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Wyniki wyszukiwania dla: transition
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Inhibition of impurities formation in the synthesis of N-alkyltheobromines stimulated by microwave irradiation. Cationic and anionic response of membrane electrodes
PublikacjaN-Alkyltheobromine (1-9) derivatives were obtained by reacting theobromine with appropriate alkyl halide under microwave irradiation at 100-150 W and by conventional synthesis. Formation of by-products of oxygen atom alkylation and 1-N-alkyltheobromine ring opening were considered. The presented compounds 1-5 have been studied as ion carriers in ion-selective membrane electrodes. Selectivity of these membranes was studied towards...
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Investigation of magnetic order in a new intermetallic compound Nd2PtGe3
PublikacjaIn the present study we report a successful synthesis of the new intermetallic compound Nd2PtGe3 by an arc-melting method. The powder X-ray diffraction analysis indicates that this compound crystallizes in an disordered variant of the AlB2-type structure (space group P6/mmm, no. 191) with lattice parameters a = 4.2455 Å and c = 4. 1933 Å. The compound exhibits a cluster-glass transition below Tf = 2.9 K, characterized through ac...
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Human System Interaction in Review: Advancing the Artificial Intelligence Transformation
PublikacjaThe industrial advancement of human society has been fundamentally driven by diverse ‘systems’ that facilitate ‘human interaction’ within physical, digital, virtual, social and artificial environments, and upon the hyper-connected layers of system-system interactions across these environments. The research and practice of Human System Interaction (HSI) has undergone exponential development due to the enhanced capabilities, increased...
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Cellulosic bionanocomposites based on acrylonitrile butadiene rubber and Cuscuta reflexa: adjusting structure-properties balance for higher performance
PublikacjaDesign and manufacture of cellulosic nanocomposites with acceptable performance is in the period of a transition from fantasy to reality. Typically, cellulosic nanofillers reveal poor compatibility with polymer matrices. Thus, adjusting the balance between structure and properties of cellulosic bionanocomposites by careful selection of parent ingredients is the first priority. Herein, we incorporated Cuscuta reflexa derived cellulose...
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Superconductivity in the Nb-Ru-Ge σ phase
PublikacjaWe show that the previously unreported ternary σ-phase material Nb20.4Ru5.7Ge3.9 (Nb0.68Ru0.19Ge0.13) is a superconductor with a critical temperature of 2.2 K. Temperature-dependent magnetic susceptibility, resistance, and specific-heat measurements were used to characterize the superconducting transition. The Sommerfeld constant γ for Nb20.4Ru5.7Ge3.9 is 91 mJ mol f.u. −1K−2 (∼3 mJ mol atom−1 K−2) and the specific-heat anomaly at...
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Effect of composition on the thermal properties and structure of M-Al-Si-O-N glasses, M = Na, Mg, Ca
PublikacjaThe primary objective of this study is to explore the relationship between the composition, structure, and thermal characteristics of M-Al-Si-O-N glasses, with M representing sodium (Na), magnesium (Mg), or calcium (Ca). The glasses were prepared by melting in a quartz crucible at 1650 °C and AlN precursor (powder) was utilized as a nitrogen source. The measured thermal properties studied were glass transition temperature (Tg),...
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Semicrystalline Polyesters Based on a Novel Renewable Building Block
PublikacjaIsohexides, like e.g. isosorbide, are well-known carbohydrate-based rigid diols which are capable of dramatically increasing the glass transition temperature of polyesters. However, their relatively low reactivity has thus far hampered large-scale industrial applications in the polymer field. Recently, with the aim to increase reactivity while at the same time retain rigidity, we have developed a new isoidide dicarboxylic acid...
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Magnetoelectric, spectroscopic, optical and elastic properties of Co-doped BaTiO3 ceramics
Publikacjahe BaTiO3 perovskite is widely used in the electronic technology due to its dielectric, piezoelectric and ferroelectric properties and is a well-known base for obtaining a promising multifunctional material. In this paper we report the extensive studies on the Co-doped BaTiO3 ceramics for the wide range cobalt content. Full structural characterization of studied samples in a 20–450 K range was provided. The results of research...
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Enhancement of self-trapped excitons and near-infrared emission in Bi3+/Er3+ co-doped Cs2Ag0.4Na0.6InCl6 double perovskite
Dane BadawczeErbium (Er) complexes are used as optical gain materials for signal generation in the telecom C-band at 1540 nm, but they need a sensitizer to enhance absorption. Na+ substitution for Ag+ and Bi3+ doping at the In3+ site is a possible strategy to enhance the broadband emission of Cs2AgInCl6, which could be used as a sensitizer for energy transfer to...
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Evaluation of Readiness of IT Organizations to Agile Transformation Based on Case-Based Reasoning
PublikacjaNowadays many of IT organization decides to change the way of delivering from classic, waterfall approach to agile. This transition is called “agile transformation” (AT). The problem of this process is that part of companies started AT without any analysis. This causes that many of transitions fails and organizations must return to old methods of delivering. Cost of return is significant and number of projects with violated project...
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Magnetism and charge density waves in RNiC2(R=Ce,Pr,Nd)
PublikacjaWe have compared the magnetic, transport, galvanomagnetic, and specific-heat properties of CeNiC2, PrNiC2, and NdNiC2 to study the interplay between charge density waves (CDW) and magnetism in these compounds. The negative magnetoresistance in NdNiC2 is discussed in terms of the partial destruction of charge density waves and an irreversible phase transition stabilized by the field-induced ferromagnetic transformation is reported....
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Vibrational Properties of LaNb0.8M0.2O4-δ (M=As, Sb, V, and Ta)
PublikacjaLaNb0.8M0.2O4-δ (where M=As, Sb, V, and Ta) oxides with pentavalent elements of different ionic sizes were synthesized by a solid-state reaction method. The vibrational properties of these oxides have been investigated. These studies revealed that the substituent element influences both Debye temperature value as well as the Raman active vibrational modes. Additionally, the low-temperature vibrational properties of LaNb0.8Sb0.2O4-δ...
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The homometallic warwickite V 2 OBO 3
PublikacjaThe synthesis, structure and elementary magnetic characterization of the homometallic warwickite V2OBO3 are reported. The material adopts the orthorhombic warwickite structure type at room temperature, space group Pnma (No. 62) with lattice parameters a = 9.2317(1) Å, b = 3.1172(1) Å, and c = 9.5313(1) Å. Temperature-dependent magnetic susceptibility, electrical resistivity, and specific heat measurements show anomalies near 35 K,...
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New technologies for green hydrogen activation, storage, and transportation
PublikacjaDeveloping new green hydrogen activation, storage, and transportation technologies is a highly complex and multidisciplinary endeavor. This challenge arises from integrating various scientific, engineering, and environmental considerations. Effective evaluation of green hydrogen technologies involves a holistic approach that considers not only the technical aspects but also economic, environmental, and social factors. These criteria...
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Experimental investigations on adiabatic frictional pressure drops of R134a during flow in 5mm diameter channel
PublikacjaThe article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a at a saturation pressure of 5.5 bar corresponding to the saturation temperature of 19.4 °C. Study cases have been set for a mass flux varying from 100 to 500 kg/m2 s. The frictional pressure drop was characterized for the refrigerant R134a, for vapor qualities ranging from 0 to 1. Long-time thermal stability of test facility allowed to gather...
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Smaller Representation of Finite State Automata
PublikacjaThis paper is a follow-up to Jan Daciuk's experiments on space-effcient finite state automata representation that can be used directly for traversals in main memory. We investigate several techniques of reducing memory footprint of minimal automata, mainly exploiting the fact that transition labels and transition pointer offset values are not evenly distributed and so are suitable for compression. We achieve a gain of around 20-30%...
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Enhanced acceptor concentration, proton conductivity, and hydration in multicomponent rare‐earth ortho‐niobates
PublikacjaThe structural properties of (La0.2Nd0.2Sm0.2Gd0.2Eu0.2)1−xCaxNbO4−δ (x = 0–0.05) series have been studied by X-ray powder diffraction at room temperature. The thermal properties were investigated using thermogravimetry, from which the concentration of proton defects was determined. Additionally, dilatometry studies were carried out, from which the thermal expansion coefficients and the phase transition temperature between low-...
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The changes of crosslink density of polyurethanes synthesised with using recycled component. Chemical structure and mechanical properties investigations.
PublikacjaThis paper aims at the utilisation of glycerolysate (Gly) obtained in polyurethane recycling process by means of crude glycerine, which has in its structure hydroxyl end groups that allow for further processing. Polyurethanes (PUs) were synthesised using prepolymer method with the mixture of neat polyol and glycerolysate, in different ratios, with 4,4-diphenylmethane diisocyanate (MDI). The prepolymer was subsequently extended...
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TiO2 and Reducing Gas: Intricate Relationships to Direct Reduction of Iron Oxide Pellets
PublikacjaIn response to the imperative for sustainable iron production with reduced CO2 emissions, this study delves into the intricate role of TiO2 in the direct reduction of iron oxide pellets. The TiO2-dependent reducibility of iron oxide pellets utilizing H2 and CO gas across varied temperatures and gas compositions is thoroughly investigated. Our findings unveil the nuanced nature of the TiO2 effect, underscored by its concentration-dependent...
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Synthesis and application of tetrazole di and triamide derivatives in ion-selective membrane electrodes
PublikacjaA number of tetrazole diamides and triamides have been synthesized and applied as ion carries in ion-selective membrane electrodes. Their selectivity and sensitivity were studied towards alkali, alkaline earth, transition and heavy metal cations. it was found that membranes doped with 3 and 2-nitrophenyl octyl ether exhibit an almost theoretial Nernstian response for NH+ over relatively wide concentration range. Elestrodes with...
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Electrical and structural properties of Nb-doped SrTiO3
PublikacjaNiobium-doped strontium titanate synthesized via conventional solid-state reaction has been studied. Influence of niobium content on the lattice parameters and electrical conductivity has been reported. Various reduction conditions have been investigated. For samples reduced in hydrogen at 1400°C, a transition from thermally activated to metallic behavior has been observed. Maximum electrical conductivity (ca. 55 Scm−1 at 650°C)...
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Neotenic phenomenon in gene expression in the skin of Foxn1- deficient (nude) mice - a projection for regenerative skin wound healing
PublikacjaMouse fetuses up to 16 day of embryonic development and nude (Foxn1- deficient) mice are examples of animals that undergo regenerative (scar-free) skin healing. The expression of transcription factor Foxn1 in the epidermis of mouse fetuses begins at embryonic day 16.5 which coincides with the transition point from scar-free to scar-forming skin wound healing. In the present study, we tested the hypothesis that Foxn1 expression...
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The use of Acoustic Emission to identification damages bearings the main and crank engines about the automatic ignition
PublikacjaThe article describes the laboratory tests, which make the first stage of the study concerning the use of the AE method to determine the technical state of the slide bearings in engines with self-ignition. The aim of the present tests was to compare the recorded signals in relation to the technical state of the material of the bearing bush and to check the possibility of using the AE method in determining the transition moment...
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Synthesis and properties of new 'N,'N-phenyltetrazole podand
PublikacjaThe synthesis of a new chromogenic N,N-phenyltetrazole receptor is reported here. The cationbinding properties of this receptor in solution were investigated by naked-eye colour change, electrochemical methods and UV-Vis spectroscopy in various solvents (CH3CN, dimethylsulphoxide (DMSO), DMSO/H2O, CH3CN/H2O and CH3CN/MeOH). In addition, the receptor was used as a sensing material in ion-selective membrane electrodes. The selectivity...
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Antagonist adhesion effects due to variable substrate surface
PublikacjaThe effects of variability of intrinsic adhesion within a joint have been studied using a single cantilever beam (SCB) test. Fracture energy was found not to be a simple function of relative areas of 2 surface pre-treatments: a 'weak' zone decreased strength more than expected from simple, additive considerations. By severing the adhesive along the strong-weak transition, fracture energy increased.The prior antagonist effect appears...
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Solving the Problem of Dynamic Adaptability of Artificial Intelligence Systems that Control Dynamic Technical Objects
PublikacjaThis paper investigates the increase in the response speed and stability of artificial intelligence systems that control dynamic technical objects. The problem of calculating the optimal time of switching an artificial intelligence system between software classes by the criterion of the rigidity degree of the model of a control object is considered. The solution of this problem is proposed for the general case of the control object...
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Experimental investigation of forced convection of water-Al2O3 nanofluids inside horizontal tubes,
PublikacjaIn this paper, forced convection of water–Al2O3 nanofluids inside horizontal copper tube is studied experimentally. Experiments were conducted for three, i.e. 0.1%, 1% and 5% nanoparticle mass concentrations under transition and turbulent flow regimes. Average heat transfer coefficients and pressure drop values were determined and compared to distilled water. Enhancement of heat transfer for lower nanoparticle concentration and...
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From flow to jamming: Lattice Gas Automaton simulations in granular materials
PublikacjaWe introduce the first extension of a Lattice Gas Automaton (LGA) model to accurately replicate observed emergent phenomena in granular materials with a special focus on previously unexplored jamming transitions by incorporating gravitational effects, energy dissipation in particle collisions, and wall friction. We successfully reproduce flow rate evolution, density wave formation, and jamming transition observed in experiments....
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Innovation and new technologies in mineral processing
WydarzeniaZapraszamy Państwa na webinarium nt. innowacji i nowych technologii w przetwórstwie surowców mineralnych z dyrektorem globalnym firmy FLSmidth Flotation. Obowiązuje rejestracja.
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Przyczółki mostowe wspomagane konstrukcjami z gruntu zbrojonego
PublikacjaW referacie przedstawiono syntezę prac związanych z oceną projektów przyczółków wykorzystujących odciążenie w postaci konstrukcji z gruntu zbrojonego geosyntetykami, realizowanych na drogach ekspresowych S3 i S7. W ramach przeprowadzonych audytów dokonano oceny zastosowanych rozwiązań szczegółowych i materiałów jak również obliczeń zamieszczonych w projektach. Zwrócono szczególną uwagę na przestrzenną prace bloków z gruntu zbrojonego...
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Shaping of the turnout diverging track with variable curvature sections
PublikacjaThe paper presents an analytical method of shaping the turnout diverging railroad track with variable curvature segments on its length, which in an evident way distinguished it from a typical solution, made up of a single circular arc with no transition curves. Two separate causes including a linear and a nonlinear curvature one in the form of a polynomial have been examined. The obtained solutions of the problem have a universal...
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Catalytic Asymmetric Synthesis of Isochroman Derivatives
PublikacjaThe isochroman scaffold constitutes an important structural unit, which is present in various bioactive natural products and synthetic pharmaceutical compounds exhibiting wide arrays of biological properties. Hence the synthesis of this class of heterocyclic compounds in a stereoselective fashion is highly significant and desirable. In the last decade, a substantial advancement has been witnessed ln the catalytic asymmetric...
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Quenching of bright and dark excitons via deep states in the presence of SRH recombination in 2D monolayer materials
PublikacjaTwo-dimensional (2D) monolayer materials are interesting systems due to an existence of optically non-active dark excitonic states. In this work, we formulate a theoretical model of an excitonic Auger process which can occur together with the trap-assisted recombination in such 2D structures. The interactions of intravalley excitons (bright and spin-dark ones) and intervalley excitons (momentum-dark ones) with deep states located...
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Tunable Dielectric Switching of (Quinuclidinium)[MnCl4] Hybrid Compounds
PublikacjaInorganic−organic hybrid QMnCl (Q = quinuclidinium) crystals were synthesized and characterized. The X-ray and variable-temperature IR/Raman analysis demonstrate that the crystals undergo a reversible structural phase transition, which originates from an order−disorder process and is related to the dynamics of the organic Q cation. Dielectric function measurements disclose a switchability between low (“OFF”) and high (“ON”) dielectric...
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Sulfurization of phosphanylphosphinidene ligand: Access to phosphinothioyltrithiophosphonato platinum(II) complexes
PublikacjaThe reactivity of phosphanylphosphinidene Pt(0) complexes [DppePt(η2-P–PtBu2)] (1) and [(pTol3P)2Pt(η2-P–PtBu2)] (2) toward sulfur was studied. Reactions of 1 and 2 with an excess of sulfur led to the formation of the first transition metal complexes 3 and 4 with phosphinothioyltrithiophosphonato ligands with the formula [tBu2P(=S)–P(=S)S2]2-. In contrast to previous reports on the phosphanylphosphinidene moiety sulfurization,...
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Nickel phase deposition on V2CTx/V2AlC as catalyst precursors for a dry methane reforming: The effect of the deposition method on the morphology and catalytic activity
PublikacjaDry reforming of methane (DRM) is a promising alternative technology for the production of syngas with simultaneous utilization of two main greenhouse gases (CH4, CO2). However, DRM technology is still an industrially immature process due to the lack of stable and active catalyst. Therefore, the search for new catalytic materials is of great research interest. Recently, MAX and MXenes materials are increasingly being tested as...
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Metoda określania maksymalnej prędkości jazdy na łukach, dostosowana do specyfiki tras tramwajowych
PublikacjaW artykule określono potrzebę obliczenia prędkości z jaką maksymalnie można poruszać się pojazdem tramwajowym na wybranych odcinkach trasy. Określono jakie wartości są niezbędne do wykonania obliczeń trakcyjnych. Dostosowano metodę do dostępnych danych, pochodzących z Mobilnych Pomiarów Satelitarnych. Porównano wyniki z algorytmami przeznaczonymi dla zastosowań kolejowych. Przeprowadzone analizy wykazały, że przy zastosowaniu proponowanego...
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Smaller representation of finite state automata
PublikacjaThis paper is a follow-up to Jan Daciuk's experiments on space-efficient finite state automata representation that can be used directly for traversals in main memory (Daciuk, 2000)[4]. We investigate several techniques for reducing memory footprint of minimal automata, mainly exploiting the fact that transition labels and transition pointer offset values are not evenly distributed and so are suitable for compression. We achieve...
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Comparison of classical and modern approach of determination of highly polar compounds by High Performance Liquid Chromatography coupled with Tandem Mass Spectrometry
PublikacjaAbstract: Sugars and sugar alcohols are known as highly polar compounds. Four analytes were taken into consideration for comparison of classical and modern approach of separation of highly polar substances. Mannitol was chosen as an example of simple sugar alcohol, sucrose and lactulose as examples of disaccharides and structural isomers, raffinose as an example of complex trisaccharide. Raffinose was also used as internal standard...
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Ranking of Heterogeneous Catalysts Metals by Their Greenness
PublikacjaCatalysis is very important process in industry and laboratory practice, especially from the point of green chemistry principles. However, eco-friendly character of heterogeneous catalysts, containing transition metal components has not been evaluated, yet. Therefore, we perform a comprehensive assessment of 18 heterogeneous metal catalysts (Pd, Pt, V, Co, Ni, Mo, Ru, Mn, Au, Cu, Cd, Zr, Fe, Rh, Ir, Sn, Zn, Ag) using multicriteria...
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Experimental study and numerical simulation on porosity dependent direct reducibility of high-grade iron oxide pellets in hydrogen
PublikacjaThe transition to more environmentally friendly steel production methods has intensified research into hydrogen-based direct reduction (HyDR) of iron oxide pellets. The aim of this study is to systematically investigate the kinetics of the reduction process, the evolution of porosity and the resulting microstructural changes on the reduction behavior of high-quality pellets during HyDR of iron ore at different temperatures. A modified...
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Technological solutions for boosting hydrogen role in decarbonization strategies and net-zero goals of world shipping: Challenges and perspectives
PublikacjaFacing the problems concerning greenhouse gas (GHG) emissions from international ocean shipping has meant that the latest regulations of the International Maritime Organization, issued on 1st January 2023, have come into force, with the aim of reducing GHG emissions from maritime activities. Hydrogen has been suggested as an alternative fuel to achieve decarbonization ambitions in the near future. Although hydrogen has been investigated...
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Modelling of joining route segments of differential curvature
PublikacjaThe paper presents a new general method of modelling route segments curvature using differential equations. The method enables joining of route segments of different curvature. Transitional curves of linear and nonlinear curvatures have been identified in the case of joining two circular arcs by S-shaped and C-oval transitions. The obtained S-shaped curves have been compared to the cubic C-Bezier curves and to the Pythagorean hodograph...
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Mentor&Student Research Lab: new type of architectural and urban design workshops, new opportunities, valuable results
PublikacjaThe space around us has significantly changed during last years. Polish cities have undergone a major transformation following political, economical and social transition [8]. Similar change is noticeable at universities and their educational programmes for architecture and spatial planning students. Nowadays designers and activists tackle completely different problems and have different opportunities than their older colleagues...
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Molecular geometry and optical activity of helically chiral N-nitrosamines derived from 1,2,3,4-tetrahydro- and 1,2,3,4,7,8,9,10-octahydro-1,10-phenanthroline
PublikacjaX-ray crystallographic analysis of the title N-nitrosamines revealed that they assume helical conformations in the solid state. Nitrosamines 1b and 2b were resolved by inclusion crystallization with optically active diols (TADDOLs). The absolute configuration of the guest molecules in the complexes 1b·3b and 2b·3b was assigned as M. The optical activity of the resolved compounds is manifested by their solid state CD spectra, which...
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Balancing agility and discipline in a research project
PublikacjaSuccessful software development requires both agility and discipline. Optimal selection of methods, however, is not an easy task. The problem becomes even more difficult for long lasting projects. Appropriate selection of methods involving skillful introduction and abandonment of certain practices in time makes the whole process dynamic. The paper presents in this context a research project which was realized in a few iterations....
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Preparation and some properties of multiblock copoly(amide-b-amide)s
PublikacjaThe paper concerns the polymers built of oligoamide hard blocks and oligoamide soft blocks (KPAA, formula I). Oligo(laurolactam) (PA12) was used as hard block and the product of reaction of dimerized fatty acid and hexamethylene diamine (PA6,36) was used as a soft one. Effects of molar ratio of these blocks on the following properties of KPAA have been investigated: limiting viscosity number ([2]), degrees of swelling in water...
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Sum-over-state expressions including second-order Herzberg–Teller effects for the calculation of absorption and resonance Raman intensities
PublikacjaThe sum-over-state expressions are derived to calculate the second-order Herzberg–Teller (HT) effects in absorption and resonance Raman spectroscopies. These effects depend on the second derivatives of the transition dipole moment with respect to the vibrational coordinates. The method is applied to the molecule of 1,3-butadiene using density functional theory calculations. It is found that the second-order HT effects are significant...
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Experimental investigation of forced convection of water/EGAl2O3 nanofluids inside horizontal tube
PublikacjaIn this paper, forced convection of water/EG-Al2O3 nanofluids inside horizontal stainless steel tube is studied experimentally. As base fluid served water/EG mixture of two ratios (60:50 and 50:50). Nanoparticle mass concentrations was 0.1% or and 1%. Transition and turbulent flow regimes were tested. Average heat transfer coefficient and pressure drop values were determined for nanofluids and compared to base fluids. Deterioration...
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The electronic characterization of the cubic Laves-phase superconductor CaRh2
PublikacjaWe present the synthesis and experimental characterization of the electronic properties of the cubic Laves phase superconductor CaRh2. Its crystal structure was confirmed by powder X-ray diffraction and its ambient temperature lattice parameter (a = 7.5326(6) Å) is in good agreement with the literature. Magnetization, resistivity and heat-capacity measurements indicate that CaRh2 is a moderate-coupling type-II superconductor (λe-p = 0.89)...