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Search results for: binary vapour cycle
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Assessment of image processing methods for the determination of propagation of squat-type defects in rails
PublicationWe demonstrate the idea of squat-type defect measurement in the rail and the concept of tracking of the defect development using the techniques of image acquisition and image processing as well as the methods of metric spaces. We introduce the concepts of a set diameter δ(A) and the metric ρ1, which come from the properties of plane figures, to compare and to observe the development of the defects. We characterize the feasibility...
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Modeling the effect of external load variations on single, serie and parallel connected microbial fuel cells
PublicationThis paper presents a microbial fuel cell (MFC) model designed to analyze the effect of the external load on MFC performance. The model takes into account the voltage and the chemical oxygen demand (COD) dependence on the external load. The value of the model parameters were calibrated by means of the voltage relaxation method tests using a controlled load current. Laboratory measurements and MATLAB Simulink model computations...
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Material Flow Analysis in a cooked mussel processing industry
PublicationGalicia (NW Spain) is an ideal environment for mussel culture owing to its excellent natural conditions. It is the first Spanish and European mussel producer and the second worldwide after China. More than 50% of the mussel collected in Galicia is used in the processing industry, which produces different products, as cooked mussel that is canned, frozen or used in the food industry. In this paper a methodology based on Life Cycle...
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Interdyscyplinarne studia doktoranckie na Politechnice Gdańskiej - przykład dobrych praktyki w zakresie realizacji projektów miękkich współfinansowanych z UE
PublicationNiniejszy artykuł przedstawia teoretyczne podstawy zarządzania projektem współfinansowanym ze środków jednego z funduszy strukturalnych Unii Europejskiej (UE), jakim jest Europejski Fundusz Społeczny (EFS). Jako metodę zarządzania projektem wskazano koncepcję Project Cycle Management - PCM. Za przykład dobrych praktyk został w artykule uznany realizowany przez Politechnikę Gdańską (PG) oraz Instytut Maszyn Przepływowych Polskiej...
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Applicability of an effective conductivity approach in modeling thoracic impedance changes
PublicationThis paper describes numerical simulations of the influence of conductivity changes inside a volume conductor on impedance changes measured on its surface. A simple model based on the finite element method has been developed to estimate an applicability of the effective conductivity theory in human chest modeling. The model consisted of a cylinder with two concentric spheres inside. Simulations were performed for two cases: first...
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Composite GFRP U-shaped footbridge
PublicationThe paper presents proposals for the use of glass fiber reinforced polymer composites for the construction of engineering objects, known and commonly used in the shipbuilding industry. An example of a pedestrian footbridge was used in this case, which, despite the considerable thickness of the structural material, was made using infusion technology in one production cycle. The designed and produced footbridge span is durable, dynamically...
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Release and Transport of Toxic, Mobile Organic Compounds (Formaldehyde and Phenols) on an Arctic Glacier
PublicationAs a result of current deglaciation, the chemical cycles of many compounds, including toxic formaldehyde and phenols, are changing. However, the processes by which these chemicals are released have yet to be studied in situ. Here, we quantify fluxes of HCHO and phenols in a glacial catchment within one summer season, obtaining a net release from the glacier of 0.106 · 106 g formaldehyde and 0.255 · 106 g phenols, which can be interpreted...
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TERMODYNAMIC CALCULATIONS OF TURBINE STEAM PARAMETERS
PublicationIn this work a heat balance was made for the nominal conditions of a block working with 18K370 turbine. For the parameters obtained, the thermal-flow calculations of the steam turbine were performed, maintaining the actual geometry of its flow system. Based on the nominal values obtained, iterative thermal and flow calculations were made for both the heat cycle of the power plant block and the steam turbine itself, seeking to obtain...
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Capillary pumped loop as a tool for collecting large heat fluxes from electronic devices on warships
PublicationThe combat potential of future warships will be directly related to the use of modern electronic devices being parts of advanced systems, such as, for instance, radar systems, fire aiming systems, fire detection systems, electric drive systems, and even electronic and radio-electronic weaponry, railguns and lasers, installed on these warships. The capacity and functionality of these devices is continually increasing, at decreasing...
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Self-Organization in Multi-Agent Systems Based on Examples of Modeling Economic Relationships between Agents
PublicationThe goal of the research was to observe and analyze self-organization patterns in Multi-Agent Systems (MAS) by modeling basic economic relationships between agents forming a closed loop of relations necessary for their survival. The paper describes a worked-out MAS including an example of a production cycle and used economic rules. A special focus is put on behavior rules and decision systems of an individual agent such as: product...
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Zabezpieczenia antykorozyjne stalowych barierek ochronnych na obiektach mostowych w ujęciu kosztów cyklu ich życia
PublicationThe article presents the Life Cycle Costs analysis of steel safety barriers operated in road lane conditions, located on a selected bridge structure. Three corrosion protection systems were proposed, analyzing them in terms of the cost of initial and planned outlays related to maintenance. Based on the LCC analysis for three options, taking into account the 25-year lifetime of the barriers, the optimal solutionwas indicated, i.e....
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Shape Memory Materials from Rubbers
PublicationSmart materials are much discussed in the current research scenario. The shape memory effect is one of the most fascinating occurrences in smart materials, both in terms of the phenomenon and its applications. Many metal alloys and polymers exhibit the shape memory effect (SME). Shape memory properties of elastomers, such as rubbers, polyurethanes, and other elastomers, are discussed in depth in this paper. The theory, factors...
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DESIGN AND THEORETICAL ANALYSIS OF A PROTOTYPE TILTING-PAD RADIAL BEARING WITH ADJUSTABLE CLEARANCE
PublicationThe article introduces a design and analysis results of a prototype ORC (organic Rankine cycle) turbo generator rotor assembly of 300kW power, supported by tilting-pad bearings of original design. The calculations were performed for a prototype turbo generator rotor. The shaft of this machine is supported with two radial bearings, lubricated with an unusual lubricant – a low-boiling-point agent. The main objective of the presented...
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Nucleation and growth of CVD diamond on fused silica optical fibres with titanium dioxide interlayer
PublicationNucleation and growth processes of thin diamond films on fused silica optical fibres have been investigated. Fibres were coated with diamond film using microwave plasma enhanced chemical vapour deposition (µPE CVD) system. Since the growth of diamond on the fused silica glass requires high seeding density, two types of glass pre-treatment were applied: titanium dioxide (TiO2) interlayer deposition and sonication in nanodiamond...
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Tailoring the optical parameters of optical fiber interferometer with dedicated boron-doped nanocrystalline diamond thin film
PublicationOptical fiber interferometer using nanocrystalline boron-doped diamond film was investigated. The diamond films were deposited on glass plates using a Microwave Plasma-Enhanced Chemical Vapour Deposition (μPE CVD) sys-tem. The growth time was 3h, with boron doping level of 10 000 ppm producing films (B-NCD-10) of thickness ~ 200 nm. The presence of boron atoms in the diamond film is evident in Raman spectrum as peaks at 1212 cm-1...
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Engineering boron and nitrogen codoped carbon nanoarchitectures to tailor molecularly imprinted polymers for PFOS determination
PublicationPer- and polyfluoroalkyl substances (PFAS) have gained significant attention as emerging contaminants due to their persistence, abundance, and adverse health effects. Consequently, the urgent need for ubiquitous and effective sensors capable of detecting and quantifying PFAS in complex environmental samples has become a priority. In this study, we present the development of an ultrasensitive molecularly imprinted polymer (MIP)...
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How do sterols determine the antufungal activitiy of amphotericin B? Free energy of binding between the drug and its membrane targets.
PublicationAmphotericin B (AmB) is a well-known polyene antibiotic used to treat systemic fungal infections. It is commonly accepted that the presence of sterols in the membrane is essential for the AmB biological activity, that is, for the formation of transmembrane ion channels. The selective toxicity of AmB for fungal cells is attributed to the fact that it is more potent against fungal cell membranes containing ergosterol than against...
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Estimation of Coherence Bandwidth for Underwater Acoustic Communication Channel
PublicationA shallow underwater acoustic communication channel is characterized by strong multipath propagation. The signal reaching the receiver consists of a direct waveform and a number of its delayed and suppressed replica. A significant time dispersion of the transmitted signal and selective fading of its spectrum are observed. Coherence bandwidth defines maximal bandwidth, wherein the channel amplitude characteristic remains constant...
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UV-induced electron transfer between triethylamine and 5-bromo-2′-deoxyuridine. A puzzle concerning the photochemical debromination of labeled DNA
Publication5-Bromo-2'-deoxyuridine (BrdU) photosensitizes DNA to strand break formation. However, this type of photodamage is completely quenched by the presence of triethylamine (TEA) which originates from RP-HPLC purification commonly employed by oligonucleotide providers. While the presence of TEA in oligonucleotide samples does not interfere with PCR or other molecular biology applications, the mechanism of photochemical reaction proceeding...
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Separation of C6 hydrocarbons on sodium dithionite reduced graphene oxide aerogels
PublicationThe ability of reduced graphene oxide aerogels (rGOAs) for challenging gas-phase separation was investigated with hexane isomers and benzene (C6 hydrocarbons) using inverse gas chromatography (IGC). For the first, rGOAs were synthesized with sodium dithionite (DTN) as a reductant. Experiments revealed that the most optimal DTN to graphene oxide mass ratio was 2:1, resulting in the highest specific surface area of 432.3 m2 g−1 and...
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Electron scattering cross sections for 1-pentene, H2C=CH-(CH2)2CH3, molecules
PublicationCross sections, both experimental and theoretical, are reported for electron scattering from 1-pentene (C5H10) molecules. Absolute grand-total cross sections (TCSs) were measured at electron impact energies ranging from 1 to 300 eV, using a linear electron-transmission technique. The dominant behaviour of the experimental TCS energy function is a distinct asymmetric enhancement with the maximum located around 6.5 eV. Discernible...
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Selection of effective cocrystals former for dissolution rate improvement of active pharmaceutical ingredients based on lipoaffinity index
PublicationNew theoretical screening procedure was proposed for appropriate selection of potential cocrystal formers possessing the ability of enhancing dissolution rates of drugs. The procedure relies on the training set comprising 102 positive and 17 negative cases of cocrystals found in the literature. Despite the fact that the only available data were of qualitative character, performed statistical analysis using binary classification...
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Application of Multivariate Adaptive Regression Splines (MARSplines) Methodology for Screening of Dicarboxylic Acids Cocrystal Using 1D and 2D Molecular Descriptors
PublicationDicarboxylic acids (DiAs) are probably one of the most popular cocrystals formers. Due to the high hydrophilicity and non-toxicity, they are promising solubilizes of active pharmaceutical ingredients (APIs). Although DiAs appear to be highly capable of forming multicomponent crystals with various compounds, some systems reported in the literature are physical mixtures the solid state without forming stable intermolecular complex....
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Weryfikacja Poziomów Nienaruszalności Bezpieczeństwa z uwzględnieniem Zagadnień Ochrony Informacji
PublicationNiniejszy rozdział poświęcono wybranym istotnym zagadnieniom analizy bezpieczeństwa funkcjonalnego, w szczególności weryfikacji poziomów nienaruszalności bezpieczeństwa SIL funkcji bezpieczeństwa implementowanych w rozproszonych systemach sterowania i zabezpieczeń z uwzględnieniem zagadnień ochrony informacji. Zaproponowano metodę opartą na informacji ilościowej i jakościowej do weryfikacji SIL (IEC 61508, 61511) z uwzględnieniem...
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AN ENERGY APPROACH TO THE FATIGUE LIFE OF SHIP PROPULSION SYSTEMS
PublicationThe conducted research investigations aimed to carry out an identification of the constructional materials fatigue state of the ship propulsions’ rotational mechanical units for diagnostic purposes. The fatigue cracks of the elements transmitting mechanical energy streams from the propulsion engines to the ship propellers or to the generators of the ship’s electric power station stand for a primary reason for the secondary, usually...
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Novel therapeutic compound acridine–retrotuftsin action on biological forms of melanoma and neuroblastoma
PublicationPURPOSE: As a continuation of our search for anticancer agents, we have synthesized a new acridine-retrotuftsin analog HClx9-[Arg(NO2)-Pro-Lys-Thr-OCH3]-1-nitroacridine (named ART) and have evaluated its activity against melanoma and neuroblastoma lines. Both tumors develop from cells (melanocytes, neurons) of neuroectodermal origin, and both are tumors with high heterogeneity and unsatisfactory susceptibility to chemotherapies....
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Multi-instrument analysis of L-band amplitude scintillation observed over the Eastern Arabian Peninsula
PublicationThe study of scintillation-causing ionospheric irregularities is important to mitigate their effects on satellite communications. It is also important due to the spatial and temporal variability of these irregularities, given that their characteristics differ from one region to another. This study investigates the spatial and temporal characteristics of L1 amplitude scintillation-causing ionospheric irregularities over the Eastern...
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Towards systemic functional safety and security management in hazardous plants
PublicationThe aim of this article is to identify and discuss some issues related to functional safety and security management in hazardous industrial plants. The safety functions are to be realised using the electric / electronic / programmable electronic systems (E/E/PESs) or the safety instrumented systems (SISs) that are designed and operated respectively according to IEC 61508 and IEC 61511 requirements in life cycle. Although the role...
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Comparative testing of numerical models of river ice jams
PublicationIce processes in general, and ice jams in particular, play a dominant role in the hydrologic regime of Canadian rivers, often causing extreme floods and affecting the life cycle of many aquatic, terrestrial, and avian species. Various numerical models have been developed to help simulate the formation and consequences of these very dynamic and often destructive jam events. To test and compare the performance of existing models,...
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Integration of natural and artificial intelligence in production systems
PublicationIntegration processes play an increasingly important role in modern economy, and seriously co-decide about the effectiveness of the company. Integration phase occurs in the system life cycle by preceding the final stages of its implementation and activation. In turn, used in software engineering (SE) iteration-evolutionary models, such as spiral model make that the integration activities can occur in varying degrees in all phases...
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Contaminants in airport runoff water
PublicationDespite the many positives ensuing from the rapid expansion of the air transport sector, airport operations as a whole are a substantial source of environmental pollution.Increases in aviation developments have serious consequences on the surrounding air, soil and water bodies like lakes, rivers and ground water. The present work deals with the determination of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls...
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Analiza porównawcza kosztów środowiskowych budowy i eksploatacji drogi ekspresowej w technologii asfaltowej i betonowej, CZĘŚĆ 1
PublicationW artykule przedstawiono opis analizy porównawczej kosztów środowiskowych budowy i eksploatacji drogi ekspresowej w technologii asfaltowej i betonowej. Do przeprowadzenia badania wykorzystano analizę LCA (ang. Life Cycle Assessment). Jako założenia przyjęto warianty konstrukcji nawierzchni opracowane dla planowanej drogi ekspresowej S6 na odcinku Lębork (wraz z obwodnicą Lęborka) –obwodnica Trójmiasta, a także trzy scenariusze...
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Review of the Complexity of Managing Big Data of the Internet of Things
PublicationTere is a growing awareness that the complexity of managing Big Data is one of the main challenges in the developing feld of the Internet of Tings (IoT). Complexity arises from several aspects of the Big Data life cycle, such as gathering data, storing them onto cloud servers, cleaning and integrating the data, a process involving the last advances in ontologies, such as Extensible Markup Language (XML) and Resource Description...
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Effect of operating conditions on N 2 O production in an anammox sequencing batch reactor containing granular sludge
PublicationNitrous oxide (N2O) is one of the gases with the greatest impact in the atmosphere due to its persistence and significant contribution to the greenhouse effect. This study provides an insight into the dynamics of N2O production in wastewater nitrogen removal systems. A 10 L sequencing batch reactor containing enriched anammox biomass was subjected to different operational conditions, i.e., temperature, feed time, NO2 /NH4 þ ratio...
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Analiza siłowni nadkrytycznych oraz ultranadkrytycznych
PublicationNiniejszy artykuł zawiera przegląd istniejących rozwiązań siłowni nadkrytycznych oraz ultra nadkrytycznych. Przedstawiono historię rozwoju bloków na parametry nadkrytyczne. Obecny stan technologii został zaprezentowany – są to następujące parametry pary świeżej: 650°C oraz 330 bar. W Polsce istnieje 8 bloków pracujących na parametry nadkrytyczne. Ich parametry pracy zostały przedstawione w tekście. Z kolei elektrownią parową posiadającą...
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Support Product Development Framework by Means of Set of Experience Knowledge Structure (SOEKS) and Decisional DNA
PublicationIn this paper, we propose a framework to support product development activi-ties by utilizing Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA). This idea will provide a new direction to researchers working on product development, especially designers and manufacturers. They will be working on the same platform and this will be reducing their communication gap. Once the final idea is perceived about product...
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The effect of elevated temperature on LCF damage growth in 2024AA – Experiment and modeling
PublicationThis paper presents the results of experimental low-cycle fatigue (LCF) tests conducted on EN-AW 2024 alloy in T3511 temper at 100 ◦C, 200 ◦C and 300 ◦C. The material’s basic fatigue characteristics were determined, such as fatigue life curve and cyclic strain curve. Both the hysteresis loop and nature of fracture surfaces obtained in macro- and microscopic observations (scanning electron microscope, SEM) were accounted for. The...
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Acoustic Processor of the MCM Sonar
PublicationThis paper presents the concept of an acoustic processor of the mine countermeasure sonar. Developed at the Department of Marine Electronics Systems, Gdansk University of Technology, the acoustic processor is an element of the MG-89, a modernised underwater acoustic station. The focus of the article is on the modules of the processor. They are responsible for sampling analogue signals and implementing the algorithms controlling...
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Types of wear and tear of biomaterials used in orthopaedic surgery
PublicationPurpose of this paper is presentation of observations on different kinds of wear and tear of biomaterials used in contemporary orthopaedic surgery. Types of prosthesis damage, encountered in medical practice, and their causes have been described. Results of many clinical studies were analysed to review prosthesis damage from the stage of implanting (such as intrusion of a foreign object between its components) to their natural...
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Problems in designing and operating the functional safety solutions of higher integriity levels
PublicationThe aim of this article is to identify and discuss some problems that have been encountered in designing and operating the functional safety solutions of higher safety integrity levels (SIL 3 and SIL 4) in the light of analyses outlined in a new version of the international standard IEC 61508:2010. Examples of such solutions are the electric / electronic / programmable electronic systems (E/E/PESs) and the safety instrumented systems...
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Safety Integrity Verification Issues of the Control Systems for Industrial Process Plants
PublicationThe aim of this article is to identify and discuss some issues that can be encountered in designing the industrial automation and control systems (IACS) for implementing safety functions. In a functional safety standard IEC 61511 for the process industry such systems are named the basic process control systems (BPCS) and the safety instrumented systems (SIS). In a generic functional safety standard IEC 61508 they are depicted as...
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Thermochemical Conversion of Biomass and Municipal Waste into Useful Energy Using Advanced HiTAG/HiTSG Technology
PublicationAn advanced thermal conversion system involving high-temperature gasification of biomass and municipal waste into biofuel, syngas or hydrogen-rich gas is presented in this paper. The decomposition of solid biomass and wastes by gasification is carried out experimentally with a modern and innovative regenerator and updraft continuous gasifier, among others. A ceramic high-cycle regenerator provides extra energy for the thermal conversion...
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Application of the F-statistic of the Fisher-Snedecor distribution to analyze the significance of the effect of changes in the compression ratio of a diesel engine on the value of the specific enthalpy of the exhaust gas flow
PublicationThe paper discusses the impact of changes in the compression ratio on the operating parameters of a diesel engine, e.g. on the temperature of exhaust gases. It presents the construction of the laboratory test stand, on which experimental measurements were realized. It is characterized how the actual changes of the compression ratio were introduced to the existing engine. The program of experimental investigations taking into account...
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Application analysis of a hybrid solid oxide fuel cell-gas turbine system for marine power plants
PublicationThe results of theoretical studies of the possibilities of using hybrid solid oxide fuel cell–gas turbine (SOFC-GT) systems for marine power plants are presented. A 500 kW auxiliary marine power plant scheme using stacks of SOFCs in combination with a regenerative gas turbine operating with over-expansion based on our recent patent application is proposed. The results of mathematical modelling showed the opportunity to obtain a...
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Experimental investigations and damage growth modeling of EN‐AW 2024 aluminum alloy under LCF loading accounting creep pre‐deformation
PublicationThis article presents the results of experimental tests of creep rupture and of low-cycle fatigue (LCF) of EN-AW 2024 aluminum alloy devoid of damage and having preliminary damage. The preliminary damage was dealt in the process of creep at elevated temperature 100C, 200C, and 300C until achievement of two different strain values at each temperature. Samples with preliminary damage were subjected to fatigue tests at room temperature....
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Comparative study of a combined heat and power plant retrofitted by CO2 capture during the combustion of syngas from sewage sludge gasification versus zero-emission combustion of hydrogen produced using renewables
PublicationWith ecological requirements aimed at limiting the production of CO2, it is necessary to produce all, or most of the energy from RES. During the transformation process, ecological and highly efficient combustion power plants will be needed. The classic cycle of combined heat and power (CCGT) with green improvements will continue to be one of the most suitable technologies for this task. This article presents the modernization of...
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Od postawy prozdrowotnej w stoczni jachtowej do ograniczania zagrożeń na stanowisku pracy formierza-laminiarza
PublicationTematyka zdrowia i bezpieczeństwa pracowników, coraz częściej popularyzowana w świecie biznesu, nadal stanowi dość mało rozpoznany obszar działalności polskich przedsiębiorstw. Niniejszy artykuł porusza ważką kwestię promocji zdrowia w miejscu pracy jako czynnika zwiększającego efektywność pracy oraz jego wpływ na osiąganie wysokiej jakości produktu. Publikacja omawia znaczenie postawy prozdrowotnej i sposobów jej kształtowania...
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On a Recurrence Arising in Graph Compression
PublicationIn a recently proposed graphical compression algorithm by Choi and Szpankowski (2012), the following tree arose in the course of the analysis. The root contains n balls that are consequently distributed between two subtrees according to a simple rule: In each step, all balls independently move down to the left subtree (say with probability p) or the right subtree (with probability 1p). A new node is created as long as...
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Superconductivity in the Nb-Ru-Ge σ phase
PublicationWe 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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Fully Tunable Analog Biquadratic Filter for Low-Power Auditory Signal Processing in CMOS Technologies
PublicationA novel Gm-C structure of a second-order continuous-time filter is proposed that allows for the independent control of the filter’s natural frequency (ω0) and quality factor (Q). The structure consists of two capacitors and four transconductors. Two transconductors together with the capacitors form a lossless second-order circuit with tunable ω0. The other two transconductors form a variable gain amplifier (VGA) which realizes...