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Dimitrov Atanasov</title> <meta name="description" content="Search results for: Kalin Dimitrov Atanasov"> <meta name="keywords" content="Kalin Dimitrov Atanasov"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button 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action="https://publications.waset.org/abstracts/search"> <div id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="Kalin Dimitrov Atanasov"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 16</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: Kalin Dimitrov Atanasov</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">16</span> Neuromyelitis Optica area Postrema Syndrome(NMOSD-APS) in a Fifteen-year-old Girl: A Case Report</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Merilin%20Ivanova%20Ivanova">Merilin Ivanova Ivanova</a>, <a href="https://publications.waset.org/abstracts/search?q=Kalin%20Dimitrov%20Atanasov"> Kalin Dimitrov Atanasov</a>, <a href="https://publications.waset.org/abstracts/search?q=Stefan%20Petrov%20Enchev"> Stefan Petrov Enchev</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Backgroud: Neuromyelitis optica spectrum disorder, also known as Devic’s disease, is a relapsing demyelinating autoimmune inflammatory disorder of the central nervous system associated with anti-aquaporin 4 (AQP4) antibodies that can manifest with devastating secondary neurological deficits. Most commonly affected are the optic nerves and the spinal cord-clinically this is often presented with optic neuritis (loss of vision), transverse myelitis(weakness or paralysis of extremities),lack of bladder and bowel control, numbness. APS is a core clinical entity of NMOSD and adds to the clinical representation the following symptoms: intractable nausea, vomiting and hiccup, it usually occurs isolated at onset, and can lead to a significant delay in the diagnosis. The condition may have features similar to multiple sclerosis (MS) but the episodes are worse in NMO and it is treated differently. It could be relapsing or monophasic. Possible complications are visual field defects and motor impairment, with potential blindness and irreversible motor deficits. In severe cases, myogenic respiratory failure ensues. The incidence of reported cases is approximately 0.3–4.4 per 100,000. Paediatric cases of NMOSD are rare but have been reported occasionally, comprising less than 5% of the reported cases. Objective: The case serves to show the difficulty when it comes to the diagnostic processes regarding a rare autoimmune disease with non- specific symptoms, taking large interval of rimes to reveal as complete clinical manifestation of the aforementioned syndrome, as well as the necessity of multidisciplinary approach in the setting of а general paediatric department in аn emergency hospital. Methods: itpatient's history, clinical presentation, and information from the used diagnostic tools(MRI with contrast of the central nervous system) lead us to the conclusion .This was later on confirmed by the positive results from the anti-aquaporin 4 (AQP4) antibody serology test. Conclusion: APS is a common symptom of NMOSD and is considered a challenge in a differential-diagnostic plan. Gaining an increased awareness of this disease/syndrome, obtaining a detailed patient history, and performing thorough physical examinations are essential if we are to reduce and avoid misdiagnosis. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=neuromyelitis" title="neuromyelitis">neuromyelitis</a>, <a href="https://publications.waset.org/abstracts/search?q=devic%27s%20disease" title=" devic's disease"> devic's disease</a>, <a href="https://publications.waset.org/abstracts/search?q=hiccup" title=" hiccup"> hiccup</a>, <a href="https://publications.waset.org/abstracts/search?q=autoimmune" title=" autoimmune"> autoimmune</a>, <a href="https://publications.waset.org/abstracts/search?q=MRI" title=" MRI"> MRI</a> </p> <a href="https://publications.waset.org/abstracts/182547/neuromyelitis-optica-area-postrema-syndromenmosd-aps-in-a-fifteen-year-old-girl-a-case-report" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/182547.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">39</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">15</span> Optics Meets Microfluidics for Highly Sensitive Force Sensing</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Iliya%20Dimitrov%20Stoev">Iliya Dimitrov Stoev</a>, <a href="https://publications.waset.org/abstracts/search?q=Benjamin%20Seelbinder"> Benjamin Seelbinder</a>, <a href="https://publications.waset.org/abstracts/search?q=Elena%20Erben"> Elena Erben</a>, <a href="https://publications.waset.org/abstracts/search?q=Nicola%20Maghelli"> Nicola Maghelli</a>, <a href="https://publications.waset.org/abstracts/search?q=Moritz%20Kreysing"> Moritz Kreysing</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Despite the revolutionizing impact of optical tweezers in materials science and cell biology up to the present date, trapping has so far extensively relied on specific material properties of the probe and local heating has limited applications related to investigating dynamic processes within living systems. To overcome these limitations while maintaining high sensitivity, here we present a new optofluidic approach that can be used to gently trap microscopic particles and measure femtoNewton forces in a contact-free manner and with thermally limited precision. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=optofluidics" title="optofluidics">optofluidics</a>, <a href="https://publications.waset.org/abstracts/search?q=force%20measurements" title=" force measurements"> force measurements</a>, <a href="https://publications.waset.org/abstracts/search?q=microrheology" title=" microrheology"> microrheology</a>, <a href="https://publications.waset.org/abstracts/search?q=FLUCS" title=" FLUCS"> FLUCS</a>, <a href="https://publications.waset.org/abstracts/search?q=thermoviscous%20flows" title=" thermoviscous flows"> thermoviscous flows</a> </p> <a href="https://publications.waset.org/abstracts/147676/optics-meets-microfluidics-for-highly-sensitive-force-sensing" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/147676.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">170</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">14</span> BingleSeq: A User-Friendly R Package for Single-Cell RNA-Seq Data Analysis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Quan%20Gu">Quan Gu</a>, <a href="https://publications.waset.org/abstracts/search?q=Daniel%20%20Dimitrov"> Daniel Dimitrov</a> </p> <p class="card-text"><strong>Abstract:</strong></p> BingleSeq was developed as a shiny-based, intuitive, and comprehensive application that enables the analysis of single-Cell RNA-Sequencing count data. This was achieved via incorporating three state-of-the-art software packages for each type of RNA sequencing analysis, alongside functional annotation analysis and a way to assess the overlap of differential expression method results. At its current state, the functionality implemented within BingleSeq is comparable to that of other applications, also developed with the purpose of lowering the entry requirements to RNA Sequencing analyses. BingleSeq is available on GitHub and will be submitted to R/Bioconductor. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=bioinformatics" title="bioinformatics">bioinformatics</a>, <a href="https://publications.waset.org/abstracts/search?q=functional%20annotation%20analysis" title=" functional annotation analysis"> functional annotation analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=single-cell%20RNA-sequencing" title=" single-cell RNA-sequencing"> single-cell RNA-sequencing</a>, <a href="https://publications.waset.org/abstracts/search?q=transcriptomics" title=" transcriptomics"> transcriptomics</a> </p> <a href="https://publications.waset.org/abstracts/120198/bingleseq-a-user-friendly-r-package-for-single-cell-rna-seq-data-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/120198.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">205</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">13</span> The Use of Actoprotectors by Professional Athletes</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kalin%20Ivanov">Kalin Ivanov</a>, <a href="https://publications.waset.org/abstracts/search?q=Stanislava%20Ivanova"> Stanislava Ivanova</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Actoprotectors are substances with hight performance enchasing potential and hight antioxidant activity. Most of these drugs have been developed in USSR for military medicine purposes. Based on their chemical composition actoprotectors could be classified into three categories: benzimidazole derivatives (ethomersol, bemitil); adamantane derivatives (bromantane), other chemical classes. First data for intake of actoprotectors from professional athletes is from 1980. The daily intake of actoprotectors demonstrate many benefits for athletes like: positive effect on the efficiency of physical work, antihypoxic effects, antioxidant effects, nootropic effects, rapid recovery. Since 1997, bromantane is considered as doping. This is a result of Summer Olympic Games in Athlanta (1996) when several Russian athletes tested positive for bramantane. Even the drug is safe for athletes health its use is considered as violation of anti- doping rules. More than 37 years bemetil has been used by professional athletes with no risk but currently it is included in WADA monitoring programme for 2018. Current perspectives are that most used actoprotectors would be considered as doping. Many clinical studies have confirmed that intake of bemitil and bromantan demonstrate positive influence on the physical work capacity but data for other actoprotectors like chlodantane, ademol, ethomersol is limited. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=actoprotector" title="actoprotector">actoprotector</a>, <a href="https://publications.waset.org/abstracts/search?q=sport" title=" sport"> sport</a>, <a href="https://publications.waset.org/abstracts/search?q=doping" title=" doping"> doping</a>, <a href="https://publications.waset.org/abstracts/search?q=bemitil" title=" bemitil"> bemitil</a> </p> <a href="https://publications.waset.org/abstracts/85179/the-use-of-actoprotectors-by-professional-athletes" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/85179.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">322</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">12</span> Realization of Wearable Inertial Measurement Units-Sensor-Fusion Harness to Control Therapeutic Smartphone Applications</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Svilen%20Dimitrov">Svilen Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Manthan%20Pancholi"> Manthan Pancholi</a>, <a href="https://publications.waset.org/abstracts/search?q=Norbert%20Schmitz"> Norbert Schmitz</a>, <a href="https://publications.waset.org/abstracts/search?q=Didier%20Stricker"> Didier Stricker</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the end-to-end development of a wearable motion sensing harness consisting of computational unit and four inertial measurement units to control three smartphone therapeutic games for children. The inertial data is processed in real time to obtain lower body motion information like knee raises, feet taps and squads. By providing a Wi-Fi connection interface the sensor harness acts wireless remote control for smartphone applications. By performing various lower body movements the users provoke corresponding game state changes. In contrary to the current similar offers, like Nintendo Wii Remote, Xbox Kinect and Playstation Move, this product, consisting of the sensor harness and the applications on top of it, are fully wearable, which means they do not rely on the user to be bound to concrete soft- or hardwareequipped space. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=wearable%20harness" title="wearable harness">wearable harness</a>, <a href="https://publications.waset.org/abstracts/search?q=inertial%20measurement%20units" title=" inertial measurement units"> inertial measurement units</a>, <a href="https://publications.waset.org/abstracts/search?q=smartphone%20therapeutic%20games" title=" smartphone therapeutic games"> smartphone therapeutic games</a>, <a href="https://publications.waset.org/abstracts/search?q=motion%20tracking" title=" motion tracking"> motion tracking</a>, <a href="https://publications.waset.org/abstracts/search?q=lower-body%20activity%20monitoring" title=" lower-body activity monitoring"> lower-body activity monitoring</a> </p> <a href="https://publications.waset.org/abstracts/65691/realization-of-wearable-inertial-measurement-units-sensor-fusion-harness-to-control-therapeutic-smartphone-applications" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/65691.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">403</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">11</span> Effect of the Nature of the Precursor on the Performance of Cu-Mn Catalysts for CO and VOCs Oxidation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Elitsa%20Kolentsova">Elitsa Kolentsova</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Dimitrov"> Dimitar Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20Ivanov"> Krasimir Ivanov</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The catalytic oxidation of methanol to formaldehyde is an important industrial process in which the waste gas in addition to CO contains methanol and dimethyl ether (DME). Evaluation of the possibility of removing the harmful components from the exhaust gasses needs a more complex investigation. Our previous work indicates that supported Cu-Mn oxide catalysts are promising for effective deep oxidation of these compounds. This work relates to the catalyst, comprising copper-manganese spinel, coated on carrier γ-Al₂O₃. The effect of preparation conditions on the active component composition and activity behavior of the catalysts is discussed. Different organometallic compounds on the base of four natural amino acids (Glycine, Alanine, Valine, Leucine) as precursors were used for the preparation of catalysts with Cu/Mn molar ratio 1:5. X-Ray and TEM analysis were performed on the catalyst’s bulk, and surface composition and the specific surface area was determined by BET method. The results obtained show that the activity of the catalysts increase up to 40% although there are some specific features, depending on the nature of the amino acid and the oxidized compound. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Cu-Mn%2F%CE%B3-Al%E2%82%82O%E2%82%83" title="Cu-Mn/γ-Al₂O₃">Cu-Mn/γ-Al₂O₃</a>, <a href="https://publications.waset.org/abstracts/search?q=CO%20and%20VOCs%20oxidation" title=" CO and VOCs oxidation"> CO and VOCs oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=heterogeneous%20catalysis" title=" heterogeneous catalysis"> heterogeneous catalysis</a>, <a href="https://publications.waset.org/abstracts/search?q=amino%20acids" title=" amino acids"> amino acids</a> </p> <a href="https://publications.waset.org/abstracts/68203/effect-of-the-nature-of-the-precursor-on-the-performance-of-cu-mn-catalysts-for-co-and-vocs-oxidation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/68203.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">240</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">10</span> Modeling and Numerical Simulation of Heat Transfer and Internal Loads at Insulating Glass Units</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Nina%20Penkova">Nina Penkova</a>, <a href="https://publications.waset.org/abstracts/search?q=Kalin%20Krumov"> Kalin Krumov</a>, <a href="https://publications.waset.org/abstracts/search?q=Liliana%20Zashcova"> Liliana Zashcova</a>, <a href="https://publications.waset.org/abstracts/search?q=Ivan%20Kassabov"> Ivan Kassabov</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The insulating glass units (IGU) are widely used in the advanced and renovated buildings in order to reduce the energy for heating and cooling. Rules for the choice of IGU to ensure energy efficiency and thermal comfort in the indoor space are well known. The existing of internal loads - gage or vacuum pressure in the hermetized gas space, requires additional attention at the design of the facades. The internal loads appear at variations of the altitude, meteorological pressure and gas temperature according to the same at the process of sealing. The gas temperature depends on the presence of coatings, coating position in the transparent multi-layer system, IGU geometry and space orientation, its fixing on the facades and varies with the climate conditions. An algorithm for modeling and numerical simulation of thermal fields and internal pressure in the gas cavity at insulating glass units as function of the meteorological conditions is developed. It includes models of the radiation heat transfer in solar and infrared wave length, indoor and outdoor convection heat transfer and free convection in the hermetized gas space, assuming the gas as compressible. The algorithm allows prediction of temperature and pressure stratification in the gas domain of the IGU at different fixing system. The models are validated by comparison of the numerical results with experimental data obtained by Hot-box testing. Numerical calculations and estimation of 3D temperature, fluid flow fields, thermal performances and internal loads at IGU in window system are implemented. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=insulating%20glass%20units" title="insulating glass units">insulating glass units</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20loads" title=" thermal loads"> thermal loads</a>, <a href="https://publications.waset.org/abstracts/search?q=internal%20pressure" title=" internal pressure"> internal pressure</a>, <a href="https://publications.waset.org/abstracts/search?q=CFD%20analysis" title=" CFD analysis"> CFD analysis</a> </p> <a href="https://publications.waset.org/abstracts/65370/modeling-and-numerical-simulation-of-heat-transfer-and-internal-loads-at-insulating-glass-units" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/65370.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">9</span> Alumina Supported Cu-Mn-La Catalysts for CO and VOCs Oxidation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Elitsa%20N.%20Kolentsova">Elitsa N. Kolentsova</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Y.%20Dimitrov"> Dimitar Y. Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Petya%20Cv.%20Petrova"> Petya Cv. Petrova</a>, <a href="https://publications.waset.org/abstracts/search?q=Georgi%20V.%20Avdeev"> Georgi V. Avdeev</a>, <a href="https://publications.waset.org/abstracts/search?q=Diana%20D.%20Nihtianova"> Diana D. Nihtianova</a>, <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20I.%20Ivanov"> Krasimir I. Ivanov</a>, <a href="https://publications.waset.org/abstracts/search?q=Tatyana%20T.%20Tabakova"> Tatyana T. Tabakova</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Recently, copper and manganese-containing systems are recognized as active and selective catalysts in many oxidation reactions. The main idea of this study is to obtain more information about γ-Al<sub>2</sub>O<sub>3 </sub>supported Cu-La catalysts and to evaluate their activity to simultaneous oxidation of CO, CH<sub>3</sub>OH and dimethyl ether (DME). The catalysts were synthesized by impregnation of support with a mixed aqueous solution of nitrates of copper, manganese and lanthanum under different conditions. XRD, HRTEM/EDS, TPR and thermal analysis were performed to investigate catalysts’ bulk and surface properties. The texture characteristics were determined by Quantachrome Instruments NOVA 1200e specific surface area and pore analyzer. The catalytic measurements of single compounds oxidation were carried out on continuous flow equipment with a four-channel isothermal stainless steel reactor in a wide temperature range. On the basis of XRD analysis and HRTEM/EDS, it was concluded that the active component of the mixed Cu-Mn-La/γ–alumina catalysts strongly depends on the Cu/Mn molar ratio and consisted of at least four compounds – CuO, La<sub>2</sub>O<sub>3</sub>, MnO<sub>2</sub> and Cu<sub>1.5</sub>Mn<sub>1.5</sub>O<sub>4</sub>. A homogeneous distribution of the active component on the carrier surface was found. The chemical composition strongly influenced catalytic properties. This influence was quite variable with regards to the different processes. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Cu-Mn-La%20oxide%20catalysts" title="Cu-Mn-La oxide catalysts">Cu-Mn-La oxide catalysts</a>, <a href="https://publications.waset.org/abstracts/search?q=carbon%20oxide" title=" carbon oxide"> carbon oxide</a>, <a href="https://publications.waset.org/abstracts/search?q=VOCs" title=" VOCs"> VOCs</a>, <a href="https://publications.waset.org/abstracts/search?q=deep%20oxidation" title=" deep oxidation"> deep oxidation</a> </p> <a href="https://publications.waset.org/abstracts/52487/alumina-supported-cu-mn-la-catalysts-for-co-and-vocs-oxidation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/52487.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">8</span> Supported Gold Nanocatalysts for CO Oxidation in Mainstream Cigarette Smoke</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20Ivanov">Krasimir Ivanov</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Dimitrov"> Dimitar Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Tatyana%20Tabakova"> Tatyana Tabakova</a>, <a href="https://publications.waset.org/abstracts/search?q=Stefka%20Kirkova"> Stefka Kirkova</a>, <a href="https://publications.waset.org/abstracts/search?q=Anna%20Stoilova"> Anna Stoilova</a>, <a href="https://publications.waset.org/abstracts/search?q=Violina%20Angelova"> Violina Angelova</a> </p> <p class="card-text"><strong>Abstract:</strong></p> It has been suggested that nicotine, CO and tar in mainstream smoke are the most important substances and have been judged as the most harmful compounds, responsible for the health hazards of smoking. As nicotine is extremely important for smoking qualities of cigarettes and the tar yield in the tobacco smoke is significantly reduced due to the use of filters with various content and design, the main efforts of cigarettes researchers and manufacturers are related to the search of opportunities for CO content reduction. Highly active ceria supported gold catalyst was prepared by the deposition-precipitation method, and the possibilities for CO oxidation in the synthetic gaseous mixture were evaluated using continuous flow equipment with fixed bed glass reactor at atmospheric pressure. The efficiently of the catalyst in CO oxidation in the real cigarette smoke was examined by a single port, puf-by-puff smoking machine. Quality assessment of smoking using cigarette holder containing catalyst was carried out. It was established that the catalytic activity toward CO oxidation in cigarette smoke rapidly decreases from 70% for the first cigarette to nearly zero for the twentieth cigarette. The present study shows that there are two critical factors which do not permit the successful use of catalysts to reduce the CO content in the mainstream cigarette smoke: (i) significant influence of the processes of adsorption and oxidation on the main characteristics of tobacco products and (ii) rapid deactivation of the catalyst due to the covering of the catalyst’s grains with condensate. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cigarette%20smoke" title="cigarette smoke">cigarette smoke</a>, <a href="https://publications.waset.org/abstracts/search?q=CO%20oxidation" title=" CO oxidation"> CO oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=gold%20catalyst" title=" gold catalyst"> gold catalyst</a>, <a href="https://publications.waset.org/abstracts/search?q=mainstream" title=" mainstream"> mainstream</a> </p> <a href="https://publications.waset.org/abstracts/79868/supported-gold-nanocatalysts-for-co-oxidation-in-mainstream-cigarette-smoke" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/79868.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">219</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">7</span> Alumina Supported Cu-Mn-Cr Catalysts for CO and VOCs oxidation </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20Ivanov">Krasimir Ivanov</a>, <a href="https://publications.waset.org/abstracts/search?q=Elitsa%20Kolentsova"> Elitsa Kolentsova</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Dimitrov"> Dimitar Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Petya%20Petrova"> Petya Petrova</a>, <a href="https://publications.waset.org/abstracts/search?q=Tatyana%20Tabakova"> Tatyana Tabakova</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This work studies the effect of chemical composition on the activity and selectivity of γ–alumina supported CuO/ MnO2/Cr2O3 catalysts toward deep oxidation of CO, dimethyl ether (DME) and methanol. The catalysts were prepared by impregnation of the support with an aqueous solution of copper nitrate, manganese nitrate and CrO3 under different conditions. Thermal, XRD and TPR analysis were performed. The catalytic measurements of single compounds oxidation were carried out on continuous flow equipment with a four-channel isothermal stainless steel reactor. Flow-line equipment with an adiabatic reactor for simultaneous oxidation of all compounds under the conditions that mimic closely the industrial ones was used. The reactant and product gases were analyzed by means of on-line gas chromatographs. On the basis of XRD analysis it can be concluded that the active component of the mixed Cu-Mn-Cr/γ–alumina catalysts consists of at least six compounds – CuO, Cr2O3, MnO2, Cu1.5Mn1.5O4, Cu1.5Cr1.5O4 and CuCr2O4, depending on the Cu/Mn/Cr molar ratio. Chemical composition strongly influences catalytic properties, this influence being quite variable with regards to the different processes. The rate of CO oxidation rapidly decrease with increasing of chromium content in the active component while for the DME was observed the reverse trend. It was concluded that the best compromise are the catalysts with Cu/(Mn + Cr) molar ratio 1:5 and Mn/Cr molar ratio from 1:3 to 1:4. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Cu-Mn-Cr%20oxide%20catalysts" title="Cu-Mn-Cr oxide catalysts">Cu-Mn-Cr oxide catalysts</a>, <a href="https://publications.waset.org/abstracts/search?q=volatile%20organic%20compounds" title=" volatile organic compounds"> volatile organic compounds</a>, <a href="https://publications.waset.org/abstracts/search?q=deep%20oxidation" title=" deep oxidation"> deep oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=dimethyl%20ether%20%28DME%29" title=" dimethyl ether (DME)"> dimethyl ether (DME)</a> </p> <a href="https://publications.waset.org/abstracts/23641/alumina-supported-cu-mn-cr-catalysts-for-co-and-vocs-oxidation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/23641.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">369</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">6</span> Alumina Supported Copper-Manganese Catalysts for Combustion of Exhaust Gases: Effect of Preparation Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20Ivanov">Krasimir Ivanov</a>, <a href="https://publications.waset.org/abstracts/search?q=Elitsa%20Kolentsova"> Elitsa Kolentsova</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Dimitrov"> Dimitar Dimitrov</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The development of active and stable catalysts without noble metals for low temperature oxidation of exhaust gases remains a significant challenge. The purpose of this study is to determine the influence of the preparation method on the catalytic activity of the supported copper-manganese mixed oxides in terms of VOCs oxidation. The catalysts were prepared by impregnation of γ-Al2O3 with copper and manganese nitrates and acetates and the possibilities for CO, CH3OH and dimethyl ether (DME) oxidation were evaluated using continuous flow equipment with a four-channel isothermal stainless steel reactor. Effect of the support, Cu/Mn mole ratio, heat treatment of the precursor and active component loading were investigated. Highly active alumina supported Cu-Mn catalysts for CO and VOCs oxidation were synthesized. The effect of preparation conditions on the activity behavior of the catalysts was discussed. The synergetic interaction between copper and manganese species increases the activity for complete oxidation over mixed catalysts. Type of support, calcination temperature and active component loading along with catalyst composition are important factors, determining catalytic activity. Cu/Mn molar ratio of 1:5, heat treatment at 450oC and 20 % active component loading are the best compromise for production of active catalyst for simultaneous combustion of CO, CH3OH and DME. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=copper-manganese%20catalysts" title="copper-manganese catalysts">copper-manganese catalysts</a>, <a href="https://publications.waset.org/abstracts/search?q=CO" title=" CO"> CO</a>, <a href="https://publications.waset.org/abstracts/search?q=VOCs%20oxidation" title=" VOCs oxidation"> VOCs oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=exhaust%20gases" title=" exhaust gases"> exhaust gases</a> </p> <a href="https://publications.waset.org/abstracts/22828/alumina-supported-copper-manganese-catalysts-for-combustion-of-exhaust-gases-effect-of-preparation-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/22828.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">413</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">5</span> Alumina Supported Copper-manganese Catalysts for Combustion of Exhaust Gases: Catalysts Characterization</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20I.%20Ivanov">Krasimir I. Ivanov</a>, <a href="https://publications.waset.org/abstracts/search?q=Elitsa%20N.%20Kolentsova"> Elitsa N. Kolentsova</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Y.%20Dimitrov"> Dimitar Y. Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Georgi%20V.%20Avdeev"> Georgi V. Avdeev</a>, <a href="https://publications.waset.org/abstracts/search?q=Tatyana%20T.%20Tabakova"> Tatyana T. Tabakova</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In recent research copper and manganese systems were found to be the most active in CO and organic compounds oxidation among the base catalysts. The mixed copper manganese oxide has been widely studied in oxidation reactions because of their higher activity at low temperatures in comparison with single oxide catalysts. The results showed that the formation of spinel CuxMn3−xO4 in the oxidized catalyst is responsible for the activity even at room temperature. That is why most of the investigations are focused on the hopcalite catalyst (CuMn2O4) as the best copper-manganese catalyst. Now it’s known that this is true only for CO oxidation, but not for mixture of CO and VOCs. The purpose of this study is to investigate the alumina supported copper-manganese catalysts with different Cu/Mn molar ratio in terms of oxidation of CO, methanol and dimethyl ether. The catalysts were prepared by impregnation of γ-Al2O3 with copper and manganese nitrates and the catalytic activity measurements were carried out in continuous flow equipment with a four-channel isothermal stainless steel reactor. Gas mixtures on the input and output of the reactor were analyzed with a gas chromatograph, equipped with FID and TCD detectors. The texture characteristics were determined by low-temperature (- 196 oС) nitrogen adsorption in a Quantachrome Instruments NOVA 1200e (USA) specific surface area&pore analyzer. Thermal, XRD and TPR analyses were performed. It was established that the active component of the mixed Cu-Mn/γ–alumina catalysts strongly depends on the Cu/Mn molar ratio. Highly active alumina supported Cu-Mn catalysts for CO, methanol and DME oxidation were synthesized. While the hopcalite is the best catalyst for CO oxidation, the best compromise for simultaneous oxidation of all components is the catalyst with Cu/Mn molar ratio 1:5. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=supported%20copper-manganese%20catalysts" title="supported copper-manganese catalysts">supported copper-manganese catalysts</a>, <a href="https://publications.waset.org/abstracts/search?q=CO" title=" CO"> CO</a>, <a href="https://publications.waset.org/abstracts/search?q=VOCs%20oxidation" title=" VOCs oxidation"> VOCs oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=combustion%20of%20exhaust%20gases" title=" combustion of exhaust gases"> combustion of exhaust gases</a> </p> <a href="https://publications.waset.org/abstracts/23639/alumina-supported-copper-manganese-catalysts-for-combustion-of-exhaust-gases-catalysts-characterization" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/23639.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">285</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">4</span> Structure-Activity Relationship of Gold Catalysts on Alumina Supported Cu-Ce Oxides for CO and Volatile Organic Compound Oxidation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tatyana%20T.%20Tabakova">Tatyana T. Tabakova</a>, <a href="https://publications.waset.org/abstracts/search?q=Elitsa%20N.%20Kolentsova"> Elitsa N. Kolentsova</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Y.%20Dimitrov"> Dimitar Y. Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20I.%20Ivanov"> Krasimir I. Ivanov</a>, <a href="https://publications.waset.org/abstracts/search?q=Yordanka%20G.%20Karakirova"> Yordanka G. Karakirova</a>, <a href="https://publications.waset.org/abstracts/search?q=Petya%20Cv.%20Petrova"> Petya Cv. Petrova</a>, <a href="https://publications.waset.org/abstracts/search?q=Georgi%20V.%20Avdeev"> Georgi V. Avdeev</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The catalytic oxidation of CO and volatile organic compounds (VOCs) is considered as one of the most efficient ways to reduce harmful emissions from various chemical industries. The effectiveness of gold-based catalysts for many reactions of environmental significance was proven during the past three decades. The aim of this work was to combine the favorable features of Au and Cu-Ce mixed oxides in the design of new catalytic materials of improved efficiency and economic viability for removal of air pollutants in waste gases from formaldehyde production. Supported oxides of copper and cerium with Cu: Ce molar ratio 2:1 and 1:5 were prepared by wet impregnation of g-alumina. Gold (2 wt.%) catalysts were synthesized by a deposition-precipitation method. Catalysts characterization was carried out by texture measurements, powder X-ray diffraction, temperature programmed reduction and electron paramagnetic resonance spectroscopy. The catalytic activity in the oxidation of CO, CH<sub>3</sub>OH and (CH<sub>3</sub>)<sub>2</sub>O was measured using continuous flow equipment with fixed bed reactor. Both Cu-Ce/alumina samples demonstrated similar catalytic behavior. The addition of gold caused significant enhancement of CO and methanol oxidation activity (100 % degree of CO and CH<sub>3</sub>OH conversion at about 60 and 140 <sup>o</sup>C, respectively). The composition of Cu-Ce mixed oxides affected the performance of gold-based samples considerably. Gold catalyst on Cu-Ce/γ-Al<sub>2</sub>O<sub>3</sub> 1:5 exhibited higher activity for CO and CH<sub>3</sub>OH oxidation in comparison with Au on Cu-Ce/γ-Al<sub>2</sub>O<sub>3</sub> 2:1. The better performance of Au/Cu-Ce 1:5 was related to the availability of highly dispersed gold particles and copper oxide clusters in close contact with ceria. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=CO%20and%20VOCs%20oxidation" title="CO and VOCs oxidation">CO and VOCs oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=copper%20oxide" title=" copper oxide"> copper oxide</a>, <a href="https://publications.waset.org/abstracts/search?q=Ceria" title=" Ceria"> Ceria</a>, <a href="https://publications.waset.org/abstracts/search?q=gold%20catalysts" title=" gold catalysts"> gold catalysts</a> </p> <a href="https://publications.waset.org/abstracts/68871/structure-activity-relationship-of-gold-catalysts-on-alumina-supported-cu-ce-oxides-for-co-and-volatile-organic-compound-oxidation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/68871.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">318</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">3</span> Alumina Supported Copper-Manganese-Cobalt Catalysts for CO and VOCs Oxidation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Elitsa%20Kolentsova">Elitsa Kolentsova</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Dimitrov"> Dimitar Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Vasko%20Idakiev"> Vasko Idakiev</a>, <a href="https://publications.waset.org/abstracts/search?q=Tatyana%20Tabakova"> Tatyana Tabakova</a>, <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20Ivanov"> Krasimir Ivanov</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Formaldehyde production by selective oxidation of methanol is an important industrial process. The main by-products in the waste gas are CO and dimethyl ether (DME). The idea of this study is to combine the advantages of both Cu-Mn and Cu-Co catalytic systems by obtaining a new mixed Cu-Mn-Co catalyst with high activity and selectivity at the simultaneous oxidation of CO, methanol, and DME. Two basic Cu-Mn samples with high activity were selected for further investigation: (i) manganese-rich Cu-Mn/γ–Al2O3 catalyst with Cu/Mn molar ratio 1:5 and (ii) copper-rich Cu-Mn/γ-Al2O3 catalyst with Cu/Mn molar ratio 2:1. Manganese in these samples was replaced by cobalt in the whole concentration region, and catalytic properties were determined. The results show a general trend of decreasing the activity toward DME oxidation and increasing the activity toward CO and methanol oxidation with the increase of cobalt up to 60% for both groups of catalyst. This general trend, however, contains specific features, depending on the composition of the catalyst and the nature of the oxidized gas. The catalytic activity of the sample with Cu/(Mn+Co) molar ratio of 2:1 is gradually changed with increasing the cobalt content. The activity of the sample with Cu/(Mn+Co) molar ratio of 1: 5 passes through a maximum at 60% manganese replacement by cobalt, probably due to the formation of highly dispersed Co-based spinel structures (Co3O4 and/or MnCo2O4). In conclusion, the present study demonstrates that the Cu-Mn-Co/γ–alumina supported catalysts have enhanced activity toward CO, methanol and DME oxidation. Cu/(Mn+Co) molar ratio 1:5 and Co/Mn molar ratio 1.5 in the active component can ensure successful oxidation of CO, CH3OH and DME. The active component of the mixed Cu-Mn-Co/γ–alumina catalysts consists of at least six compounds - CuO, Co3O4, MnO2, Cu1.5Mn1.5O4, MnCo2O4 and CuCo2O4, depending on the Cu/Mn/Co molar ratio. Chemical composition strongly influences catalytic properties, this effect being quite variable with regards to the different processes. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Cu-Mn-Co%20catalysts" title="Cu-Mn-Co catalysts">Cu-Mn-Co catalysts</a>, <a href="https://publications.waset.org/abstracts/search?q=oxidation" title=" oxidation"> oxidation</a>, <a href="https://publications.waset.org/abstracts/search?q=carbon%20oxide" title=" carbon oxide"> carbon oxide</a>, <a href="https://publications.waset.org/abstracts/search?q=VOCs" title=" VOCs"> VOCs</a> </p> <a href="https://publications.waset.org/abstracts/68064/alumina-supported-copper-manganese-cobalt-catalysts-for-co-and-vocs-oxidation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/68064.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">222</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">2</span> National Assessment for Schools in Saudi Arabia: Score Reliability and Plausible Values</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Dimiter%20M.%20Dimitrov">Dimiter M. Dimitrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdullah%20Sadaawi"> Abdullah Sadaawi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The National Assessment for Schools (NAFS) in Saudi Arabia consists of standardized tests in Mathematics, Reading, and Science for school grade levels 3, 6, and 9. One main goal is to classify students into four categories of NAFS performance (minimal, basic, proficient, and advanced) by schools and the entire national sample. The NAFS scoring and equating is performed on a bounded scale (D-scale: ranging from 0 to 1) in the framework of the recently developed “D-scoring method of measurement.” The specificity of the NAFS measurement framework and data complexity presented both challenges and opportunities to (a) the estimation of score reliability for schools, (b) setting cut-scores for the classification of students into categories of performance, and (c) generating plausible values for distributions of student performance on the D-scale. The estimation of score reliability at the school level was performed in the framework of generalizability theory (GT), with students “nested” within schools and test items “nested” within test forms. The GT design was executed via a multilevel modeling syntax code in R. Cut-scores (on the D-scale) for the classification of students into performance categories was derived via a recently developed method of standard setting, referred to as “Response Vector for Mastery” (RVM) method. For each school, the classification of students into categories of NAFS performance was based on distributions of plausible values for the students’ scores on NAFS tests by grade level (3, 6, and 9) and subject (Mathematics, Reading, and Science). Plausible values (on the D-scale) for each individual student were generated via random selection from a statistical logit-normal distribution with parameters derived from the student’s D-score and its conditional standard error, SE(D). All procedures related to D-scoring, equating, generating plausible values, and classification of students into performance levels were executed via a computer program in R developed for the purpose of NAFS data analysis. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=large-scale%20assessment" title="large-scale assessment">large-scale assessment</a>, <a href="https://publications.waset.org/abstracts/search?q=reliability" title=" reliability"> reliability</a>, <a href="https://publications.waset.org/abstracts/search?q=generalizability%20theory" title=" generalizability theory"> generalizability theory</a>, <a href="https://publications.waset.org/abstracts/search?q=plausible%20values" title=" plausible values"> plausible values</a> </p> <a href="https://publications.waset.org/abstracts/184074/national-assessment-for-schools-in-saudi-arabia-score-reliability-and-plausible-values" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/184074.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">18</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">1</span> Evaluating of Chemical Extractants for Assessment of Bioavailable Heavy Metals in Polluted Soils</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Violina%20Angelova">Violina Angelova</a>, <a href="https://publications.waset.org/abstracts/search?q=Krasimir%20Ivanov"> Krasimir Ivanov</a>, <a href="https://publications.waset.org/abstracts/search?q=Stefan%20Krustev"> Stefan Krustev</a>, <a href="https://publications.waset.org/abstracts/search?q=Dimitar%20Dimitrov"> Dimitar Dimitrov</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Availability of a metal is characterised by its quantity transgressing from soil into different extractants or by its content in plants. In literature, the terms 'available forms of compounds' and 'mobile' are often considered as equivalents of the term 'accessible' to plants. Rapid and a sufficiently reliable method for defining the accessible for plants forms turns out to be their extraction through different extractants, imitating the functioning of the root system. As a criterion for the pertinence of the extractant to this purpose usually serves the significant statistic correlation between the extracted quantities of the element from soil and its content in plants. The aim of this work was to evaluate the effectiveness of various extractions (DTPA-TEA, AB-DTPA, Mehlich 3, 0.01 M CaCl₂, 1M NH₄NO₃) for the determination of bioavailability of heavy metals in industrially polluted soils from the metallurgical activity near Plovdiv and Kardjali, Bulgaria. Quantity measurements for contents of heavy metals were performed with ICP-OES. The results showed that extraction capacity was as follows: Mehlich 3>ABDTPA>DTPA-TEA>CaCl₂>NaNO₃. The content of the mobile form of heavy metals depends on the nature of metal ion, the nature of extractant and pH. The obtained results show that CaCl₂ extracts a greater quantity of mobile forms of heavy metals than NH₄NO₃. DTPA-TEA and AB-DTPA are capable of extracting from the soil not only the heavy metals participating in the exchange processes but also the heavy metals bound in carbonates and organic complexes, as well as bound and occluded in oxide and secondary clay minerals. AB-DTPA extracts a bit more heavy metals than DTPA-TEA. The darker color of the solutions obtained with AB-DTPA indicates that considerable quantities organic matter are being destructed. A comparison of the mobile forms of heavy metals extracted from clean and highly polluted soils has revealed that in the polluted soils the greater portion of heavy metals exists in a mobile form. High correlation coefficients are obtained between the metals extracted with different extractants and their total content in soil (r=0.9). A positive correlation between the pH, soil organic matter and the extracted quantities of heavy metals has been found. The results of correlation analysis revealed that the heavy metals extracted by DTPA-TEA, AB-DTPA, Mehlich 3, CaCl₂ and NaNO₃ correlated significantly with plant uptake. Significant correlation was found between DTPA-TEA, AB-DTPA, and CaCl₂ with heavy metals concentration in plants. Application of extracting methods contains chelating agents would be recommended in the future research onthe availabilityof heavy metals in polluted soils. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=availability" title="availability">availability</a>, <a href="https://publications.waset.org/abstracts/search?q=chemical%20extractants" title=" chemical extractants"> chemical extractants</a>, <a href="https://publications.waset.org/abstracts/search?q=heavy%20metals" title=" heavy metals"> heavy metals</a>, <a href="https://publications.waset.org/abstracts/search?q=mobile%20forms" title=" mobile forms"> mobile forms</a> </p> <a href="https://publications.waset.org/abstracts/68204/evaluating-of-chemical-extractants-for-assessment-of-bioavailable-heavy-metals-in-polluted-soils" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/68204.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">355</span> </span> </div> </div> </div> </main> <footer> <div id="infolinks" class="pt-3 pb-2"> <div class="container"> <div style="background-color:#f5f5f5;" class="p-3"> <div class="row"> <div class="col-md-2"> <ul class="list-unstyled"> About <li><a href="https://waset.org/page/support">About Us</a></li> <li><a href="https://waset.org/page/support#legal-information">Legal</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/WASET-16th-foundational-anniversary.pdf">WASET celebrates its 16th foundational anniversary</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Account <li><a href="https://waset.org/profile">My Account</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Explore <li><a href="https://waset.org/disciplines">Disciplines</a></li> <li><a href="https://waset.org/conferences">Conferences</a></li> <li><a href="https://waset.org/conference-programs">Conference Program</a></li> <li><a href="https://waset.org/committees">Committees</a></li> <li><a href="https://publications.waset.org">Publications</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Research <li><a href="https://publications.waset.org/abstracts">Abstracts</a></li> <li><a href="https://publications.waset.org">Periodicals</a></li> <li><a href="https://publications.waset.org/archive">Archive</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Open Science <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Science-Philosophy.pdf">Open Science Philosophy</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Science-Award.pdf">Open Science Award</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Society-Open-Science-and-Open-Innovation.pdf">Open Innovation</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Postdoctoral-Fellowship-Award.pdf">Postdoctoral Fellowship Award</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Scholarly-Research-Review.pdf">Scholarly Research Review</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Support <li><a href="https://waset.org/page/support">Support</a></li> <li><a href="https://waset.org/profile/messages/create">Contact Us</a></li> <li><a href="https://waset.org/profile/messages/create">Report Abuse</a></li> </ul> </div> </div> </div> </div> </div> <div class="container text-center"> <hr style="margin-top:0;margin-bottom:.3rem;"> <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" class="text-muted small">Creative Commons Attribution 4.0 International License</a> <div id="copy" class="mt-2">© 2024 World Academy of Science, Engineering and Technology</div> </div> </footer> <a href="javascript:" id="return-to-top"><i class="fas fa-arrow-up"></i></a> <div class="modal" id="modal-template"> <div class="modal-dialog"> <div class="modal-content"> <div class="row m-0 mt-1"> <div class="col-md-12"> <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button> </div> </div> <div class="modal-body"></div> </div> </div> </div> <script src="https://cdn.waset.org/static/plugins/jquery-3.3.1.min.js"></script> <script src="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/js/bootstrap.bundle.min.js"></script> <script src="https://cdn.waset.org/static/js/site.js?v=150220211556"></script> <script> jQuery(document).ready(function() { /*jQuery.get("https://publications.waset.org/xhr/user-menu", function (response) { jQuery('#mainNavMenu').append(response); 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