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Search results for: comparative%20study
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Experimental study on steel columns subjected to impact load under earthquake conditions
PublicationEarthquakes affecting urbanized regions cause exceptional loads to load bearing structural elements such as columns. Such a boost in the load conditions can lead to severe damages which, in a worst case scenario, can lead to a total collapse of a building. This boost is caused by the horizontal ground movement generating a rise in the internal forces due to considerable large displacement between the top and bottom support of columns....
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Study of preference for surround microphone techniques, used in the recording of choir and instrumental ensemble
PublicationThe aim of this paper is to describe the process of choosing the best surround microphone technique for recording of choir with an instrumental ensemble. First, examples of multichannel microphone techniques including those used in the recording are described. Then, the assumptions and details of music recording in Radio Gdansk Studio are provided as well as the process of mixing of the multichannel recording. The extensive subjective...
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Mathematical study of a tissue-implant connection in a ventral herniarepair in a context of the system's parameters
PublicationW pracy przedstawiono problem operowania przepuklin brzusznych u ludzi. Zaproponowano jednowymiarowy model układu powieź-implant. Na podstawie analizy wrażliwości zidentyfikowano najważniejsze parametry problemu.
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Atimicrobial Resistance of Enterococcus spp. in Muncipal wasterwater Treatment Plant - Model Study
PublicationIn this study the removal of resistant Enterococcus spp. was evaluated using the laboratory-scale wastewater treatment model plant (M-WWTP), designed as a multiphase (anaerobic, anoxic and aerobic) system (Q = 27 dm3 per day) and continuously supplied with the wastewater obtained from the full-scale WWTP, after grid. The activated sludge from the secondary clarifier was recirculated to the anaerobic chamber (with the ratio equal...
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Technical and Economic Analysis of an Intermediate Size Photovoltaic Power Plant. Case Study
PublicationThe article presents an analysis of the construction of a photovoltaic power plant with an installed capacity of about 30 kW. The principles of selecting the basic elements of the plant are shown. The impact of a high constant price on the profitability of the project is highlighted. The article also describes the existing mechanisms for subsidizing the investment.
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Nodal models of Pressurized Water Reactor core for control purposes – A comparison study
PublicationThe paper focuses on the presentation and comparison of basic nodal and expanded multi-nodal models of the Pressurized Water Reactor (PWR) core, which includes neutron kinetics, heat transfer between fuel and coolant, and internal and external reactivity feedback processes. In the expanded multi-nodal model, the authors introduce a novel approach to the implementation of thermal power distribution phenomena into the multi-node...
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Experimental Study on Effectiveness of a Prototype Seismic Isolation System Made of Polymeric Bearings
PublicationSeismic isolation is identified as one of the most popular and effective methods of protecting structures under strong dynamic excitations. Base isolators, such as Lead Rubber Bearings, High Damping Rubber Bearings, and Friction Pendulum Bearings, are widely used in practice in many earthquake-prone regions of the world to mitigate structural vibrations, and therefore minimize loss of life and property damage during seismic events....
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Biosilica from sea water diatoms algae—electrochemical impedance spectroscopy study
PublicationHere, we report on an electrochemical impedance study of silica of organic origin as an active electrode material. The electrode material obtained from carbonized marine biomass containing nanoporous diatoms has been characterised by means of XRD, IR, SEM and EIS. Dif- ferent kinds of crystallographic phases of silica as a result of thermal treatment have been found. The electrode is electrochemically stable during subsequent cyclic...
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Effectiveness of pollutants removal in hybrid constructed wetlands – different configurations case study
PublicationIn recent years, an increase in interest in hybrid constructed wetland systems (HCWs) has been observed. The aim of the paper is to compare different HCW configurations in terms of mass removal rates and efficiency of pollutants removal. Analysed data have been collected at multistage constructed wetlands in Poland, which are composed by at least two beds: horizontal subsurface flow (SSHF) and vertical subsurface flow (SSVF). The...
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Integrating Art into Places in Transition - Rose Kennedy Greenway in Boston as a Case Study
PublicationAmong the many projects realized in public spaces, some are truly unique – and these are the ones that build the identity of a place. The aim of this paper is to examine how integrating art and cultural strategies into public space can enhance and reinforce the sense of a place. Particular attention is devoted to urban spaces that we call “places in transition”, where public art improves the city’s imaginative capacity, enlivens...
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Acoustic lifecycle study of the double-layer porous asphalt on E4 in Huskvarna, Sweden
PublicationIn 2010 a double-layer porous asphalt concrete (DPAC) pavement was constructed on the E4 motorway through the Swedish city Huskvarna. Earlier experience in Sweden indicated that it was feasible to obtain a high initial noise reduction but due to the widespread use of studded tires in winter, clogging and ravelling created losses of around 2 dB per year, with an expected acoustical lifetime of only 3 years. However, the improved...
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Improving voltage levels in low-voltage networks with distributed generation – case study
PublicationThe use of distributed generation in low-voltage networks may cause the voltage variation in them, within the wide range. In unfavourable circumstances, the voltage may reach unacceptable values. The paper presents the effect of distributed generation on voltage levels in a selected low-voltage rural distribution network in Poland. An analysis of possible methods for improving voltage levels in this network is conducted. The most...
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The dynamics of the total outputs of Japanese information and communication technology sectors: A further study
PublicationThe purpose of this study is to continue the previous studies which discussed the impacts of the changes of final demands on the total outputs of the Information and Communication Technology (ICT) sectors of the specific country. More specifically, this study aims to conduct a deeper analysis regarding these impacts. This study focuses on the case of Japan. This study employs a demand-pull Input-Output (IO) quantity model, one...
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Emergent approach to Knowledge Management by Small Companies: multiple case-study research
PublicationPurpose: The aim of this paper is to examine knowledge management approach followed by small companies on the example of firms from the knowledge-intensive business services (KIBS) sector. Design/methodology/approach: The study is based on the results of a qualitative survey involving 12 owners and managers of small companies operating in the KIBS sector. The survey uses the case study method. Findings: The findings confirm that...
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Using contextual conditional preferences for recommendation taska: a case study in the movie domain
PublicationRecommendation engines aim to propose users items they are interested in by looking at the user interaction with a system. However, individual interests may be drastically influenced by the context in which decisions are taken. We present an attempt to model user interests via a set of contextual conditional preferences. We show that usage of proposed preferences gives reasonable values of the accuracy and the precision even when...
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Shaking table experimental study on diagnosis of damage and its evaluation in steel structure
PublicationCelem artykułu jest pokazanie wyników badań eksperymentalnych przeprowadzonych na stole sejsmicznym dotyczących identyfikacji uszkodzeń modelu dwukondygnacyjnej konstrukcji stalowej. Uszkodzenie zdefiniowano poprzez spadek sztywności i symulowano poprzez zamianę słupów modelu na elementy o mniejszym przekroju poprzecznym. Wyniki badań pokazują charakterystyczny spadek wartości naturalnych częstotliwości konstrukcji wraz ze wzrostem...
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Study of the Flow Dynamics of Surface Water Masses in the Area of the Coastal Gulf of Gdansk
PublicationThe paper describes two methods of predicting the movement of small objects with surface water masses. One of the methods uses graph theory to describe the motion of water masses in port docks. The results of this study were compared to a simulation using the hydrodynamic numerical model M3D. The results obtained in a virtual environment were related to the experiments in the real world. In the coastal area of the Gulf of Gdansk,...
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STUDY OF SEASONAL ACOUSTIC PROPERTIES OF SEA WATER IN SELECTED WATERS OF THE SOUTHERN BALTIC
PublicationClimate Research of the globe is a current task, in particular to confirm the general hypothesis of global warming associated with an increase in average temperature. The sea acoustic climate is derived from the concept of climate and refers to the conditions of propagation of acoustic waves in a particular basin. In this paper, the results of systematic measurements of temperature, salinity and velocity distributions of sound...
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A PROPOSAL FOR ONE-IMAGE PHOTOGRAMMETRY SYSTEM FOR MEASURING THE CLEARANCE DISTANCE. CASE STUDY
PublicationMeasurement of the clearance distance (both in the context of the rail and road) is one of the current and increasingly discussed topics in the context of photogrammetric and image processing (computer vision) methods. The article presents a description of a simple and rapid method of measure the clearance distance between the obstacles by using one-image photogrammetry. The proposed method was tested for the railway, tram and...
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Comprehensive study on graphene hydrogels and aerogels synthesis and their ability of gold nanoparticles adsorption
PublicationGraphene hydrogels were prepared by ascorbic acid-assisted gelation of graphene oxide (GO) aqueous suspensions both in acidic and basic conditions. Different mass ratio of ascorbic acid (AA) to GO was used (namely 20:1 and 10:1). In order to eliminate the influence of AA on the final structure of hydrogels, samples without AA were prepared by a hydrothermal gelation of GO in an autoclave. An in-depth structural characterization...
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Corrosion Study of Ceria Protective Layer Deposited by Spray Pyrolysis on Steel Interconnects
PublicationSingle fuel cells and electrolysis cells are assembled into stacks using interconnects in order to increase power and gas production capacity. The most common choice for the interconnect material is stainless steel. It has good electrical and mechanical properties and is also cost effective. One of the problems when using steel is the formation of a thermally grown oxide scale during use which has a lower electrical conductivity...
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A PRELIMINARY STUDY ON THE OPTIMAL CHOICE OF AN IMPLANT AND ITS ORIENTATION IN VENTRAL HERNIA REPAIR
PublicationThis paper addresses the problem of ventral hernia repair. The main goals are to find an optimal surgical mesh for hernia repair and to define its optimal orientation in the abdominal wall to minimise the maximum force at the tissue-implant juncture. The optimal mesh is chosen from a set of orthotropic meshes with different stiffness ratios for typical hernia placement in the abdominal area. The implant is subjected to an anisotropic...
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Study of the electrochemical stability of polypyrrole coating on iron in sodium salicylate aqueous solution
PublicationIn this work electrochemical stability of optimized PPy film on iron in aqueous solution of sodium salicylate is studied. The main drawback of conducting polymers is their possibility to undergo an irreversible degradation (overoxidation). The overoxidized polymers lose their properties, for example, conductivity and redox activity, what excludes them from some practical applications. This study demonstrates that lowering the concentration...
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STUDY ON THE EFFECTIVENESS OF THE TURBINE CONDENSER AIR EXTRACTION SYSTEM USING HYDRO EJECTORS
PublicationThe aim of the paper is to investigate the effectiveness of the 18K380 steam turbine condenser air extraction system using hydro ejectors. Motivation for the analysis is a need of improvement of the energy conversion ratio of the power plant. To achieve this goal it is necessary to establish efficiency of each subsystem of the energy cycle. The air extraction system is not a highly power consuming system but it has great impact...
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Study of Phase and Chemical Composition of Bi1-xNdxFeO3 Powders Derived by Pressureless Sintering
PublicationIn the present paper studies on Bi1xNdxFeO3 for x =0.1-0.4 are reported. The mixed oxide method followed with pressureless sintering was employed for ceramics fabrication. Thermal behavior of stoichiometric mixtures of simple oxide powders, viz. Bi2O3, Nd2O3 and Fe2O3 was studied by simultaneous thermal analysis. It was found that with an increase in neodymium content the weight loss increased from 0.75% to 3.16% for x =0.1 and...
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Offshore surface waters of Antarctica are free of microplastics, as revealed by a circum-Antarctic study
PublicationIn 2018, during a circum navigation of Antarctica below 62° S by the sailing boat Katharsis II, the presence of plastics was investigated with surface sampling nets at ten evenly spaced locations (every 36° of longitude). Although fibres that appeared to be plastic (particles up to 2 cm) were found in numbers ranging from 1 particle (0.002 particles per m3) to 171 particles (1.366 particles per m3) per station, a Fourier-transform...
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Shaking table experimental study on the effectiveness of polymer bearings for seismic isolation of structures
PublicationSeismic isolation has been recognised to be a very effective way of protecting structures from damage during earthquakes. It allows us to extend the natural period of the structure and therefore avoid resonance with the ground motion. Moreover, by increasing damping in the isolation devices, more energy can be dissipated and thus the structural response can be further reduced. The aim of this paper is to show the results of the...
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Study of the formation of calcareous deposits on cathodically protected steel in Baltic sea water
PublicationPurpose – The purpose of this paper is to investigate whether the sedimentation of calcareous deposits occurs on cathodically protected steel in Baltic sea water. Design/methodology/approach – Steel electrodes were cathodically polarized in natural Baltic sea water at potential þ0.150 V vs Zn electrode in potentiostatic mode. During exposure chronoamperometric measurements were carried out. After the exposure, the electrode’s surface...
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Bringing Bathymetry LiDAR to Coastal Zone Assessment: A Case Study in the Southern Baltic
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Bringing Bathymetry LiDAR to Coastal Zone Assessment: A Case Study in the Southern Baltic
PublicationOne of the major tasks in environmental protection is monitoring the coast for negative impacts due to climate change and anthropopressure. Remote sensing techniques are often used in studies of impact assessment. Topographic and bathymetric procedures are treated as separate measurement methods, while methods that combine coastal zone analysis with underwater impacts are rarely used in geotechnical analyses. This study presents...
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Study on the Coastline Evolution in Sopot (2008–2018) Based on Landsat Satellite Imagery
PublicationThe coastline is the boundary between the water surface in a reservoir or watercourse and the land, which is characterised by high instability and functional diversity. For these reasons, research on coastal monitoring has been conducted for several decades. Currently, satellite images performed with synthetic aperture radars (SARs) are used to determine its course and variability together with high-resolution multispectral imagery...
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On Nonlinear Bending Study of a Piezo-Flexomagnetic Nanobeam Based on an Analytical-Numerical Solution
PublicationAmong various magneto-elastic phenomena, flexomagnetic (FM) coupling can be defined as a dependence between strain gradient and magnetic polarization and, contrariwise, elastic strain and magnetic field gradient. This feature is a higher-order one than piezomagnetic, which is the magnetic response to strain. At the nanoscale, where large strain gradients are expected, the FM effect is significant and could be even dominant. In...
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Effect of Flow Normalization in Micro-Pin-Finned Heat Sink: Numerical Study
PublicationThe micro-pin-fin heat sink (MPFHS) is widely employed for the heat transfer enhancement of microchannel heat sinks. In the current paper, the effect of flow normalization on the thermohydraulic performance of micro-pin-finned heat sinks is studied numerically. Two geometries of MPFHSs, the conventional design micro-pin-fin heat sink (CD-MPFHS) with a uniform-width micro pin fin and the proposed design micro-pin-fin heat sink (PD-MPFHS)...
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A Study of Cross-Linguistic Speech Emotion Recognition Based on 2D Feature Spaces
PublicationIn this research, a study of cross-linguistic speech emotion recognition is performed. For this purpose, emotional data of different languages (English, Lithuanian, German, Spanish, Serbian, and Polish) are collected, resulting in a cross-linguistic speech emotion dataset with the size of more than 10.000 emotional utterances. Despite the bi-modal character of the databases gathered, our focus is on the acoustic representation...
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THE UNSUSTAINABILITY OF PUBLIC-SECTOR ORGANIZATIONAL NETWORKS: A CASE STUDY OF VOLUNTARY COURT NETWORKS
PublicationPurpose: The purpose of this study is to identify the problem of sustainability of public-sector 12 organizational networks on the example of common courts and what it implies for further 13 research. Methodology: The study used qualitative research tools in the form of structured 14 interviews. Interviews were conducted with 36 presidents and directors of common courts. 15 After conducting and transcribing each interview, their...
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Modelling study of flow boiling heat transfer of perspective fluids for refrigeration technology
PublicationThere is a gap of knowledge on flow boiling at high saturation temperatures and higher values of reduced pressure. Thus far, the in-house developed semi-empirical model for flow boiling and flow condensation showed a satisfactory accuracy for calculations for various refrigeration fluids for a wide scope of reduced pressures. This study presents results of calculations of heat transfer coefficient of perspective refrigeration fluids,...
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Barriers to and Facilitators of Scientific Productivity: A Case Study from Polish Technical University
PublicationScientific productivity plays an essential role in the creation of innovation and it stimulates social and economic growth. This study aimed to identify the barriers to and facilitators of scientific productivity in engineering and technology field, as perceived from the perspective of academic managers. Along with quality approach, the study relied on semi-structured interviews with managing bodies, i.e. seven deans and deputy...
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Self-assessment of competencies of students and graduates participating in didactic projects – Case study
PublicationAim/purpose: the aim of this article is to examine the opinions of students and graduates of the faculty of economics of a technical university as regards their selfassessment of their preparation for entering the modern labour market. All the respondents participated during their studies in didactic projects aimed at improving their competencies taking into account the expectations of potential employers. Design/methodology/approach:...
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A general approach to study molecular fragmentation and energy redistribution after an ionizing event
PublicationWe propose to combine quantum chemical calculations, statistical mechanical methods, and photoionization and particle collision experiments to unravel the redistribution of internal energy of the furan cation and its dissociation pathways. This approach successfully reproduces the relative intensity of the different fragments as a function of the internal energy of the system in photoelectron–photoion coincidence experiments and...
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Theoretical and experimental study on scattering of low-energy electrons by dimethyl and diethyl ethers
PublicationWe report a joint theoretical and experimental investigation on low-energy electron scattering by dimethyl and diethyl ethers. The experimental elastic differential cross sections were measured at impact energies from 1 eV up to 30 eV and scattering angle range of 10◦ to 130◦. Theoretical elastic differential, integral and momentum-transfer cross sections are calculated at impact energies up to 30 eV, employing the Schwinger multichannel...
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Selected anionic and cationic surface active agents: case study on the Kłodnica sediments
PublicationSurface active agents (surfactants) are a group of chemical compounds, which are used as ingredients of detergents, cleaning products, cosmetics and functional products. After use, wastes containing surfactants or their degradation products are discharged to wastewater treatment plants or directly into surface waters. Due to their specific properties of SAAs, compounds are able to migrate between different environmental compartments...
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Visualizing Carotid Bodies With Doppler Ultrasound Versus CT Angiography: Preliminary Study
PublicationOBJECTIVE. The purpose of this article is to evaluate the utility of ultrasound in identifying carotid bodies (CBs) in patients with drug-resistant arterial hypertension. SUBJECTS AND METHODS. We enrolled 13 patients with drug-resistant hypertension into a trial for surgical CB excision. CT angiography (CTA) and Doppler ultrasound (DUS) of the cervical arteries were performed before surgery. CBs were identified in a blind manner...
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Study of Statistical Text Representation Methods for Performance Improvement of a Hierarchical Attention Network
PublicationTo effectively process textual data, many approaches have been proposed to create text representations. The transformation of a text into a form of numbers that can be computed using computers is crucial for further applications in downstream tasks such as document classification, document summarization, and so forth. In our work, we study the quality of text representations using statistical methods and compare them to approaches...
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A Study on Emission of Airborne Wear Particles from Car Brake Friction Pairs
PublicationThe emission of airborne wear particles from friction material / cast iron pairs used in car brakes was investigated, paying special attention to the influence of temperature. Five low-metallic materials and one non-asbestos organic material were tested using a pin-on-disc machine. The machine was placed in a sealed chamber to allow airborne particle collection. The concentration and size distribution of 0.0056 to 10 μm particles...
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Study on some of the strength properties of soft clay stabilized with plastic waste strips
PublicationIt is well known that if plastic wastes are not well managed, it has a negative impact on the environment as well as on human health. In this study, recycling plastic waste in form of strips for stabilizing weak subgrade soil is proposed. For this purpose, a weak clay soil sample was mixed with 0.2%, 0.3%, and 0.4% of plastic strips by weight of soil, and the experimental results were compared to the control soil sample with 0%...
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Is mesh fixation necessary in laparoendoscopic techniques for M3 inguinal defects? An experimental study.
Publicationrepairs, in case of large direct hernias (M3) mesh fixation is recommended to reduce recurrence risk. Despite lack of highquality evidence, the recommendation was upgraded to strong by expert panel. The authors conducted a research experiment to verify the hypothesis that it is possible to preserve the mesh in the operating field in large direct hernias (M3) without the need to use fixing materials. Method The authors conducted...
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Irregularities in university processes concerning the Lean Management typology: The pilot study results
PublicationPurpose: Identify the attitudes regarding key irregularities in university activities of universities referring to muda, mura, and muri from the perspective of two groups of stakeholders - academic teachers and administration/service personnel. Study design/methodology/approach: A pilot quantitative study with the use of a questionnaire containing 48 statements regarding six categories of irregularities assessed according to the...
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Effect of temperature change on refractive index of an egg white and yolk: a preliminary study
PublicationIn this article, the refractive index of an egg white and yolk depending on temperature in range 30 - 47 °C over 1550 nm was determined. The measurement head was constructed as fiber optic Fabry-Perot interferometer with interference between polished fiber end-face and aluminum weighing dish. The measurement setup has been made of an optical spectrum analyzer, a superluminescent diode with a central wevelength of 1550 nm, 2:1 fiber...
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Shaking table experimental study on models of steel buildings with different types of joints
PublicationThe aim of this paper is to study the response of models of steel buildings with destroyed and non-destroyed joints. The study was conducted experimentally using the shaking table tests. Two steel models were considered. Several types of joints were taken into account: totally destroyed joints, partially destroyed joints, welded joints and joints stiffened with additional metal. Six ground motions were taken into account. The acceleration...
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Experimental and Numerical Study on Mechanical Characteristics of Aluminum/Glass Fiber Composite Laminates
PublicationThe fiber-metal composites made of aluminum sheets and glass fibers reinforced with a polyester resin as the matrix were studied. The composites were prepared by hand lay-up method. Some aspects of manufacturing affecting the composite behavior were considered. In particular, the influences of the arrangement of layers and their number on the mechanical and physical properties of composites with ten different compositions were...