Wyszukiwarka
Filtry
wszystkich: 597
wybranych: 585
-
Katalog
Filtry wybranego katalogu
Wyniki wyszukiwania dla: energy transition
-
Computer-aided reconstruction of the railway track axis geometrical shape
PublikacjaIn the paper a method of the railway track axis geometrical shape identification in a horizontal plane, directly from the continuous satellite measurements, is presented. In this method, an algorithm for the design of railway track sections located in the horizontal arc is used. The algorithm uses an analytical description of the layout by means of suitable mathematical formulas. The design procedure has a universal character and...
-
Study of the effect of thermally reduced graphene oxide on the physical and mechanical properties of flexible polyurethane foams
PublikacjaFlexible polyurethane foams were obtained from a two-component system via the one-step method. The foams were modified with thermally reduced graphene oxide added in the amount equal to 0.25, 0.5 and 0.75 wt%. The morphology, static and dynamic properties, and thermal stability of modified foams were determined. The application of carbon filler resulted in the visible increase in the cell size, apparent density and rigidity of...
-
Computer-Aided Design of Railroad Horizontal Arc Areas in Adapting to Satellite Measurements
PublikacjaThis paper presents a method of designing railway sections located in horizontal arcs. The adopted procedure is universal, i.e., it creates the possibility of varying both the type and the length of the assumed transition curves. This means that the applied analytical formulas apply to the boundary conditions of the transition curves and all of the simplifications widely existing in common algorithms have been eliminated. The presented...
-
Structure and hyperfine interactions in Bi1−xNdxFeO3 solid solutions prepared by solid-state sintering
PublikacjaThe series of polycrystalline ceramic powders, Bi1xNdxFeO3 (x = 0.11) was successfully synthesized by mixed oxide method followed by pressureless sintering. X-ray diffraction and Mössbauer spectroscopy were used as complementary methods to study structure and hyperfine interactions of the samples. It was found that with an increase of Nd content, within the range of x = 0.20.3 a structural phase transition from rhombohedral to...
-
Ontology as a Tool for the IT Management Standards Support
PublikacjaIn this paper the authors discuss the initial idea of using ontologies to model requirements of the standards that support IT management processes. The Open Group Architecture Framework (TOGAF) is set as an example. A need for transition from the generic model do the organization-specific one is indicated. The described example serves as a ground for considering the usefulness of such modeling approach in the wider spectrum of...
-
Effect of starch fillers on the dynamic mechanical properties of rubber biocomposite materials
PublikacjaIn the paper the results of dynamic mechanical study of the biocomposites containing one of two types of (potato or corn) strach used as fillers in different amount were discussed. The composites were obtained from rubbery mixture containing natural rubber (NR) as a main component. Thermomechanical analyses (by DMA) showed that the used quantity of strach fillers only slightly influence on the glass transition temperature of vulcanizates.
-
Unraveling the role of boron dimers in the electrical anisotropy and superconductivity in boron-doped diamond
PublikacjaWe use quantum mechanics (QM) to determine the states formed by B dopants in diamond. We find that isolated B sites prefer to form BB dimers and that the dimers pair up to form tetramers (BBCBB) that prefer to aggregate parallel to the (111) surface in the <110> direction, one double layer below the H-terminated surface double layer. These tetramers lead to metallic character (Mott metal Insulator Transition) with holes in the...
-
Chiral Schiff base complexes as an effective catalyst in Diels-Alder reaction
PublikacjaDiels Alder reaction is a very important tool in carbon-carbon bond formation. It is a cycloaddition between a conjugated diene and a second compound called dienophile. Where one or more heteroatoms are present in the diene and/or dienophile framework, the cycloaddition is called hetero-Diels-Alder reaction (HDA). The asymmetric Diels-Alder reaction is among the most powerful available methodologies for that construction of optically...
-
Effect of Cr and Mn doping on ferroelectric and dielectric properties of Li1.72Na0.28Ge4O9 single crystals
PublikacjaLi1.72Na0.28Ge4O9 single crystals pure and slightly doped with chromium and manganese, obtained by Czochralski growth, were investigated for their ferroelectric and dielectric properties. The change in stoichometry of Li2− x Na x Ge4O9 (x = 0.28) crystals doped with Cr and Mn (0.1 mol.%) had an influence on the value of ferroelectric-to-paraelectric phase transition temperature, T c. The applied doping affects the T c value by...
-
Exploring the role of social networks among entrepreneurial Polish immigrants
PublikacjaThe paper reports on the explanatory case study among seven Polish enterprising migrants from Aberdeen Scotland. The aim of the paper is to examine role of social support structure and social networks for enterprising Poles. It also attempts to extend of Waldinger et al (2000) ethnic business development model in the context of entrepreneurial strategies taken from by immigrants from their country of origin, claiming that transition...
-
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...
-
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...
-
Analytical method of modelling the geometric system of communication route
PublikacjaThe paper presents a new analytical approach to modelling the curvature of a communication route by making use of differential equations. The method makes it possible to identify both linear and nonlinear curvature. It enables us to join curves of the same or opposite signs of curvature. Solutions of problems for linear change of curvature and selected variants of nonlinear curvature in polynomial and trigonometric form were analyzed....
-
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),...
-
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...
-
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...
-
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...
-
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...
-
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....
-
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...
-
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,...
-
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...
-
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...
-
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%...
-
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...
-
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...
-
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-...
-
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...
-
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...
-
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...
-
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...
-
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)...
-
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...
-
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...
-
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...
-
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...
-
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,...
-
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...
-
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...
-
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...
-
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...
-
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....
-
About being entrepreneurial in challenging environments – theorizing on the social enterprise behavior in Poland
PublikacjaEntrepreneurial behaviors in challenging institutional environments have been widely investigated in the literature. One of the characteristics of these environments is resource scarcity. This is particularly valid in the context of social entrepreneurship. The aim of this paper is to identify entrepreneurial behaviors in social entrepreneurship and what is happening behind these processes in the context of transition country,...
-
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...
-
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...
-
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...
-
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)...
-
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...
-
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...
-
Terbium Substituted Lanthanum Orthoniobate: Electrical and Structural Properties
PublikacjaThe results of electrical conductivity studies, structural measurements and thermogravimetric analysis of La1−xTbxNbO4+δ (x = 0.00, 0.05, 0.1, 0.15, 0.2, 0.3) are presented and discussed. The phase transition temperatures, measured by high-temperature x-ray diffraction, were 480 °C, 500 °C, and 530 °C for La0.9Tb0.1NbO4+δ, La0.8Tb0.2NbO4+δ, and La0.7Tb0.3NbO4+δ, respectively. The impedance spectroscopy results suggest mixed conductivity...