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UK travel agents’ evaluation of eLearning courses offered by destinations: an exploratory study.
PublicationThis study aims to develop an understanding of the use of e-learning courses created for travel agents by Destination Management Organizations (DMOs). It explores agents’ perceptions of such courses. The research examines the views of 304 UK-based travel agents using online survey and investigates whether age, sex, type of agency, work experience, and educational level have influence on e-learning uptake. The satisfaction of travel...
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Scientific research in the Department of Machine Design and Automotive Engineering
PublicationShort descriptions of various research subjects taken up at the Department of Machine Design and Automotive Engineering are included in the paper. The subjects cover a wide range of bearing systems and tribology research and the research on tires and road surfaces. A third field of activity is biomedical engineering – with the attempts to improve methods of modelling biological materials in FEM calculations. The Department has...
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Data Partitioning and Task Management in the Clustered Server Layer of the Volunteer-based Computation System
PublicationWhile the typical volunteer-based distributed computing system focus on the computing performance, the Comcute system was designed especially to keep alive in the emergency situations. This means that designers had to take into account not only performance, but the safety of calculations as well. Quadruple-layered architecture was proposed to separate the untrusted components from the core of the system. The main layer (W) consists...
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Experiments and numerical modeling of meat and bone meal pyrolysis in a rotary kiln
PublicationThe paper presents aspects of modelling the pyrolysis of meat and bone meal (MBM) in a rotary kiln. The pyrolysis of MBM produces a solid fraction which can be used as a fuel, a liquid fraction with potential chemical applications and a low heating value gas. The meat and bone meal pyrolysis was carried out at the temperature of 900 oC. Main features of experiments and numerical model of the pyrolysis were described. The model...
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Acoustics-related aspects of historic interior modernization projects
PublicationThe paper presents three historic interiors in which modernization projects have been carried out having an important impact on their acoustic qualities. Two of the described case studies are positive examples of solving the problem of a natural contradictions between modern technical standards and strict discipline imposed by the heritage conservation system. On the other hand, the effect of neglecting the acoustic needs when...
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Thermal self-action effects of acoustic beam in a vibrationally relaxing gas
PublicationThermal self-action of acoustic beam in a molecular gas with excited internal degrees of molecules’ freedom, is studied. This kind of thermal self-action differs from that in a Newtonian fluid. Heating or cooling of a medium takes place due to transfer of internal vibrational energy. Equilibrium and non-equilibrium gases, which may be acoustically active, are considered. A beam in an acoustically active gas is self-focusing unlike...
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Determinants of the surface quality, density and dimensional correctness in selective laser melting of the Ti-13Zr-13Nb alloy
PublicationSelective laser melting is widely used for custom-designed elements. Successful manufacturing depends on laser treatment parameters and material features. This research aimed to determine the effects of laser power, scan time and hatch distance on surface quality, relative density and dimensional precision for cuboids made of the Ti-13Zr-13Nb alloy. The influence of energy density, energy flux and pre-heating was seen to be decisive...
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Design of power cable lines partially exposed to direct solar radiation – special aspects
PublicationPower cable lines are usually buried in the ground. However, in some cases, their ending sections are mounted along the supports of overhead lines. This leads to a situation where the cables are exposed to direct solar radiation and, consequentially, overheat. The paper presents the advanced computer modelling of power cables’ heating, considering their insolation as well as the effect of wind. The temperature and current-carrying...
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The influence of anchoring group position in ruthenium dye molecule on performance of dye-sensitized solar cells
PublicationThe effect of anchoring group position and, in consequence, the orientation of the ruthenium dye molecule on titania surface on the performance of dye-sensitized solar cells has been studied intensively. Three model ruthenium sensitizing dyes bearing carboxylic anchoring group in ortho, meta or para position were synthesized and well characterized by spectroscopic, electrochemical, photophysical and photochemical measurements....
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Dietary intervention with beetroot juice during doxorubicin cancer chemotherapy in vivo reduces markers of oxidative stress
PublicationCancer chemotherapy with doxorubicin, despite high antitumor activity and broad spectrum of this drug, is on decline due to toxic side effects. The clinical efficacy of anthracyclines have continuously prompted the search for new adjuvants to alleviate undesirable side toxicity incurred by this group of cytostatics. The recent approaches involve the application of synthetic or purified natural antioxidants in combination with doxorubicin...
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Fundamenty palowe, obliczenia z zastosowaniem zasad Eurokodu 7 i doświadczeń krajowych
PublicationPrzedstawiono zagadnienia obliczania fundamentów palowych w nawiązaniu do zaleceń Eurokodu 7. Zwrócono uwagę, że zgodnie z założeniami Eurokodu 7, projektant i inżynier ma swobodę w wyborze metod obliczeniowych.Przytoczono i zarekomendowano metody i propozycje miedzy innymi obliczania statycznego układów palowych, określania nośności pali, prognozowania osiadań fundamentów palowych oraz charakterystyk obciążenie-osiadanie pali...
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Dariusz Mikielewicz prof. dr hab. inż.
PeopleProfessor Dariusz Mikielewicz – born on February 6, 1967. in Gdansk. Here in 1974 he enrolled first to the Elementary School No. 17, and then in the Grammar School No. 5, named after Stefan Żeromski in Gdansk-Oliwa. After graduating from the Secondary School, with honors, in 1985 he successfully passed the entrance exams to the Faculty of Mechanical Engineering of Technical University of Gdansk, where he graduated with a very good...
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Imunofan - RDKVYR peptide - stimulates skin cell proliferation and promotes tissue repair
PublicationRegeneration and wound healing are vital to tissue homeostasis and organism survival. One of the biggest challenges of today's science and medicine is finding methods and factors to stimulate these processes in the human body. Effective solutions to promote regenerative responses will accelerate advances in tissue engineering, regenerative medicine, transplantology, and a number of other clinical...
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Microwave radiation in the synthesis of urethane prepolymers
PublicationThis paper describes the use of microwave radiation in the synthesis of urethane prepolymers in bulk (without solvent). The prepolymers were synthesized using 1,6-hexamethylene diisocyanate (HDI) and poly (ε-caprolactone) diol (PCL) at a molar ratio of 4:1. The reaction was carried out without a catalyst in the reactor with a conventional heating system (oil bath) or in the microwave reactor (MW Reactor NOVA 09) at temperatures...
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FURTHER REMARKS ON THE NEO-CLASSICAL NAVIER-STOKES EQUATIONS
PublicationThe seminal Navier-Stokes equations have been stated yet before creation of principles of thermodynamics and the first and second laws. In the literature there is the common opinion that the Navier-Stokes equations cannot be taken as a thermodynamically correct model of “working fluid” which is able to describe transformation of “ heat” into “work” and vice versa. Therefore, in the paper, a new exposition of thermodynamically...
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An electric ring thruster as auxiliary manoeuvring propulsion system for watercraft - construction analysis
PublicationThe reported project aimed at examining properties and purposefulness of use of modern electromagneticbearings for a screw propeller in a prototype version of a synchronous ring motor with rare earths magnets.Bearings of this type generate electromagnetic forces which keep the rotor in a state of levitation. Therotating machine with magnetic bearings can work in any environment which reveals diamagnetic properties(air, vacuum,...
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Quantification of Compatibility Between Polymeric Excipients and Atenolol Using Principal Component Analysis and Hierarchical Cluster Analysis
PublicationAn important challenge to overcome in the solid dosage forms technology is the selection of the most biopharmaceutically efficient polymeric excipients. The excipients can be selected, among others, by compatibility studies since incompatibilities between ingredients of the drug formulations adversely affect their bioavailability, stability, efficacy, and safety. Therefore, new, fast, and reliable methods for detecting incompatibility...
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Sodium alginate decreases the permeability of intestinal mucus
PublicationIn the small intestine the nature of the environment leads to a highly heterogeneous mucus layer primarily composed of the MUC2 mucin. We set out to investigate whether the soluble dietary fibre sodium alginate could alter the permeability of the mucus layer. The alginate was shown to freely diffuse into the mucus and to have minimal effect on the bulk rheology when added at concentrations below 0.1%. Despite this lack of interaction...
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A New Adaptive Method for the Extraction of Steel Design Structures from an Integrated Point Cloud
Open Research DataA new automatic and adaptive algorithm for edge extraction from a random point cloud was developed and presented herein. The proposed algorithm was tested using real measurement data. The developed algorithm is able to realistically reduce the amount of redundant data and correctly extract stable edges representing the geometric structures of a studied...
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Mn-Co spinel coatings on Crofer 22 APU by electrophoretic deposition: Up scaling, performance in SOFC stack at 850 °C and compositional modifications
PublicationCeramic coatings for metallic interconnects play a key role in limiting corrosion and chromium evaporation in solid oxide cells. This study presents the upscaling of the electrophoretic deposition (EPD) technique to process Mn-Co spinels on real-dimension Crofer 22 APU interconnects and the test in a SOFC stack. Area specific resistance of long-term test conducted for 5000 h at 850 °C demonstrated that two-steps sintering has a...
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SEM images of Mo2Ga2C MAX material
Open Research DataIn the dataset, are included SEM images of molybdenum gallium carbide MAX materials.
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Implementation of didactic simulation models in Open Source and SCORM compliant LMS systems.
PublicationModele symulacyjne są cenną pomocą w procesie dydaktycznym. Ich zastosowanie w systemach komputerowego wspomagania nauczania znacząco podnosi ich efektywność oraz pozwala na przeprowadzanie wirtualnych ćwiczeń laboratoryjnych (na przykład podczas nauczania na odległość). Niestety stosowane obecnie systemy LMS (Lerning Management System) nie są zadowalająco przystosowane do obsługi symulacyjnej zawartości dydaktycznej. W artykule...
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Metodyka projektowania łożysk ślizgowych z tamą hydrodynamiczną.
PublicationW artykule przedstawiono nową metodykę projektowania poprzecznych łożysk ślizgowych z tamą hydrodynamiczną. Zaproponowana metoda pozwala na wyznaczanie charakterystyk statycznych i dynamicznych dowolnych łożysk poprzecznych, w których wykonano jedną lub wiele tam hydrodynamicznych. W omawianej metodzie wykorzystano dwa niezależne programy komputerowe (BEARing i ArtBEAR). W celu oszacowania dokładności wybranej metody wykonano obliczenia...
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ANALYSIS OF BRACE STIFFNESS INFLUENCE ON STABILITY OF THE TRUSS
PublicationThe paper is devoted to the numerical and experimental research of stability of a truss with side elastic supports at the top chord. The structure is a model of a real roof truss scaled by factor ¼. The linear buckling analysis and non-linear static analysis were carried out. The buckling length factor for the compressed top chord was calculated and the limit load for the imperfect truss shell model with respect to brace stiffness...
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Experimental Tests Of Sandwich Beams In The Design Process Of GFRP Shell Footbridge Structure
PublicationThe paper includes selected aspects of the study to elaborate architectural, material and construction design of pedestrian footbridge spans made of composite materials. The considered footbridge is a sandwich-type shell structure. The cooperation of PET foam core with outer lining surfaces is crucial for its load bearing capacity. The paper is aimed to experimental investigation of sandwich beams subjected to bending loading....
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Numerical analysis of crack propagation in silicone nitride
PublicationThe properties of ceramics, specifically low density, high hardness, high temperature capability and low coefficient of thermal expansion are of most interest to rolling element manufacturers. The influence of ring crack size on rolling contact fatigue failure has been studied using numerical fracture analysis. Such cracks are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculation...
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Structure and thermal expansion of liquid bismuth
PublicationExperimental structural data for liquid Bi were used for estimation of the main structure parameters as well as the thermal expansion coefficient both in supercooled and superheated temperature ranges. It was shown that the equilibrium melt had a positive thermal expansion coefficient within a temperature range upon melting and a negative one at higher temperatures. The former was related to structure changes upon melting, whereas...
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The Brain of the city
PublicationIn order to highlight the characteristics of the West End of Wrocław, we conducted a site analysis. Using the strengths of the site, we were able to create a unique concept of the district while minimizing the impacts of weaknesses by design. The purpose of redesigning the West End of Wrocław is to attract new people to the district through the transformation of an identity. Initially, we conducted a SWOT analysis to identify the...
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Productive aging
PublicationThe term “productive aging” refers to the participation of older adults in different activities that contribute to generating goods and services and develop the capacity to produce goods and services. In that sense, it includes both the economic activity of this group – serving in the paid workforce – and its social productivity, understood as volunteer activities (Bass et al. 1993). In the broader sense, “productive aging” can...
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Application of TMS320c67xx signal processors for SONIC-self-optimizing narrowband interference canceler
PublicationThe paper presents a laboratory system for testing active control algorithms of acoustics noise in ducts. An applied algorithm - self-optimizing narrowband interference canceller (SONIC), allows one to remove narrowband disturbances of constant or slowly time-varying frequencies. Example experimental results of using the laboratory system for supression of sinusoidal disturbance are described. An electronic part of the system was...
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Long-term operation of Kickuth-type constructed wetland applied to municipal wastewater treatment in temperate climate
PublicationThe purpose of this paper is to discuss the problem of changes of effectiveness of Kickuth-type constructed wetland with subsurface flow applied to domestic wastewater treatment. This study is based on an example of a wetland 3000 m2 in surface, serving 800 inhabitants, located in Poland. The results of chemical analysis showed that after an initial year of ‘start-up time’, the efficiency of pollutant removal gradually increased...
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Nonlinear Excitation of the Non-Wave Perturbations by the Magnetoacoustic Waves in the Non-Isentropic Plasma
PublicationNonlinear excitation of slow modes by the planar magnetosonic perturbations in a plasma is discussed. Plasma is an open system due to radiation and external heating. This may stipulate enhancement of wave perturbations and hence the acoustical activity of plasma. Plasma is assumed to be a homogeneous ideal gas with infinite electrical conductivity. The straight magnetic field is orthogonal to the velocity of fluid’s...
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Simple colorimetric copper(II) sensor – spectral characterization and possible applications
PublicationNew o-hydroxyazocompound L bearing pyrrole residue was obtained in the simple synthetic protocol. The structure of L was confirmed and analyzed by X-ray diffraction. It was found that new chemosensor can be successfully used as copper(II) selective spectrophotometric regent in solution and can be also applied for the preparation of sensing materials generating selective color signal upon interaction with copper(II). Selective colorimetric...
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Resonant DC link inverters for AC motor drive systems – critical evaluation
PublicationIn this survey paper, resonant and quasiresonant DC link inverters are reexamined for AC motor drive applications. Critical evaluation of representative topologies is based on simulation and waveform analysis to characterize current/voltage stress of components, control timing constraints and feasibility. A special concern over inverter common-mode voltage and voltage gradient du/dt limitation capacity is discussed for motor bearing...
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Simplified Method of Modelling Behaviour of Ship in Waves with Partially Flooded Compartments
PublicationThis paper contains a description of a numerical model for calculating behaviour of ships in waves. There are many models available, but the one described here can be characterised with a set of parameters that have a decisive impact on the final values of roll motion amplitude and frequency. In this paper, it is shown how a fitting of a standard-shape hull characterised by certain readily available parameters affects...
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Policy Monitoring on Accessible Technology for Inclusive Education – Research Findings and Requirements for a Software Tool
PublicationStatistics about disabled people usually do not receive as much attention as statistics highlighting other socio-economic problems. However, such statistics is important due to its actual weight.According to the World Health Organization (WHO), about 15% of the world population, meaning one billion people, live with disabilities, and 80% of them live in developing countries. UNESCO claims that 90% of the children with disabilities...
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SUBJECTIVE PERCEPTION OF MUSIC GENRES IN THE FIELD OF MUSIC INFORMATION RETRIEVAL SYSTEMS
PublicationThe aim of this paper is to evaluate the relationship between perception of music genres and subjective features of music that can be assigned to them. For this purpose a group of subjective features such as loudness, melody, rhythm, volume, instrumentation was chosen to describe music genres. A group of 30 listeners with normal hearing, ranging from 20 to 40, was created. Each sub-ject participating in listening tests was asked...
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SUBJECTIVE PERCEPTION OF MUSIC GENRES IN THE FIELD OF MUSIC INFORMATION RETRIEVAL SYSTEMS
PublicationThe aim of this paper is to evaluate the relationship between perception of music genres and subjective features of music that can be assigned to them. For this purpose a group of subjective features such as loudness, melody, rhythm, volume, instrumentation was chosen to describe music genres. A group of 30 listeners with normal hearing, ranging from 20 to 40, was created. Each sub-ject participating in listening tests was asked...
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Consciousness Study of Subjects with Unresponsive Wakefulness Syndrome Employing Multimodal Interfaces
PublicationThe paper presents a novel multimodal-based methodology for consciousness study of individuals with unresponsive wakefulness syndrome. Two interfaces were employed in the experiments: eye gaze tracking system – CyberEye developed at the Multimedia Systems Department, and EEG device with electrode placement in the international 10-20 standard. It was a pilot study for checking if it is possible to determine objective methods based...
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An new method of audio-visual correlation analysis
PublicationThis paper presents a new methodology of conducting the audio-visual correlation analysis employing the gaze tracking system. Interaction between two perceptual modalities, seeing and hearing, their interaction and mutual reinforcement in a complex relationship was a subject of many research studies. Earlier stage of the carried out experiments at the Multimedia Systems Department (MSD) showed that there exists a relationship between...
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Acoustic Sensing Analytics Applied to Speech in Reverberation Conditions
PublicationThe paper aims to discuss a case study of sensing analytics and technology in acoustics when applied to reverberation conditions. Reverberation is one of the issues that makes speech in indoor spaces challenging to understand. This problem is particularly critical in large spaces with few absorbing or diffusing surfaces. One of the natural remedies to improve speech intelligibility in such conditions may be achieved through speaking...
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Rapid method for the determination of organochlorine pesticides and PCBs in fish muscle samples by microwave-assisted extraction and analysis of extracts by GC-ECD
PublicationA procedure for the multiresidue determination of organochlorine pesticides and polychlorinated biphenyls in fish muscle samples has been developed. The method is based on the microwave-assisted extraction (MAE) of food samples from an acetonitrile-water (95 + 5, v/v) mixture followed by SPE cleanup of the extracts and analysis by GC with an electron capture detector. MAE operational parameters, such as the extraction solvent,...
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How water mediates the long-range interactions between remote protein molecules
PublicationThe high crowding of macromolecules in the cytoplasm affects the processes that occur inside a living cell. It can, for example, promote the forming of various loosely connected structures of proteins. It also means that bulk water is, essentially, not present there. The relatively thin layer of solvent that separates macromolecules may be able to participate in the long-range interactions between them and make them respond to...
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TEORIA DECYZYJNYCH PROCESÓW SEMI-MARKOWA I JEJ ZASTOSOWANIE W PROJEKTOWANIU I EKSPLOATACJI OKRĘTOWYCH SILNIKÓW GŁÓWNYCH I INNYCH URZĄDZEŃ SIŁOWNI OKRĘTOWYCH
PublicationW referacie zaprezentowano znaczenie teorii procesów semi-Markowa w naukach technicznych, zwłaszcza w teorii niezawodności urządzeń technicznych, teorii bezpieczeństwa ich działania oraz statystycznej teorii podejmowania decyzji eksploatacyjnych. W referacie wyeksponowano także przydatność teorii procesów semi-Markowa w teorii i praktyce eksploatacji wspomnianych urządzeń technicznych na przykładzie tak istotnych urządzeń w transporcie...
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Thermal properties of strontium–borate glasses and glass-ceramics containing bismuth and vanadium oxides measured with DSC method
Open Research DataThermal properties of strontium–borate glasses and glass-ceramics containing bismuth and vanadium oxides was measured by DSC.
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Thermal properties of ceramic Bi2VO5.5 and strontium–borate glass-ceramics containing crystalites of Bi2VO5.5. measured with DSC
Open Research DataThermal properties of ceramic Bi2VO5.5 and strontium–borate glass-ceramics containing Bi2VO5.5 crystallites was measured by DSC.
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Wykorzystanie obszarów morskich pod zabudowę o przeznaczeniu wielofunkcyjnym
PublicationW artykule opisano możliwości zagospodarowania obszarów wodnych na potrzeby rozwoju obszarów miejskich. W kontekście obecnych uwarunkowań ekologicznych oraz bogactwa zasobów obszarów wodnych budownictwo wielofunkcyjne na wodzie ma duże szanse na rozwiązanie problemów dotyczących braku przestrzeni na lądzie. Wiąże się to z rozszerzeniem tradycyjnego podejścia stosowanego przy projektowaniu o elementy związane ze specyfiką konstrukcji...
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Syntheses of N-Substituted Thymine Thioacetamides. A Novel Approach to Site Selective Acylation of Diaminoalkanes
PublicationA new series of N-substituted thiocarbamoyl derivs. contg. histamine, tryptamine, and other moieties having at least one amino group attached to an aliph. chain has been synthesized from (1-thyminyl)thioacetamide in good isolated yields (69-86%). N-[2-(4-Imidazolyl)ethyl](1-thyminyl)thioacetamide was hydrolyzed to its amide on prolonged heating in water. Ammonium sulfide (20-22% soln. in water) has found interesting new applications...
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Measurement of temperature-dependent viscosity and thermal conductivity of alumina and titania thermal oil nanofluids
PublicationThe results of simultaneous measurements of dynamic viscosity, thermal conductivity, electrical conductivity and pH of two nanofluids, i.e. thermal oil/Al2O3 and thermal oil/TiO2 are presented. Thermal oil was selected as a base liquid because of possible application in ORC systems as an intermediate heating agent. Nanoparticles were tested at the concentration of 0.1%, 1% and 5% by weight within temperature range from 20°C to...
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INVESTIGATION OF JOURNAL SLIDE BEARINGS UNDER THE ANGLE OF THEIR FUNCTIONING
PublicationPaper presents the structure and principle of operation of a stand for measurements of influence of the lubrication method and process on functioning of journal slide bearings in their various technical states. Measurements performed on the stand make it possible to take advantage of the new method of evaluating the influence of physical and chemical properties of lubricating oil on the coefficient of friction in the mixed friction...