">frailty model</a>, <a href="https://publications.waset.org/abstracts/search?q=ranked%20set%20sampling" title=" ranked set sampling"> ranked set sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=efficiency" title=" efficiency"> efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=simple%20random%20sampling" title=" simple random sampling"> simple random sampling</a> </p> <a href="https://publications.waset.org/abstracts/76811/different-sampling-schemes-for-semi-parametric-frailty-model" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/76811.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">211</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6832</span> Some Generalized Multivariate Estimators for Population Mean under Multi Phase Stratified Systematic Sampling</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Muqaddas%20Javed">Muqaddas Javed</a>, <a href="https://publications.waset.org/abstracts/search?q=Muhammad%20Hanif"> Muhammad Hanif</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The generalized multivariate ratio and regression type estimators for population mean are suggested under multi-phase stratified systematic sampling (MPSSS) using multi auxiliary information. Estimators are developed under the two different situations of availability of auxiliary information. The expressions of bias and mean square error (MSE) are developed. Special cases of suggested estimators are also discussed and simulation study is conducted to observe the performance of estimators. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=generalized%20estimators" title="generalized estimators">generalized estimators</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-phase%20sampling" title=" multi-phase sampling"> multi-phase sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=stratified%20random%20sampling" title=" stratified random sampling"> stratified random sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=systematic%20sampling" title=" systematic sampling"> systematic sampling</a> </p> <a href="https://publications.waset.org/abstracts/27296/some-generalized-multivariate-estimators-for-population-mean-under-multi-phase-stratified-systematic-sampling" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/27296.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">729</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6831</span> Assessment of Water Quality Network in Karoon River by Dynamic Programming Approach (DPA)</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20Nasri%20Nasrabadi">M. Nasri Nasrabadi</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20A.%20Hassani"> A. A. Hassani </a> </p> <p class="card-text"><strong>Abstract:</strong></p> Karoon is one of the greatest and longest rivers of Iran, which because of the existence of numerous industrial, agricultural centers and drinking usage, has a strategic situation in the west and southwest parts of Iran, and the optimal monitoring of its water quality is an essential and indispensable national issue. Due to financial constraints, water quality monitoring network design is an efficient way to manage water quality. The most crucial part is to find appropriate locations for monitoring stations. Considering the objectives of water usage, we evaluate existing water quality sampling stations of this river. There are several methods for assessment of existing monitoring stations such as Sanders method, multiple criteria decision making and dynamic programming approach (DPA) which DPA opted in this study. The results showed that due to the drinking water quality index out of 20 existing monitoring stations, nine stations should be retained on the river, that include of Gorgor-Band-Ghir of A zone, Dez-Band-Ghir of B zone, Teir, Pole Panjom and Zargan of C zone, Darkhoein, Hafar, Chobade, and Sabonsazi of D zone. In additional, stations of Dez river have the best conditions. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=DPA" title="DPA">DPA</a>, <a href="https://publications.waset.org/abstracts/search?q=karoon%20river" title=" karoon river"> karoon river</a>, <a href="https://publications.waset.org/abstracts/search?q=network%20monitoring" title=" network monitoring"> network monitoring</a>, <a href="https://publications.waset.org/abstracts/search?q=water%20quality" title=" water quality"> water quality</a>, <a href="https://publications.waset.org/abstracts/search?q=sampling%20site" title=" sampling site"> sampling site</a> </p> <a href="https://publications.waset.org/abstracts/16660/assessment-of-water-quality-network-in-karoon-river-by-dynamic-programming-approach-dpa" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/16660.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">377</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6830</span> Movies and Dynamic Mathematical Objects on Trigonometry for Mobile Phones</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kazuhisa%20Takagi">Kazuhisa Takagi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper is about movies and dynamic objects for mobile phones. Dynamic objects are the software programmed by JavaScript. They consist of geometric figures and work on HTML5-compliant browsers. Mobile phones are very popular among teenagers. They like watching movies and playing games on them. So, mathematics movies and dynamic objects would enhance teaching and learning processes. In the movies, manga characters speak with artificially synchronized voices. They teach trigonometry together with dynamic mathematical objects. Many movies are created. They are Windows Media files or MP4 movies. These movies and dynamic objects are not only used in the classroom but also distributed to students. By watching movies, students can study trigonometry before or after class. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dynamic%20mathematical%20object" title="dynamic mathematical object">dynamic mathematical object</a>, <a href="https://publications.waset.org/abstracts/search?q=javascript" title=" javascript"> javascript</a>, <a href="https://publications.waset.org/abstracts/search?q=google%20drive" title=" google drive"> google drive</a>, <a href="https://publications.waset.org/abstracts/search?q=transfer%20jet" title=" transfer jet"> transfer jet</a> </p> <a href="https://publications.waset.org/abstracts/67497/movies-and-dynamic-mathematical-objects-on-trigonometry-for-mobile-phones" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/67497.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">260</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6829</span> A Comparison between Empirical and Theoretical OC Curves Related to Acceptance Sampling for Attributes</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Encarnacion%20Alvarez">Encarnacion Alvarez</a>, <a href="https://publications.waset.org/abstracts/search?q=Noem%C4%B1%20Hidalgo-Rebollo"> Noemı Hidalgo-Rebollo</a>, <a href="https://publications.waset.org/abstracts/search?q=Juan%20F.%20Munoz"> Juan F. Munoz</a>, <a href="https://publications.waset.org/abstracts/search?q=Francisco%20J.%20Blanco-Encomienda"> Francisco J. Blanco-Encomienda</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Many companies use the technique named as acceptance sampling which consists on the inspection and decision making regarding products. According to the results derived from this method, the company takes the decision of acceptance or rejection of a product. The acceptance sampling can be applied to the technology management, since the acceptance sampling can be seen as a tool to improve the design planning, operation and control of technological products. The theoretical operating characteristic (OC) curves are widely used when dealing with acceptance sampling. In this paper, we carry out Monte Carlo simulation studies to compare numerically the empirical OC curves derived from the empirical results to the customary theoretical OC curves. We analyze various possible scenarios in such a way that the differences between the empirical and theoretical curves can be observed under different situations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=single-sampling%20plan" title="single-sampling plan">single-sampling plan</a>, <a href="https://publications.waset.org/abstracts/search?q=lot" title=" lot"> lot</a>, <a href="https://publications.waset.org/abstracts/search?q=Monte%20Carlo%20simulation" title=" Monte Carlo simulation"> Monte Carlo simulation</a>, <a href="https://publications.waset.org/abstracts/search?q=quality%20control" title=" quality control"> quality control</a> </p> <a href="https://publications.waset.org/abstracts/19429/a-comparison-between-empirical-and-theoretical-oc-curves-related-to-acceptance-sampling-for-attributes" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/19429.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">466</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6828</span> Sampling Effects on Secondary Voltage Control of Microgrids Based on Network of Multiagent</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20J.%20Park">M. J. Park</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20H.%20Lee"> S. H. Lee</a>, <a href="https://publications.waset.org/abstracts/search?q=C.%20H.%20Lee"> C. H. Lee</a>, <a href="https://publications.waset.org/abstracts/search?q=O.%20M.%20Kwon"> O. M. Kwon</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper studies a secondary voltage control framework of the microgrids based on the consensus for a communication network of multiagent. The proposed control is designed by the communication network with one-way links. The communication network is modeled by a directed graph. At this time, the concept of sampling is considered as the communication constraint among each distributed generator in the microgrids. To analyze the sampling effects on the secondary voltage control of the microgrids, by using Lyapunov theory and some mathematical techniques, the sufficient condition for such problem will be established regarding linear matrix inequality (LMI). Finally, some simulation results are given to illustrate the necessity of the consideration of the sampling effects on the secondary voltage control of the microgrids. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=microgrids" title="microgrids">microgrids</a>, <a href="https://publications.waset.org/abstracts/search?q=secondary%20control" title=" secondary control"> secondary control</a>, <a href="https://publications.waset.org/abstracts/search?q=multiagent" title=" multiagent"> multiagent</a>, <a href="https://publications.waset.org/abstracts/search?q=sampling" title=" sampling"> sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=LMI" title=" LMI"> LMI</a> </p> <a href="https://publications.waset.org/abstracts/51477/sampling-effects-on-secondary-voltage-control-of-microgrids-based-on-network-of-multiagent" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/51477.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">333</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6827</span> Dynamic Amplification Factors of Some City Bridges</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=I.%20Paeglite">I. Paeglite</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Paeglitis"> A. Paeglitis</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The paper presents a study of dynamic effects obtained from the dynamic load testing of the city highway bridges in Latvia carried out from 2005 to 2012. 9 pre-stressed concrete bridges and 4 composite bridges were considered. 11 of 13 bridges were designed according to the Eurocodes but two according to the previous structural codes used in Latvia (SNIP 2.05.03-84). The dynamic properties of the bridges were obtained by heavy vehicles passing the bridge roadway with different driving speeds and with or without even pavement. The obtained values of the Dynamic amplification factor (DAF) and bridge natural frequency were analyzed and compared to the values of built-in traffic load models provided in Eurocode 1. The actual DAF values for even bridge deck in the most cases are smaller than the value adopted in Eurocode 1. Vehicle speed for uneven pavements significantly influence Dynamic amplification factor values. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=bridge" title="bridge">bridge</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20effects" title=" dynamic effects"> dynamic effects</a>, <a href="https://publications.waset.org/abstracts/search?q=load%20testing" title=" load testing"> load testing</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20amplification%20factor" title=" dynamic amplification factor"> dynamic amplification factor</a> </p> <a href="https://publications.waset.org/abstracts/10727/dynamic-amplification-factors-of-some-city-bridges" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/10727.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">383</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6826</span> The Variable Sampling Interval Xbar Chart versus the Double Sampling Xbar Chart</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Michael%20B.%20C.%20Khoo">Michael B. C. Khoo</a>, <a href="https://publications.waset.org/abstracts/search?q=J.%20L.%20Khoo"> J. L. Khoo</a>, <a href="https://publications.waset.org/abstracts/search?q=W.%20C.%20Yeong"> W. C. Yeong</a>, <a href="https://publications.waset.org/abstracts/search?q=W.%20L.%20Teoh"> W. L. Teoh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The Shewhart Xbar control chart is a useful process monitoring tool in manufacturing industries to detect the presence of assignable causes. However, it is insensitive in detecting small process shifts. To circumvent this problem, adaptive control charts are suggested. An adaptive chart enables at least one of the chart’s parameters to be adjusted to increase the chart’s sensitivity. Two common adaptive charts that exist in the literature are the double sampling (DS) Xbar and variable sampling interval (VSI) Xbar charts. This paper compares the performances of the DS and VSI Xbar charts, based on the average time to signal (ATS) criterion. The ATS profiles of the DS Xbar and VSI Xbar charts are obtained using the Mathematica and Statistical Analysis System (SAS) programs, respectively. The results show that the VSI Xbar chart is generally superior to the DS Xbar chart. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=adaptive%20charts" title="adaptive charts">adaptive charts</a>, <a href="https://publications.waset.org/abstracts/search?q=average%20time%20to%20signal" title=" average time to signal"> average time to signal</a>, <a href="https://publications.waset.org/abstracts/search?q=double%20sampling" title=" double sampling"> double sampling</a>, <a href="https://publications.waset.org/abstracts/search?q=charts" title=" charts"> charts</a>, <a href="https://publications.waset.org/abstracts/search?q=variable%20sampling%20interval" title=" variable sampling interval"> variable sampling interval</a> </p> <a href="https://publications.waset.org/abstracts/45295/the-variable-sampling-interval-xbar-chart-versus-the-double-sampling-xbar-chart" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/45295.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">286</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6825</span> Dynamic Fault Tree Analysis of Dynamic Positioning System through Monte Carlo Approach</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=A.%20S.%20Cheliyan">A. S. Cheliyan</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20K.%20Bhattacharyya"> S. K. Bhattacharyya </a> </p> <p class="card-text"><strong>Abstract:</strong></p> Dynamic Positioning System (DPS) is employed in marine vessels of the offshore oil and gas industry. It is a computer controlled system to automatically maintain a ship’s position and heading by using its own thrusters. Reliability assessment of the same can be analyzed through conventional fault tree. However, the complex behaviour like sequence failure, redundancy management and priority of failing of events cannot be analyzed by the conventional fault trees. The Dynamic Fault Tree (DFT) addresses these shortcomings of conventional Fault Tree by defining additional gates called dynamic gates. Monte Carlo based simulation approach has been adopted for the dynamic gates. This method of realistic modeling of DPS gives meaningful insight into the system reliability and the ability to improve the same. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dynamic%20positioning%20system" title="dynamic positioning system">dynamic positioning system</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20fault%20tree" title=" dynamic fault tree"> dynamic fault tree</a>, <a href="https://publications.waset.org/abstracts/search?q=Monte%20Carlo%20simulation" title=" Monte Carlo simulation"> Monte Carlo simulation</a>, <a href="https://publications.waset.org/abstracts/search?q=reliability%20assessment" title=" reliability assessment "> reliability assessment </a> </p> <a href="https://publications.waset.org/abstracts/58683/dynamic-fault-tree-analysis-of-dynamic-positioning-system-through-monte-carlo-approach" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/58683.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">774</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6824</span> Identifying Unknown Dynamic Forces Applied on Two Dimensional Frames</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=H.%20Katkhuda">H. Katkhuda</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A time domain approach is used in this paper to identify unknown dynamic forces applied on two dimensional frames using the measured dynamic structural responses for a sub-structure in the two dimensional frame. In this paper a sub-structure finite element model with short length of measurement from only three or four accelerometers is required, and an iterative least-square algorithm is used to identify the unknown dynamic force applied on the structure. Validity of the method is demonstrated with numerical examples using noise-free and noise-contaminated structural responses. Both harmonic and impulsive forces are studied. The results show that the proposed approach can identify unknown dynamic forces within very limited iterations with high accuracy and shows its robustness even noise- polluted dynamic response measurements are utilized. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dynamic%20force%20identification" title="dynamic force identification">dynamic force identification</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20responses" title=" dynamic responses"> dynamic responses</a>, <a href="https://publications.waset.org/abstracts/search?q=sub-structure" title=" sub-structure"> sub-structure</a>, <a href="https://publications.waset.org/abstracts/search?q=time%20domain" title=" time domain"> time domain</a> </p> <a href="https://publications.waset.org/abstracts/8992/identifying-unknown-dynamic-forces-applied-on-two-dimensional-frames" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/8992.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">361</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6823</span> Using Possibility Books to Develop Creativity Mindsets - a New Pedagogy for Learning Science, Math, and Engineering</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Michael%20R.%20Taber">Michael R. Taber</a>, <a href="https://publications.waset.org/abstracts/search?q=Kristin%20Stanec"> Kristin Stanec</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents year-two of a longitudinal study on implementing Possibility Books into undergraduate courses to develop a student's creativity mindset: tolerating ambiguity, willingness to risk failure, curiosity, and openness to embrace possibility thinking through unexpected connections. Courses involved in this research span disciplines in the natural and social sciences and the humanities. Year one of the project developed indices from which baseline data could be analyzed. The two significant indices ( > 0.7) were "creativity mindset" and "intentional interactions." Preliminary qualitative and quantitative data analysis indicated that students found the new pedagogical intervention as a safe space to learn new strategies, recognize patterns, and define structures through innovative notetaking forms. Possibility Books in Natural Science courses were designed to develop students' conceptualization of science and math. Using Possibility Books in all disciplines provided a space for students to practice divergent thinking (i.e.,Possibilities), convergent thinking (i.e., forms that express meaning), and risk-taking (i.e., the vulnerability associated with expression). Qualitative coding of open responses on a post-survey revealed two major themes: 1) Possibility Books provided a mind space for learning about self, and 2) provided a calming opportunity to connect concepts. Quantitative analysis indicated significant correlations between focused headspace and notetaking (r = 0.555, p < 0.001), focused headspace, and connecting with others (r = 0.405, p < 0.001). <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=pedagogy" title="pedagogy">pedagogy</a>, <a href="https://publications.waset.org/abstracts/search?q=science%20education" title=" science education"> science education</a>, <a href="https://publications.waset.org/abstracts/search?q=learning%20methods" title=" learning methods"> learning methods</a>, <a href="https://publications.waset.org/abstracts/search?q=creativity%20mindsets" title=" creativity mindsets"> creativity mindsets</a> </p> <a href="https://publications.waset.org/abstracts/190233/using-possibility-books-to-develop-creativity-mindsets-a-new-pedagogy-for-learning-science-math-and-engineering" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/190233.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">23</span> </span> </div> </div> <ul class="pagination"> <li class="page-item disabled"><span class="page-link">‹</span></li> <li class="page-item active"><span class="page-link">1</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=dynamic%20headspace%20sampling&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=dynamic%20headspace%20sampling&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=dynamic%20headspace%20sampling&page=4">4</a></li> <li class="page-item"><a class="page-link" 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