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wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: QUATERNARY AMMONIUM COMPOUNDS
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Numerical simulation of the quaternary aquifer groundwater flow of the northern Vistula delta plain
PublikacjaW pracy przedstawiono wyniki obliczeń krążenia wód podziemnych w czwartorzędowym poziomie wodonośnym rejonu Żuław Gdańskich. Czwartorzędowy poziom wodonośny odgrywa najważniejszą rolę w zaopatrzeniu w wodę aglomeracji gdańskiej. W obliczeniach wykorzystano programy Modflow i Modpath zawarte w pakiecie (GMS 3.1). Odtworzono warunki przed uruchomieniem ujecia Lipce wykorzystując obliczenia dla stanu ustalonego krążenia wody w warstwie...
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Recent breakthroughs in the stability testing of pharmaceutical compounds
PublikacjaPharmaceutical development is mostly focused on the research leading to approval of a new and viable active substance. However, there is a number of old generation compounds that are still being used in contemporary medicinal practice. So that new analytical developments should cover not only the safety of newly developed drug substances, which is obvious, but should also be directed into the search of individual stability issues...
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Thermomechanical and Fire Properties of Polyethylene-Composite-Filled Ammonium Polyphosphate and Inorganic Fillers: An Evaluation of Their Modification Efficiency
PublikacjaThe development of new polymer compositions characterized by a reduced environmental impact while lowering the price for applications in large-scale production requires the search for solutions based on the reduction in the polymer content in composites’ structure, as well as the use of fillers from sustainable sources. The study aimed to comprehensively evaluate introducing low-cost inorganic fillers, such as copper slag (CS),...
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Endocrine Disrupting Compounds – Problems and Challenges
PublikacjaIn this chapter, information about some of the estrogenic compounds and their environmental fate and biological influence can be found. Special attention is paid to the review of the analytical approaches used at the stages of detection and determination of Endocrine Disrupting Compounds (EDCs) in the environmental samples. Also, a brief characterization of both cellular and non-cellular bioassays is presented. The discovery of...
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Analysis and characterization of coordination compounds by resonance Raman spectroscopy
PublikacjaResonance Raman spectroscopy has become a powerful tool to study excited-state geometries, excited-state charge distributions and photoinduced reaction dynamics in coordination compounds. Due to their rich photophysical properties coordination compounds are utilized for a variety of applications ranging from DNA sensing to photocatalysis. This review features recent applications of various resonance Raman scattering techniques...
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Mutagenic and Carcinogenic Compounds in Food
PublikacjaFood is a major environmental human cancer risk factor. One of the reasons for this is that food products contain substances that exhibit mutagenic and carcinogenic potential which may induce the transformation of normal somatic cells into cancerous cells. These compounds occur in food as a result of microbial contaminations (mycotoxins produced by molds), are generated from natural food components upon processing (e.g. heterocyclic...
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Selected organophosphorus compounds with biological activity. Applications in medicine
PublikacjaThe purpose of this article is to provide an overview of the latest applications of organophosphorus compounds (OPs) that exhibit biological activity. A large family of OPs have become popular in recent years. The practical application of OPs in modern medicine has been attributed to their unique properties. In this article, the methods used to select these compounds will be emphasized. This paper will first outline the findings...
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Neon-Bearing Ammonium Metal Formates: Formation and Behaviour under Pressure
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Ammonium Hydroxide Mediated Hydrothermal Crystallization of Hydroxyapatite Coatings on Titanium Substrate
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Apparent molar volumes and compressibilities of tetrabutyl-ammonium bromide in organic solvents
PublikacjaW oparciu o pomiary gęstości i szybkości rozchodzenia się dźwięku w niewodnych roztworach bromku czterobutyloamoniowego obliczono pozorne objętości molowe w przedziale temperatur od 288,15 K do 323,15 K oraz pozorne ściśliwości w temperaturze 298,15 K. Graniczne wielkości pozornej objętości molowej i ściśliwości wyznaczono w oparciu o równanie Massona, jak i równanie Redlicha, Rosenfelda i Mayera oraz z wykorzystaniem teorii Pitzera....
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Features of ammonium-ions sorption by natural zeolites under dynamic conditions.
PublikacjaW pracy przedstawiono: charakterystykę naturalnych zeolitów, obszar ich praktycznego wykorzystania w zakresie adsorpcyjnego usuwania niektórych zanieczyszczeń z wód oraz wyniki badań procesu adsorpcji jonów amoniowych z wodnych roztworów modelowych (w układzie dynamicznym) na wybranych zeolitach naturalnych.
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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...
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A convenient and efficient alfa-sulfenylation of carbonyl compounds
PublikacjaA method for alfa-sulfenylation of carbonyl compounds by a 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-disulfanyl derivatives has been developed. Readily available reagents, mild reaction conditions, and excellent yields with high selectivity makes this method quite simple, convenient and practical.
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TG-FTIR, DSC and quantum chemical studies of the thermal decomposition of quaternary methylammonium halides
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Synthesis, structural, electronic and linear electro-optical features of new quaternary Ag2Ga2SiS6 compound
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Phosphinophosphoranes: Mixed-Valent Phosphorus Compounds with Ambiphilic Properties
PublikacjaHerein, we present a simple synthesis of mixed-valent phosphinophosphoranes bearing three- and five-coordinate phosphorus centers. Compounds with phosphorus–phosphorus bonds were synthesized via a reaction of lithium phosphides RR′PLi with cat2PCl (cat = catecholate), whereas derivatives with methylene-linked phosphorus centers were obtained via a reaction of phosphanylmethanides RR′CH2Li with cat2PCl. The presence of accessible...
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Non-Nutritive Bioactive Compounds in Food of Plant Origin
PublikacjaThe increasing knowledge on the health benefits of certain food ingredients, in particular, those of plant origin, opened the discussion of the possibility of using edible plants or their active components in the prevention of non-communicable diseases. The health-promoting properties of plant foods are related to the presence of non-nutritive compounds, mainly plant secondary metabolites, which can affect many biological mechanisms...
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The properties, functions and use of selenium compounds in living organisms
PublikacjaSelenium occurs in the environment in inorganic and organic compounds. For many years it was regarded as a toxic element, causing numerous illnesses and diseases. But research in the last 50 years has revealed a "bright side" to this element, especially as a component of selenoproteins, selenium makes a significant contribution to the health of humans and animals. The selenium content in an organism depends on its concentration...
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Radiosensitization of DNA in presence of Pt(II)-based compounds
PublikacjaX-ray irradiation of plasmid DNA in presence of platinum (II)-based compounds was carried out in order to assess the radiosensitization capabilities of these drugs. In present investigations pBR322 plasmid DNA was used to monitor the effectiveness of chosen compounds in inducing strand breaks. Samples were incubated in the presence of potential radiosensitisers: platinum (II) bromide and cis-diamminedibromoplatinum (II). The results...
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Distribution of volatile organohalogen compounds in petrochemical plant water streams
PublikacjaThe study assesses halogenated volatile organic compound concentrations in the water and wastewaterstreams of a petrochemical plant. Water samples were collected at 11 sampling points during 5 samplingcampaigns. The samples were collected from the oil dewaxing unit and in the wastewater treatmentplant. Dichloromethane and 1,2-dichloroethane were the most frequently determined compounds. Tetrachloroethenewas also detected at the...
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Bioactive compounds and the antioxidant capacity in new kiwi fruit cultivars
PublikacjaThe aim of this investigation was to find the best among seven different kiwi fruit cultivars (‘Hayward’, ‘Daheung’, ‘Haenam’, ‘Bidan’, ‘Hort16A’, ‘Hwamei’ and ‘SKK12’) for human consumption and to classify them as groups. Therefore, the contents of bioactive compounds and the level of antioxidant capacities of these cultivars were determined in four different extracts and compared. It was found that the contents of the bioactive...
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NUTRITIONAL AND PHARMACEUTICAL APPLICATIONS OF BIOACTIVE COMPOUNDS IN TROPICAL FRUITS
PublikacjaDuring the past two decades our international scientific group investigated in vitro the physicochemical and nutritional characteristics of some cultivars of durian at various stages of ripening, mangosteen and new cultivars of snake fruit in comparison with widely used avocado, kiwifruit and mango, and in vivo their influence on laboratory animals. The main objective of the present study was to screen and compare the properties...
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DETERMINATION OF SURFACTANTS IN ENVIRONMENTAL SAMPLES. PART II. ANIONIC COMPOUNDS
PublikacjaSurfactants (SAA) with negative charge of polar group are named as anionic compounds. They are main constituent of most products containing synthetic surfactants. The linear alkylbenzene sulfonates (LAS), alkyl ethoxysulfates (AES) and alkyl sulfates (AS) are typically applied from this class of compounds. Those surfactants are ingredients of household detergents and cleaners, laundry detergents, cosmetic. Moreover they can be...
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Pathways of nitrogen compounds depletion in hybrid constructed wetlands
PublikacjaHybrid Constructed Wetlands are composed of two or more filters with mixed flow direction of sewage. Apparently in the HCWS the benefits of both types of bed are merged, resulting in better effluent quality (organic and nitrogen componds removal). Such heterogeneous environment creates possibilities for different ways of nitrogen "disappearing". The objective of the present study was to compare the removal of nitrogen with accompanying...
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Antiferromagneticspinglass-likebehaviorinsinteredmultiferroic AurivilliusBim+1Ti3Fem−3O3m+3 compounds
PublikacjaThe structure,hyperfine interactionsandmagneticpropertiesoftheseriesofmultiferroicBim+1Ti3Fem−3 O3m+3 Aurivilliuscompoundswith m¼4–8 werestudiedusingX-raydiffraction, 57Fe Mössbauer spectroscopyandvibratingsamplemagnetometry.Sampleswerepreparedbytheconventionalsolid- state sinteringmethod.Bulkmagneticmeasurementsshowedthatfor m¼4 thecompoundis paramagnetic downto2Kwhileinthecompoundwith m¼5 theantiferromagnetictypetransition wasobservedat11K.Inthecaseofcompoundswith...
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Application of electrochemical sensors and sensor matrixes for measurement of odorous chemical compounds
PublikacjaIn this paper describes the principle of operation of the electrochemical sensors and the sensor matrixes comprised of electrochemical sensors intended for measurement of odorous compounds. Critical comparison of these sensors’ advantages and disadvantages has been made. The fields of economy contributing to release of odours and the potential sources of their emission have been identified. Commercially available electrochemical...
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Radio- and photosensitization of DNA with compounds containing platinum and bromine atoms
Publikacja. Irradiations of plasmid DNA by both X-rays and UV light in the presence and absence of compounds containing platinum and bromine atoms were performed in order to asses the sensitization potential of these compounds. Plasmid DNA pBR322 was incubated with platinum (II) bromide, hydrogen hexabromoplatinate (IV), hydrogen hexahydroxyplatinate (IV) and sodium hexahydroxyplatinate (IV). Incubation was followed by X-ray or UV irradiations....
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State of the art and prospects of methods for determination of lipophilicity of chemical compounds
PublikacjaLipophilicity of the compounds is useful to (i) explain their distribution in biological systems, which is different in plant and in animal organisms, (ii) predict the possible pathways of pollutant transport in the environment, and (iii) support drug discovery process and select optimal composition in terms of bioactivity and bioavailability. The lipophilic properties can be determined by two main approaches, experimental, which...
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New procedure for the control of the treatment of industrial effluents to remove volatile organosulfur compounds
PublikacjaWe present a new procedure for the determination of volatile organosulfur compounds in samples of industrial effluents using dispersive liquid–liquid microextraction and gas chromatography with flame photometric detection. Initially, the extraction parameters were optimized. These included: type and volume of extraction solvent, volume of disperser solvent, salting out effect, pH, time and speed of centrifugation as well as extraction...
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Derivatization of acidic herbicides with selected tetraalkyl ammonium and trimethyl sulfonium hydroxides for their GC analysis.
PublikacjaPrzedstawiono badania na temat oznaczania herbicydów z grupy fenoksykwasów (MCPP, MCPA, 2,4-D, 2,4,5-T) i fenoli (Dinoterb, Dinoseb, Pentachlorofenol) z wykorzystaniem chromatografii gazowej po uprzedniej derywatyzacji. Proces derywatyzacji przeprowadzano w dozowniku chromatografu gazowego za pomocą TMPH, TMSH i TMAH. Zbadano wpływ temperatury dozownika chromatografu, środowisko reakcji (rozpuszczalnik) i nadmiar odczynnika na...
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Simple smartphone-based methods for the determination of bioactive compounds in wine
PublikacjaA set of simple smartphone-based methods of bioactive compounds determination were developed for wine analysis. Procedures for smartphone-based determination of the total content of phenolic compounds, flavonoids, anthocyanins and biogenic amines, as well as measurement of antioxidant activity were developed and fully validated. The experimental setup is based on smartphone and 3D-printed device, though it is very simple and can...
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Formation of intermetallic compounds in the solid-liquid composites of the Ga-Ni system
PublikacjaThe processes of formation of intermetallic compounds in the composite system of liquid gallium-nickel powder by the methods of x-ray diffraction, scanning electron microscopy and differential thermal analysis have been studied. A change in the phase composition was discovered and the influence of thermal treatment of the composites under investigation on the phase formation processes was analyzed. The mechanism of gallium enriched...
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Removal of BTEX Compounds From Waste Gases; Destruction and Recovery Techniques
PublikacjaThe tendency for BTEX compounds (benzene, toluene, ethylbenzene, xylenes) to spread into all compartments of the environment together with their influence on both ecosystem and human health means that the emission of thesecompounds into the air is becoming the matter of worldwide concern. The legal regulations introduced by the European Union governing the assessment and management of air quality obliges member states to systematically...
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Impact of high-pressure processing on the bioactive compounds of milk - A comprehensive review
PublikacjaHigh-pressure processing (HPP) is a promising alternative to thermal pasteurization. Recent studies highlighted the effectivity of HPP (400–600 MPa and exposure times of 1–5 min) in reducing pathogenic microflora for up to 5 logs. Analysis of modern scientific sources has shown that pressure affects the main components of milk including fat globules, lactose, casein micelles. The behavior of whey proteins under HPP is very important...
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Oxychlorination of organic compounds
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Organohalogen compounds in the environment.
PublikacjaPrzedyskutowano problem związków chloroorganicznych w środowisku, takich jak: pestycydy chloroorganiczne, polichlorowane bifenyle, polichlorowane dibenzodioksyny i furany. Omówiono podstawowe właściwości fizykochemiczne, toksykologiczne oraz ścieżki przemian w środowisku.
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Azo macrocyclic compounds
PublikacjaArtykuł przeglądowy dotyczący azozwiązków makrocyklicznych
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Azo macrocyclic compounds.
PublikacjaArtykuł przeglądowy omawiający głównie syntezę i właściwości związków makrocyklicznych takich jak: etery koronowe, kryptandy, kaliksareny i inne, które połączono z fragmentem zawierającym resztę azobenzenową lub jej analogi. Artykuł napisany został w oparciu o prace własne autorów z lat 1992-2001 oraz na podstawie literatury obcej zebranej na podstawie Chemical Abstracts z lat 1990-2001.
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Novel Quaternary TlGaSn2Se6 Single Crystal as Promising Material for Laser Operated Infrared Nonlinear Optical Modulators
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Stable nanoconjugates of transferrin with alloyed quaternary nanocrystals Ag–In–Zn–S as a biological entity for tumor recognition
PublikacjaOne way to limit the negative effects of anti-tumor drugs on healthy cells is targeted therapy employing functionalized drug carriers. Here we present a biocompatible and stable nanoconjugate of transferrin anchored to Ag-In-Zn-S quantum dots modified with 11-mercaptoundecanoic acid (Tf-QD) as a drug carrier versus typical anticancer drug, doxorubicin. Detailed investigations of Tf-QD nanoconjugates without and with doxorubicin...
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Preliminary Results from the Removal of Phosphorus Compounds with Selected Sorption Material
PublikacjaDue to the resources of phosphorous are limited and are exhausted in the next 30 years the management of the resources is become current issue. Most of the phosphorus compounds is lost forever, because it is discharged with sewage into surface waters, causing eutrophication and in this way causing a further problem and challenge. On the other hand, there is a considerable need for phosphorus compounds, primarily in bioavailable...
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Phytoecdysteroid containing plants – a source of bioactive compounds with potential anticarcinogenic effects
PublikacjaEcdysteroids are a group of steroids synthesized in inver- tebrates as molting hormones and also in some plants as secondary metabolites acting as a defense against parasites. These compounds do not naturally occur in mammals and are not structurally related to mammalian steroid hor- mones, consequently do not activate mammalian hormone receptors. Ecdysteroids exhibit very low toxicity to mam- mals and to date no serious side effects...
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Nutritional and Pharmaceutical Properties of Bioactive Compounds in Organic and Conventional Growing Kiwifruit
PublikacjaThe bioactivity of two kiwifruit’s cultivars growing under organic and conventional conditions were studied and compared. The bioactive compounds were extracted with water and ethanol using similar conditions which are applied in pharmaceutical applications and for daily fruit consumption such as tea drink. Antioxidant radical scavenging assays [ferric-reducing/antioxidant power (FRAP); cupric reducing antioxidant capacity (CUPRAC);...
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Determination of Surfactants in Environmental Samples. Part III. Non-Ionic Compounds
PublikacjaNon-ionic surface active agents are a diverse group of chemicals which have an uncharged polar head and a non-polar tail. They have different properties due to amphiphilic structure of their molecules. Commercial available non-ionic surfactants consist of the broadest spectrum of compounds in comparison with other types of such agents. Typically, non-ionic compounds found applications in households and industry during formulation...
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The speciation of organotin compounds in sediment and water samples from the port of Gdynia
PublikacjaOrganotin compounds (OTC) are toxic towards all living organisms. The application of organitin-based antifouling systems is becoming the main source of OTC in the ocean. Harbor sediments and water contain large deposits of organotin compounds due to application of antifouling systems in the shipping industry. OTC contamination presents a potential risk to the marine environment. Sediment and water samples were collected in 2009...
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Synthesis and properties of HoT2Al20 (T = Ti, V, Cr) intermetallic cage compounds
PublikacjaPolycrystalline samples of HoT2Al20 (T = Ti, V, Cr) intermetallics were synthesized using a step-wise arc-melting technique. All three compounds adopt the CeCr2Al20-type crystal structure with Ho atoms positioned inside oversized icosahedral cages formed by Al atoms. The structure of HoV2Al20 compound is reported. The materials properties were studied by means of electrical resistivity, magnetic susceptibility, and specific heat...
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Biologically active compounds based on the carbazole scaffold - synthetic and mechanistic aspects
PublikacjaDoctoral dissertation is divided into three main parts: introduction, results and discussion and experimental. The introduction is divided into four main parts which describe: 5-hydroxytryptamine receptors, the most popular antidepressants, new compounds based on the carbazole structure with affinity for serotonin receptors, telomeres and telomerase with their functions, telomerase inhibition strategies, carbazoles approved in...
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Identification of aromatic compounds in odours mixture by gas chromatography and field olfactometry techniques
PublikacjaThis paper shows the results of investigation on identification aromatic compounds present in odorous mixture in atmospheric air samples collected in a vicinity of the oil refinery LOTOS S.A., located in Gdansk, during March and April period have be presented. The studies were conducted by the use of comprehensive two-dimensional gas chromatograph equipped with a cryogenic modulator and coupled with a time-of-flight mass spectrometer,...
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Superconductivity in Bismuth Pyrochlore Lattice Compounds RbBi2 and CsBi2: The Role of Relativistic Effects
PublikacjaSuperconducting properties of two bismuthide intermetallic compounds, RbBi2 and CsBi2, were studied by means of experimental measurements and ab initio calculations. We show that in both compounds, the superconductivity emerges from the pyrochlore Bi lattice and its formation is heavily influenced by relativistic effects. Based on our analysis of the effect of spin–orbit coupling on the electron–phonon coupling, we suggest a possible...
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The role of the sawage treatment plant in the removal of genotoxic compounds from the environment
PublikacjaOne reason for increased incidence of various types of cancer are environmental pollutants particularly of anthropogenic origin. All human activities may pollute the environment, but some have significant impact, just to mention energy industry, mining, transportation, chemical and petrochemical industries and housing. Environmental pollutants are a large group of compounds in terms of their physicochemical properties, some of...