Filters
total: 1668
filtered: 1481
-
Catalog
Chosen catalog filters
displaying 1000 best results Help
Search results for: RADIOWAVE PROPAGATION
-
Ionic liquids for nano- and microstructures preparation. Part 1: Properties and multifunctional role
PublicationIonic liquids (ILs) are a broad group of organic salts of varying structure and properties, used in energy conversion and storage, chemical analysis, separation processes, as well as in the preparation of particles in nano- and microscale. In material engineering, ionic liquids are applied to synthesize mainly metal nanoparticles and 3D semiconductor microparticles. They could generally serve as a structuring agent or as a reaction...
-
New Trends in Sample Preparation Techniques for the Analysis of the Residues of Pharmaceuticals in Environmental Samples
PublicationPharmaceutical 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...
-
Preparation and characterization of Pt–N/TiO2 photocatalysts and their efficiency in degradation of recalcitrant chemicals
PublicationSeries of Pt–N/TiO2 photocatalysts were synthesized using the sol–gel method. The photocatalysts’ characteristics by X-ray diffractometry (XRD), scanning transmission electron microscopy (STEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) showed that sample with the molar ratio Ti:N equal 1:4 and platinum nanoparticles size of about 3 nm had anatase structure, about 94 m2/g specific surface area...
-
Preparation and characterization of silk fibroin/collagen sponge modified by chemical cross-linking
Publication -
Effect of preparation method on the properties of potato starch acetates with an equal degree of substitution
Publication -
The methodology of technical due diligence report preparation for an office, residential and industrial buildings
Publication -
Toward the preparation of the HAuF6 , HAu2 F11 , and HAu3 F16 superacids: Theoretical study
Publication -
New preparation of a carbon-TiO2 photocatalyst by carbonization of n-hexane deposited on TiO2
Publication -
A new method for preparation of rutile phase titania photoactive under visible light
Publication -
Preparation of silver nanoparticles in reverse micelles and antibacterial activity of silver modified-paints
PublicationW publikacji została opisana metoda otrzymywania nanocząstek srebra oraz farb modyfikowanych srebrem i ich wpływ na zahamowanie rozwoju wybranych bakterii i grzybów. Podjęto również próbę porównania wpływu rodzaju prekursora srebra oraz substancji powierzchniowo czynnej na stabilność otrzymanych nanocząstek srebra. Przygotowane mikroemulsje zawierały od 500 do 2000 ppm srebra
-
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...
-
The influence of the substrate temperature on the preparation of DNA films for studies under vacuum conditions
PublicationPrzeanalizowano wpływ temperatury na formowanie warstw DNA. Sprawdzono wpływ stabilizatorów na jakość otrzymanych próbek. Stwierdzono, że optymalnymi warunkami przygotowywania filmów do badań w warunkach próżniowych jest - 10 st. C przy minimalnej zawartości NaOH.
-
Chapter 31. Preparation of silver doped titanium dioxide nanoparticles in microemulsion system
PublicationNanocząstki TiO2 domieszkowanego srebrem przygotowano w mikroemulsji woda-AOT-cykloheksan. Zbadano wpływ zawartości srebra (od 1,5 do 8,5% mol.) na aktywność fotokatalityczą oraz właściwości bakterio- i grzybobójcze. Stwierdzono, że TiO2 modyfikowany za 6,5% mol. Ag wykazuje najwyższą aktywność w reakcji degradacji fenolu oraz najwyższą aktywność mikrobiologiczną. Aktywność mikrobiologiczną wyznaczano jako minimalne stężenie hamujące...
-
Quechers sample preparation method variants for analysis of pesticide residues in fruits and vegetables
PublicationThis 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...
-
Preparation of porous TiO2 films by means of pulsed laser deposition for photocatalytic applications
PublicationIn this work the preparation and structure properties of porous thin films of TiO2 were investigated. The films were produced by means of the pulsed laser deposition technique using laser pulses at 266nm (10Hz) and at fluencies of 1-3.5J/cm2. The process was performed in vacuum using O2 buffer gas and films were deposited on the SiO2 glass or Si substrate. X-ray diffraction (XRD) and Raman analysis of the structure and chemical...
-
Influence of Preparation Procedure on Physicochemical and Antibacterial Properties of Titanate Nanotubes Modified with Silver
Publication -
Silybum marianum glycerol extraction for the preparation of high-value anti-ageing extracts
Publication -
Preparation of TiO2-based catalysts modified with thioacetamide and thiourea for visible light photocatalysis
PublicationZa pomocą dwóch różnych metod preparatyki przygotowano aktywne w świetle widzialnym katalizatory tytanowe modyfikowane tioacetamidem i tiomocznikiem. Aktywność fotokatalityczną otrzymanych proszków zbadano w reakcji degradacji fenolu w roztworze wodnym w obecności światła widzialnego. Zbadano wpływ ilości zastosowanej w trakcie syntezy domieszki organicznej na aktywność fotokatalityczną otrzymanych katalizatorów. Wybrane próbki...
-
Selenium enrichment in broccoli sprouts as an initial step in the preparation of Certified Reference Material
PublicationSelenium is considered one of the essential elements in animals and humans. The main source of selenium intake for humans is the diet. Selenium deficiency has one of the most concerning issues worldwide. Broccoli sprouts are five-to-six-day old broccoli plants,...
-
Preparation, characterization, and manufacturing of new polymeric materials for 3D printing for medical applications
PublicationThis work concerns the synthesis, formation, and characteristics of new filaments for 3D printing in FDM™/FFF technology for medical purposes. Two types of filaments were developed, i.e. degradable polyurethane and biodegradable polylactide-starch. The influence of the 3D printing process on selected filament properties was investigated. A detailed analysis of the filament formation process by the extrusion method was carried out,...
-
Use of clinoptilolite for the immobilization of heavy metal ions and preparation of autoclaved building composites
Publication -
Preparation and characterization of catalyst mix Fe-Co/MgO for carbon nanotubes growth
Publication -
The influence of the substrate temperature on the preparation of DNA films for studies under vacuum conditions
PublicationExperiments were carried out to determine the dependence of the physical form of supercoiled DNA films on the initial temperature of the substrate. Such films are often used in irradiation experiments involving low energy particles, like electrons or photons. In order to obtain absolute values for cross sections for such experiments, the spatial distribution of the sample in the film has to be well estimated. These investigations...
-
State of the art in sample preparation for human breast milk metabolomics—merits and limitations
PublicationHuman 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...
-
PREPARATION AND CHARACTERIZATION OF CoFe2O4/TiO2-PANI HYBRID NANOCOMPOSITE WITH MAGNETIC AND PHOYOCATALYTIC ACTIVITY
PublicationHybrid nanocomposites consisting of inorganic component and organic conducting polymer are promising materials, which can be applied in heterogeneous photocatalysis. Titanium(IV) oxide is widely used photocatalysts due to its non-toxicity, low cost and chemical stability. The main disadvantage of TiO2 is low photocatalytic activity under visible light. Conducting polymers, also known as conjugated polymers are polymer materials...
-
Preparation of Allyl Alcohol Oligomers Using Dipicolinate Oxovanadium(IV) Coordination Compound
PublicationCurrently, new precatalysts for olefin oligomerization are being sought in the group of vanadium(IV) complexes. Thus, the aim of our research was to examine the catalytic activity of the oxovanadium(IV) dipicolinate complex [VO(dipic)(H2O)2] 2 H2O (dipic = pyridine-2,6-dicarboxylate anion) in 2-propen-1-ol oligomerization as well as to characterize oligomerization products using matrix-assisted laser desorption/ionization–time-of-flight...
-
Preparation and Characterization of Defective TiO2. The Effect of the Reaction Environment on Titanium Vacancies Formation
PublicationAmong various methods of improving visible light activity of titanium(IV) oxide, the formation of defects and vacancies (both oxygen and titanium) in the crystal structure of TiO2 is an easy and relatively cheap alternative to improve the photocatalytic activity. In the presented work, visible light active defective TiO2 was obtained by the hydrothermal reaction in the presence of three different oxidizing agents: HIO3, H2O2, and...
-
Liquefaction of alder wood as the source of renewable and sustainable polyols for preparation of polyurethane resins
PublicationLiquefaction of wood-based biomass gives different polyol properties depending on the reagents used. In this article, alder wood sawdust was liquefied with glycerol and poly(ethylene glycol) solvents. Liquefaction reactions were carried out at temperatures of 120, 150 and 170 °C. The obtained bio-polyols were analyzed in order to establish the process efficiency, hydroxyl number, acid value, viscosity and structural characteristics...
-
The spectral finite element model for analysis of flexural-shear coupled wave propagation. Part 2: Delaminated multilayer composite beam
Publication -
Conducted emi identification in power electronic converters : modeling of EMI generation and propagation using circuit simulation and wiener filtering methods.
PublicationThis work presents the circuit simulations and the conventional signal processing technique (Wiener filtering) in order to reconstruct conducted ElectroMagnetic Interferences (EMI), generated and propagated in power electronics converters. In the simulation study, the most accurate presently available models of components of circuit have been used and improved. The proposed Wiener filtering method allows to identifying the transfer...
-
Corrosion fatigue crack propagation rate characteristics for weldable ship and offshore steels with regard to the influence of loading frequency and seawater temperature
PublicationAfter Vosikovsky (1975), the corrosion fatigue crack growth rate (CFCGR) characteristics have been divided into three regions. The region-III rates are very close to mechanical fatigue crack growth rates. CFCGR formulae, including the long-crack length effect (in region I only), the loading frequency effect (in region II only), and the saltwater temperature effect, have been proposed. It has been assumed that CFCGR is proportional...
-
The spectral finite element model for analysis of flexural-shear coupled wave propagation. Part 2, Delaminated multilayer composite beam
PublicationW pracy przedstawiono, wykorzystując metodę elementów spektralnych, analizę wpływu delaminacji na propagację fali giętno-ścinającej w belce kompozytowej.
-
The spectral finite element model for analysis of flexural-shear coupled wave propagation. Part 1, Laminated multilayer composite beam
PublicationW pracy przedstawiono model spectralnego elementu skończonego umożliwiającego symulację propagacji fali giętno-ścinającej w materiałąch kompozytowych.
-
Preparation, morphology and properties of natural rubber composites filled with untreated short jute fibres
PublicationGreen composites were obtained by incorporation of short jute fibres in natural rubber matrix using a laboratory two-roll mill. The influence of untreated fibre content (1, 2.5, 5, 7.5 and 10 phr) on the mechanical properties, dynamic mechanical properties, swelling properties was examined. The behaviour of prepared green composites under cyclic compression was also investigated. Fibre dispersion in rubber matrix was studied by...
-
Use of electrochemical methods to examine different surface preparation methods for organic coatings on steel
PublicationObróbka strumieniowo - ścierna jest jedną z powszechnie stosowanych metod przygotowania powierzchni. Wśród nowoczesnych metod coraz większe zainteresowanie wzbudza przygotowanie powierzchni wodą pod wysokim ciśnieniem (z ang. waterjetting). W porównaniu z konwencjonalnymi metodami ''waterjetting'' jest nowoczesną oraz przyjazną środowisku metodą. W literaturze brakuje informacji na temat skuteczności owej metody do zastosowań...
-
Preparation of Ag/Cu-doped titanium (IV) oxide nanoparticles in W/O microemulsion
PublicationNanocząstki Cu-TiO2 oraz Ag/Cu-TiO2 otrzymano w mikroemulsji W/O. Właściwości fotokatalityczne zbadano w procesie degradacji fenolu (0,21mM) w zakresie światła widzialnego. Właściwości biobójcze zbadano poprzez wyznaczenie minimalnego stężenia zahamowania wzrostu (MIC) na szczepach bakterii E. coli, St. aureus oraz grzybów S. Cerevisiae i z rodziny Candida. Dla otrzymanych fotokatalizatorów określono wpływ stężenia domieszki metali...
-
Preparation of DNA films for studies under vacuum conditions. The influence of cations in buffer solutions
PublicationBadania zostały przeprowadzone w celu określenia optymalnych warunków wymaganych do przygotowania jednolitych filmów superskręconego plazmidowego DNA do wykorzystania w doświadczeniach napromieniowania w warunkach wysokiej próżni. Badania pokazują, że znaczne szkody w DNA powstają w wyniku odpompowywania filmów DNA z roztworów zawierających jedynie czysta wodę.
-
A Robust Method for Sample Preparation of Gastrointestinal Stromal Tumour for LC/MS Untargeted Metabolomics
Publication -
Ordered TiO2 nanotubes: the effect of preparation parameters on the photocatalytic activity in air purification process
PublicationVertically ordered TiO2 nanotube arrays were synthesized by anodic oxidation of titanium foil in glycerol, ethylene glycol and water-based electrolytes. The effect of electrolyte composition, anodization voltage, ultrasonic treatment and calcination time on the morphology of the resulting thin films, as well as on their photocatalytic activity in toluene removal, used as a model volatile organic compound, was investigated. Toluene,...
-
Thermal Decomposition of Carbamoyl Meldrum’s Acids: A Starting Point for the Preparation of 1,3-Oxazine Derivatives
PublicationThe ability to undergo [4 + 2] versus [2 + 2] cycloaddition was under investigation for ketenes thermally generated from carbamoyl Meldrum’s acid. Usually, 1,3-oxazino-5-carbamoylo-4,6-diones are formed when carbamoyl Meldrum’s acid reacts with imine. However, in some cases, a reaction takes an unexpected course, leading to the formation of tetraponerines alkaloids derivatives or cyclic iminoethers.
-
Preparation and characterization of Langmuir-Blodgett films of 16-membered azobenzocrown ether with naphthalene residue
PublicationOtrzymano i charakteryzowano filmy Langmuira-Blodgett 16-członowej azobenzokorony z resztą naftalenową. Monowarstwy Langmuira były z sukcesem przenoszone na stałe substraty z utworzeniem filmów LB. Filmy osadzone na elektrodach z ITO zostały również użyte jako elektrody w woltametrii cyklicznej i uzyskano rezultaty wskazujące na to, że filmy te wykazują wyraźną odpowiedź na jony metali.
-
Preparation of Internal Standards for 2D-UPLC-MS/MS Quantification of Noncanonical DNA Bases
Publication -
Novel strategy for preparation of highly porous carbon sheets derived from polystyrene for supercapacitors
Publication -
Microwave-assisted preparation of Li3V2(PO4)3/C composite with high-rate capacity
Publication -
Preparation and Characterization of Indomethacin Supramolecular Systems with β-Cyclodextrin in Order to Estimate Photostability Improvement
PublicationCyclodextrins have found wide application in contemporary chemistry, pharmacy andmedicine. Because of their unique properties, cyclodextrins are constantly used in research on solubility or stability improvement, as well as other physicochemical properties of medicinal substances. Indomethacin (IND) is a photolabile molecule that also attracts the interest of researchers due to its therapeutic potential and the need to...
-
Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen
PublicationThis 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...
-
Simple method for preparation of Dialkyl (2,3-dihydro-1,3-thiazol-2-yl)-phosphonates
PublicationAbstract A simple synthesis of dialkyl (2,3-dihydro-1,3-thiazol-2-yl)-phosphonates from thiazoliumsalts and trialkyl phosphites is described. The series of dialkyl (2,3-dihydro-1,3-thiazol-2-yl)-phosphonates with various substituents in positions 3, 4, and 5 of the thiazole ring wereprepared. However, only phosphonates with an aryl on the nitrogen atom were stable enoughfor chromatographic purification, although all the new phosphonates...
-
Determination of volatile organic compounds using solventless sample preparation techniques and gas chromatography
PublicationIn 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...
-
New procedure of silica gel surface modification. Preparation of gaseousstandard mixtures for calibration purposes.
PublicationPrzedstawiono nową procedurę modyfikacji powierzchni żelu krzemionkowego z wykorzystaniem trimetyloaminy jako odczynnika. Próbki chemiczne modyfikowanego nośnika zostały wykorzystane do sporządzenia gazowych mieszanin wzorcowych (chlorek metylu jako składnik mierzony) techniką termicznego rozkładu związków powierzchniowych. Głównym celem badań było sprawdzenia przydatności nowej procedury modyfikacji powierzchni żelu do...
-
An improved preparation of N2-tert-butoxycarbonyl- and N2-benzyloxycarbonyl-(S)-2,4-diaminobutanoic acids.
PublicationN-Benzyloksykarbonylo i N-tert-butoksykarbonylo-(S)-asparaginę przekształcono do odpowiednio chronionego kwasu (S)-2,4-diaminobutanowego z dobrą wydajnością, w reakcji z octanem jodobenzenu w temp. 0 st.C w mieszaninie tetrahydrofuranu i wody.