Wyszukiwarka
Filtry
wszystkich: 622
wybranych: 596
Wyniki wyszukiwania dla: analytical methods
-
Application of deep eutectic solvents in analytical sample pretreatment (update 2017–2022). Part A: Liquid phase microextraction
PublikacjaSustainable development in all branches of human activity has become an unequivocal necessity in the last two decades, and green chemistry goes hand in hand with it. Various ways have been proposed in analytical chemistry to meet the current requirements of green chemistry. One such approach is the research of new reagents and solvents for analytical purposes. Deep eutectic solvents (DESs) began being investigated and used in analytical...
-
Analytical approach for membrane action in laterally-restrained reinforced concrete square slabs under uniformly distributed loads
PublikacjaLaterally-restrained reinforced concrete slabs can mobilise compressive membrane action and subsequent tensile membrane action under extreme loading conditions, thereby enhancing the load resistance under uniformly distributed loads. Previous analytical study focuses primarily on tensile membrane action in simply-supported slabs. This paper describes an analytical approach for membrane action in laterally-restrained square slabs....
-
Implementing an Analytical Model to Elucidate the Impacts of Nanostructure Size and Topology of Morphologically Diverse Zinc Oxide on Gas Sensing
PublikacjaThe development of state-of-the-art gas sensors based on metal oxide semiconductors (MOS) to monitor hazardous and greenhouse gas (e.g., methane, CH4, and carbon dioxide, CO2) has been significantly advanced. Moreover, the morphological and topographical structures of MOSs have significantly influenced the gas sensors by means of surface catalytic activities. This work examines the impact of morphological and topological networked...
-
Characteristics, Chemical Modification Processes as well as the Application of Silica and its Modified Forms
PublikacjaThe variety of chemical modifications of the surface of silica and its modified forms cause thesematerials to find a consistently wider scope of application. In the publication, the characteristicsof silica, silica gel, aerogel and xerogel are presented. The obtainment, application and propertiesof these materials are discussed. Methods of chemical modifications of surface structures withthe use of different chemical compounds...
-
Non-proportional full-order Luenberger observers of induction motors
PublikacjaThe paper recapitulates recently conducted investigations of non-proportional Luenberger observers, applied to reconstruction of state variables of induction motors. Three structures of non-proportional observers are analyzed, a proportional-integral observer, modified integral observer and observer with integrators. Criteria for gain selection of the observer are described, classical ones based on poles, as well as additional,...
-
Influence of stirrups in a concrete shell on strengthening reinforced concrete column
PublikacjaTwelve concrete columns, with a 150x150mm square section and three columns with a circular section (d=200mm), are tested to investigate the effect of strengthening by RC jacket. Based on a confined concrete model for axial static loading, an analytical methods, reported in the literature are proposed to predict the behavior of columns with RC jacket. The results support the conception that the effect of strengthening depends...
-
Application of chromogenic dye in biogenic amines determination using spectrophotometry
PublikacjaBiogenic amines content can be the source of information in the field of freshness and suitability of certain foods for consumption. However, most analytical methods for their determination require complicated sample preparation and expert knowledge. Because of that, a novel approach based on chromogenic dye application was proposed. After the SN1 reaction of an amine with S 0378 dye, the absorbance of the solution was measured...
-
Isoprostanes-Biomarkers of Lipid Peroxidation: Their Utility in Evaluating Oxidative Stress and Analysis
PublikacjaIsoprostanes (IsoPs) are key biomarkers for investigating the role of free radical generation in the pathogenesis of human disorders. To solve IsoPs-related problems with regard to isoprostanes, analytical tools are required. This paper reviews the problems and trends in this field focusing on the methodology for assaying biomarkers in exhaled breath condensate (EBC) samples. A large amount of work has been done in the qualitative...
-
Novel sorptive extraction techniques in bioanalysis evaluated by Blue Applicability Grade Index: The paradigm of fabric phase sorptive extraction and capsule phase microextraction
PublikacjaFabric phase sorptive extraction (FPSE) and capsule phase microextraction (CPME) are two sol-gel derived microextraction techniques that emerged in the last decade towards the minimization of the environmental impact of conventional sample preparation approaches. Complementary to the well-established green metric tools, Blue Applicability Grade Index (BAGI) was recently proposed for the evaluation of method’s practicability. In...
-
Insights into the microbial community of treated wastewater, its year-round variability and impact on the receiver, using cultivation, microscopy and amplicon-based methods
PublikacjaApart from chemical constituents, wastewater treatment plant (WWTP) effluents also release microorganisms that can be important to the receiving water bodies either from a sanitary point of view, or taking to the account the biogeochemical potential of the recipients. However, little is known about the treated wastewater microbial community, its composition, seasonal changes, functions and fate in the waters of the receiver. Thus,...
-
Solventless and solvent-minimized sample preparation techniques for determining currently used pesticides in water samples: A review
PublikacjaThe intensification of agriculture means that increasing amounts of toxic organic and inorganic compounds are entering the environment. The pesticides generally applied nowadays are regarded as some of the most dangerous contaminants of the environment. Their presence in the environment, especially in water, is hazardous because they cause human beings to become more susceptible to disease. For these reasons, it is essential to...
-
Oznaczanie tlenu – od metody Winklera do czujników enzymatycznych (Determination of oxygen – from Winkler Method to enzymatic sensor)
PublikacjaMonitoring of dioxygen levels is of utmost importance from the view-point of life processes, medical diagnostics, nutrition and chemical industries. In all these measurements both low and high levels of this element are important. The common methods for the determination of dioxygen are the Winkler method, Clark electrode and pulsoxymeters. A new, already strong field of research can be now recognized – the development of miniaturized...
-
Uncertainty of the liquid mass flow measurement using the orifice plate
PublikacjaThe article presents an estimation of measurement uncertainty of a liquid mass flow using the orifice plate. This subject is essential because of the widespread use of this type of flow meters. Not only the quantitative estimation but also the qualitative results of those measurements are important. To achieve these results the authors of the paper propose to use the theory of uncertainty. The article shows the analysis of the...
-
Chronic Rhinosinusitis—Microbiological Etiology, Potential Genetic Markers, and Diagnosis
PublikacjaChronic rhinosinusitis (CRS) is a significant public health problem. Bacterial colonization and impaired mucociliary clearance play a significant role in the inflammatory process. Several inflammatory pathways and host defense elements are altered in CRS, which may contribute to observed differences in the microbiome. To date, researching CRS has been difficult due to limited access to the studied tissue and a lack of available...
-
Determination of thiocyanate (biomarkers of ETS) and other inorganic ions in human nasal discharge samples using ion chromatography
PublikacjaEnvironmental tobacco smoke (ETS) is a mixture of air and tobacco smoke containing more than 4000 chemical substances. In view of the health risks of many of these substances, studies are needed to determine biomarkers of exposure to ETS constituents in people who actively or passively are exposed to the toxic compounds. The methodologies for determining most biomarkers from saliva, urine and blood samples are known, but methods...
-
Chosen Analysis Results Of The Prototype Multicell Piezoelectric Motor
PublikacjaThis paper presents the design, modeling and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one - referred to as a “single cell” (single actuator). Combined three resonant actuators generate three traveling waves...
-
New concept and analysis of the multicell piezoelectric motor
PublikacjaThis work presents the design, modeling and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one - referred to as a ”single cell” (single actuator). Combined three resonant actuators generate three traveling waves...
-
Nowe rozwiązania metodyczne i techniczne w zakresie techniki mikroekstrakcji do fazy stracjonarnej
PublikacjaSample preparation has been recognized as a critical step of the analytical process, being even considered as the bottleneck of the overall process. Enrichment of target compounds, transfer of the analytes into a solvent compatible with the analytical instrumentation, minimization of potential interferences, and efficient sample clean-up, are among the main aims of sample preparation techniques. In this regard, liquid-liquid extraction...
-
Thermal analysis and experimental verification of permanent magnet synchronous motor by combining lumped-parameter thermal networks with analytical method
Publikacja -
Analysis of pesticide residue in tomato samples using analytical protocol based on application of QuEChERS technique and GC-ECD system
PublikacjaQuEChERS sample preparation method was used for the determination of 10 pesticides and their metabolites in tomato samples, coupled to gas chromatography with electron capture detector (GCECD). The experimental parameters including oven temperature program, amount of the sample and purifying agent were optimized. The GC-ECD method was validated in terms of linearity, selectivity and recovery. The limits of detection (LODs) of the...
-
Environmental problems and health risks with disposable baby diapers: Monitoring of toxic compounds by application of analytical techniques and need of education
PublikacjaDue to the widespread use of disposable diapers in healthy babies as well as children prone to allergiesand premature babies with reduced immunity, disposable diapers should only be made of non-toxic andnatural ingredients. Unfortunately, disposable diaper manufacturers are reluctant to present their exactchemical composition, claiming that their trade secrets apply. However, several reports show thatdisposable diapers of well-known...
-
Kontrola i zapewnienie jakości wyników pomiarów analitycznych =Quality control and quality assurance (QC/QA) of analytical results
PublikacjaWyniki, które winny być źródłem informacji analitycznej, są uzyskiwane w następstwie przeprowadzanych pomiarów. Na tym etapie stosuje się odpowiednie "narzędzia analityczne", które stanowią metodyki analityczne i urządzenia kontrolno-pomiarowe. "Narzędzia" muszą być właściwie przygotowane do pracy, tak aby uzyskiwane wyniki były miarodajne, czyli aby odzwierciedlały w sposób dokładny (jednocześnie precyzyjny i poprawny) rzeczywistą...
-
Estimating the uncertainty of discharge coefficient predicted for oblique side weir using Monte Carlo method
PublikacjaSide weir is a hydraulic structure, which is used in irrigation systems to divert some water from main to side channel. It is installed at the entrance of the side channel to control and measure passing water into the side channel. Many studies provided side weir water surface profile and coefficient of discharge to measure water discharge diverted into the side channel. These studies dealt with different side weir shapes (rectangular,...
-
Developments in Methods of Analysis for Naphthalene Sulfonates
Publikacja -
Analysis
PublikacjaNew food products and diverse formulations containing the regulated steviol glycoside(s) as well as Stevia extracts or Stevia leaves have been brought on the global market. The upcoming multitude of such food products, but also their falsification and adulteration, does have impact on food analysis. Robust high-throughput methods that cope with different food matrices are required for food control to ensure food safety. The analysis...
-
Probabilistic sensitivity of the limit states of structures using Monte Carlom simulation
PublikacjaThe paper presents the concept of probabilistic sensitivity of structural limit states with respect to given design variables. A general idea is presented, illustrated by a simple case solved in an analytical way. More general approach is presented for the engineering structures, in this case a dedicated Monte Carlo simulation procedure is involved as part of the methodology. Illustration of the engineering case is done, by means...
-
Hybrid Method Analysis of Unshielded Guiding Structures
PublikacjaA combination of mode matching, finite element methods and generalized impedance matrix is presented in a context of propagation problems for open guiding structures. The computational domain is divided into two regions: the first one is a circular cylinder containing whole guiding structure and the second one surrounds this artificial cylinder. The impedance matrix is calculated with the use of finite element method in the first...
-
Efficient Finite Element Analysis of Axially Symmetrical Waveguides and Waveguide Discontinuities
PublikacjaA combination of the body-of-revolution and finite element methods is adopted for full-wave analysis of waveguides and waveguide discontinuities involving angular field variation. Such an approach is highly efficient and much more flexible than analytical techniques. The method is performed in two different cases: utilizing a generalized impedance matrix to determine the scattering parameters of a single waveguide section and utilizing...
-
Wideband Modeling of DC-DC Buck Converter with GaN Transistors
PublikacjaThe general wideband modeling method of the power converter is presented on the example of DC-DC buck converter with GaN High Electron Mobility Transistors (HEMT). The models of all basic and parasitic components are briefly described. The two methods of Printed Circuit Board (PCB) layout parameter extraction are presented. The results of simulation in Saber@Sketch simulation software and measurements are compared. Next, the model...
-
Distinction of clenbuterol intake from drug or contaminated food of animal origin in a controlled administration trial – the potential of enantiomeric separation for doping control analysis
PublikacjaThe differentiation of clenbuterol abuse and unintentional ingestion by contaminated meat is crucial with respect to the valuation of an adverse analytical finding in human sports doping control. The proportion of the two enantiomers of clenbuterol may serve as potential discriminating parameter. For the determination of the individual enantiomers, specific methods were developed and validated for the different matrices under investigation...
-
The miniaturised emission chamber system and home-made passive flux sampler studies of monoaromatic hydrocarbons emissions from selected commercially-available floor coverings
PublikacjaThe estimation of the emission rate of organic compounds released from various types of indoor materials can be performed using stationary environmental test chambers (ETC) classified as ex-situ methods or small-scale portable analytical devices based on the use of passive technique at the stage of analytes sampling from the gaseous phase (in-situ methods). The paper presents results of emissions of selected organic compounds from...
-
Methods for quantifying lysophosphatidic acid in body fluids: A review
Publikacja -
Removal of sulfur from a solvent extract
PublikacjaThe presence of sulfur in a solvent extract that is to be analyzed chromatographically impairs and sometimes precludes properinterpretation of the chromatogram, as the sulfur peak masks the peaks of other compounds present in the sample, and sulfur alsodisrupts the operation of the mass detector. This means that discrepancies in the results can lead to erroneous interpretations andfalse assessments of environmental risk. For this...
-
Application of chiral chromatography for enantiomeric separation of currently used pesticides from various chemical groups
PublikacjaChiral pesticides account for more than 25 % of currently used pesticides and this ratio is still increasing. According to the number of chiral centers in the structure, a pesticide may consist of two or multiple enantiomers or stereoisomers. Studies into the stereoselective behaviour of pesticides started in the early 1990s and most research efforts focused on understanding the environmental fate and effects of these pesticides....
-
Vibro piles performance prediction using result of CPT
PublikacjaVibro piles belong to the group of full displacement piles with an expanded base, characterised by a very high load capacity, especially in non-cohesive soils. The problem is to adopt a reliable method for the determination of full load–settlement (Q–s) curve. A frequent difficulty is the determination of the load capacity limit based on the static load test because the course of the load–settlement curve is of a linear nature....
-
Estimation of Conservative Contaminant Travel Time through Vadose Zone Based on Transient and Steady Flow Approaches
PublikacjaEstimation of contaminant travel time through the vadose zone is needed for assessing groundwater vulnerability to pollution, planning monitoring and remediation activities or predicting the effect of land use change or climate change on groundwater quality. The travel time can be obtained from numerical simulations of transient flow and transport in the unsaturated soil profile, which typically require a large amount of data and...
-
Chapter 11 – Application of Chemical Sensors and Sensor Matrixes to Air Quality Evaluation
PublikacjaIndoor and outdoor air quality is one of the key factors influencing human health. However, air quality evaluation is not easy task. Air is a complex system, which is subjected to changes even within short period of time. Progress in analytical methods and analytical tools provides increasingly more reliable information on the condition and quality of indoor and outdoor air. This progress, however, generates an increase in the...
-
Analytical procedures for the determination of fuel combustion products, anti-corrosive compounds, and de-icing compounds in airport runoff water samples
PublikacjaThe purpose of this study is to propose and evaluate new procedures for determination of fuel combustion products, anti-corrosive and de-icing compounds in runoff water samples collected from the airports located in different regions and characterized by different levels of the activity expressed by the number of flights and the number of passengers (per year). The most difficult step in the analytical procedure used for the determination...
-
Analytical method of determining dynamic properties of thermocouples used in measurements of quick – changing temperatures of exhaust gases in marine diesel engines
PublikacjaThe article presents selected issues of mathematical modeling of heat exchange between the thermocouple and the exhaust gas flowing them, in unsteady conditions. On the way of energy balancing consideration of thermodynamic processes developed differential equations describing the dynamic properties for three versions of the design sheathed thermocouples: with weld isolated from the sheath, with weld welded the sheath and with...
-
Analytical investigation of phase assemblages of alkali-activated materials in CaO-SiO2-Al2O3 systems: The management of reaction products and designing of precursors
Publikacja -
Separation of Monovinyl and Divinyl Protochlorophyllides Using C30 Reverse Phase High Performance Liquid Chromatography Column: Analytical and Preparative Applications
Publikacja -
Analytical model with non-adiabatic effects for pressure drop and heat transfer during boiling and condensation flows in conventional channels and minichannels
PublikacjaIn the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for boiling flow and condensation flow with account of non- adiabatic effects for some recent data collected from literature. The first effect, the modification of interface shear stresses in annular flow pattern is considered through incorporation of the so called "blowing parameter". The mechanism of...
-
Biocomposites from recycled resources as candidates for laboratory reference material to validate analytical tools used in organic compounds emissions investigation
PublikacjaA suitably chosen reference material should meet specific criteria like representing one of the compound classes most commonly occurring in indoor materials as well as having optimal long-term stability during storage and transport to its destination point and having a compact size. The described interdisciplinary pilot research was aimed to develop and characterize a polymer-based candidate for the laboratory reference material...
-
Comprehensive determination of flavouring additives and nicotine in e-cigarette refill solutions. Part I: Liquid chromatography-tandem mass spectrometry analysis
PublikacjaLiquid chromatography-tandem mass spectrometry with electrospray ionization (HPLC-ESI–MS/MS) methods were developed for the simultaneous determination of 42 flavouring compounds and nicotine in liquids for e-cigarettes. The chromatographic separation was performed using an Ace® Ultracore™ SuperC18™ (100 × 2.1 mm, 2.5 μm) column in both acidic and alkaline pH conditions to separate all the compounds. A simple “dilute & shoot” approach...
-
Recent Developments in Methods of Analysis for Fluoride Determination
Publikacja -
Traffic Noise Analysis Applied to Automatic Vehicle Counting and Classification
PublikacjaProblems related to determining traffic noise characteristics are discussed in the context of automatic dynamic noise analysis based on noise level measurements and traffic prediction models. The obtained analytical results provide the second goal of the study, namely automatic vehicle counting and classification. Several traffic prediction models are presented and compared to the results of in-situ noise level measurements. Synchronized...
-
IZOLACJA I IDENTYFIKACJA NATURALNYCH SUBSTANCJI BARWIĄCYCH OBECNYCH W PRÓBKACH FARB ARTYSTYCZNYCH I TKANINACH POCHODZENIA HISTORYCZNEGO
PublikacjaNatural organic dyes are group of substances that belong to various types of chemical compounds. The most commonly used in paintings and dyeing textiles were naturally occurring dyestuffs from group of anthraquinones, flavones and indigoid dyes. Identification of coloring substances present in historical artistic paints provides relevant information for a wide range of specialists dealing with works of art and in the field of conservation science....
-
The Use of Ultra-Fast Gas Chromatography for Fingerprinting-Based Classification of Zweigelt and Rondo Wines with Regard to Grape Variety and Type of Malolactic Fermentation Combined with Greenness and Practicality Assessment
PublikacjaIn food authentication, it is important to compare different analytical procedures and select the best method. The aim of this study was to determine the fingerprints of Zweigelt and Rondo wines through headspace analysis using ultra-fast gas chromatography (ultra-fast GC) and to compare the effectiveness of this approach at classifying wines based on grape variety and type of malolactic fermentation (MLF) as well as its greenness...
-
Volatile Organohalogen Compounds Determination with Dispersive Liquid-Liquid Microextraction Applying Solvent Lighter than Water
PublikacjaBackground: Volatile organohalogen compounds (VOX) are a group of environmental pollutants that risk the quality of drinking water. These compounds are characterized by certain acute and chronic toxicities, possessing mutagenic properties. Because of these potential risks factors that these compounds cause, the maximum allowable concentrations (MACs) have been established by respective organizations. The abundance of VOX, their...
-
Characterization of the Functionally Graded Shear Modulus of a Half-Space
PublikacjaIn this article, a method is proposed for determining parameters of the exponentialy varying shear modulus of a functionally graded half-space. The method is based on the analytical solution of the problem of pure shear of an elastic functionally graded half-space by a strip punch. The half-space has the depth-wise exponential variation of its shear modulus, whose parameters are to be determined. The problem is reduced to an integral...