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Search results for: microwave solvothermal synthesis
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Photocatalytic Synthesis of Chemicals
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Synthesis of malonylenamides and thiomalonylenamides
Publication5-[Hydroksyl(aryl(amino))methylene]-2,2-dimethyl-1,3-dioxane-4,6-dione is convenient source of ketenes which can be trapped with various nucleophiles like alcohols, thiols and amines. In reaction between in situ generated ketene and enolizable imines we can easily obtain corresponding malonylenamides. This facile method can be used to obtain thiomalonylenamides using 5-[sulfhydrylo(alkyl(amino))methylene]-2,2-dimethyl-1,3-dioxane-4,6-dione...
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Electrochemical Synthesis of Photocatalyst
PublicationPonowne wykorzystywanie i recykling fotokatalizatora nanocząsteczkowego jest nie wystarczająco rozwiązanym problem. Powszechnie fotokatalizatory są unieruchomiane przez zol-żel lub zanurzeniowo-powłokowe procedury. Jednak istnieją udokumentowane przypadki wyczerpania fotokatalizatora lub zmniejszenia jego działalności fotokatalitycznej. Synteza elektrochemiczna fotokatalizatora z natychmiastowym unieruchomieniem nie jest własciwie...
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Lipopeptides - synthesis and their properties
PublicationZaprezentowano syntezę nowych pochodnych tripeptydu Gly-Hyp-Lys o potencjalnie lepszych właściwościach lipofilowych. Modyfikacje polegały na acylowaniu N-końca glicyny kwasami tłuszczowymi (np. palmitynowym i stearynowym). Syntezę lipopeptydów zawierających fragment Gly-X-Y (gdzie: X= Met,Hyp,Hyp-Met,Gly-Hyp; Y=Lys,D-Lys) przeprowadzono na fazie stałej z zastosowaniem procedury Fmoc. Do wydłużanie łańcucha peptydowego zastosowano...
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Synthesis of adenosine analogues
PublicationAdenozyna jest endogennym nukleozydem purynowym, który nie tylko stanowi prekursor nukleotydów adeninowych, ale jest także neuromodulatorem odgrywającym istotną rolę w funkcjonowaniu wielu komórek. Swoje działanie ujawnia poprzez wiązanie z receptorami dla adenozyny, których zidentyfikowano do tej pory cztery podtypy: A1, A2A, A2B oraz A3. Należą one do rodziny receptorów sprzężonych z białkami G. Adenozyna znalazła zastosowanie...
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Lipopeptides - synthesis and their properties
PublicationPrzedstawiono syntezę nowych peptydów zawierających Hyp, Met, Gly podstawionych w miejscu histydyny tripeptydu o sekwencji Gly-His-Lys oraz ich odpowiednie modyfikacje na N- i C-końcach. Syntezę zaprojektowanych analogów prowadzono na fazie stałej z zastosowaniem procedury Fmoc. Po otrzymaniu zaplanowanego łańcucha peptydowego metodą karbodiimidową (z zastosowaniem DIC oraz HOBt), przystąpiono do wprowadzania na N-koniec glicyny...
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Emulsifi ers from renewable materials: an eco-friendly synthesis and properties
PublicationThe focus of this study was the preparation of novel bio based polyglycerol emulsifiers characterized by a one pot synthesis, thus by modified properties with respect to interfacial activity and effectiveness as emulsion stabilizers. The final products of the esterification process, carried out in the presence of carboxylates were used directly as emulsifiers (without purification or fractionation). Polyglycerol emulsifiers obtained...
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The synthesis and structure of a potential immunosuppressant: N-mycophenoyl malonic acid dimethyl ester
PublicationThe synthesis of a potential immunosuppressant, i.e. dimethyl ester of N-mycophenoyl malonic acid was optimized in the reaction of mycophenolic acid (MPA) with amino malonic dimethyl ester in the presence of propanephosphonic anhydride (T3P) as a coupling reagent. The structural properties of the obtained MPA derivative were investigated by NMR, MS and single crystal X-ray diffraction methods. Theoretical considerations of conformational...
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On Decision-Making Strategies for Improved-Reliability Size Reduction of Microwave Passives: Intermittent Correction of Equality Constraints and Adaptive Handling of Inequality Constraints
PublicationDesign optimization of passive microwave components is an intricate process, especially if the primary objective is a reduction of the physical size of the structure. The latter has become an important design consideration for a growing number of modern applications (mobile communications, wearable/implantable devices, internet of things), where miniaturization is imperative due to a limited space allocated for the electronic circuitry....
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Synthesis and Characterization of Monometallic (Ag, Cu) and Bimetallic Ag-Cu Particles for Antibacterial and Antifungal Applications
PublicationIn this paper, the experimental studies are concerned with the effect of the synthesis parameters on the formation of monometallic Ag and Cu nanoparticles (NPs). We consider the synthesis strategies verification for the bimetallic core-shell and alloy particles preparation. It was successfully obtained by chemical reduction method. The obtained colloidal solution is characterized by the transmission electron microscopy (TEM) with...
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Voiceless Stop Consonant Modelling and Synthesis Framework Based on MISO Dynamic System
PublicationA voiceless stop consonant phoneme modelling and synthesis framework based on a phoneme modelling in low-frequency range and high-frequency range separately is proposed. The phoneme signal is decomposed into the sums of simpler basic components and described as the output of a linear multiple-input and single-output (MISO) system. The impulse response of each channel is a third order quasi-polynomial. Using this framework, the...
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A new approach to the stereoselective synthesis of trans-3-carbamoyl-b-lactam moieties†
PublicationOne-pot synthesis of optically active 1,4-disubstituted-3-carbamoyl-azetidinones from 5-[(N-arylamino)- (hydroxyl)methylene]-2,2-dimethyl-1,3-dioxa-4,6-diones and chiral aldimines is achieved via thermal generation of carbamoyl ketenes and subsequent [2+2] cycloaddition. Three possible chiral induction approaches were tested and (R)-(+)-1-phenylethylamine was confirmed as the best chiral auxiliary. Among the four possible diastereoisomers,...
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Phosphate tricyclic coumarin analogs as steroid sulfatase inhibitors: synthesis and biological activity.
PublicationIn the present work, we report convenient methods for the synthesis and biological evaluation of phosphate tricyclic coumarin derivatives as potential steroid sulfatase inhibitors. The described synthesis includes the straightforward preparation of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-4-one, 3-hydroxy-7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c]chromen-6-one modified...
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Two complementary approaches for the synthesis and isolation of stable phosphanylphosphaalkenes
PublicationPhospha-Wittig (phosphanylphosphinidene titanium(IV) complex) and phospha-Peterson (lithiated diphosphane) reactions were used to obtain phosphanylphosphaalkenes with the general formula XYC=P-PtBu2 (X = alkyl, aryl group or H; Y = alkyl or aryl group). Therefore, two series of reactions with different ketones and aldehydes were performed. An examination revealed that the two methods are complementary. For smaller carbonyl compounds,...
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A study of the kinetics of bismuth telluride synthesis by an oxide reduction method
PublicationThe kinetics of a reduction of bismuth and tellurium oxides in a hydrogen atmosphere, leading to the formation of thermoelectric bismuth telluride is investigated. The evaluation of the reaction kinetics was based on a thermogravimetric analysis performed in non-isothermal conditions. A non-parametric analysis method and the Friedman method were used for the evaluation of the data. Additionally, for a better understanding of the...
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A Green Chemistry "environmentally friendly" approach to the synthesis of chloro-intermediates of ephedrine/pseudoephedrine
PublicationMethylamphetamine is an addictive stimulant drug that strongly activates certain systems in the brain. It is closely related chemically to amphetamine, but the central nervous system effects of methamphetamine are greater. There is much interest in methylamphetamine among scientists and therefore the synthesizes of methylamphetamine and its metabolites are carried out on a large scale in chemical laboratories. Globally, ephedrine...
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Kinetic analysis of the reduction of a ternary system of Bi, Sb and Te oxides by hydrogen for BiSbTe3 synthesis
PublicationReduction in a hydrogen atmosphere of Bi2O3, Sb2O3 and TeO2 mixes oxides for the synthesis of BiSbTe3 was analysed. The reduction reactions of Sb2O3 and Sb2O4 oxides, as well as Bi2O3+Sb2O3 and Sb2O3+3TeO2 mix- tures, were also evaluated. The reduction of Sb2O4 is investigated for the first time. The reactions of the mixed oxides systems also were not the subject of research so far despite being used for synthesis of the (Bi,Sb)2Te3...
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Structure-rheology relationship of fully bio-based linear polyester polyols for polyurethanes - Synthesis and investigation
PublicationThe synthesis of polyols from renewable substances as an alternative for petrochemical-based polyols play important matter in the polyurethane industry. In this work, the fully bio-based linear polyester polyols with different catalyst amounts were synthesized via two-step polycondensation method. The effect of various catalyst content on the structure and rheological behavior were established. Fourier Transform Infrared Spectroscopy,...
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Synthesis and structure of Bi 5 FeTi 3 O 15 ceramics
PublicationAim of the present research was to fabricate and study crystal structure and phase composition of Bi5FeTi3O15 (BTFO) ceramics exhibiting Aurivillius - type structure. By means of simultaneous thermal analysis and X-ray diffraction analysis the process of synthesis of BTFO ceramics has been studied. Mixed oxide method followed by pressureless sintering was used for ceramics preparation. Three endothermic thermal effects have been...
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Knowledge-Based Expedited Parameter Tuning of Microwave Passives by Means of Design Requirement Management and Variable-Resolution EM Simulations
PublicationThe importance of numerical optimization techniques has been continually growing in the design of microwave components over the recent years. Although reasonable initial designs can be obtained using circuit theory tools, precise parameter tuning is still necessary to account for effects such as electromagnetic (EM) cross coupling or radiation losses. EM-driven design closure is most often realized using gradient-based procedures,...
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Expedited Re-Design of Multi-Band Passive Microwave Circuits Using Orthogonal Scaling Directions and Gradient-Based Tuning
PublicationGeometry scaling of microwave circuits is an essential but challenging task. In particular, the employment of a given passive structure in a different application area often requires re-adjustment of the operating frequencies/bands while maintaining top performance. Achieving this necessitates utilization of numerical optimization methods. Nonetheless, if the intended frequencies are distant from the ones at the starting point,...
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An automated microwave planar filter design based on space mapping optimization
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Low order autoregressive (AR) models for FDTD analysis of microwave filters.
PublicationArtykuł opisuje zastosowanie modeli AR w celu poprawy efektywności analizy struktur filtrujących metodą różnic skończonych w dziedzinie czasu (FD-TD). Opisanych jest szereg kryteriów pozwalających na automatyczne tworzenie modeli AR sygnałów czasowych, w tym wybór fragmentu odpowiedzi układu stanowiący podstawę ekstrakcji współczynników modelu, współczynnika decymacji oraz rzędu modelu. Skuteczność wprowadzonych kryteriów...
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Hybrid analysis of microwave components in cylindrical coordinates with function expansion in subdomains.
PublicationW artykule zaproponowano wydajną metodę przyspieszenia analizy FDTD, poprzez podział dziedziny obliczeniowej i zastosowanie różnych algorytmów w różnych elementach dziedziny. Zaproponowano uniwersalną metodę łączenia techniki PEE (Partial Eigenfunction Expansion)i niezmodyfikowanej FDTD w jednej analizie. Uzyskano redukcję liczby zmiennych oraz wydłużenie kroku czasowego.
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Microwave plasma application in decomposition and steam reforming of model tar compounds
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Book review: Simulation-Driven Design Optimisation and Modelling for Microwave Engineering
PublicationCelem książki jest przedstawienie aktualnego stanu badań dotyczących projektowania układów mikrofalowych poprzez modelowanie i optymalizacje wspomagane symulacjami elektromagnetycznymi. Grupa międzynarodowych ekspertów zajmujących się rożnymi aspektami komputerowo wspomaganego projektowania układów mikrofalowych, podsumowuje i dokonuje przeglądu ostatnich osiągnięć w tej dziedzinie oraz przedstawia szereg praktycznych zastosowań....
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Accurate modelling of microwave structures using shape-preserving response prediction
PublicationArtykuł prezentuje metodologię dokładnego modelowania struktur mikrofalowych. Jest to zmodyfikowana wersja techniki opartej na procedurze przewidywania odpowiedzi z zachowaniem kształtu (shape-preserving response prediction, SPRP), która oszacowuje odpowiedź struktury mikrofalowej otrzymanej poprzez kosztowną obliczeniowo symulację elektromagnetyczną za pomocą taniego obliczeniowo modelu tejże struktury. Modyfikacja polega na wykorzystaniu...
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Inspection of protective linings using microwave spectroscopy combined with chemometric methods
PublicationOpisano nowa niedestrukcyjna metodę kontroli jakości nowych wykładzin ochronnych na podłożu metalowym oraz oceny ich stanu w trakcie eksploatacji przy zastosowaniu spektroskopii mikrofalowej w szerokim zakresie częstotliwości od 6,5 do 13 GHz. Uzyskane dane pomiarowe dodane zostały obróbce chemometrycznej w celu redukcji ilości danych doświadczalnych i wizualizacji rezultatów. Przedstawiono podstawy teoretyczne metody oraz wyniki...
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Benzene-induced hydro(solvo)thermal synthesis of Cu2+ and Zn2+ coordination polymers based on 1,3-benzenedicarboxylate
PublicationHydro(solvo)thermal reactions of Cu(NO3)2·2.5H2O or Zn(NO3)2·6H2O with 1,3-H2bdc provided two structurally different coordination polymers; a 2D network “metallacalixarene” based on the paddlewheel-type cluster with the formula [Cu(1,3-bdc)·H2O]·H2O (1) and a 3D framework [Zn(1,3-bdc)] (2), respectively. The use of a base was unnecessary in this synthesis; however, the presence of benzene played a crucial role in the crystallization...
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Synthesis of 3-D Graphene via Combustion Synthesis of Magnesium and Calcium/Magnesium Oxalates
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Synthesis, microstructure and electrical properties of nanocrystalline calcium doped lanthanum orthoniobate
PublicationThe single phase lanthanum orthoniobate with tetragonal structure has been synthesized by the means of mechanosynthesis method. The studies have shown the crystal structure of La0.98Ca0.02NbO4 depends on the synthesis stage. The samples were predominantly in the tetragonal phase with a trace amount of the monoclinic phase. The SEM studies of morphology and microstructure have shown nanocrystallinity of the materials. The Raman...
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An Attempt to Create Speech Synthesis Model That Retains Lombard Effect Characteristics
PublicationThe speech with the Lombard effect has been extensively studied in the context of speech recognition or speech enhancement. However, few studies have investigated the Lombard effect in the context of speech synthesis. The aim of this paper is to create a mathematical model that allows for retaining the Lombard effect. These models could be used as a basis of a formant speech synthesizer. The proposed models are based on dividing...
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Rearrangement of azoxybenzocrowns into chromophoric hydroxyazobenzocrowns and the use of hydroxyazobenzocrowns for the synthesis of ionophoric biscrown compounds
PublicationThe Wallach rearrangement was used as a method for preparing p-hydroxyazobenzocrown ethers starting from different azoxybenzocrowns as substrates. Synthesis of a series of p-hydroxyazobenzocrowns under modified conditions and characterization of the obtained products are presented. o-Hydroxyazobenzocrowns were identified among the products of the photochemical rearrangement of azoxybenzocrowns. Novel biscrowns were synthesized...
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Multivariate Assessment of Procedures for Molecularly Imprinted Polymer Synthesis for Pesticides Determination in Environmental and Agricultural Samples
PublicationIn the case of quantitative and qualitative analysis of pesticides in environmental and food samples, it is required to perform a sample pre-treatment process. It allows to minimalize the impact of interferences on the final results, as well as increase the recovery rate. Nowadays, apart from routinely employed sample preparation techniques such as solid-phase extraction (SPE) or solid-phase microextraction (SPME), the application...
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One-Step Combustion Synthesis of Novel Nanocarbons via Magnesiothermic Reduction of Carbon-Containing Oxidants
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Silanethiolates - synthesis, properties and structures.
PublicationW pracy wskazano podstawowe drogi syntezy oraz podano zwięzłą charakterystykę silanotiolanów - w większości związków kompleksowych posiadających jako główny ligand grupę silanotiolanową, na ogół (t-BuO)3SiS. Przy pomocy odpowiednio dobranych przykładów zilustrowano właściwości tych związków - wskazano ciekawsze elementy struktury molekularnej oraz specyficzne cechy spektralne.
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The prns butterfly synthesis in the FPGA
Publicationw pracy przedstawiono sprzętową implementację elementarnych obliczeń, określanych jako obliczenia motylkowe, dla splotu realizowanego z użyciem wielomianowego systemu resztowego(ang. polynomial residue number system - prns). obliczenia są wykonywane z zastosowaniem reprezentacji systemu diminished-1. opisano syntezę układu realizującego obliczenie motylkowe w środowisku xilinx w układzie virtex 4. podano również wymaganą ilość...
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Synthesis and properties of CaFe2As2single crystals
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Rapid method for the determination of organochlorine pesticides and PCBs in fish muscle samples by microwave-assisted extraction and analysis of extracts by GC-ECD
PublicationA procedure for the multiresidue determination of organochlorine pesticides and polychlorinated biphenyls in fish muscle samples has been developed. The method is based on the microwave-assisted extraction (MAE) of food samples from an acetonitrile-water (95 + 5, v/v) mixture followed by SPE cleanup of the extracts and analysis by GC with an electron capture detector. MAE operational parameters, such as the extraction solvent,...
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Integrated Experimental and Theoretical Approach for Efficient Design and Synthesis of Gold-Based Double Halide Perovskites
PublicationApplied cutting-edge electronic structure and phonon simulations provide a reliable knowledge about the stability of perovskite structures and their electronic properties, which are crucial for design of effective nanomaterials. Gold is one of the exceptional elements, which can exist both as a monovalent and a trivalent ion in the B site of a double perovskite such as A2BI BIIIX6. However, until now, electronic properties of Cs2AuI AuIIIX6...
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From tryptophan to novel mitochondria-disruptive agent, synthesis and biological evaluation of 1,2,3,6-tetrasubstituted carbazoles
PublicationMitochondrial targeting plays an important role in anticancer therapy. The Mn(III)-promoted cyclization of 5- (1H-indol-3-yl)-3-oxopentanoic acid allow to obtain novel substituted carbazole derivatives that can act as mitochondria-disruptive agents. The starting materials used for the synthesis of these new aminocarbazoles are oxopentanoate derivatives of tryptophan. The scope and limitation of this method of synthesis are determined...
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Two-step Conversion of Crude Glycerol Generated by Biodiesel Production into Biopolyols: Synthesis, Structural and Physical Chemical Characterization
PublicationIn this work biopolyols were synthesized via two-step process from crude glycerol and castor oil. For better evaluation of analyzed process, the impact of its time and temperature on the structure and properties of biopolyols was determined. Obtained results fully justified conducting of synthesis in two steps. Prepared materials were characterized by hydroxyl value and water content comparable to polyols industrially applied in...
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Synthesis of 3-Carbamoyl b-Lactams via Manganese(III)-Promoted Cyclization of N-Alkenylmalonamides
PublicationManganese(III)-promoted cyclization of N-alkenylmalonamides (¼N-alkenylpropanediamides) gave 3-(aryl/(alkylamino)carbonyl) b-lactams as well as 3-(aryl/(alkylamino)thiocarbonyl) b-lactams. The relative configuration of the obtained products was unambiguously determined by X-ray crystallography. The proposed method is very useful for the one-pot synthesis of a number of 3-(aryl/ (alkylamino)carbonyl) b-lactams, especially those...
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Synthesis of Novel Arginine Building Blocks with Increased Lipophilicity Compatible with Solid-Phase Peptide Synthesis
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Alternative method for the synthesis of imidazo[5,1-f][1,2,4]triazin-4(3H)-one—a substrate for the preparation of phosphodiesterase (5) inhibitors
PublicationImidazo[5,1-f][1,2,4]triazin-4(3H)-ones, as isosteres of purine, are of interest for pharmaceutical research as potential substrates for the synthesis of cGMP-PDE5 inhibitors. We present a novel, alternative method for the synthesis of imidazotriazinones, that differs from the previously reported ones with respect to the method of construction of the triazinone ring in the molecule. The key step in our approach is condensation...
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Metal (Mo, W, Ti) Carbide Catalysts: Synthesis and Application as Alternative Catalysts for Dry Reforming of Hydrocarbons—A Review
PublicationDry reforming of hydrocarbons (DRH) is a pro-environmental method for syngas production. It owes its pro-environmental character to the use of carbon dioxide, which is one of the main greenhouse gases. Currently used nickel catalysts on oxide supports suffer from rapid deactivation due to sintering of active metal particles or the deposition of carbon deposits blocking the flow of gases through the reaction tube. In this view,...
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High Q-factor Microwave Fabry-Perot Resonator With Distributed Bragg Reflectors
PublicationZrealizowany został rezonator Fabry-Perot pracujący na częstotliwości 39 GHz i wykorzystujący dwie pary ćwierćfalowych kwarcowych reflektorów Bragga. Dla fali o długości 98.26 mm otrzymano dobroć ok. 560,000, co oznacza 4.3-krotny wzrost w porównaniu z identycznym rezonatorem bez reflektorów Bragga. Analizę problemu wykonano przy pomocy metody różnic skończonych w dziedzinie częstotliwości (FDFD) i porównano z uproszczonym rozwiązaniem...
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Removal of metal particles from carbon nanotubes using conventional and microwave methods
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Compatible DC and small-signal MOSFET models for radio and microwave frequency simulation
PublicationZaprezentowano nowy model stałoprądowy tranzystora MOS i kompatybilny z nim uogólniony nie-quasi-statyczny model małosygnałowy. Model stałoprądowy został eksperymentalnie zweryfikowany dla tranzystorów MOS o długości kanału od 75 nm do kilkunastu mikrometrów, a model małosygnałowy od zera herców do 30 GHz.
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Metal ion directed template synthesis using 2-acetyl-1,3-indandione and ethylenediamine: steric and electronic restrictions
PublicationA template synthesis using 2-acetyl-1,3-indandione and ethylenediamine results in formation of octahedral Ni complex, whose crystal structure has been resolved using single crystal X-ray diffraction. The structure indicates that only exocyclic enolic oxygen atom of the triketone takes part in the condensation with ethylenediamine.