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Wyniki wyszukiwania dla: sample assessment
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Fractional delayor application in self-tuning sub-sample delay estimator
PublikacjaW artykule przedstawiono nowe rozwiązanie samonastrajalnego estymatora opóźnienia sygnału sinusoidalnego. Estymator działa w czasie dyskretnym. Proponowane rozwiązanie wykorzystuje kaskadowe połączenie cyfrowego filtru ułamkowo opóźniającego służącego do synchronizacji próbkowania i liniowo-fazowego cyfrowego filtru Hilberta. Oryginalność polega na zastosowaniu tu filtrów cyfrowych o bardzo małej złożoności numerycznej. Jest ona...
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Soxhlet Extraction and New Developments Such as Soxtec in: Comprehansive Sampling and Sample Preparation
PublikacjaSoxhlet extraction is one of the most popular techniques for extraction of analytes from solid materials. Since its discovery in 1879, the standard Soxhlet technique has been routinely applied in almost every analytical laboratory. Up to this day, Soxhlet extraction technique remains a standard technique to which the performance of modern extraction techniques is compared.Over the years, an intensive research on different modifications...
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Dynamic Headspace Sampling as an Initial Step for Sample Preparation in Chromatographic Analysis
PublikacjaThis work represents a brief summary of the use of dynamic headspace (DHS) as a technique for sample preparation in chromatographic analysis. Despite numerous developments in the area of analyte isolation and enrichment, DHS remains one of the fundamental methods used with GC. In our opinion, interest in this technique will not diminish significantly because it conforms to stipulations of green analytical chemistry. Moreover, DHS...
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Modern techniques of sample preparation for determination of organic analytes by gas chromatography
PublikacjaW pracy dokonano przeglądu szerokiego spektrum technik przygotowania próbki, ze szczególnym uwzględnieniem technik o charakterze prośrodowiskowym. Opisu technik dokonano pod kątem wykorzystywanych mechanizmów izolacji analitów oraz stosowanych rozwiązań aparaturowych. Przegląd rozwiązań aparaturowych uzupełniono o podstawy teoretyczne izolacji bazującej na zjawisku podziału analitów.
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Green sample preparation techniques for chromatographic determination of small organic compounds
PublikacjaAccurate monitoring of the state of the environment requires the introduction of additional isolation and/or preconcentration step prior to the chromatographic determination. In this work the information about novel methodological and instrumental solutions in relation to different variants of microextraction techniques are presented. Attention is focused on analytical procedure and suitable analytical tools for extraction of the...
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Variable Ratio Sample Rate Conversion Based on Fractional Delay Filter
PublikacjaIn this paper a sample rate conversion algorithm which allows for continuously changing resampling ratio has been presented. The proposed implementation is based on a variable fractional delay filter which is implemented by means of a Farrow structure. Coefficients of this structure are computed on the basis of fractional delay filters which are designed using the offset window method. The proposed approach allows us to freely...
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Solventless sample preparation techniques based on solid- and vapour-phase extraction
PublikacjaThe main objective of this review is to critically evaluate recent developments in solventless sample preparation techniques. The potential of a variety of sample preparation techniques based on solid- and vapour-phase extraction techniques is evaluated. Direct thermal extraction and derivatization processes to facilitate the extraction of analytes in different areas are included. The applicability, disadvantages and advantages...
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Coacervative extraction as a green technique for sample preparation for the analysis of organic compounds
PublikacjaOne of the present trends in analytical chemistry is miniaturization, which is one of the methods of green analytical chemistry application. A particular emphasis is placed on the elimination of the use of large amounts of organic solvents which are toxic and harmful to the environment, maintaining high efficiency of the extraction process, high recovery values and low values of quantification (LOQ) and detection (LOD) limits....
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Application of modern sample-preparation techniques to the determination of chloropropanols in food samples
PublikacjaChloropropanols are heat-induced food toxicants that recently caused concern among industrial and scientific experts. World and European organizations related to food safety asked researchers to investigate mitigation strategies regarding these contaminants. The essential objective of this project was development of fast analytical methods enabling reliable determination and quantification of 3-monochloropropane-1,2-diol, 2-monochloropropane-1,3-diol...
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New sample preparation strategies for comprehensive lipidomics of human breast milk
PublikacjaGLOBAL PROFILING ANALYSIS OF HUMAN BREAST MILK (HBM) LIPIDS IS HINDERED BY COMPLEX COMPOSITION OF HBM. THIS PROBLEM IS HUGE FROM ANALYTICAL POINT OF VIEW, SINCE DUE TO THAT DETECTION OF ALL HBM LIPIDS DURING ONE ANALYTICAL RUN IS LIMITED. THUS, SAMPLE PREPARATION STEP CONSTITUTES A CRUCIAL STEP IN UNTARGETED LIPIDOMIC ANALYSIS OF HBM, ESPECIALLY WHEN SEMI-QUANTITATIVE ANALYSIS IS ASSUMED. HEREIN, WE PRESENT A COMPARISON OF PUBLISHED...
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SAMPLE-AND-HOLDING METHOD FOR GAS SENSING APPLIED FOR RESISTANCE GAS SENSORS
PublikacjaThe DC resistance of a Taguchi gas sensor is influenced by the ambient gas. To improve the selectivity and sensitivity of a sensor the fluctuation enhanced sensing (FES) was used. The paper proposes a novel methodology of utilizing FES technique that sample composition of an ambient atmosphere and hold it for further processing (sample-and-holding technique). The method uses the heated gas sensor to sample an ambient atmosphere...
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On the Application of Magnetoacoustic Emission for a Nondestructive Assessment of the Post Welding Heat Treatment of High Chromium Steel Weld Seams
PublikacjaThe paper analyses the possibility of post weld heat treatment (PWHT) quality assessment with the help of magnetoacoustic emission (MAE) signal measurements. Two welded superheater tubes, made of high chromium VM12 steel, were analysed—as welded and heat treated one. The analysed sample in the as welded state exhibited significantly higher hardness, accompanied by a big difference in the MAE signal intensity (of order of about...
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Thermal degradation assessment of canola and olive oil using ultra-fast gas chromatography coupled with chemometrics
PublikacjaOil blending is often used to enhance the properties of vegetable oils. The admixture of a more thermally stable oil makes the resulting blend more suitable for use in frying. A new method of quality assessment of vegetable oils used in frying is presented in this paper. In this method, ultra-fast gas chromatography coupled with flame ionization detector and chemometrics is employed. Principal component analysis was used for data...
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Survey of ICT students' views on self-assessment of professional preparation after remote study
PublikacjaThe contemporary post-pandemic reality is characterised by an undisputable shift toward remote education and work. The aim of this article is to identify the assessment of ICT evaluation of different forms of study, including desktop, remote and hybrid forms; to find out their preferences towards different forms of education and work, and to determine their sense of self-efficacy in terms of professional tasks undertaken after...
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Application of multivariate statistics in assessment of green analytical chemistry parameters of analytical methodologies
PublikacjaThe study offers a multivariate statistical analysis of a dataset, including the major metrological, “greenness” and methodological parameters of 43 analytical methodologies applied for aldrin determination (a frequently analyzed organic compound) in water samples. The variables (parameters) chosen were as follows: metrological (LOD, recovery, RSD), describing the “greenness” (amount of the solvent used, amount of waste generated)...
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Hazard assessment of sediments from a wetland system for treatment of landfill leachate using bioassays
PublikacjaFour bioassays were used in this study for the hazard assessment of sediments from sediment traps and several ponds in a treatment wetland for landfill leachate at Atleverket, Sweden. In the 6-day solid phase microbiotest with the sediment-dwelling crustacean Heterocypris incongruens both acute and chronic effects were observed with a gradual decrease and loss of toxicity with treatment in the wetland system. Some samples showed...
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Vietnamese version of the Dual Filial Piety Scale: preliminary validation in a student sample
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Influence of sample thickness non-uniformities on the modulated photocur-rents in amorphous solids
PublikacjaOtrzymano przybliżone wzory opisujące modulowane fotoprądy dla przypadków próbki kanapkowej o nierównomiernej grubości, reprezentowanej przez układ równolegle połączonych próbek o różnych grubościach. Na ich podstawie obliczono przebieg fotoprądów dla przypadku jednorodnego i gaussowskiego rozkładu grubości próbki oraz dla wykładniczego rozkładu pułapek.
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Quechers sample preparation method variants for analysis of pesticide residues in fruits and vegetables
PublikacjaThis article describes the comparison of different versions of an easy, rapid and low-cost sample preparation approach for the determination of pesticide residues in fruits and vegetables by concurrent use of gas and liquid chromatography coupled to MS or ECD for detection. The sample preparation approach is known as QuEChERS, which stands for quick, easy, cheap, effective, rugged and safe. It is a combination of liquid-liquid...
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Comparative Analysis of Numerical and Experimental Studies of the Airflow Around the Sample of Urban Development
PublikacjaIn this paper, on the background of a short overview of the recent advances in the field of Environmental Wind Engineering (EWE), a comparison of wind tunnel experiment and numerical simulation for some cases of airflow around an urban layout have been reported. The purpose of the study is quantitative and qualitative comparison of measurements in the wind tunnel as well as numerical simulation using Ansys Fluent software. The...
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Determination of pesticide residues in fruits and vegetables using QuEChERS sample preparation method
PublikacjaThe intensive development of agriculture means that more and more toxic organic and inorganic compounds are entering the environment. Because of their widespread use, environmental stability, selective toxicity and bioaccumulative capability, pesticides belong to the most hazardous substances contaminating the environment. They are particularly dangerous in fruits and vegetables, because they are one of the reasons why people are...
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Gain Correction for Nearly Optimal Variable Fractional Sample Delay Filter Design
PublikacjaJedną z najbardziej efektywną numerycznie metodą projektowania filtrów jest metoda okien. Sprawia to, że takie podejście bardzo dobrze nadaje się do implementacji filtrów ułamkowoopóźniających o zmiennym opóźnieniu, gdzie wymagana jest częsta aktualizacja współczynników takiego filtru. Z drugiej strony, jeżeli wymagane są filtry wysokiej jakości wybór okna jest najczęściej problematyczny. Z tego powodu w pracy rozpatrzono użycie...
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New Trends in Sample Preparation Techniques for the Analysis of the Residues of Pharmaceuticals in Environmental Samples
PublikacjaPharmaceutical residues in the environment is a field of special interest due to the adverse effects to either human health or aquatic and soil environment. Pharmaceuticals have been already detected in underground, surface and wastewaters, soils, manure and sediments. The growing awareness of environmental pollution arising from human activity forces the need for their comprehensive determination. Environmental samples are complex...
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State of the art in sample preparation for human breast milk metabolomics—merits and limitations
PublikacjaHuman breast milk (HBM) contains metabolites that are diverse in chemical structure and concentration. These metabolites range from high-abundance to low-abundance compounds and from polar to nonpolar. This complex nature of HBM makes HBM samples difficult to analyze, especially in global metabolomic studies for the determination and characterization of complete sets of metabolites. In this review, the state of the art in sample...
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Entropy Measures in the Assessment of Heart Rate Variability in Patients with Cardiodepressive Vasovagal Syncope
PublikacjaSample entropy (SampEn) was reported to be useful in the assessment of the complexity of heart rate dynamics. Permutation entropy (PermEn) is a new measure based on the concept of order and was previously shown to be accurate for short, non-stationary datasets. The aim of the present study is to assess if SampEn and PermEn obtained from baseline recordings might differentiate patients with various outcomes of the head-up tilt test...
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Portable Electronic Nose Based on Electrochemical Sensors for Food Quality Assessment
PublikacjaThe steady increase in global consumption puts a strain on agriculture and might lead to a decrease in food quality. Currently used techniques of food analysis are often labour-intensive and time-consuming and require extensive sample preparation. For that reason, there is a demand for novel methods that could be used for rapid food quality assessment. A technique based on the use of an array of chemical sensors for holistic analysis...
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Determination of volatile organic compounds using solventless sample preparation techniques and gas chromatography
PublikacjaIn this paper the latest advances in the determination of volatile organic compounds using solvent-free extraction techniques in the sample preparation step are presented. A paper is focus mainly on one of the most popular sample preparation technique: solid-phase microextraction technique (SPME) combined with different detection systems and its applications to sampling of VOCs from the samples with different matrices. This paper...
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Relationships between biomarkers of inflammation, ovarian steroids, and age at menarche in a rural polish sample
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A Robust Method for Sample Preparation of Gastrointestinal Stromal Tumour for LC/MS Untargeted Metabolomics
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Sample Concentration of Charged Small Molecules and Peptides in Capillary Electrophoresis by Micelle to Cyclodextrin Stacking
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Evaluation of occupational exposure in a slide bearings factory on the basis of urine and blood sample analyses
PublikacjaZbadano wpływ pracy w zakładach łożysk ślizgowych na zdrowie pracowników. Przeprowadzono analizę próbek moczu i krwi pobranych od 42 pracowników i 6 osób zatrudnionych w administracji przedsiębiorstwa, stanowiących grupę kontrolną. Oznaczono zawartość Al, Cu, Pb i Zn we krwi i moczu pracowników dwukrotnie, przed i po terapii za pomocą chelatowania, stosując ICP-MS oraz metodę dodatku wzorca. Istotność różnic w zawartości pierwiastków...
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Sample processing for DNA chip array-based analysis of enterohemorrhagic Escherichia coli (EHEC)
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Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen
PublikacjaThis paper describes a novel method of samplepreparation for the determination of trace concentrations ofpolycyclic aromatic hydrocarbons (PAHs) in high-boilingpetroleum products. Limits of quantitation of the investigatedPAHs in materials of this type range from tens ofnanograms per kilogram to <20 μg/kg. The studies revealedthat in order to separate most of interferences from theanalytes without a significant loss of PAHs, it...
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Influence of plastic deformation on stray magnetic field distribution of soft magnetic steel sample
PublikacjaThe effect of various combinations of conditions, i.e., presence of the Earth’s magnetic field during and after deformation on the distribution of stray magnetic field of S355 steel sample, which is locally deformed, was investigated. Some of the stages of the experiment were carried out in zero magnetic field. Compensation of the Earth’s magnetic field was obtained by the application of a pair of Helmholtz coils. These coils are...
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A framework estimating the minimum sample size and margin of error for maritime quantitative risk analysis
PublikacjaThe average accident frequency is essential for quantitative risk analysis and is conventionally estimated from accident statistics. This paper has systematically synthesised the knowledge on statistical errors and offered the missing instructions, a framework, for determining the minimum sample size and the margin of error (MOE) when calculating the average accident frequency from an accident database at hand. We have applied...
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Pre-analytical aspects in metabolomics of human biofluids – sample collection, handling, transport, and storage
PublikacjaMetabolomics is the field of omics research that offers valuable insights into the complex composition of biological samples. It has found wide application in clinical diagnostics, disease investigation, therapy prediction, monitoring of treatment efficiency, drug discovery, or in-depth analysis of sample composition. A suitable study design constitutes the fundamental requirements to ensure robust and reliable results from the...
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Determination of environmental pollutants in soil and sediments - some aspects of sample clean-up and GC analysis
PublikacjaPrzedstawiono wstępne wyniki badań nowej procedury analitycznej przeznaczonej do badań próbek i osadów dennych na zawartość związków organicznych (WWAPCB). Procedura składa się z następujących etapów: - ekstrakcji analitów z wykorzystaniem techniki ASE, - oczyszczania ekstraktów (kolumienki), - chromatograficznego rozdzielania i oznaczania analitów.
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Seeking genetic signature of radiosensitivity - a novel method for data analysis in case of small sample sizes
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Evaluation of sample injection precision in respect to sensitivity in capillary electrophoresis using various injection modes
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The Indirect Relationship Between Spiritual Experiences and Subjective Wellbeing Through Hope? A Sample of Chilean Students
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Self-adjusting sub-sample delay estimator based on fractional delaying Hilbert transform filter
PublikacjaZaprezentowano nowe rozwiązanie samo-nastrajalnego estymatora opóźnienia sygnału sinusoidalnego, działającego w czasie dyskretnym. Zastosowano filtr Hilberta o skończonej odpowiedzi ipulsowej (FIR od ang. finite impulse response) zagregowany z filtrem ułamkowo-opóźniającym. Zilustrowano performancję estymatora, również w obecności szumu. Przeanalizowano jego złożoność numeryczną.
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Sample preparation for gas chromatographic determination of halogenated volatile organic compounds in environmental and biological samples
PublikacjaPodstawowym elementem przygotowania próbek środowiskowych i biologicznych do analizy jest etap izolacji i/lub wzbogacania polegający na przeniesieniu analitów z matrycy pierwotnej charakteryzującej się złożonym i często zmiennym składem (próbka oryginalna) do matrycy wtórnej z równoczesnym usunięciem substancji przeszkadzających (izolacja)i zwiększeniem stężenia analitów do poziomu powyżej granicy oznaczalności stosowanego przyrządu...
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Monitoring of volatile organic compounds (VOCs) in atmospheric air. Part II. Sample collection and preparation
PublikacjaThe paper reviews literature information on air sampling techniques commonly used for monitoring volatile organic compounds (VOCs) levels in atmospheric air. It describes containers for collecting samples of atmospheric air, such as vacuum canisters and bags made from synthetic materials. It discusses dynamic, passive and denudational techniques for sampling analytes from air combining isolation with preliminary enrichment, and...
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Deep eutectic solvents in analytical sample preconcentration Part B: Solid-phase (micro)extraction
PublikacjaOne of the key challenges of modern analytical chemistry is the monitoring of trace amounts of contaminants using sensitive and selective instrumental techniques. Due to the variety and complexity of some samples, it is often necessary to properly prepare a sample and to perform a preconcentration of trace amounts of analytes. In line with the principles of Green Analytical Chemistry (GAC), it is important for an analytical procedure...
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Do the young employees perceive themselves as digitally competent and does it matter?
PublikacjaPurpose – The study aims to examine the digital competence of young employees (under 30 years of age) who graduated from the technical university. Self-assessment of selected digital competencies was examined along with the determination of a self-efficacy level in the area of using digital competencies. Design/methodology/approach – Quantitative research was conducted using the computer-assisted web interview method on a sample...
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How does stakeholder pressure influence CSR-practices? A construction industry model based on a European sample
PublikacjaThe stakeholder pressure is one of the most vital powers which determines CSR implementation and can provide organizations with the motivation to adopt corporate social responsibility (CSR) strategy, as the stakeholder theory claims. The current investigation replications Kowalczyk’s (2019) study, who examined the same structure of relations based on the Polish sample. The essence of this replication is to find out whether CSR-...
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Alginate-based sorbents in miniaturized solid phase extraction techniques - Step towards greenness sample preparation
PublikacjaIn response to growing concerns about environmental degradation, one of the main areas of research activity in recent years has been to make sample preparation methods more sustainable and eco-friendly. The increasing greenness of this step can be achieved by minimizing the usage of reagents, automating individual stages, saving energy and time, and using non-toxic, biodegradable substances. Therefore, the use of natural materials...
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Recent developments in biological sample testing methods for the confirmation of gestational exposure to tobacco smoke anddrugs of abused
PublikacjaSubstance use is most prevalent in reproductive-aged people also by women during pregnancy. In national prevalence surveys among women aged 15 to 44 years, 10.8 % of women reported using alcohol during pregnancy, 17 % reported smoking during pregnancy, and 4.4 % reported abusing any illicit substances during pregnancy. Virtually all illegal drugs, such as heroin and cocaine, pose dangers to a pregnant woman. Legal substances, such...
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Effect of sample-preparation methods on the quantification of selected flavonoids in plant materials by high performance liquid chromatography
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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...