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Search results for: CHIRAL DETERMINATION
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In-tube extraction for the determination of the main volatile compounds in Physalis peruviana L
PublicationAn analytical procedure based on in-tube extraction followed by gas chromatography with mass spectrometry has been developed for the analysis of 24 main volatile components in cape gooseberry (Physalis peruviana L.) samples. According to their chemical structure, the compounds were organized into different groups: one hydrocarbon, one aldehyde, four alcohols, four esters, and 14 monoterpenes. By single-factor experiments, incubation...
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Application of TOPSIS for Selection and Assessment of Analytical Procedures for Ibuprofen Determination in Wastewater
PublicationThis paper describes the possible implementation of the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) as green analytical chemistry metrics tools. TOPSIS is one of the multi-criteria decision analysis (MCDA) tools that is applied in the selection of the best alternative from many possible. In this case we have applied it to assess the nineteen analytical procedures for ibuprofen determination in wastewater...
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Green aspects of techniques for the determination of currently used pesticides in environmental samples
PublicationPesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical methods. The analysis of environmental samples for the presence of pesticides is very difficult: the processes involved in sample preparation are...
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Recent developments in the determination of residual solvents in pharmaceutical products by microextraction methods
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Time variable gain for long range sonar with chirp sounding signal
PublicationThe main purpose of applaying Time Variable Gain (TVG) in active sonars with digital signal processing is to reduce dynamic range of echo signal and adapt it to the dynamic range of the analogue to digital conversion. With high transmission losses level, the dynamic range of the input signal in long range sonars can be very high and even exceed 200dB. When chirp sounding signals with matched filtration are used, sonars can raech...
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Chirp Rate and Instantaneous Frequency Estimation: Application to Recursive Vertical Synchrosqueezing
PublicationThis letter introduces new chirp rate and instantaneous frequency estimators designed for frequency-modulated signals. These estimators are first investigated from a deterministic point of view, then compared together in terms of statistical efficiency. They are also used to design new recursive versions of the vertically synchrosqueezed short-time Fourier transform, using a previously published method (D. Fourer, F. Auger, and...
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Sonar Pulse Detection Using Chirp Rate Estimation and CFAR Algorithms
PublicationThis paper presents a new approach to sonar pulse detection. The method uses chirp rate estimators and algorithms for the adaptive threshold, commonly used in radiolocation. The proposed approach allows detection of pulses of unknown parameters, which may be used in passive hydrolocation or jamming detection in underwater communication. Such an analysis is possible thanks to a new kind of imaging, which presents signal energy in...
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Chiralne i achiralne struktury supramolekularne z udziałem oksamidów i ich pochodnych tiokarbonylowych
PublicationCelem pracy była synteza serii oksamidów oraz ich analogów tio- i ditiokarbonylowych, a następnie zbadanie zdolności tych związków do samoorganizacji w kryształach oraz kokryształach z innymi substancjami. Istotnym elementem tych badań było ustalenie wpływu chiralności cząsteczek na sposób ich upakowania w sieci krystalicznej. Ponadto długofalowa absorpcja tiopochodnych umożliwiła przeprowadzenie studiów spektroskopowych otrzymanych...
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Accurate and continuous adhesive fracture energy determination using an instrumented wedge test
PublicationThe wedge test and the related double cantilever beam test are practical methods of assessing structural adhesive fracture energy. In the former, and to a lesser extent the latter, a recognised problem is the difficulty of following the length of the growing crack, required to calculate fracture energy with any accuracy. We present a novel method of measurement of crack length that has the advantages of being accurate and allowing...
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Structural Investigations and Determination of Current and Voltage Characteristics in Htsc 2G SF12050 Tapes
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Micellar liquid chromatography for lipophilicity determination of new biologically active 1,3‐purinodiones
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Quantitative determination of titin and nebulin in poultry meat by SDS-PAGE with an internal standard
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Unmodelled Effects in the Horizontal Velocity Field Determination: ASG-EUPOS Case Study
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Rapid quantitative determination of butter adulteration with palm oil using the DSC technique
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Determination (monitoring) of PAHs in surface waters: why operationally defined procedure is needed
PublicationW pracy przedstawiono i skomentowano rezultaty badań międzylaboratoryjnych oznaczania wielopierścieniowych węglowodorów aromatycznych w wodzie czystej i wodzie zawierającej zawiesinę. Badania wskazują, ze wyniki oznaczania zależa od zastosowanej techniki izolacji analitów z próbki i końcowej procedury ich rozdzielania i oznaczania. Przeprowadzone badania wskazują, że nowoczesna analityka nie dysponuje technikami izolacji, które...
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The state of the art in the field of non-stationary instruments for the determination and monitoring of atmospheric pollutants
PublicationW artykule przedstawiono informacje oparte zarówno na danych literaturowych jak i własnych doświadczeniach dotyczące:-podstawowych tendencji rozwojowych w zakresie analityki i monitoringu zaneczyszczeń powietrza atmosferycznego-wymogów metrologicznych stawianych różnych typom urządzeń kontrolno-pomiarowych;-klasyfikacji analizatorów i monitorów wykorzystywanych w monitoringu powietrza.
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The effect of the temperature change rate on determination of the critical pitting temperature of stainless steels
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Determination of amino acids in urine of patients with prostate cancer and benign prostate growth
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Determination of Urinary Pterins by Capillary Electrophoresis Coupled with LED-Induced Fluorescence Detector
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Determination of the chemical structure of potential organic impurities occurring in drug substance opipramol
PublicationThe tricyclic antipsychotic and antidepressant drug opipramol (opipramole) was examined with regard to the chemical structure of its organic impurities. Impurities were isolated from the technical product by chromatographic methods and their chemical structures were established by 1H NMR, MS and FTIR and further confirmed by comparison with commercially available products or with products obtained by independent synthesis, and...
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Do we need a catalyst in the determination of dissolved organic carbon in environmental samples?
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Application of PLE for the determination of essential oil components from Thymus vulgaris L.
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Determination of Safety Levels of Electronic Devices Exposed to Impact of Strong Electromagnetic Pulses
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Modification of ASM3 for the determination of biomass adsorption/storage capacity in bulking sludge control
PublicationSystemy osadu czynnego z selektorami (SAS) umożliwiają ograniczenie nadmiernego wzrostu bakterii nitkowatych, które odpowiadają za zjawisko zwanę ''puchnięciem osadu''. Celem tych badań było opracowanie modelu matematycznego opisującego szybkie usuwanie substratu w systemach SAS. W tym celu zmodyfikowano Model Osadu Czynnego nr 3 (ASM3) poprzez dodanie równań opisujących zjawiska adsorpcji i bezpośredniego wzrostu bakterii na zaadsorbowanym...
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A new scuffing shock test method for the determination of the resistance to scuffing of coated gears
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The triple-sorbents solid-phase extraction for pharmaceuticals and estrogens determination in wastewater samples
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Determination of PCBs in river sediment samples—proficiency test for selected Polish laboratories
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Organomercury Compounds in Environmental Samples: Emission Sources, Toxicity, Environmental Fate, and Determination
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Neurohypophyseal Receptors-Ligands: Where We Are After the Landmark Rhodopsin Structure Determination
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Organomercury compounds in environmental samples: emission sources, toxicity, environmental fate and determination.
PublicationIn view of the specific properties of mercury and its capability of forming compounds that can be bioaccumulated and biomagnified at successive levels of the trophic pyramid, it has become necessary to gather detailed information on the sources of emission of this element into the environment and its fate there. Moreover, the increasing awareness of the relationship between the toxicity of mercury and its chemical form has sharpened...
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Determination of causes of accelerated local corrosion of austenitic steels in water supply systems
PublicationThis paper concerns an inspection of a water supply system, made of AISI 304 steel, which showed signs of local corrosion at the weld. Such corrosion caused material perforation after very short periods of operation. It was revealed that steel was sensitised during the welding process. It was also proven that chromium micro-segregation occurred in the alloy leading to galvanic cell formation which initialised the process of pitting...
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Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition
PublicationAmines are important biological compounds, and so their analysis and monitoring in various matrices is worthy of investigation and development.Due to the polar nature of amines, chromatographic analysis of free amines is generally unsatisfactory owing to adsorption and decomposition of the solute on the column, resulting in peak tailing and losses. Therefore, many derivatization reactions are employed to reduce the polarity, improve...
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Experimental Determination of Limit Adhesive Shear Strtess between Solid Wall and Liquid
PublicationTheoretically slip of a fluid with respect to the solid wall should occur even at a very low velocity of motion. However theoretical analysisand some empirical data suggest that there must be a limit value of shear stress, below which the slip does not appear. A simple metyhod of this stress determination was proposed in the paper.
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LC-MS and LC-NMR as Complementary Techniques for the Determination of Pharmaceuticals in Dosage Formulations
PublicationPharmaceuticals contain not only pharmacologically active compounds but also a range of excipients. The danger exists that impurities may also be present in such drugs, which may adversely affect their efficacy and even endanger patient health and life. Monitoring the composition of pharmaceutical products is therefore essential. The trace amounts of such impurities in pharmaceuticals are often identified and determined with liquid...
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DETERMINATION OF DIFFUSIBLE HYDROGEN CONTENT IN DEPOSITED METAL OF RUTILE ELECTRODES BY GLYCERIN METHOD
PublicationThe presence of diffusible hydrogen in welded joints is one of the causes of formation the welding imperfections. Improvement of weldability can be achieved by reducing the hydrogen amount in welded joints. This requires, among others, the finding of sources of hydrogen. For high hydrogen processes the commonly used method of determining the diffusible hydrogen amount is the glycerin method. This paper concerns issues related to...
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THE DETERMINATION OF ABRASION RESISTANCE OF SELECTED BIOMATERIALS FOR THE FRICTION PAIRS IN THE HIP JOINT ENDOPROSTHESIS
PublicationThe key requirement for the modern endoprosthesis is high durability of the friction components, which results in long and trouble-free operation in the human body. The durability of currently used endoprosthesis is often limited by tribological wear processes of friction components (e.g. between the head and the acetabular component in a hip joint endoprosthesis) [8, 19, 23, 24]. In order to compare the tribological wear, tribological...
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Experimental determination of dynamic properties of cylindrical steel tank model filled with liquid
PublicationIn technical branches, such as chemical or petroleum industries, cylindrical steel tanks are essential structures used for storage of liquid products. Any failure might have disastrous consequences, therefore their safety and reliability is essential. The aim of the present paper is to show the results of the experimental study which has been conducted on a scaled model of a real tank used in Poland. The investigation was carried...
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Determination of Selected Organic Acids in Animal Farm Water Samples by Ion Chromatography
PublicationLow molecular mass carboxylic acids (LCAs) occur in many environmental compartments due to natural processes and human activity. They are an important group of organic pollutants of waste water that mainly includes, volatile fatty acids, and also dicarboxylic, aromatic, hydroxy- and ketoacids. LCAs are present in the environment at concentrations between 1 to 5000 ppm and different methods have been reported for their determination...
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Determination of the chemical structure of potencial organic impurities occuring in the drug substance opopramol
PublicationThe tricyclic antipsychotic and antidepressant drug opipramol was examined with regard to the chemical structure of its organic impurities. Impurities were isolated from the technical product by chromatographic methods and their chemical structures were estabilished by HMNR, MS and FTIR.
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Determination of metals in water samples by atomic absorption spectrometry and flame emission spectrometry
PublicationMetal species in environmental waters are relevant to characterize the metal toxicity, the mobility between different environmental compartments, and for remediation purposes in case of contamination. The concentration of many trace metals in natural water samples are generally at µg/l level. The paper describes determination of metals in water samples based on flame atomic emission and flame atomic absorption spectrometry.
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Determination of pesticide residues in fruits and vegetables using QuEChERS sample preparation method
PublicationThe 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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Determination of short-chain monocarboksylic acids in cattle farm and dairy industry wastewater
PublicationThe paper describes application of various techniques to determine short-chain monocarboksylic acids (SCMAs) in samples from the successive steps from milk production: from wastewater from cattle farm to wastewater from dairy industry. Each technique of sample preparation is followed by gas chromatographic analysis.
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Parametric method for determination of motion characteristics of underwater vehicles, applicable in preliminary designing.
Publicationartykuł zawiera opis metody wstępnego projektowania autonomicznych pojazdów podwodnych (auv), przydatnej szczególnie w przypadku, gdy w założeniach projektowych stawiane są wymogi dotyczące parametrów kinematyczno-dynamicznych ruchu pojazdu. koncepcja metody zasadza się na równaniach dynamiki opisujących ruch płaski pojazdu w kierunku poziomym i pionowym, wywołanych odpowiednio napędem śrubowym lub balastem wodnym. równania ruchu...
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The effect of adding a standard on the result of determination of polychlorinated biphenyls in bottom sediment samples
PublicationBottom sediments are a very important component of aquatic ecosystems. The sediment matrix is highly diverse and heterogeneous; in consequence, compounds entering the aquatic environment from different sources are considerably enriched at its surface. Bottom sediments are regarded as natural sorbents, since they accumulate many harmful substances, such as heavy metals and stable organic contaminants.Extraction is a key stage in...
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Method for determination of the chemical composition of phases of the iron catalyst precursor for ammonia synthesis
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Oznaczanie fazy stałej w tłuszczach. Determination of solid fat content in fats.
PublicationW pracy dokonano przeglądu metod oznaczania indeksu fazy stałej (SFI - solid fat index) oraz zawartości fazy stałej (SFC - solid fat content) w tłuszczach. Obok metody NMR, obecnie powszechnie stosowanej i zalecanej przez normy, przedstawiono też inne metody analityczne które stosowano, lub stosuje się do tego typu analiz.
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Determination of PCBs in river sediment samples - proficiency test for selected Polish laboratories
PublicationW pracy opisano wyniki badań międzylaboratoryjnych dotyczących oznaczania zawartości analitów z grupy polichlorowanych bifenyli w próbkach osadu rzecznego. Badania organizowane były przez Katedrę Chemii Analitycznej Wydz. Chemicznego PG we współpracy ze Stowarzyszeniem RefMat oraz firmą LGC Promochem Sp. z o.o.
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The new analyzer based on single pellistor sensor for determination of hydrogen and methane in air
PublicationW artykule przedstawiono rezultaty niedawnych badań nad konstrukcją prostego i selektywnego analizatora do monitoringu stężenia gazów wybuchowych w powietrzu. Opisano konstrukcję takiego urządzenia i wyniki prób laboratoryjnych dla gazowych mieszanin wzorcowych.
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Determination of equivalent circuit parameters of an induction motor using field calculation software
PublicationSimulation of the drive system comprising a power electronic converter and an induction motor requires that the equivalent circuit parameters of the motor are known. These parameters can be either measured or calculated. A method of calculation of self and mutual inductances that are parameters of a polyphase model of the motor is presented in the paper. All self-inductances and mutual inductances have been calculated using the...
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Determination of stability constants of complexes of selected amide ionophores with alkali metal cations
PublicationPodano właściwości kompleksujące jony litowców czterech jonoforów typu amidów. Wyznaczono wartości stałych kompleksów z jonów Li+, Na+, K+ metodą potencjometryczną z zastosowaniem elektrod jonoselektywnych stosując dwie różne procedury: 1) stosując jako kation referencyjny TMA+, 2) stosując chromofor kompleksujący H+.