Filtry
wszystkich: 709
wybranych: 619
Wyniki wyszukiwania dla: SPEKTROFOTOMETRIA UV-VIS
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Hydrothermal modification of TiO2 nanotubes in water and alkali metal electrolytes (LiNO3, NaNO3, KNO3) – Direct evidence for photocatalytic activity enhancement
PublikacjaThe influence of hydrothermal annealing (HA) of TiO2 nanotubes (TiO2-NTs) in various baths (H2O, LiNO3, NaNO3, KNO3 performed for 4 h, 24 h, 64 h), on their photocatalytic and photoelectrocatalytic properties, was studied. The use of electrolytes was to enable the monitoring of photoactivity changes as a result of the expected impact on the population of hydroxyl groups on the surface. The assumption turned out to be correct and...
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Photocatalytic activity of zinc oxide nanorods incorporated graphitic carbon nitride catalyst
PublikacjaBackground Photocatalysts are user-friendly and serve as compatible materials for degrading industrial dye pollutants. This study utilizes zinc oxide/graphitic carbon nitride (ZnO/g-C3N4) nanocomposites against degrading methylene blue (MB). Methods The hydrothermal method assisted sonication technique was used to fabricate the ZnO/g-C3N4 composite with varying ratios of ZnO/g-C3N4 (1:0.25, 1:0.50, 1:1). The synthesized materials...
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The effect of gold shape and size on the properties and visiblelight-induced photoactivity of Au-TiO2
PublikacjatIn the present investigation, TiO2modified with a different geometry and size of gold particles, suchas nanospheres (NSPs), nanostars (NSTs) and nanorods (NRs), were prepared by the immobilizationmethod. The effect of the gold shape, size and TiO2matrix type (TiO2microspheres or rutile TIO-6 TiO2)were systematically investigated. The obtained photocatalysts were thoroughly characterized by UV–visdiffuse-reflectance spectroscopy...
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In vivo imaging of the human eye using a two-photon excited fluorescence scanning laser ophthalmoscope
PublikacjaBACKGROUND. Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans...
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Embedded gas sensing setup for air samples analysis
PublikacjaThis paper describes a measurement setup (eNose) designed to analyze air samples containing various volatile organic compounds (VOCs). The setup utilizes a set of resistive gas sensors of divergent gas selectivity and sensitivity. Some of the applied sensors are commercially available and were proposed recently to reduce their consumed energy. The sensors detect various VOCs at sensitivities determined by metal oxide sensors’ technology...
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A new method and equipment for the detection of presence and estimation of the content of the petroleum-based fraction in lubricating oils, especially those emitted to the atmosphere
PublikacjaLubricating oil, used in cutting equipment, works in the so-called open lubrication system and is entirely emitted to the environment. When such an oil contains even a small portion of the crude oil-derived fraction, which is still very common, the oil is a serious environmental pollution. In addition, the oil mist poses a serious threat to the health of employees. Current legal regulations require users of saws and harvesters...
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Nowe rozwiązania metodyczne i aparaturowe w zakresie analityki zanieczyszczeń środowiska
PublikacjaDążność do opracowania coraz to nowszych metod analitycznych umożliwiających wykrywanie i oznaczanie analitów występujących w próbkach środowiskowych na niskich poziomach zawartości stanowi nie lada wyzwanie dla współczesnych chemików - analityków. Ogromne znaczenie dla jakości uzyskiwanych wyników analitycznych i ich przydatności dla podejmowania decyzji w zakresie ochrony środowiska i gospodarki ma etap przygotowania próbek....
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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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Characterization and Technical Application of Fine Photocatalytical Particles - A Study of the Immobilization of Photocatalysts
PublikacjaThe main aim of this dissertation was the transfer of photocatalytical laboratory scale experiments to semi-technical scale. Preliminary experiments of the purification of organic chlorine-loaded waters and the immobilization of photocatalysts were performed, which yielded the research back to the roots of synthesis. The first applied research was carried out on treatment of recreational water. Several light sources, particularly...
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Comet assay-based methods for measuring DNA repair in vitro; estimates of inter- and intra-individual variation.
PublikacjaZdolność do naprawy uszkodzeń DNA jest jednym z najważniejszych wyznaczników podatności na choroby nowotworowe. Dlatego też użytecznym staje się możliwość pomiaru stopnia naprawy DNA w próbkach materiału badawczego pobranego od ochotników. Celem pracy było, po pierwsze, opracowanie w warunkach in vitro prostej metody (z wykorzystaniem techniki testu kometowego), w której naprawa DNA odbywa się poprzez wycinanie nukleotydów (NER)....
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Catalysts for advanced oxidation processes: Deep eutectic solvents-assisted synthesis – A review
PublikacjaNew catalyst synthesis techniques, including green materials, are extensively studied for heterogeneous photocatalytic advanced oxidation processes (AOPs) on spotlight of sustainable development. Deep eutectic solvents (DESs) started to be used in this field as environmentally friendly alternative to ionic liquids (ILs). During the catalyst synthesis, DESs can act as stabilizers, capping agents, structure directing agents, templates,...
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Metabolomic and antioxidant properties of different varieties and origins of Dragon fruit
PublikacjaDragon fruit has appealed much concern from consumers as a novelty fruit with potent nutritional and medicinal benefits. Dragon fruit quality warrants comprehensive evaluation, based on the contents of pigments and health- promoting natural compounds in different varieties. This study was aimed to evaluate the differences among dragon fruit varieties extracted with methanol–water (CD3OD-D2O) and methanol (CD3OD) by proton nuclear magnetic...
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A new simple approach to prepare rare-earth metals-modified TiO2 nanotube arrays photoactive under visible light: Surface properties and mechanism investigation
PublikacjaApplication of Ti90RE10 alloys (RE = Ho, Er, Nd, Y, Ce, Tm) as a working electrode, instead of Ti pure foil in anodic oxidation in a fluoride-based electrolyte, resulted in formation of well-ordered nanotubes made of TiO2 and RE2O3 mixture, which could be efficiently used for pollutant removal from water and air phase upon UV and visible irradiation and easily separable from the reaction mixture to recycle. The as-prepared NTs...
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Ionic liquids for nano- and microstructures preparation. Part 2: Application in synthesis
PublikacjaIonic liquids (ILs) are widely applied to prepare metal nanoparticles and 3D semiconductor microparticles. Generally, they serve as a structuring agent or reaction medium (solvent), however it was also demonstrated that ILs can also play a role of a co-solvent, metal precursor, reducing as well as surface modifying agent. The crucial role and possible types of interactions between ILs and growing particles have been presented in...
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Chemical investigation on the mechanism and kinetics of the atmospheric degradation reaction of Trichlorofluoroethene by OH⋅ and Its subsequent fate in the presence of O2/NOx
PublikacjaThe M06-2X/6-311++G(d,p) level of theory was used to examine the degradation of Trichlorofluoroethene (TCFE) initiated by OH⋅ radicals. Additionally, the coupled-cluster single-double with triple perturbative [CCSD(T)] method was employed to refine the single-point energies using the complete basis set extrapolation approach. The results indicated that OH-addition is the dominant pathway. OH⋅ adds to both the C1 and C2 carbons,...
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Badania wpływu demulgacji i doboru optymalnego demulgatora na skład fazy gazowej i ciekłej ścieków pooksydacyjnych
PublikacjaOczyszczanie ścieków pooksydacyjnych, pochodzących z oksydacji pozostałości z destylacji próżniowej ropy naftowej i produkcji tzw. asfaltów utlenianych, szczególnie drogowych, a także przemysłowych, stanowi duży problem technologiczny i środowiskowy. Wynika to z obecności w ściekach różnych grup związków organicznych, w tym m.in. organicznych związków siarki, tlenu i azotu. Pewna ich część jest zaabsorbowana w wodzie i częściowo...
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Predicting sulfanilamide solubility in the binary mixtures using a reference solvent approach
PublikacjaBackground. Solubility is a fundamental physicochemical property of active pharmaceutical ingredients. The optimization of a dissolution medium aims not only to increase solubility and other aspects are to be included such as environmental impact, toxicity degree, availability, and costs. Obtaining comprehensive...
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Występowanie surfaktantów w próbkach środowiskowych
PublikacjaOd czasu wytworzenia pierwszego syntetycznego surfaktantu naukowcy wprowadzali wiele zmian w ich składzie, które miały na celu poprawę działania preparatów oraz zmniejszanie ich negatywnego oddziaływania na poszczególne elementy środowiska. Obecnie surfaktanty stosowane są zarówno jako środki piorące, myjące, czyszczące (chemia gospodarcza, kosmetyki) oraz w przemyśle spożywczym,włókienniczym, metalurgicznym, rafineryjnym, petrochemicznym,...
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Nanoparticles preparation using microemulsion systems
PublikacjaMetallic nanoparticles become of current interests because they exhibit unique properties compared with those of metal atoms or bulk metal due to the quantum size effect and their large surface area, which make them attractive for applications in optics, electronics, catalysis biology and medicine. TiO2 has been used for environmental remediation purposes such as in the purification of water and air and also solar-to chemical energy...