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Numerical modelling and analysis of steel specimens subjected to marine immersed corrosion and tensile load
PublicationThe present study develops numerical models to analyse the behaviour of steel specimens subjected to marine immersed corrosion degradation and tensile load. The finite element method with the use of the explicit dynamic solver LS-DYNA, satisfying the quasi-static conditions, is employed. Two numerical models are developed, where in the first one, the scans of surfaces gathered from corroded plate specimens are implemented directly...
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Design of a compact planar transmission line for miniaturized rat-race coupler with harmonics suppression
PublicationThis paper presents an elegant yet straightforward design procedure for a compact rat-race coupler (RRC) with an extended harmonic suppression. The coupler’s conventional λ/4 transmission lines (TLs) are replaced by a specialized TL that offers significant size reduction and harmonic elimination capabilities in the proposed approach. The design procedure is verified through the theoretical, circuit, and electromagnetic (EM) analyses,...
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Analysis of passenger car crash with a cable barrier installed with anti-glare screens on a horizontal convex road curve with 400 m radius
PublicationHigh-tension cable barriers have been used on roads for a relatively short period compared with other types of road barriers. Hence, there remains a need for further research on various crash scenarios. An important issue is the performance of a cable barrier on a road curve, particularly when a vehicle impacts the convex side of the barrier. To address this issue, the analysis in this study considers a system of anti-glare screens...
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The impact of natural fibers’ characteristics on mechanical properties of the cement composites
PublicationThe paper reviews the properties of cement composites reinforced with short fibres. The effect of natural fibres was investigated: cotton, sisal, jute, ramie, bamboo, and synthetic fibres: polymer and polypropylene. It was noticed that the fibres change the consistency of the mixture up to 15%. In the composite flexural strength tests, a change in strength by +/− 8% was observed, depending on the type of fibres used. The research...
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Does being socially good save firms from bankruptcy? A systematic literature review and bibliometric analysis
PublicationThe purpose of the review was to find out, does being responsible saves firms from bank-ruptcy? What is the relationship between corporate social responsibility and default risk? What meth-ods and measures are used in the literature to evaluate this relationship? And what is the theoretical underpinning of the studies? Moreover, to explore what are the gaps for future work, Web of Science and Scopus databases were utilised to obtain...
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Effect of sintering temperature on electrochemical performance of porous SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) oxygen electrodes for solid oxide cells
PublicationThis work evaluates the effects of the sintering temperature (800 °C, 900 °C, 1000 °C) of SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) porous electrodes on their electrochemical performance as potential oxygen electrode materials of solid oxide cells. The materials were prepared by a solid-state reaction method and revealed the expected cubic perovskite structure. After milling, the powders were characterised by a sub-micrometre particle...
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General grants and development – a relationship without a future? The effects of the structure of general grants on the development of local government units in Poland
PublicationThe purpose of this paper is to attempt to identify the reasons for the lack of relationship between general grant revenue and investment expenditure of local government units. The author formulated the hypothesis that there is no link between general grants and investment expenditure and that the reason for this are the current spending on education, absorbing the entire amount of general grants received by local government units....
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Non-volatile molecular composition and discrimination of single grape white of chardonnay, riesling, sauvignon blanc and silvaner using untargeted GC–MS analysis
PublicationThis study developed and applied a GC–MS method aiming at molecular fingerprinting of 120 commercial single grape white wines (Chardonnay, Riesling, Sauvignon Blanc and Silvaner) for possible authentication according to grape variety. The method allowed detection of 372 peaks and tentative identification of 146 metabolites including alcohols, organic acids, esters, amino acids and sugars. The grape variety effect explained 8.3%...
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Experimental tests of lintel hybrid beams
PublicationThe results of experimental tests of lintel hybrid beams made of air concrete and prestressed concrete were presented in paper. Blocks of air concrete was a protective element for the construction one. The length of hybrid beams was 3.0 m, while total height 27 cm. It was assumed that hybrid beams will work in the simply-supported scheme (with a 10 cm support) loaded uniformly over the entire length. The object of the tests were...
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Proposed method for estimating the costs of safety barrier life cycle
PublicationToday barrier types are frequently selected for their price with little regard for the total costs the structure will incur over its lifetime. One of the basic tools designed to manage road infrastructure is the life cycle cost method (LCC, Life cycle cost). It sums up the costs to plan, design, build, operate (use and maintain) and decommission a road structure. Having developed dynamically at the turn of the century the method...
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Dissociative ionization dynamics of dielectric gas C3F7CN
PublicationFluoronitrile C3F7CN is a promising candidate for the replacement of SF6 dielectric gas in high-voltage insulation. We present a combined experimental and theoretical study on its ionization dynamics probed in the 0-100 eV energy range. We exploited the total ion collection technique to determine the absolute ionization cross section, mass spectrometry to determine the fragment branching ratios and ab initio nonadiabatic molecular...
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Daylighting Education in Practice Verification of a new goal within a European knowledge investigation
PublicationTwo independent surveys were conducted in 2017 and in 2018 among architecture students across Europe to investigate their knowledge on daylighting and the impact of that knowledge on the visual perception of daylit spaces. A total of 600 responders were involved. This paper presents findings from the second survey, which was distributed in six European countries. Based on the findings from the first survey, a new goal was set for...
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Synthesis, microstructure and electrical properties of nanocrystalline calcium doped lanthanum orthoniobate
PublicationThe single phase lanthanum orthoniobate with tetragonal structure has been synthesized by the means of mechanosynthesis method. The studies have shown the crystal structure of La0.98Ca0.02NbO4 depends on the synthesis stage. The samples were predominantly in the tetragonal phase with a trace amount of the monoclinic phase. The SEM studies of morphology and microstructure have shown nanocrystallinity of the materials. The Raman...
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Assessment of metal removal in a surface flow constructed wetland treating landfill leachate
PublicationThe study concerns heavy metal retention and transformation processes in a free water surface constructed wetland treating landfill leachate in a temperate climate. The total effectiveness of heavy metals removal in the analyzed CW was evaluated basing on heavy metals inflow and outflow concentrations. The concentrations of eight heavy metals (Fe, Mn, Zn, Pb, Ni, Cu, Cr, Cd) in landfill leachate (LL) and sediments were measured....
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Analysis of Roughness, the Material Removal Rate, and the Acoustic Emission Signal Obtained in Flat Grinding Processes
PublicationIn this work, the analysis of the acoustic emission (AE) signal in grinding processes is addressed. The proposed analysis method decomposes the acoustic signal into three frequency ranges. The total energy of each range is determined, as well as the highest frequency. Different grinding experiments were carried out, according to a full factorial design of experiments (DOE), in which feed speed, depth of cut, and transversal step...
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Introduction to the RSC Advances themed collection on nano and microscale modifications of biomaterials
PublicationThe dramatically increasing development of novel biomaterials, their manufacturing techniques, and surface modications, as well as their application in in vivo tests and clinical trials, is evident. It is interesting to note in what a relatively short time the well-known long-term implants have become medical standard: titanium dental implants started in 1965, and total hip arthroplasty (not very successful) was rst attempted...
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Fabrication and Crystal Structure of Sol-Gel Deposited BST Thin Films with Compositional Gradient
PublicationIn the present research technology of compositionally graded barium strontium titanate Ba1-xSrxTiO3 thin films deposited on stainless steel substrates by sol-gel spin coating followed with thermal annealing at T = 650°C is reported. Results of thermal behavior of the sol-gel derived powders with compositions used for fabrication of graded structure (i.e. with Sr mole fraction x = 0.5, 0.4 and 0.3) are described. X-ray diffraction...
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Unsupervised machine-learning classification of electrophysiologically active electrodes during human cognitive task performance
PublicationIdentification of active electrodes that record task-relevant neurophysiological activity is needed for clinical and industrial applications as well as for investigating brain functions. We developed an unsupervised, fully automated approach to classify active electrodes showing event-related intracranial EEG (iEEG) responses from 115 patients performing a free recall verbal memory task. Our approach employed new interpretable...
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The influence of selenium addition during germination of Brassica seeds on health-promoting potential of sprouts
PublicationThe correlation among selenium uptake, the content of bioactive compounds in sprouts, and biological activities triggered in cultured human cells by sprout extracts was investigated. Seeds of Brassica crops and rye were treated with SeO2 water solution. The selenium levels in sprouts increased from 1.0-4.1 to 53.3-382 μg/g dw with no influence on plant physiology according to the indices used. Neither the composition of glucosinolates...
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Influence of Ionic Liquid Structure on Supported Ionic Liquid Membranes Effectiveness in Carbon Dioxide/Methane Separation
PublicationThis paper indicates the possibility of application of imidazolium ionic liquids immobilized in polymeric supports—supported ionic liquid membranes—in CO2 separation from gaseous streams (e.g., biogas). Imidazolium salts containing alkyl fluoride anions, bis(trifluoromethylsulfonyl)imide and trifluoromethanesulfonate, selectively separating CO2 were used. The permeability of CO2 through membranes was investigated under gas pressure...
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Multiple output differential OTA with linearizing bulk-driven active-error feedback loop for continuous-time filter applications
PublicationA CMOS circuit realization of a highly linear multiple-output differential operational transconductance amplifier (OTA) has been proposed. The presented approach exploits a differential pair as an input stage with both the gate and the bulk terminals as signal ports. For the proposed OTA, improved linearity is obtained by means of the active-error feedback loop operating at the bulk terminals of the input stage. SPICE simulations...
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Study of Icosahedral Clusters in Close-packed Simple Liquids
PublicationThe local structure of liquid copper was determined using Steinhardt order parameters, with particular attention paid to icosahedral clusters. The positions of atoms were obtained from three sets of molecular dynamics simulations, with the forces obtained from: the Sutton-Chen (SC) potential, the Naval Research Laboratory total energy tight-binding (NRL-TB) method and the divide-and-conquer learn-on-the-fly (DCLOTF) method, respectively....
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Teaching civil engineering in English at Gdansk University of Technology
PublicationThe effects of globalization, as well as many possibilities of easy and cheap ways of travelling, have led to the increase in number of different types of university studies conducted in English. This paper describes advantages and disadvantages after seven years of experience of conducting three-semester MSc Studies in Civil Engineering in English at Gdansk University of Technology, Poland. The studies started in 2009 after a...
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Pounding between Inelastic Three-Storey Buildings under Seismic Excitations
PublicationStructural interactions between adjacent, insufficiently separated buildings have been repeatedly observed during damaging ground motions. This phenomenon, known as the structural pounding, may result in substantial damage or even total collapse of structures. The aim of the present paper is to show the results of the nonlinear numerical analysis focused on pounding between inelastic three-storey buildings under seismic excitations....
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FDTD Simulations on Disjoint Domains with the Use of Discrete Green's Function Diakoptics
PublicationA discrete Green's function (DGF) approach to couple disjoint domains in the finite-difference time-domain (FDTD) grid is developed. In this method, total-field/scattered-field (TFSF) FDTD domains are associated with simulated objects whereas the interaction between them is modeled with the use of the DGF propagator. Hence, source and scatterer are simulated in separate domains and updating of vacuum cells, being of little interest,...
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How proteins bind to DNA: target discrimination and dynamic sequence search by the telomeric protein TRF1
PublicationTarget search as performed by DNA-binding proteins is a complex process, in which multiple factors contribute to both thermodynamic discrimination of the target sequence from overwhelmingly abundant off-target sites and kinetic acceleration of dynamic sequence interrogation. TRF1, the protein that binds to telomeric tandem repeats, faces an intriguing variant of the search problem where target sites are clustered within short fragments...
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Influence of the Addition of Selected Spices on Sensory Quality and Biological Activity of Honey
PublicationBee honey is nutritious and has numerous health benefits, but its taste is for many people too bland. Honey with addition of spices could be important to the food industry as a functional product with positive health image and interesting taste. Such product would definitely meet health-driven consumers’ expectations. Therefore, the aim of this study was to evaluate the effect of addition of selected spices on sensory, antimicrobial,...
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Modelling Wetland Growing Season Rainfall Interception Losses Based on Maximum Canopy Storage Measurements
PublicationThis study estimates rainfall interception losses from natural wetland ecosystems based on maximum canopy storage measurements. Rainfall interception losses play an important role in water balance, which is crucial in wetlands, and has not yet been thoroughly studied in relation to this type of ecosystem. Maximum canopy storage was measured using the weight method. Based on these measurements, daily values of interception losses...
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Numerical Modelling of Connections Between Stones in Foundations of Historical Buildings
PublicationThe aim of this paper is to analyse the behaviour of old building foundations composed of stones (the main load-bearing elements) and mortar, based on numerical analysis. Some basic aspects of historical foundations are briefly discussed, with an emphasis on their development, techniques, and material. The behaviour of a foundation subjected to the loads transmitted from the upper parts of the structure is described...
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Local buckling of composite channel columns
PublicationThe investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is taken into account here. The buckling mode of the member flange is defined by rotation angle a flange about the line of its connection with the web. The channel column under investigation is made of unidirectional fibre-reinforced laminate. Two approaches to member orthotropic...
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A new human IgG avidity test, using mixtures of recombinant antigens (rROP1, rSAG2, rGRA6), for the diagnosis of difficult-to-identify phases of toxoplasmosis
PublicationThe preliminary diagnostic utility of two mixtures of Toxoplasma gondii recombinant antigens (rROP1+rSAG2 and rROP1+rGRA6) in IgG ELISA and IgG avidity test has been evaluated. A total of 173 serum samples from patients with toxoplasmosis and seronegative people were examined. The sensitivity of IgG ELISA for rROP1+rSAG2 and rROP1+rGRA6 was 91.1% and 76.7%, respectively, while the reactivity for sera from patients where acute toxoplasmosis...
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Preparation and characterization of porous scaffolds from chitosan-collagen-gelatin composite
PublicationNovel porous scaffolds composed of chitosan, collagen and gelatin were prepared and characterized. For preparing scaffolds gelatin and collagen isolated from fish skins with various physicochemical properties were used. In order to reduce preparation solubility glutaraldehyde in the amount of 1%, w/w relative to the total biopolymers weight in solution was used. All obtained biomaterials showed a homogeneous porosity. Protein polymer...
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The effect of anthropogenic activity on BTEX, NO2, SO2, and CO concentrations in urban air of the spa city of Sopot and medium-industrialized city of Tczew located in North Poland
PublicationThe major goal of the present study is to compare the air quality of two urban locations situated in Northern Poland – the spa City of Sopot and the medium-industrialized city of Tczew using chemometric methods. As a criterion for the assessment of atmospheric air quality, measurements of benzene, toluene, ethylbenzene and total xylenes were used (collected from atmospheric air using diffusion-type passive samplers) as well as...
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Impact of Cultivation Conditions, Ethylene Treatment, and Postharvest Storage on Selected Quality and Bioactivity Parameters of Kiwifruit “Hayward” Evaluated by Analytical and Chemometric Methods
PublicationOrganic, semiorganic, and conventional “Hayward” kiwifruits, treated with ethylene for 24 h and stored during 10 days, were assessed by UV spectrometry, fluorometry, and chemometrical analysis for changes in selected characteristics of quality (firmness, dry matter and soluble solid contents, pH, and acidity) and bioactivity (concentration of polyphenols via Folin-Ciocalteu and p-hydroxybenzoic acid assays). All of the monitored...
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THE APPLICATION OF KALMAN FILTERING TO PREDICT VERTICAL RAIL AXIS DISPLACEMENTS OF THE OVERHEAD CRANE BEING A COMPONENT OF SEAPORT TRANSPORT STRUCTURE
PublicationAs the devices designed to transport materials, the overhead cranes should meet certain geometric requirements for their operation to be safe. The presently available geodetic equipment, in particular total stations, provides opportunities for precise 3D measurements of coordinates of the controlled points. These coordinates make a basis for correcting the height of crane runway axes. The paper presents a method to calculate position...
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UNDECLARED WORK IN POLAND CHARACTERISTICS AND PREVALENCE
PublicationThis article aims to present the significance and prevalence of the phenomenon of undeclared work. First, we discuss the definitional issues of this phenomenon. Then, we present previous estimates on shadow economy and undeclared work in Poland, based on statistics provided by Central Statistical Office and other research entities. Our analysis covers the years 2000–2014. In the last part of the article, we use data from the Labour...
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Dynamics of productivity in higher education. Cross-European evidence based on bootstrapped Malmquist indices
PublicationThis study presents patterns of productivity change in a large set of 266 public higher education institutions (HEIs) from 7 European countries across the time period 2001-2005. We adopt consistent bootstrap estimation procedures to obtain confidence intervals for Malmquist indices of HEI productivity and their components. Consequently, we are able to assess statistical significance of the changes in HEIs' productivity, efficiency...
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The role of SSVF and SSHF beds in concentrated wastewater treatment, design recommendation
PublicationThe return flows of reject water from sewage sludge dewatering alter the activated sludge process ina conventional WWTP and increase TN concentration in the final effluent from WWTP. The objectiveof the investigation carried out was to consider the application of multistage treatment wetland(MTW) for the treatment of reject water from sewage sludge dewatering in a centrifuge (RWC). Thispaper aims to present the design and performance...
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The influence of sterilization with EnbioJet Microwave Flow Pasteurizer on composition and bioactivity of aronia and blue-berried honeysuckle juices
PublicationIn this study, fruit juices that are rich sources of anthocyanins, obtained from aronia (Am. chokeberry, Aronia melanocarpa) and blueberry honeysuckle (Lonicera caerulea L. var. edulis) were used to examine the preservation of plant phytochemicals and bioactivity upon sterilization -either thermal, or with an EnbioJet microwave flow pasteurizer. The chemical properties verified included determinations of anthocyanins and other...
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Evaluation of the influence of grapevine growing conditions on wine quality
PublicationScientists are increasingly interested in the viticulture concept of terroir, which states that unique properties of wine are strictly related to the environmental conditions under which grapes are cultivated. The aim of the research was to compare the parameters characterizing wines produced in Poland, such as pH, conductivity, total organic carbon (TOC), and concentration of anions (F−, Cl−, NO2−, NO3−, PO43−, SO42−). It was...
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Influence of processing conditions on crystal structure of BiNbO 4 ceramics
PublicationBismuth niobate (BiNbO4) has attracted attention as a low-fired ceramics with promising microwave application potential. It belongs to the bismutocolumbite oxides with similarly to scheelite-like stibiotantalite structure (SbTaO4) A3+B5+O4. Aim of the present research was to fabricate BiNbO4 ceramics by solid state reaction route from the mixture of simple oxides viz. Bi2O3, and Nb2O5, and study its phase composition as well as...
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Efficient optimization approaches for microwave assisted extraction of high-quality antioxidant compounds from Salvia officinalis L.: UHPLC-HRMS differential analysis of phenolic profiles obtained by ultrasound and microwave extraction
PublicationThe study aims to optimize MAE of total phenolic compounds (TPC) and antioxidant capacity from Salvia officinalis L. leaves using a definitive screening design (DSD) and I-optimal design. UHPLC-HRMS analysis was used to identify and compare the composition of MAE and UAE optimal extracts. The results showed that DSD and I-optimal design were successfully applied for the optimization of MAE targeting phenolics and other antioxidants...
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MODELOWANIE TURBINY WIATROWEJ Z DWOMA PRZECIWBIEŻNIE OBRACAJĄCYMI SIĘ WIRNIKAMI
PublicationW artykule przedstawiono sposoby modelowania dwuwirnikowej turbiny wiatrowej z wykorzystaniem technik Obliczeniowej Mechaniki Płynów. Omówiono uproszczone metody modelowania Actuator Disc i Actuator Line Method oraz aspekty związane z dokładnym odwzorowaniem turbiny na siatce obliczeniowej. Zaprezentowano przykładowe wyniki obliczeń turbiny dwuwirnikowej złożonej z wirników NREL o mocy nominalnej 5 MW każdy. Do wykonania badań...
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Badania stabilności biologicznej wody w wybranych systemach wodociągowych
PublicationW pracy przedstawiono wyniki badań mikrobiologicznych wody powierzchniowej i wód podziemnych z rejonu Trójmiasta, które zasilają systemy dystrybucji charakteryzujące się nikim stosunkiem powierzchni kontaktu do objętości przesyłanej wody (≈0,65) w aspekcie ich stabilności biologicznej. Dokonano oceny skuteczności zastosowanych procesów uzdatniania w usuwaniu ogólnej liczby bakterii (OLB), a w badaniach laboratoryjnych określono...
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Iranian future healthcare professionals’ knowledge and opinions about rare diseases: cross‑sectional study
PublicationBackground: Rare diseases are a new global health priority, requiring evidence-based estimates of the global prevalenceof diseases to inform public policymakers and provide a serious challenge to the healthcare system that must not be ignored. The purpose of this study is to investigate Iranian future healthcare professionals’ knowledge and opinions about rare diseases.Results: A total of 6838 students responded...
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Selective Harmonic Elimination PWM For a Cascaded Multi-level Inverter
PublicationThis paper deals with the selective harmonic elimination pulse width modulation (SHE-PWM) technique. This technique is used for the elimination of selected dominant low order harmonics in the multi-level inverter output voltage. The presence of these harmonics is the essential drawback of such kind of inverters; especially when it is used for the control of different AC drivers. The SHE-PWM is based...
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Applicability of phenolic acids as effective enhancers of cocrystals solubility of methylxanthines
PublicationApplicability of phenolic acids as potential cocrystal formers for methylxanthine derivatives was analyzed both in terms of cocrystallization probabilities and solubility advantage. The cocrystal formation abilities were evaluated using mixing enthalpy estimated within the conductor like screening model for real solvents (COSMO-RS) framework. The solubility improvement of potential cocrystals was estimated by formulation of the...
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Thickness accuracy of sash gang sawing
PublicationThin lamellae, corresponding to the layer components of structural glued members, i.e. 2-ply or 3-ply glued parquet, can be manufactured in re-sawing operations of kiln-dried wood blocks. These must be prepared with high dimensional accuracy and adequate surface quality following specific technical requirements for lamellae thickness variations, especially in the upper layers of the glued composite parquet. The accuracy of oak...
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Young shoots of red cabbage are a better source of selected nutrients and glucosinolates in comparison to the vegetable at full maturity
PublicationCruciferous vegetables are a valuable source of ingredients with health benefits. The most characteristic compounds of cruciferous vegetables with identified anticancer properties are glucosinolates. Young shoots and sprouts of red cabbage are becoming a popular fresh food rich in nutrients and bioactive compounds. The objective of this research was to determine, for the first time in a comprehensive approach, whether young shoots...
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Ensuring sustainable development of urban public transport: A case study of the trolleybus system in Gdynia and Sopot (Poland)
PublicationElectromobility is a vital tool in reducing the environmental impact of transportation. A technologically mature means of public transport is the trolleybus. Based on a case study of the Polish cities of Gdynia and Sopot, this paper explores the factors that influence the development of the trolleybus system. Recent developments of in-motion charging (IMC) technology are analysed what provides a new analytical framework for the...