Search results for "DETECT"
showing 10 items of 5902 documents
Nanosensor Devices for CBRN-Agents Detection: Theory and Design
2018
Pressing challenges of recent decades, associated with agents that are aggressive towards humans – substances and radiation of chemical, biological, radiological, and nuclear (CBRN) agents – require scientific and technological responses. These responses lie in the areas of agent detection and protection from them. The mentioned bio destructive agents can be divided into 2 groups: (1) chemical and biochemical, and (2) radiative (leading to chemical destruction of biomass). In this study, we consider models of universal track nanosensors that are capable of producing a correlated electrical response to the flow of active agents.
A Full-Scale Agent-Based Model to Hypothetically Explore the Impact of Lockdown, Social Distancing, and Vaccination During the COVID-19 Pandemic in L…
2021
Background The COVID-19 outbreak, an event of global concern, has provided scientists the opportunity to use mathematical modeling to run simulations and test theories about the pandemic. Objective The aim of this study was to propose a full-scale individual-based model of the COVID-19 outbreak in Lombardy, Italy, to test various scenarios pertaining to the pandemic and achieve novel performance metrics. Methods The model was designed to simulate all 10 million inhabitants of Lombardy person by person via a simple agent-based approach using a commercial computer. In order to obtain performance data, a collision detection model was developed to enable cluster nodes in small cells that can b…
Reduced In Vivo Aortic Uptake of Radiolabeled Oxidation-Specific Antibodies Reflects Changes in Plaque Composition Consistent With Plaque Stabilizati…
2004
Objective— Labeled oxidation-specific antibodies (Ox-AB) detect, quantify, and noninvasively image lipid-rich atherosclerotic lesions. However, it is unknown whether Ox-AB detect plaque stabilization. Methods and Results— The aortic uptake of intravenously injected 125 I-MDA2 (Ox-AB to malondialdehyde [MDA]–low-density lipoprotein [LDL]) was quantitated in: (1) LDL receptor−/− mice with established atherosclerosis continued on Western diet (Progression) or switched to chow (Regression) or chow+vitamins E and C (Regression-VIT) for 6 months; and (2) Watanabe rabbits (3- to 57-months old) with naturally evolved atherosclerotic lesions. In mice, the Progression group had more extensive athero…
Sampling and analysis of pesticides in ambient air.
2008
Developments in the sampling and determination of pesticides in ambient air have been discussed and data on the occurrence of pesticides in atmosphere have been presented. Developments in active sampling methods were reviewed and the different materials used for trapping pesticides from gas and particulate phases were discussed. Likewise, the use and developments of passive air samplers were reviewed. This article pays special attention to the analysis of pesticides trapped from ambient air, and recapitulate the procedures for extraction, clean-up and determination of these substances. Improvements in sampling procedures, analytical methods and monitoring activities are necessary to advance…
Experimental characterization of variable-speed packaged rooftop units in presence of evaporator fouling
2022
Variable-speed packaged rooftop units have been increasingly adopted in the commercial sector. If not properly maintained, the fouling of heat exchangers and the improper refrigerant charge could increase energy consumption. In this work, the response of variable-speed rooftop units to evaporator fouling is investigated based on experiments on a variable-speed 17.5 kW rooftop unit. A novel testing procedure is proposed, aimed at covering a broad range of operating conditions by a reduced number of tests. Two opposite cases were investigated: (i) even in presence of fouling, the controller can restore the required cooling capacity, and (ii) the intensity of the fouling does not allow the con…
Occurrence and risk assessment of mycotoxins, acrylamide, and furan in Latvian beer.
2018
This work reports data on the occurrence of nine mycotoxins and two food processing contaminants - acrylamide and furan - in a total of 100 beers produced in Latvia. Mycotoxins were detected by high-performance liquid chromatography (HPLC) coupled with time-of-flight mass spectrometry, acrylamide by HPLC coupled with quadrupole-Orbitrap mass spectrometry, and furan by headspace gas chromatography-mass spectrometry. The most frequently occurring mycotoxins were HT-2 and deoxynivalenol (DON), which were detected in 52% and 51% of the analysed samples. The highest content was observed for DON, reaching the maximum of 248 µg kg-1. Furan was ubiquitous, and 74% of the samples contained acrylamid…
Determination of alcohols in essential oils by liquid chromatography with ultraviolet detection after chromogenic derivatization
2013
Abstract An HPLC-UV method to determine compounds having a hydroxyl functional group in plant essential oils is developed. The sample is diluted with 1,4-dioxane and the analytes are derivatized with phthalic anhydride. The derivatives (phthalates hemiesters) are separated on a C8 column using an acetonitrile (ACN)/water gradient. Separation conditions were optimized using the DryLab® method development software. For the alcohols and phenols present in mint and rose essential oils, optimization led to a ca. 40 min gradient time and a column temperature of 8 °C. The alcohol and its derivatives were identified using HPLC with mass spectrometry (MS) detection. A large sensitivity enhancement w…
Search for neutral MSSM Higgs bosons at LEP
2006
The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of "benchmark" models, including CP-conserving and CP-violating scenarios. Thes…
Studies of Quantum Chromodynamics with the ALEPH Detector
1998
Previously published and as vet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant. tests of its flavour independence, tests of the SU(3) gauge structure of QCD, study of coherence effects, and measurements of single-particle inclusive distributions and two-particle correlations for many identified baryons and mesons. (C) 1998 Elsevier Science B.V.
Characterization and quantitation of mixtures of alkyl ether sulfates and carboxylic acids by capillary electrophoresis with indirect photometric det…
2003
The separation, characterization, and determination of mixtures of alkyl ether sulfates (AES) and fatty acids (C10-C16) in background electrolytes (BGEs) containing acetonitrile (ACN)-water mixtures is addressed. Due to inhibition of the ionization of the carboxylate groups, the migration time and the resolution between the fatty acids decreased when the water content of the BGE was reduced, but efficiency and resolution between the AES oligomers improved. The migration times increased and resolution improved by substituting 5% ACN by an equivalent amount of dioxane. A complete separation of the two surfactant classes, up to the AES oligomers with 8 ethylene oxide units (EOs) with respect t…