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Search results for: peierls transition
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Effect of electron count and chemical complexity in the Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor
PublicationHigh-entropy alloys are made from random mixtures of principal elements on simple lattices, stabilized by a high mixing entropy. The recently discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous materials; e.g., it has a well-defined superconducting transition along with an exceptional robustness against disorder....
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Wydłużanie krzywej przejściowej w analitycznej metodzie projektowania
PublicationW pracy przedstawiono problematykę wydłużania krzywych przejściowych, wykorzystując do tego celu analityczną metodę projektowania. Podstawę analizy stanowiły obliczenia numeryczne przeprowadzone dla szerokiego zestawu parametrów charakteryzujących standardowy układu geometryczny. Po sformułowaniu odpowiednich zależności teoretycznych rozpatrzono kwestie znaczenia wielkości promienia łuku kołowego i kąta zwrotu trasy na uzyskane...
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The Urban Mentoring as a New Method of Participatory Urban Planning in Poland
PublicationTwenty-five years after the return of democracy and the beginning of basing the country's economy on neoliberal developmental paradigm, Poland adopted the regulations regarding management of urban policy, which had been wait for over a decade (accession to the EU). The National Urban Policy as well as the Act on revitalization have defined, in a modern manner, the field of cooperation between the local government, the administration...
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Wild oscillations in a nonlinear neuron model with resets: (I) Bursting, spike-adding and chaos
PublicationIn a series of two papers, we investigate the mechanisms by which complex oscillations are generated in a class of nonlinear dynamical systems with resets modeling the voltage and adaptation of neurons. This first paper presents mathematical analysis showing that the system can support bursts of any period as a function of model parameters, and that these are organized in a period-incrementing structure. In continuous dynamical...
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Preparation and structure of nanocrystalline sol-gel derived Cu doped LiTi2O4 powders
PublicationAmong the spinel oxides materials, lithium titanate (Li1+xTi2-xO4 where 0 ≤ x ≤ 0.33) could be very interested from pratical applications point of view. Lithium titanate is a II type spinel oxide superconductor with relatively high (~13 K for x = 0) superconducting transition temperature Tc. Above Tc lithium titanate shows metallic behaviour and can be used e.g. as electrodes for rechargeable lithium-ion batteries. Since the discovery...
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Polaronic and Mott insulating phase of layered magnetic vanadium trihalide VCl3
PublicationTwo-dimensional (2D) van der Waals (vdW) magnetic 3d-transition metal trihalides are a new class of functional materials showing exotic physical properties useful for spintronic and memory storage applications. In this article, we report the synthesis and electromagnetic characterization of single-crystalline vanadium trichloride, VCl 3 , a novel 2D layered vdW Mott insulator, which has a rhombohedral structure (R3, No. 148) at...
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Spatial planning on regional level
PublicationPolish spatial planning results from typical for countries of Central and Eastern Europe transition . They have undergone the transformation from decentralized management system based on the dominance of state to the system of representative democracy, based on self-government administration; also territorial on regional level.
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Study of Integer Spin S = 1 in the Polar Magnet β-Ni(IO3)2
PublicationPolar magnetic materials exhibiting appreciable asymmetric exchange interactions can potentially host new topological states of matter such as vortex-like spin textures; however, realizations have been mostly limited to half-integer spins due to rare numbers of integer spin systems with broken spatial inversion lattice symmetries. Here, we studied the structure and magnetic properties of the S = 1 integer spin polar magnet β-Ni(IO3)2...
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Transformation of Energy Markets: Description, Modeling of Functioning Mechanisms and Determining Development Trends
PublicationOne of the key contemporary economic and social issues today is the global energy transition. Energy transition processes are having a significant impact on the development of world economies, increasing their TFP and leading to an increase in their level of innovation through the transfer of myriad new technologies. These processes also contribute to an increase in foreign direct investment and, consequently, an increase in the...
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A simple model of the trap-assisted recombination with the excitonic Auger mechanism
PublicationWe present a simple model of the trap-assisted recombination combined with the excitonic Auger mechanism. It has been shown that only six independent transitions of electrons and holes should be taken into account to describe a combination of the Shockley–Read–Hall (SRH) recombination with this excitonic process. This is in opposition to a well-known model of the SRH mechanism with the free carriers Auger effect via deep states,...
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Effect of pine impregnation and feed speed on sound level and cutting power in wood sawing
PublicationThe sound levels along with the cutting power registered during the sawing process of the impregnated and non-impregnated pine wood at two feed speeds are shown and compared in this paper. Statistically significant differences in the acoustic signals occurred at the lower feed rate. The differences became smaller with an increase in the feed speed. In contrast to the sound signal, the differences...
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On the electronic structure of methyl butyrate and methyl valerate
PublicationWe present novel results of the analysis of the electronic structure of two aliphatic esters: methyl butyrate and methyl valerate. High-resolution photoabsorption spectra were collected and analyzed over the energy range 4.0–10.8 eV and showed for both the molecules not only a clear band of the HOMO to LUMO transition, but also vibronic structure associated with the first Rydberg-valence transition. Photoelectron spectra recorded...
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MgPdSb─An Electron-Deficient Half-Heusler Phase
PublicationThe half-Heusler family consists of many semiconducting intermetallic compounds, virtually all of them having a valence electron count (VEC) of 18. We have studied an electron-deficient (VEC = 17) phase MgPdSb and its Pd-stuffed variant MgPd1.25Sb. The cubic F4̅3m crystal structure was confirmed by the Rietveld refinement of powder X-ray diffraction (XRD) data. The lattice parameter is a = 6.284 and 6.335 Å for MgPdSb and MgPd1.25Sb,...
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The Boltzmann sequence-structure channel
PublicationWe rigorously study a channel that maps binary sequences to self-avoiding walks in the two-dimensional grid, inspired by a model of protein statistics. This channel, which we also call the Boltzmann sequence-structure channel, is characterized by a Boltzmann/Gibbs distribution with a free parameter corresponding to temperature. In our previous work, we verified experimentally that the channel capacity has a phase transition for...
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Flow Maps and Flow Patterns of R1233zd(E) in a Circular Minichannel at Low, Medium and High Values of Saturation Pressure
PublicationThere is a gap in knowledge regarding the flow pattern of low-boiling working fluids in the range of high saturation temperatures (above 120°C) and medium and high reduced pressures (0.5-0.9). Data are present in the literature for similar values of reduced pressures, but for lower values of saturation temperature. This is due to the existing refrigeration applications of these working fluids. At high values of reduced pressure,...
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Synthesis, crystal structure and cytotoxic activity of ruthenium(II) piano-stool complex with N,N-chelating ligand
PublicationA mononuclear compound of the general formula [(η6-p-cymene)RuIICl(2,2′-PyBIm)]PF6 has been synthesized from a bidentate N,N-donor ligand, viz. 2,-(2′-pyridyl)benzimidazole (2,2′-PyBIm) and the corresponding chloro-complex [(η6-p-cymene)Ru(μ-Cl)Cl]2 (precursor). The isolated coordination compound was characterized by IR, UV–vis and 1H, 13C NMR spectroscopies. The single crystal X-ray analysis of the complex reveals that the asymmetric...
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High-conducting Bi4V2-xFexO11-δ ceramics containing Fe2O3 nanocrystals: Structure and properties
PublicationThe topography, structure, thermal, magnetic, and electrical properties of Bi4V2-xFexO11-δ ceramics substituted with x = 0.5 and 0.7 Fe were studied. The microscope analysis showed the presence of iron-rich nanocrystals formed on the Bi-Fe-V-O grains. The X-ray diffraction studies confirmed that grains are built mostly of tetragonal Bi4V1.5Fe0.5O10.5 phase. Thermal properties analysis showed an order-disorder type γ ↔ γʹ phase...
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(CsX)Cu5O2(PO4)2 (X = Cl, Br, I): A Family of Cu2+ S = 1/2 Compounds with Capped-Kagomé Networks Composed of OCu4 Units
PublicationThree new salt inclusion compounds (CsX)Cu5O2(PO4)2 (X = Cl, Br, I), phosphate analogues of the kagomé mineral averievite, are reported. Their crystal structures are composed of trigonal networks of corner-sharing OCu4 anion-centered tetrahedra, forming capped-kagomé planes, which can also be regarded as two-dimensional slices along the [111] direction of a pyrochlore lattice. Magnetization and heat capacity measurements reveal...
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Novel Polyurethanes as Antifouling Paint Matrices
PublicationThe new poly(ester-ether urethane)s (PEEUR) were prepared in two stage synthesis from formerly obtained oligo(alkylene ester-ether)diols (OAEE) and 4,4‘-diphenylmethane diisocyanate (MDI). PEEUR samples were subjected to crosslinking with styrene in the presence of radical polymerization initiators: methyl ethyl ketone peroxide (MEKPO) or cobalt 2-ethyl cyclohexanoate (EtHCo). Crosslinked PEEUR were characterized by their physicochemical...
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APPLICATION OF THE THEORY OF SEMI-MARKOV PROCESSES TO DETERMINE A LIMITING DISTRIBUTION OF THE PROCESS OF CHANGES OF ABILITY AND INABILITY STATES OF FUEL SUPPLY SYSTEMS IN HEAVY FUEL DIESEL ENGINES
PublicationThe paper presents applicability of the theory of semi-Markov processes to determine a limiting distribution of the process of changes of technical states of fuel systems for marine engines running on heavy fuel oils. The proposed study of this process includes the components of such fuel systems like: 1 - injectors, 2 - high pressure hoses, 3 - injection pumps, 4 - low pressure hoses, 5 – fine filters, 6 - coarse filters, 7 – fuel-feed...
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Computer-aided reconstruction of the railway track axis geometrical shape
PublicationIn 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...
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Computer-Aided Design of Railroad Horizontal Arc Areas in Adapting to Satellite Measurements
PublicationThis 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...
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Study of the effect of thermally reduced graphene oxide on the physical and mechanical properties of flexible polyurethane foams
PublicationFlexible 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...
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Structure and hyperfine interactions in Bi1−xNdxFeO3 solid solutions prepared by solid-state sintering
PublicationThe 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...
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Seaweed as a resource for Anaerobic Digestion
PublicationExtensive growth of algae contributes to disruptive changes to the water ecosystems. This is mainly caused by redundant nutrients that are washed off the land and end up in waters. Tackling eutrophication by recovery of nutrients can be a solution to the problem. Cast marine biomass can be a resource for renewable energy technologies like anaerobic digestion. Such approach can contribute to the transition to a circular bio-economy and...
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Ontology as a Tool for the IT Management Standards Support
PublicationIn 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...
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Effect of starch fillers on the dynamic mechanical properties of rubber biocomposite materials
PublicationIn 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.
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Unraveling the role of boron dimers in the electrical anisotropy and superconductivity in boron-doped diamond
PublicationWe 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...
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Security of export transactions in the offer of leading banks on the Polish market
PublicationThe following article presents the so-called conditioned payment methods, i.e. instruments for securing export transactions, such as letter of credit, documentary collection, bank guarantees, factoring and forfaiting. The characteristics of each particular method are presented as well as the transactions using them are described. In the following paper, the author included also the leading Polish banks, which offer the above- mentioned...
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Możliwość oszacowania niezawodności silników o zapłonie samoczynnym z zastosowaniem teorii procesów semi-Markowa oraz podejmowania decyzji eksploatacyjnych z uwzględnieniem wiarygodności diagnozy o stanie technicznym tego rodzaju silników spalinowych = Possibility of estimating the reliability of diesel engines by applying the theory of semi-Markov processes and making operational decisions by considering reliability of diagnosis on technical state of this sort of combustion engines/
PublicationThe paper presents semi-Markov models of technical state transitions for diesel engines, useful for determining reliability of the engines. A possibility of application of a three-state model with a simplified matrix function, or even a two-state model, to determine reliability of the engines, has been described herein on examples of known from literature semi-Markov models, for the case when appropriate diagnosing systems (SDG)...
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New lanthanide–CB[6] coordination compounds: relationships between the crystal structure and luminescent properties
PublicationThe reaction between cucurbit[6]uril (CB[6]) and lanthanide chlorides (Eu, Sm, Tb and Tm) in acidic aqueous media led to four new structures. The compounds obtained are isostructural with general formula [Ln2(H2O)12(H2O@CB[6])]Cl6(H2O)4 (Ln = Eu3+ (1), Sm3+ (2), Tb3+ (3) and Tm3+ (4)) and crystallize in the P21/c space group. For the complexes with Eu3+, Sm3+ and Tb3+, the luminescent properties in the solid state and aqueous media...
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Study of ultraviolet-visible fluorescence emission following resonant Auger decay of the 2p-1nl core-excited states of argon atoms
PublicationWe have studied the excitation and relaxation of Ar+ ions populated in resonant Auger decay from the Ar 2p−1nl core-excited states by using ultraviolet-visible fluorescence spectroscopy and photon-photon delayed coincidence technique. Fluorescence emission yields were measured in the photon energy range of 240-–255 eV for the 3s23p4(1D)5s(2D) → 3s23p4(1D)4p(2F) (393 nm) and 3s23p4(1D)4d(2F) → 3s23p4(1D)4p(2F) (335 nm) transitions...
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Radiative lifetime of a BODIPY dye as calculated by TDDFT and EOM-CCSD methods: solvent and vibronic effects
PublicationThe radiative emission lifetime and associated S1 excited state properties of a BODIPY dye are investigated with TDDFT and EOM-CCSD calculations. The effects of a solvent are described with the polarizable continuum model using the linear response (LR) approach as well as state-specific methods. The Franck–Condon (FC), Herzberg–Teller (HT) and Duschinsky vibronic effects are evaluated for the absorption and emission spectra, and...
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Chiral Schiff base complexes as an effective catalyst in Diels-Alder reaction
PublicationDiels 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...
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Ab initio chemical kinetics of Isopropyl acetate oxidation with OH radicals
PublicationGlobal reactivity descriptors of isopropyl acetate (IPA) and thermo-kinetic aspects of its oxidation via OH radicals have been studied. Transition state theory (TST) was utilized to estimate the bimolecular rate constants. Ten oxidation pathways have been investigated, and all of them are exothermic. The potential energy diagram has been sketched using different pre- and post-reactive complexes for all reaction pathways. Rate coefficient...
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Exploring the role of social networks among entrepreneurial Polish immigrants
PublicationThe 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...
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ZMIANY STRUKTURY DEMOGRAFICZNEJ LUDNOŚCI – WYZWANIA DLA RYNKU PRACY
PublicationPolska, podobnie jak i inne kraje europejskie doświadcza w przyspieszonym tempie zmian demograficznych, które w krajach o rozwiniętych gospodarkach rynkowych rozpoczęły się w latach 60. XX wieku. Procesy nieodwracalne, związane ze starzeniem się społeczeństwa na początku zaobserwowano w Skandynawii, następnie proces ten objął kraje Europy Zachodniej, Europy Południowej, w latach 90. XX wieku – również Europę Środkową i Wschodnią....
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A comparison of structural and luminescence properties of lead(II) coordination polymers with isomeric thiophenecarboxylate ligands
PublicationTwo new lead(II) coordination polymers with isomeric thiophenecarboxylates, namely [Pb(2tpCOO)2]n (1) and [Pb(3tpCOO)2(H2O)]n (2) (2tpCOO− = thiophene-2-carboxylate, 3tpCOO− = thiophene-3-carboxylate), were synthesized and characterized. Single crystal X-ray crystallography revealed a distorted pentagonal pyramidal geometry {PbO6} around Pb in 1 and a distorted dodecahedral geometry {PbO8} in 2. The distortion derived from the...
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Singular Surface Curves in the Resultant Thermodynamics of Shells
PublicationWithin six-parameter shells theory we discuss the governing equations of shells with material or non-material singular curves. By singular curve we mean a surface curve where are discontinuities in some surface fields. As an example we consider shells with junctions and shells undergoing stress-induced phase transitions.
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Sanctions and their role in preventing the appropriation of the creditor’s property rights in bankruptcy proceedings–the case of Poland
PublicationThe aim of this paper is to fill the cognitive gap regarding the role of sanc-tions in the protection of a creditor’s property rights in the event of an entrepreneur insolvency. The impact of sanctions on transaction costs, including their identifica-tion and types, as well as the impact on the protection of creditor rights, has been poorly recognized in the subject literature to date. This article investigates...
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Investigation of magnetic order in a new intermetallic compound Nd2PtGe3
PublicationIn 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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Analytical method of modelling the geometric system of communication route
PublicationThe 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....
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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
PublicationN-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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Modeling SPMD Application Execution Time
PublicationParallel applications in a Single Process Multiple Data paradigm assume splitting huge amounts of data to multiple processors working in parallel at small data packets. As the individual data packets are not independent, the processors must interact with each other to exchange results of the calculations with their adjacent partners and take these results into account in their own computations. An example of SPMD is geometric parallelism...
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HISTORY OF INITIAL ENERGY AND WATER NETWORK DEVELOPMENT IN QATAR
PublicationQatar: A country which had to be associated with neighboring countries like UAE or Saudi Arabia for people to know about it, stands proud today due to the ample production and exporting of Black Gold. A country with almost no vegetation or suitable weather to harvest crops, turned from being heavily dependent on trading Pearls to exporting natural oil and gas to all over the globe. The paper outlines in details the history of the...
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Cellulosic bionanocomposites based on acrylonitrile butadiene rubber and Cuscuta reflexa: adjusting structure-properties balance for higher performance
PublicationDesign 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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Magnetoelectric, spectroscopic, optical and elastic properties of Co-doped BaTiO3 ceramics
Publicationhe 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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Human System Interaction in Review: Advancing the Artificial Intelligence Transformation
PublicationThe 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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Effect of composition on the thermal properties and structure of M-Al-Si-O-N glasses, M = Na, Mg, Ca
PublicationThe 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
PublicationIsohexides, 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...