Search results for: GEOTHERMAL DOUBLET
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Comparitive study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels
PublicationIn the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation...
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The use of thermal imaging camera to estimate velocity profiles based on temperature distribution in a free convection boundary layer
PublicationThis work describes an attempt to assess whether the temperature field from a thermal imaging camera can be converted into a velocity field with an accuracy sufficient for qualitative conducting or describing the phenomenon, i.e. when the Navier-Stokes, Fourier-Kirchhoff and continuity equations are mutually coupled. The consequence of this link between temperature fields and velocity is the possibility to formulate the hypothesis...
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Metody strojenia regulatorów typu PID z wykorzystaniem technologii syntezy regulatorów od stanu
PublicationUkłady sterujące typu PID są jednymi z najbardziej popularnych regulatorów wykorzystywanych w układach regulacji. W związku z tym znanych jest szereg metod doboru wartości ich parametrów (nastaw). Obok różnych metod inżynierskich czy analitycznych strojenia tego typu regulatorów, dostępne są również podejścia bazujące na optymalizacji. Wskaźnikiem jakości znajdującym w nich zastosowanie jest np. całka z kwadratu uchybu. W artykule...
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Supercapacitors - charge redistribution and restoring voltage
PublicationThe charge in supercapacitor is stored on electrodes and in electrolyte. The charges on electrodes create the Helmholtz double layer which is formed immediately with time constant of the order of seconds, while the charge storage in electrolyte is going on with time constant of the order of hundreds seconds. When the charged supercapacitor is shorted for few seconds, the charge from electrodes is discharged while the charge in...
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Transient States during Short-circuit in a Line Powered by UPS and its Impact on Earth Fault Loop Impedance Measurement and Power Quality
PublicationThe short-circuit in a line powered by Uninterruptible Power Supply (UPS) during different UPS operation modes is presented in the article. The transient state condition related to the short-circuit in a line fed from double conversion On-line UPS is discussed in detail. The results of the measurements of earth fault loop impedance (FLI) in circuits powered by UPS with the instruments of various manufacturers are presented. The...
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Mathematical Approach to Assess a Human Gait
PublicationA purpose of the paper was to create a mathematical approach to assess a human gait. The scope of the study was to model a normal gait in the sagittal plane and frontal plane of the body. Applying the Newton-Euler formulation, three multibody biomechanical models were derived to describe single support phase and double support phase of the gait. To model a gait in the sagittal plane the open-close sagittal 6DOF model and the open-close...
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DETECTION OF DEBONDING IN STEEL BARS EMBEDDED IN CONCRETE USING GUIDED WAVE PROPAGATION
PublicationThe paper presents a non-destructive diagnostic technique based on guided wave propagation phenomenon used to assess the adhesive bonding between a steel bar and a concrete cover. Double-layered cylindrical specimens with different levels of debonding and its location were investigated. The influence of bonding length on the excitation of multiple modes of longitudinal guided waves was analysed. Numerical simulations of guided...
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Dissociative electron attachment and anion-induced dimerization in pyruvic acid
PublicationWe report partial cross sections for the dissociative electron attachment to pyruvic acid. A rich fragmentation dynamics is observed. Electronic structure calculations facilitate the identification of complex rearrangement reactions that occur during the dissociation. Furthermore, a number of fragment anions produced at electron energies close to 0 eV are observed, that cannot originate from single electron-molecule collisions....
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Unusual behaviour of (Np,Pu)B2C
PublicationTwo transuranium metal boron carbides, NpB2C and PuB2C have been synthesized by argon arc melting. The crystal structures of the {Np,Pu}B2C compounds were determined from single-crystal X-ray data to be isotypic with the ThB2C-type (space group R3m, a = 0.6532(2) nm; c = 1.0769(3) nm for NpB2C and a = 0.6509(2) nm; c = 1.0818(3) nm for PuB2C; Z = 9). Physical properties have been derived from polycrystalline bulk material in the...
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Realizacja przetwornika obrazu CMOS z wbudowaną konwersją A/C i cyfrowym układem CDS
PublicationW artykule przedstawiono realizację w technologii CMOS 180 nm przetwornika obrazu z wbudowaną konwersją analogowo-cyfrową oraz z funkcją cyfrowej redukcji szumu. Przedstawiona realizacja przetwornika obrazu różni się od znanych z literatury rozwiązań tym, że układ redukcji szumu CDS (Correlated Double Sampling) umieszczono w każdym pikselu obrazu. Dzięki tej modyfikacji możliwe jest zastąpienie migawki szczelinowej przez migawkę...
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Defining the thermal conductivity of thermally heterogeneous hollow wall bricks used as elements for increasing the comfort of buildings
PublicationThe article presents numerical calculation analysis in the scope of determining thermal conductivity coefficientλeq[W/(m·K)] of thermally heterogeneous hollow bricks of thermally heterogeneous structure (a combinationof structural material with thermal insulation material). Numerical calculations were conducted by means ofprofessional software TRISCO-KOBRU 86, serving thermal circulation analysis in a 2D field in stationary approach.The...
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The energy approach to fatigue crack growth of S355 steel welded specimens subjected to bending
PublicationThe study presents the results of the research on the rate of fatigue crack growth subjected to bending in the ferritic-pearlitic structure. The studies were carried out at a constant amplitude of the moment and at various values of the load ratios R and at the operating frequency of the machine of 28.4 Hz. Flat specimens made of S355 steel and with fillet welds and with double-sided blunt external notches as well as concave...
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Magnetic-field-induced electric quadrupole moments for relativistic hydrogenlike atoms: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublicationWe consider a Dirac one-electron atom placed in a weak, static, uniform magnetic field. We show that, to the first order in the strength of the external field, the only electric multipole moments, which are induced by the perturbation in the atom, are those of an even order. Using the Sturmian expansion of the generalized Dirac-Coulomb Green function we derive a closed-form expression for the electric quadrupole moment induced...
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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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Molecular basis for the DNA damage induction and anticancer activity of asymmetrically substituted anthrapyridazone PDZ-7
Publicationnthrapyridazones, imino analogues of anthraquinone, constitute a family of compounds with remarkable anti-cancer activity. To date, over 20 derivatives were studied, of which most displayed nanomolar cytotoxicity towards broad spectrum of cancer cells, including breast, prostate and leukemic ones. BS-154, the most potent derivative, had IC50 values close to 1 nM, however, it was toxic in animal studies. Here, we characterize another...
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DSC and TG results for strontium ferrite molybdate: pristine La, or Nb-doped
Open Research DataThis dataset consists of DSC and TG data collected for SFM, LSFM (La-doped) and SFMNb (Nb-doped) compounds, which were undertaken to analyze the reoxidation process of reduced compounds and its transition to double-perovskite structure .The appropriate amount of the powder (~10 mg with 10% tolerance factor) were placed into the alumina crucible and...
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Charge dependence of fragmentation process induced by ion collisions with furan molecule
PublicationThe goal of this work is to describe the system evolution after ion-molecule interaction. We combine different quantum chemistry and statistical mechanics approaches in order to give extended description of the process. Herein we report on a recent study of the fragmentation mechanism of neutral, singly- and doubly-ionized furan molecule in the gas phase.
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Nowa metoda obliczania rozpływu prądów zwarciowych w przewodach odgromowych linii wysokiego napięcia
PublicationReferat przedstawia nowatorską metodę obliczania wartości prądów płynących w przewodach odgromowych w czasie zwarć, pozwalającą na dobór przewodów odgromowych pod względem wytrzymałości cieplnej. Proponowana metoda charakteryzuje się większą dokładnością i większą uniwersalnością niż powszechnie stosowane metody, pozwalając tym samym na dobór przewodów odgromowych z mniejszym ryzykiem niepewności. Prezentowana metoda obliczeniowa...
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Wpływ parametrów strugi paliwa wtryskiwanego do cylindra silnika okrętowego na początkową fazę rozpylania
PublicationPrzedmiotem rozprawy jest analiza procesu wtrysku oleju napędowego do cylindra silnika okrętowego z zapłonem samoczynnym i bezpośrednim wtryskiem paliwa. Analiza tego zagadnienia została przeprowadzona w aspekcie wpływu makro parametrów strugi na początkową fazę rozpylania oleju napędowego. Celem niniejszej pracy jest określenie wpływu współczynnika L/D (długość otworu/średnica) otworu wylotowego wtryskiwacza na zmianę charakterystyki...
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Negative Poisson’s ratio from pentagons: A new auxetic structure combining three different auxetic mechanisms
PublicationA novel class of two-dimensional auxetic structures based on the pentagon motif is proposed. Their mechanical properties are investigated by combining molecular mechanics simulations with a simple three-parameter mechanical model which assumes perfectly elastic behavior. It is predicted that the proposed structures – termed as double re-entrant honeycomb – may possess unique mechanical characteristics, which include complete and...
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Dissociative electron attachment to benzoic acid (C7H6O2)
PublicationThe dissociative electron attachment (DEA) to benzoic acid (C6H5COOH) has been studied using an experimental crossed beam setup of a quadrupole mass spectrometer and a trochoidal electron monochromator. Relative partial cross sections for the DEA to produce negative ion fragments show the main channels for dissociation. The comparison of the present results with the ultraviolet photoelectron spectrum of benzoic acid [J. Meeks,...
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Microstrip four-port circulator using a ferrite coupled line section
PublicationThis paper describes an alternative configuration of a four-port circulator realized in a microstrip ferrite coupled line technology. The proposed fully planar device employs two three-port circulators consisting of a ferrite coupled line junction and T junction. Both circulators are connected through the same arm, hence, the problem of anti-parallel magnetization met in this type of circulators is avoided without the increase...
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Modelling an accelerometer for robot position estimation
PublicationThe article describes a new model of a MEMS accelerometer for usage in inertial measurement units (IMU). Such units allow to measure orientation and location of the sensor/system and therefore can be applied for systems positioning. The main purpose of the paper is to model pertinent accelerometer functions substantial in determination of the location of the sensor by means of double integration of acceleration. The model takes...
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Optimized Stress and Geometry Control of Spherical structures under Lateral Loadings
PublicationIn this paper, a numerical model of a double-layer spherical structure has been examined under lateral loadings. When the structure has been distorted due to loadings, the dislocated joints have been moved to their original positions utilizing the adjustment techniques based on the force method. Meanwhile, the members’ internal forces were kept in the desired domain. Optimization techniques were also implemented in order to minimalize...
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Evaluation of position estimation based on accelerometer data
PublicationThe paper concerns the problem of integrating data from accelerometers. A suitable model of a MEMS accelerometer is presented which is a part of inertial measurement units (IMU). Such units allow to measure orientation as well as to localize systems. They also appear to be applicable for systems positioning. The main purpose of the paper is to discuss conditions that must be satisfied to calculate the location of the sensor by...
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The Creation of an Antimicrobial Coating on Contact Lenses by The Use of Nanocopper
PublicationThe aim of the research was to creation an antimicrobial coating on contact lens and examine the ability of copper nanoparticles to decrease microbial adhesion and prevent the growth of bacteria. The creation was based on the immersion method in solution with dispersed nanoparticles of copper at concentration 200 pm. There were evaluated follows factors: time of immersion and base to dispersed nanoparticles. Three solutions: ethyl...
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Influence of steel brackets supporting crane runway girders structure on the stress distribution in the brackets
PublicationThe paper presents a numerical analysis of steel brackets supporting a double-span crane runway girders. The purpose of the study was to assess the new structural solution based on the stress distribution in the brackets. In order to simplify the connection, the bottom flange of the crane runway girder is based directly on the upper flange of the bracket. As a result, the support reaction is no longer applied in the plane of the...
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Extending touch-less interaction with smart glasses by implementing EMG module
PublicationIn this paper we propose to use temporal muscle contraction to perform certain actions. Method: The set of muscle contractions corresponding to one of three actions including “single-click”, “double-click” “click-n-hold” and “non-action” were recorded. After recording certain amount of signals, the set of five parameters was calculated. These parameters served as an input matrix for the neural network. Two-layer feedforward neural...
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Towards Changes of Macro-Economic Structures in Middle Eastern Countries. Empirical Evidence for 1970–2018
PublicationMiddle East countries share a wide bundle of specific structural economic features and one of the latest is a high dependency of these economies on fossil fuels, which is quantitatively demonstrated through the share of oil and gas revenues in total export, but also in gross domestic product composition. This high economic dependency on natural resources on one hand has recently generated a material wealth of Middle Eastern countries...
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Novel 1,2,4-Oxadiazole Derivatives in Drug Discovery
PublicationAbstract: Five-membered 1,2,4-oxadiazole heterocyclic ring has received considerable attention because of its unique bioisosteric properties and an unusually wide spectrum of biological activities. Thus, it is a perfect framework for the novel drug development. After a century since the 1,2,4-oxadiazole have been discovered, the uncommon potential attracted medicinal chemists’ attention, leading to the discovery of a few presently...
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Capacitance Enhancement by Incorporation of Functionalised Carbon Nanotubes into Poly(3,4-Ethylenedioxythiophene)/Graphene Oxide Composites
PublicationThis paper reports on the role of oxidised carbon nanotubes (oxMWCNTs) present in poly-3,4-ethylenedioxytiophene (PEDOT)/graphene oxide (GOx) composite. The final ternary composites (pEDOT/GOx/oxMWCNTs) are synthesised by an electrodeposition process from the suspension-containing monomer, oxidised carbon nanotubes and graphene oxide. Dissociated functional groups on the surface of graphene oxide play a role of counter-ions for the...
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Rekonstrukcja ewolucji układu przestrzennego średniowiecznego miasta i portu Szczecin Reconstruction of the Spatial Evolution of the Medieval City and Port of Szczecin
PublicationPraca rekonstruuje ewolucję układu osadniczego Szczecina w okresie od połowy VIII w. do początku XIV w., w oparciu o interpretację dostępnej literatury naukowej dotyczącej historii i archeologii Szczecina oraz metodę analizy planistycznej. Bardzo istotnym elementem opisu struktury urbanistycznej wczesnośredniowiecznego Szczecina było określenie roli i położenia portu. W wyniku analizy zmian układu przestrzennego miasta w omawianym...
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Betaine and L-carnitine ester bromides: Synthesis and comparative study of their thermal behaviour and surface activity
PublicationSix esters of both betaine and L-carnitine bromides, featuring alkyl groups ranging from C8 to C18 in length, have been synthesized. The thermal behaviour of these twelve bio-based salts has been analyzed and compared by thermal gravimetric analysis and differential scanning calorimetry. The L-carnitine alkyl ester bromides melted below 100 C and can hence be considered ionic liquids (ILs) with full rights. Conversely, the betaine...
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Hyaluronan-Chondroitin Sulfate Anomalous Crosslinking Due to Temperature Changes
PublicationGlycosaminoglycans are a wide class of biopolymers showing great lubricating properties due to their structure and high affinity to water. Two of them, hyaluronic acid and chondroitin sulfate, play an important role in articular cartilage lubrication. In this work, we present results of the all-atom molecular dynamics simulations of both molecules placed in water-based solution. To mimic changes of the physiological conditions,...
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Surface active fatty acid ILs: Influence of the hydrophobic tail and/or theimidazolium hydroxyl functionalization on aggregates formation
PublicationNine structurally-related fatty acid ionic liquids have been prepared and their thermal behavior as well as their ability to self-assemble in water has been investigated. The thermal properties were studied by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), while the aggregation behavior was analyzed by tensiometry, isothermal titration calorimetry (ITC), conductometry, dynamic light scattering (DLS),...
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Multiscale model for blood flow after a bileaflet artificial aortic valve implantation
PublicationCardiovascular diseases are the leading cause of mortality in the world, mainly due to atherosclerosis and its consequences. The article presents the numerical model of the blood flow through artificial aortic valve. The overset mesh approach was applied to simulate the valve leaflets motion and to realize the moving mesh, in the aortic arch and the main branches of cardiovascular system. To capture the cardiac system’s response...
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An experimental investigation on the effect of new continuous core-baffle geometry on the mixed convection heat transfer in shell and coil heat exchanger
PublicationIn the article, the authors presented the influence of continuous core-baffle geometry at mixed convection heat transfer in shell and coil heat exchanger. Experiments were carried out for a large power range, i.e. from 100W to 1200W and mass flow rates ranging from 0.01 kg/s to 0.025 kg/s. During the experiments, the mass flow rate of cooling water, the temperature of water at the inlet and outlet as well as the wall temperature...
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Corrigendum to “An investigation on residual stress and fatigue life assessment of T-shape welded joints” [Eng. Fail. Anal. 141 (2022) 106685]
PublicationThis paper aims to quantitatively evaluate the residual stress and fatigue life of T-type welded joints with a multi-pass weld in different direction. The main research objectives of the experimental test were to test the residual stress by changing direction along with multiple wielding passes and determine the fatigue life of the welded joints. The result shows that compressive residual stress increases in the sample gradually...
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Studies on Aminoanthraquinone-Modified Glassy Carbon Electrode: Synthesis and Electrochemical Performance toward Oxygen Reduction
PublicationIn this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes were studied towards the electrochemical reduction of oxygen in aqueous and non-aqueous solutions. The reaction of 1-chloro-9,10-anthraquinone with aliphatic diamines was applied for the synthesis of amino-9,10-anthraquinone derivatives. The obtained AQ derivatives were grafted onto the surface of glassy carbon electrodes by electropolymerisation...
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Evaluating the position of a mobile robot using accelerometer data
PublicationThis paper analyses the problem of determining the position of a robot using an accelerometer, which is an essential part of inertial measurement units (IMU). The information gained from such a gauge, however, requires double integration of sensor data. To assure an expected effect, a mathematical model of a low-cost accelerometer of the MEMS type is derived. Moreover, in order to improve the performance of positioning based on...
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Efficient Fabry-Perot Open Resonator Analysis by the use of a Scattering Matrix Method
PublicationIn this paper a comparative study of the computational efficiency of two modeling methods applied to the analysis of the plano- and double-concave Fabry-Perot open resonators is presented. In both numerical approaches, a scattering matrix method was applied, which allows splitting the analysis of the resonator into several sections, including the one with a spherical mirror, which requires the largest computing resources. Two modeling...
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An investigation on residual stress and fatigue life assessment of T-shape welded joints
PublicationThis paper aims to quantitatively evaluate the residual stress and fatigue life of T-type welded joints with a multi-pass weld in different direction. The main research objectives of the experimental test were to test the residual stress by changing direction along with multiple wielding passes and determine the fatigue life of the welded joints. The result shows that compressive residual stress increases in the sample gradually...
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Radio- and photosensitization of DNA with compounds containing platinum and bromine atoms
Publication. Irradiations of plasmid DNA by both X-rays and UV light in the presence and absence of compounds containing platinum and bromine atoms were performed in order to asses the sensitization potential of these compounds. Plasmid DNA pBR322 was incubated with platinum (II) bromide, hydrogen hexabromoplatinate (IV), hydrogen hexahydroxyplatinate (IV) and sodium hexahydroxyplatinate (IV). Incubation was followed by X-ray or UV irradiations....
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Evaluating the mobile robot positions using accelerometer data
PublicationThis paper analyzes the problem of determining the position of a robot using an accelerometer, which is an essential part of inertial measurement units (IMU). The information gained from such a gauge, however, requires double integration of sensor data. To assure an expected effect, a mathematical model of a low-cost accelerometer of the MEMS type is derived. Moreover, in order to improve the performance of positioning based on...
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Earth wires currents calculation by tableau analysis
PublicationThe paper presents a new method to compute a phase-to-earth fault current distribution in overhead transmission line. The method is based on the tableau analysis of an unbalanced, multi-wire model of a transmission line. It allows for the calculation of current distribution in overhead earth wires along the transmission line. Additionally, it may be used to calculate currents in a tower’s earthing system as well as voltages over...
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Ageing of Society — Local Disparities. Classification of the Pomorskie Voivodship Communes According to the Pace and Progress of Local Communities’ Ageing
PublicationThe article deals with the issues of local disparities in the field of advancement and pace of demographic ageing. The subjects of the research were communes of the Pomorskie Voivodship. The purpose of the article — i.e., diagnosing and assessing the progress and pace of ageing of local communities in all 123 communes of the Pomorskie Voivodship, was achieved using a combination of traditional measures of ageing: age factor,...
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Container
PublicationThe main aim of the project is to improve interpersonal communication and promote better functionality in the City of Hamburg. An important element is to satisfy the needs of people living and working in diff erent districts. In our project, we sought to give people an outlet and enabled the possibility of creating landscapes. The unusual advantage of the city is that it allows the use of waterways, which in turn become a link...
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Experimental and theoretical investigation of the reactivity of [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2}] towards selected ketones
PublicationIn this work, we report a new type of reactivity of [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2}] (1) towards ketones (BDI* = 2,6-diisopropylphenyl-β-methyldiketiminate ligand). In the reaction of 1 with acetone, cyclopentanone or cyclohexanone, a ketone moiety is inserted into Ti–Pphosphanyl or Ti–Pphosphido bonds to form complexes with a new C–P–P moiety, providing [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2-C(Me)2O}] (2a), [(BDI*)Ti(Cl){η2-OC(Me)2P(SiMe3)-PiPr2}]...
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A method to synthesise groove cam Geneva mechanisms with increased dwell period
PublicationThe present study develops a method to synthesise the groove cam Geneva mechanism with increased dwell period. The main condition of the synthesis is to provide the desired law of motion of the wheel. Additional synthesis conditions are the limitation of the maximum pressure angle and the limitation of the minimum curvature radius of the cam profile. Unlike the conventional Geneva mechanisms, the synthesised groove cam Geneva mechanisms...
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Higher harmonics of the intensity modulated Photocurrent/Photovoltage spectroscopy response - a tool for studying photoelectrochemical nonlinearities
PublicationIn this work, a higher harmonic analysis (HHA) of the intensity modulated photocurrent/photovoltage (IMPS/IMVS) spectroscopy data is proposed as a potent tool for studying nonlinear phenomena in photoelectrochemical and photovoltaic systems. Analytical solutions of kinetic equations were constructed for cases of single and double resonance accounting for various sources of higher harmonics. These sources correspond to the physical...