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Search results for: LEWIS ACIDS
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Study of pH and temperature effect on lipophilicity of catechol-containing antioxidants by reversed phase liquid chromatography
PublicationLipophilicity of selected antioxidant phytochemicals, including flavonoids, phenolic acids and xanthonoids, was determined by reversed phase high performance liquid chromatography with UV detection (RP-HPLC-UV). The analyses run at different temperature and pH conditions in isocratic mode suggested that lipophilicity as distribution coefficient (logD) between aqueous and organic phase decreases with increasing temperature. For...
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Comparative Study on Assisted Solvent Extraction Techniques for the Extraction of Biologically Active Compounds from Sideritis raeseri and Sideritis scardica
PublicationThe plants in the Sideritis genus are postulated to exhibit several important medicinal properties due to their unique chemical composition. To isolate the targeted phytochemical compounds, the selection of a suitable extraction method is of primary importance. In this work, a comparative study on the phytochemical profiles of various Sideritis raeseri and Sideritis scardica extracts has been carried out. An untargeted metabolomics...
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Nonprotein nitrogenous compounds
PublicationThe non-protein nitrogen (NPN) fraction is an important group of food components for both technological and nutritional reasons. Free amino acids (FAAs), oligopeptides, amines, nucleic acids, and nucleotides, as well as other low-molecular nitrogen-containing components (cyanogenic glycosides, alkaloids, thiazoles, oxazoles, pyrroles, and pyrazines), are found in most foods. Their content depends on many factors, starting from...
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Pochodne kwasu neopentylidenofosforoditiowego jako substraty do syntezy ugrupowania trisulfidowego
PublicationBadania przeprowadzone w Katedrze Chemii Organicznej Wydziału Chemicznego Politechniki Gdańskiej na przestrzeni ostatnich kilku lat, pokazały wszechstronność pochodnych kwasu neopentylidenofosforoditiowego [32] w syntezie symetrycznie i niesymetrycznie podstawionego ugrupowania disulfidowego. Wyniki powyższych badań doprowadziły do opracowania nowej strategii syntetycznej, umożliwiającej otrzymywanie...
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Opracowanie dogodnej metody tworzenia wiązań S-C o hybrydyzacji atomu węgla sp oraz sp2
PublicationBadania przeprowadzone w Katedrze Chemii Organicznej Wydziału Chemicznego Politechniki Gdańskiej na przestrzeni ostatnich kilku lat, pokazały wszechstronność pochodnych kwasu neopentylidenofosforoditiowego. Dotychczasowe wyniki badań doprowadziły mnie do opracowania nowych strategii syntetycznych, umożliwiających otrzymywanie związków zawierających wiązanie C-S o hybrydyzacji atomu węgla sp oraz sp2. Analizując wyniki badań opracowałam...
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Anomalous Behavior of Hyaluronan Crosslinking Due to the Presence of Excess Phospholipids in the Articular Cartilage System of Osteoarthritis
PublicationLubrication of articular cartilage is a complex multiscale phenomenon in synovial joint organ systems. In these systems, synovial fluid properties result from synergistic interactions between a variety of molecular constituent. Two molecular classes in particular are of importance in understanding lubrication mechanisms: hyaluronic acid and phospholipids. The purpose of this study is to evaluate interactions between hyaluronic acid...
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4- (Tri-tert-butoxysilylthiomercurio)benzoic acid. Acta Cryst. Sect. E Struct. Rep. [online]**2003 vol. 59 s. m125-m127, 2 rys. 2 tab. bibliogr. 12 poz. Kwas 4-(tri-tert-butoksysililotiortęcio)benzoesowy.
PublicationTytułowy związek otrzymano poprzez reakcję kwasu 4-hydroksyrtęciobenzoesowe-go z tri-tert-butoksysilanotiolem. Przy użyciu rentgenowskiej analizy struk-turalnej monokryształów wyznaczono strukturę cząsteczkową i krystaliczną te-go związku.
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Surface Treatment of Rubber Waste
PublicationThis chapter deals with the study of different approaches to improve the compatibility of waste rubber with polymeric matrixes of high density polyethylene (HDPE) by using surface treatments to increase adhesion. Different surface treatments such as etching with sulphuric and nitric acids, the use of a silane as a coupling agent and chlorination with trichloroisocyanuric acid (TCI) have been applied. The modification of waste rubber...
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Two highly thermostable paralogous single-stranded DNA-binding proteins from Thermoanaerobacter tengcongensis
PublicationThe thermophilic bacterium Thermoanaerobacter tengcongensis has two single-stranded DNA-binding (SSB) proteins, designated TteSSB2 and TteSSB3. In a SSB complementation assay in Escherichia coli, only TteSSB3 took over the in vivo function of EcoSSB. We have cloned the ssb genes obtained by PCR and have developed E. coli overexpression systems. The TteSSB2 and TteSSB3 consist of 153 and 150 amino acids with a calculated molecular...
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Identification and properties of the psychrophilic bacterium Desulfolatea psychrophila single-stranded DNA binding proteins
PublicationTo study the biochemical properties of SSB from Desulfolatea psychrophila (DpsSSB), we have cloned the ssb genes obtained by PCR and have developed Escherichia coli overexpression systems. The gene consists of an open reading frame of 426 nucleotides encoding SSB protein of 142 amino acids with a calculated molecular mass of 15.6 kDa and it is the smallest known bacterial SSB protein indentified to date. The amino-acid sequence...
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The effect of lyophilization on selected biologically active components (vitamin c, catalase, lysozyme), total antioxidant capacity and lipid oxidation in human milk
PublicationHuman milk is rich in polyunsaturated fatty acids, as well as lysozyme, vitamin C and other bioactive compounds. The effect of lyophilization on the content of antioxidants (vitamin C and catalase CAT), bactericidal compounds (lysozyme), total antioxidant capacity (TAC) and lipid peroxidation in human milk was investigated in this study. Samples of mature human milk were collected from five healthy women who gave birth on the scheduled...
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Design and synthesis of TiO2/Ti3C2 composites for highly efficient photocatalytic removal of acetaminophen: The relationships between synthesis parameters, physicochemical properties, and photocatalytic activity
PublicationIn this study, we report the potential of TiO2/Ti3C2 composite fabricated by oxidation of MXene for degradation of persistent organic pollutants. The effect of the synthesis conditions (time, temperature, and reaction environment) on the morphology, physicochemical properties, and photocatalytic activity was investigated. It was found that acetaminophen degradation was positively correlated with TiO2 content in the composite structure. Furthermore,...
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System oceny efektywności użytkowania aparatów słuchowych
PublicationCelem rozprawy jest opracowanie metody oceny efektywności protezowania słuchu przy użyciu aparatów słuchowych, która pozwoli w łatwy sposób poddawać ocenie korzyść z użytkowania protez słuchowych w najbardziej typowych sytuacjach akustycznych. Przedstawiono genezę podjętych badań i na tej podstawie zaproponowano cele i tezy rozprawy doktorskiej. W pracy w pierwszej kolejności zawarto przegląd dotyczący rodzajów ubytku słuchu i...
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Local electrochemical impedance spectroscopy in dynamic mode of galvanic coupling
PublicationA novel method that combines local electrochemical impedance spectroscopy and mapping in dynamicmode is proposed. Method was validated over two galvanic couplings, namely zinc/copper and cad-mium/copper. Impedance spectrum response for all measuring points was obtained by means ofsimultaneous implementation of selected range of frequencies. Proposed method allows the measure-ment in a more time-efficient manner, at the same time...
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XRD patterns of V2O5 thin films deposited on isotropic etching silicon substrates (111)
Open Research DataThe DataSet contains the XRD patterns of V2O5 thin films deposited on isotropic etching silicon substrates (111). The silicon wafers were etched in a mixture of nitric acid, hydrofluoric acid, and acetic acid in the ratio of 40:1:15. The soaking time for the substrates was from 30 to 90 seconds. The thin films were obtained by the sol-gel method. ...
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SEM micrographs of V2O5 thin films deposited on isotropic etching silicon substrates (111)
Open Research DataThe DataSet contains the scanning electron microscopy (SEM) micrographs of V2O5 thin films deposited on isotropic etching silicon substrates (111). The silicon wafers were etched in a mixture of nitric acid, hydrofluoric acid, and acetic acid in the ratio of 40:1:15. The soaking time for the substrates was from 30 to 90 seconds. The thin films were...
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Scarabaeidae as human food – A comprehensive review
PublicationRising global population and sustainable protein demand have sparked interest in unique food sources. Entomophagy, or insect consumption, presents a solution and Scarab beetles, part of the Scarabaeidae family, offer a novel food option. The comprehensive review underscores their potential as human food, with strong nutrition, low environmental impact, and the ability to ease strain on conventional agriculture. Nutritional analysis...
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A new B-D-galactosidase with a low temperature optimum isolated from the Antarctic Arthrobacter sp. 20B: gene cloning, purification and characterization.
PublicationA psychrotrophic bacterium producing a coldadaptedB-galactosidase upon growth at low temperatureswas classiWed as Arthrobacter sp. 20B. A genomic DNAlibrary of strain 20B introduced into Escherichia coliTOP10F' and screening on X-Gal (5-bromo-4-chloro-3-indolyl-B-D-galactopyranoside)-containing agar plates ledto the isolation of B-galactosidase gene. The B-galactosidasegene (bgaS) encoding a protein of 1,053 amino acids,with a...
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Novel single-stranded DNA-binding protein from psyvhrophilic bacterium Psychrobacter arcticus
PublicationTo study the biochemical properties of SSB from Psychrobacter arcticus (ParSSB), we have cloned the ssb genes obtained by PCR and have developed Escherichia coli overexpression systems. The gene consists of an open reading frame of 642 nucleotides encoding SSB protein of 213 amino acids with a calculated molecular mass of 22.8 kDa. The amino-acid sequence of ParSSB exhibits 49% identity and 57% similarity to Escherichia coli SSB....
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Green monoterpenes based deep eutectic solvents for effective BTEX absorption from biogas
PublicationThe combustion of biogas which contains significant amounts of monoaromatic hydrocarbons, i.e. benzene, ethylbenzene, toluene, and xylene (BTEX) can cause many technological, environmental, and health problems. Therefore, in these studies, a new physical absorption method based on deep eutectic solvents (DES) consisting of monoterpenes and carboxylic acids was developed for BTEX removal. A total of 39 DES were synthesized, of which...
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Bacterial cellulose vs. bacterial cellulose nanocrystals as stabilizer agents for O/W pickering emulsions
PublicationThe growing interest in Pickering emulsions in functional food systems resulted in the need to find suitable stabilizers for them. The work considers the use of bacterial cellulose for this purpose, and its aim was to compare the properties of disintegrated bacterial cellulose, before and after freeze-drying, and its nanocrystals obtained using H2SO4 under variable of time and concentration conditions. The structure of nanocrystals...
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Synthesis and polymerisation techniques of molecularly imprinted polymers
PublicationMolecularly Imprinted Polymers (MIPs) are materials that has been processed using the molecular imprinting technique which permit to obtain well-defined three-dimensional cavities, with affinity to a template molecule, in the polymer matrix. Technology involves three strategies, i.e., covalent, non-covalent and semi-covalent approach, but the most popular is non-covalent approach. The most important components for the synthesis...
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The transition of HIV within and between affected populations in Poland
PublicationThe aim of the paper is the estimation of probabilities that describe the transition of HIV within and between the following three populations: homosexual and bisexual men, injecting drug users and heterosexual persons in Poland in the years 1995-2006
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Assessment of urinary cystatin C levels in HIV-1-infected patients with preserved kidney function
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Phytochemical screening and biological evaluation of Greek sage (Salvia fruticosa Mill.) extracts
PublicationThis study explores the influence of extraction solvents on the composition and bioactivity of Salvia fruticosa extracts. Ultrasound-assisted extraction with water, ethanol and their mixtures in variable proportions was used to produce four different extracts. An untargeted UPLC/MS‑based metabolomics was performed to discover metabolites profile variation between the extracts. In the analyzed samples, 2704 features had been detected,...
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The Use of Artificial Neural Networks and Decision Trees to Predict the Degree of Odor Nuisance of Post-Digestion Sludge in the Sewage Treatment Plant Process
PublicationThis paper presents the application of artificial neural networks and decision trees for the prediction of odor properties of post-fermentation sludge from a biological-mechanical wastewater treatment plant. The input parameters were concentrations of popular compounds present in the sludge, such as toluene, p-xylene, and p-cresol, and process parameters including the concentration of volatile fatty acids, pH, and alkalinity in...
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INVESTIGATION OF ACIDIC SOLUTIONS BY POTENTIOMETRIC TASTE SENSOR WITH ALL SOLID STATE ELECTRODES
PublicationPotentiometric taste sensors with electrodes containing lipophilic compound / polymer membranes were already used to distinguish commercial liquid products. In this paper a new potentiometric taste sensor consisting of six All Solid State Electrodes (ASSEs) has been presented. Each of the membrane contains a selected lipophilic compound. The set-up consists of a reference electrode and six ASSEs. The inner layer made of a conducting...
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Cytotoxicity of chitosan hydrogels aginst L929 cells
Open Research DataThis study presents absorbance values of formazan product (converted from MTT) which corresponds to the cytotoxicity of chitosan compounds (dissolved in carbonic acid, dissolved in carbonic acid endotoxin free, and dissolved in hydroxyacetic acid) aginst adult mouse fibroblast L929 cells. The experiments were carried out according to the ISO 10993-5:2009(E)...
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Mechanism of Isomerization and Acid-Induced Transformations of 3-Hydroxy-4,4'-dimethoxy-3'-methyl-3-oxo-7,7'-bis(piperidino-carbonyloxy)-2,2'-spirobi-[2H,2'H,3H,3'H-benzo[b]thiophene]. Unusual Equilibrium between the Spiro and 3-Hydroxy-benzothiophene Systems.
PublicationStwierdzono, że 3'-hydroksy-4,4'-dimetoksy-3'-metylo-3-okso-7,7'-bis(piperydynokarbonyloksy)-2,2'-spirobi[2H,2'H,3H,3'H-benzo[b]tiofen] występuje w roztworach postaci mieszaniny dwóch diastereoizomerów pozostających w dynamicznej równowadze. Mechanizm tej równowagi oparty jest na odwracalnym otwarciu pierścienia z 1,5 przeniesieniem protonu i utworzeniu przjściowej formy 3-hydroksybenzotiofenu.
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Stability Investigation of the PCM Nanocomposites
PublicationEnsuring the stability is a key issue to be solved for the technical application of nanocomposites. In this work, fatty acid P1801 served as base phase change material (PCM)P1801, and its main ingredients are palmitic acid (58%) and stearic acid (38%). Titania (TiO2) and alumina (Al2O3) with mass concentrations of 1% and 5% were selected as nanoparticles, while polyvinylpyrrolidone (PVP) or oleic acid (OA) with mass concentrations...
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In vitro antioxidative and binding properties of phenolics in traditional, citrus and exotic fruits
PublicationMany polyphenols bind proteins, therefore our research was focused on the potential of protein binding to polyphenols of investigated fruits and their health-related effects. The contents of polyphenols and related antioxidant activities of traditional, citrus and exotic fruits were compared. The presence of polyphenols (flavonoids and phenolic acids) in the investigated samples and their interaction with human serum albumin (HSA)...
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Detection of Bioactive Compounds in Organically and Conventionally Grown Asparagus Spears
PublicationIn the recent reports, there are contradictory conclusions about the nutritional and health properties of organic and conventionally growing vegetables. We hypothesized that organic cultivation system results in higher quality of asparagus (Asparagus officinalis L.) because of organic manure and effective organisms. Therefore, new analytical methods were applied in order to find the differences in bioactive compounds between the...
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Qualitative analysis of phospholipids and their oxidised derivatives – used techniques and examples of their applications related to lipidomic research and food analysis
PublicationPhospholipids (PLs) are important biomolecules that not only constitute structural building blocks and scaffolds of cell and organelle membranes, but also play a vital role in cell biochemistry and physiology. Moreover, dietary exogenous PLs are characterized by high nutritional value and other beneficial health effects, which are confirmed by numerous epidemiological studies. For this reason, PLs are of high interest in lipidomics...
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Chapter 4. Electricity generation from glucose microbial fuel cell
PublicationThe microbial fuel cell was constructed to generate electricity with simultaneous digestion of a glucose fuel by a bacterial biofilm. The decomposition of glucose resulted in releasing of electrons to an anode and to production of some by-products, e.g. metane or organic acids. It was found that maximum electric power density strongly depended on the proton transport through the proton exchange membrane seperating the anolyte and...
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The influence of time of hearing aid use on auditory perception in various acoustic situations
PublicationThe assessment of sound perception in hearing aids, especially in the context of benefits that a prosthesis can bring, is a complex issue. The objective parameters of the hearing aids can easily be determined. These parameters, however, do not always have a direct and decisive influence on the subjective assessment of quality of the patient’s hearing while using a hearing aid. The paper presents the development of a method for...
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Piotr Skurski prof. dr hab.
PeoplePiotr Stanisław Skurski (ur. 25 sierpnia 1969 w Gdańsku) – polski chemik specjalizujący się w chemii kwantowej i fizycznej, profesor nauk chemicznych, profesor zwyczajny Wydziału Chemii Uniwersytetu Gdańskiego, kierownik Katedry Chemii Teoretycznej i Pracowni Chemii Kwantowej na tym wydziale, a także Professor of Chemistry w Henry Eyring Center for Theoretical Chemistry na Uniwersytecie Utah w Stanach Zjednoczonych. W latach 2011-2016 członek...
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GC Chromatograms for isomerization of alpha-pinene
Open Research DataData contain results of the catalytic tests for the isomerization of alpha-pinene for the Ti3C2Tx MXenes produced via acidic etching aluminum from MAX Phase (Ti3C2-Al-Ti3C2-Al-Ti3C2) using different etching agents, HF/HCl and HF/H2SO4 with different weight ratios (1:3, 1:4, and 1:5). The samples were labeled as MXene HF/HCl X:Y and MXene HF/H2SO4 X:Y,...
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TGA data of MXenes catalysts
Open Research DataData contain results from TGA measurement of the Ti3C2Tx MXenes produced via acidic etching aluminum from MAX Phase (Ti3C2-Al-Ti3C2-Al-Ti3C2) using different etching agents, HF/HCl and HF/H2SO4 with different weight ratios (1:3, 1:4, and 1:5). The samples were labeled as MXene HF/HCl X:Y and MXene HF/H2SO4 X:Y, where X:Y means the acids weight ratios. ...
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Adsorption and desorption of N2 measurement of MXenes catalysts
Open Research DataData contain results from adsorption and desorption of N2 measurement of the Ti3C2Tx MXenes produced via acidic etching aluminum from MAX Phase (Ti3C2-Al-Ti3C2-Al-Ti3C2) using different etching agents, HF/HCl and HF/H2SO4 with different weight ratios (1:3, 1:4, and 1:5). The samples were labeled as MXene HF/HCl X:Y and MXene HF/H2SO4 X:Y, where X:Y...
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Characterization of two aminotransferases from Candida albicans
PublicationAminoadipate aminotransferase (AmAA) is an enzyme of α-aminoadipate pathway (AAP) for l-lysine biosynthesis. AmAA may also participated in biosynthesis or degradation of aromatic amino acids and in d-tryptophan based pigment production. The AAP is unique for fungal microorganisms. Enzymes involved in this pathway have specific structures and properties. These features can be used as potential molecular markers. Enzymes catalyzing...
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Synthesis of amides under microwave irradiation
PublicationAmides belong to the most important carboxylic acid derivatives. They are constituents of natural compounds like peptides and proteins. They found applications in many branches of science and industry, especially in pharmaceutical and polymer science. Conventional procedures for amide preparation involve reaction between amine and carboxylic acid or their more active derivatives such as acid chlorides, acid anhydrides or esters....
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Pursuing Analytically the Influence of Hearing Aid Use on Auditory Perception in Various Acoustic Situations
PublicationThe paper presents the development of a method for assessing auditory perception and the effectiveness of applying hearing aids for hard-of-hearing people during short-term (up to 7 days) and longer-term (up to 3 months) use. The method consists of a survey based on the APHAB questionnaire. Additional criteria such as the degree of hearing loss, technological level of hearing aids used, as well as the user experience are taken...
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Colour Terms in Five Linguistic Images of the World: The Semantic Perspective
PublicationSocial and cultural factors shape the linguistic perception of colour. At the same time, colour terms co-create the linguistic image of the world, which allows us to interpret reality and profile our statements and beliefs. This paper presents six basic colour terms: white, black, red, green, yellow, and blue (both as adjectives and as nouns) in the five different linguistic images of the world of the following languages: English,...
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XRD patterns of MXenes catalysts
Open Research DataData contain results from XRD measurements of the Ti3C2Tx MXenes produced via acidic etching aluminum from MAX Phase (Ti3C2-Al-Ti3C2-Al-Ti3C2) using different etching agents, HF/HCl and HF/H2SO4 with different weight ratios (1:3, 1:4, and 1:5). The samples were labeled as MXene HF/HCl X:Y and MXene HF/H2SO4 X:Y, where X:Y means the acids weight ratios....
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Raman spectra of MXenes catalysts
Open Research DataData contain results from Raman spectroscopy of the Ti3C2Tx MXenes produced via acidic etching aluminum from MAX Phase (Ti3C2-Al-Ti3C2-Al-Ti3C2) using different etching agents, HF/HCl and HF/H2SO4 with different weight ratios (1:3, 1:4, and 1:5). The samples were labeled as MXene HF/HCl X:Y and MXene HF/H2SO4 X:Y, where X:Y means the acids weight ratios. ...
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SEM images of MXene catalysts
Open Research DataData contain results SEM measurements of the Ti3C2Tx MXenes produced via acidic etching aluminum from MAX Phase (Ti3C2-Al-Ti3C2-Al-Ti3C2) using different etching agents, HF/HCl and HF/H2SO4 with different weight ratios (1:3, 1:4, and 1:5). The samples were labeled as MXene HF/HCl X:Y and MXene HF/H2SO4 X:Y, where X:Y means the acids weight ratios. MAX...
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Detection of UPEC IH11128 ability to form biofilm in a standard congo red (CR) method of colony staining.
Open Research DataA standard method of testing E. coli's ability to form biofilm is based on the analysis of morphologyof bacterial colonies grown on yeast extract/casamino acids (YESCA) nutrient agar medium containing congored (CR) as an indicator dye of ECM production. The CR dye adsorbed from the culture medium bybacteria binds to the components of the ECM, including...
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Observing its long-term effects on a short-term, multi-day evaluation of the effectiveness of hearing aid use
PublicationThe main objective of the research study was to develop a method for evaluating the effectiveness of hearing protection with hearing aids tailored to the needs and prevailing conditions in the acoustic environments where the elderly most often reside. The method was also intended to estimate the benefits of hearing aids and allow prediction of such an effect based on a short-term trial. It is noteworthy that a short-term evaluation...
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The effect of exogenous application of methyl jasmonate on the lipid and carbohydrate content and composition of winter triticale (Triticosecale Wittm.) grain and the severity of fungal infections in triticale plants and grain
PublicationKernels of winter triticale (Triticosecale Wittm. cv. Dinaro) were analyzed. In the autumn of 2015, the effect of methyl jasmonate (MJ) on the germination of triticale kernels and the development of triticale seedlings was analyzed in a laboratory before kernels were sown in experimental plots. Kernels harvested from plots in August 2016 were analyzed to determine their lipid and carbohydrate content and composition and the severity...
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Cavitation-based technologies for pretreatment and processing of food wastes: Major applications and mechanisms – A review
PublicationConversion of food wastes to valuable products is an important topic for sustainable development. Feedstock hydrolysis is a stage strongly affecting the anaerobic digestion process, and resistance of food waste towards hydrolysis causes a decrease in product yield. Such as biomethane, biohydrogen, biohythane, VFAs, and lactic acids. Moreover, mass transfer is a serious limitation of transesterification for the production of biodiesel....