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Wyniki wyszukiwania dla: CHROMATIC INDEX
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Markowitz’s portfolio theory – optimal length of estimation window for gold and the biggests companies on the Warsaw Stock Exchange
PublikacjaThe following article is dedicated to the construction of an investment portfolio consisting of 3 investments from the Polish capital market found in the WIG20 index and from investment in gold. The purpose of the study was to determine the optimal length of the estimation window for building a portfolio with minimal risk and maximum efficiency. The length of the estimation window was also assessed in terms of the rate of return...
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Implementation of the FOPID Algorithm in the PLC Controller - PWR Thermal Power Control Case Study
PublikacjaIn the paper authors describe proposition of design and verification procedures of the discrete Fractional Order PID (FOPID) algorithm for control of the Pressurized Water Reactor (PWR) thermal power near its nominal operating point. The FOPID algorithm synthesis consists of: off-line optimal tunning of its parameters in continuous time-domain with LQ (Linear Quadratic) performance index and simplified models of nuclear reactor...
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Enhancement of fiber-optic low-coherence Fabry-Pérot interferometer with ZnO ALD films
PublikacjaIn this paper investigation of the enhanced fiber-optic low coherence Fabry-Pérot interferometer with zinc oxide (ZnO) film deposited by atomic layer deposition (ALD) was presented. Model of the interferometer, which was constructed of single-mode optical fiber with applied ZnO ALD films, was built. The interferometer was also examined by means of experiment. Measurements were performed for both reflective and transmission modes,...
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Towards Synthetic and Balanced Digital Government Benchmarking
PublikacjaReliable benchmarking is essential for effective management of the government digitalization efforts. Existing benchmarking instruments generally fail to support this target. One problem is the diversity of instruments, resulting in a split image of digital progress and adding ambiguity to policy decisions. Another problem is disconnect in assessing progress between digital and traditional “analog” governance, lending support to...
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Probabilistic Methods in Reliability Assessment of Engineering Lightweight Structures
PublikacjaThe paper considers the probability-based analysis of structural safety measures. Two different numerical examples of representative lightweight structures are considered – a submerged truss tower supporting an offshore platform, and an overhead power line support truss tower. On the basis of these examples, the importance of a motivated selection of analysis method and a proper choice of the number of important variables is shown....
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Iterative‐recursive estimation of parameters of regression models with resistance to outliers on practical examples
PublikacjaHere, identification of processes and systems in the sense of the least sum of absolute values is taken into consideration. The respective absolute value estimators are recognised as exceptionally insensitive to large measurement faults or other defects in the processed data, whereas the classical least squares procedure appears to be completely impractical for processing the data contaminated with such parasitic distortions. Since...
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Wavelet transform analysis reveals differences between patients with impaired LVEF and healthy individuals
PublikacjaHeart failure (HF) is a global pandemic. It af- fects 64 million people worldwide, with stead- ily increasing incidence, morbidity, mortality, and economic burden [1]. Forecasts indicate continued rising prevalence, especially among the elderly and in low-to-middle socio-de- mographic index regions [2]. Left ventricular ejection fraction (LVEF) significantly impacts HF treatment and prognosis [3]. The sequence of physiological...
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Fluorescence of p-hydroxyazobenzocrowns – Tautomeric equilibrium effect
PublikacjaThe spectroscopic properties of a series of para-hydroxyazobenzocrowns, including three novel compounds, were investigated using UV–Vis absorption and emission spectroscopy. This study presents, for the first time, determined quantum yield (QY) values for macrocycles of this category, ranging between 0.122 and 0.195. The highest values were obtained for crowns bearing two phenyl substituents in benzene rings. The impact of aromatic...
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The complete stereochemistry of the antibiotic candicidin A3 (syn. ascosin A3, levorin A3)
PublikacjaHerein, the stereostructure of the aromatic heptaene macrolide (AHM) antifungal antibiotic candicidin A3 (syn. ascosin A3, levorin A3) has been established upon the 2D NMR studies, consisting of DQF-COSY, TOCSY, ROESY, HSQC and HMBC experiments, as well as upon extensive molecular dynamics simulations. The geometry of the heptaenic chromophore was defined as: (22E, 24E, 26Z, 28Z, 30E, 32E, 34E). The previously unreported absolute...
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Dynamic coloring of graphs
PublikacjaDynamics is an inherent feature of many real life systems so it is natural to define and investigate the properties of models that reflect their dynamic nature. Dynamic graph colorings can be naturally applied in system modeling, e.g. for scheduling threads of parallel programs, time sharing in wireless networks, session scheduling in high-speed LAN's, channel assignment in WDM optical networks as well as traffic scheduling. In...
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The Efficiency and Productivity Evaluation of National Innovation Systems in Europe
PublikacjaPurpose: An efficient innovation system currently plays a crucial role in creating competitive prevalence, contributing to the economic growth of individual states. The innovation system is influenced by many socioeconomic factors, including in international rankings of innovativeness of economies. These classifications have some limitations. Primarily, they do not examine the efficiency, which means they do not analyze the...
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Deep eutectic solvent-based shaking-assisted extraction for determination of bioactive compounds from Norway spruce roots
PublikacjaPolyphenolic compounds play an essential role in plant growth, reproduction, and defense mechanisms against pathogens and environmental stresses. Extracting these compounds is the initial step in assessing phytochemical changes, where the choice of extraction method significantly influences the extracted analytes. However, due to environmental factors, analyzing numerous samples is necessary for statistically significant results,...
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Hybrid battery based on arylated carbon nanotubes and laccase
PublikacjaSingle-walled carbon nanotubes (SWCNT) were covalently modified with anthracene and anthraquinone and used for the construction of cathodes for biocatalytic reduction of dioxygen. The nanotubes with aromatic groups casted onto the electrode increased the working surface of the electrode and enabled efficient direct electron transfer (DET) between the enzyme and the electrode. The aryl groups enter the hydrophobic pocket of the...
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Rearrangement of azoxybenzocrowns into chromophoric hydroxyazobenzocrowns and the use of hydroxyazobenzocrowns for the synthesis of ionophoric biscrown compounds
PublikacjaThe Wallach rearrangement was used as a method for preparing p-hydroxyazobenzocrown ethers starting from different azoxybenzocrowns as substrates. Synthesis of a series of p-hydroxyazobenzocrowns under modified conditions and characterization of the obtained products are presented. o-Hydroxyazobenzocrowns were identified among the products of the photochemical rearrangement of azoxybenzocrowns. Novel biscrowns were synthesized...
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Novel Diazocrowns with Pyrrole Residue as Lead(II) Colorimetric Probes
PublikacjaNovel 18- and 23-membered diazomacrocycles were obtained with satisfactory yields by diazocoupling of aromatic diamines with pyrrole in reactions carried under high dilution conditions. X-ray structure of macrocycle bearing five carbon atoms linkage was determined and described. Compounds were characterized as chromogenic heavy metal ions receptors. Selective color and spectral response for lead(II) was found in acetonitrile and...
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Wpływ temperatury na skład produktów pirolizy
PublikacjaPraca prezentuje wyniki badań pirolizy biomasy przy różnych temperaturach maksymalnych prowadzenia pro- cesu. Biomasą użytą w eksperymentach były zrębki brzozowe. Analizowano udziały masowe pięciu frakcji pro- duktów: karbonizatu, smół lekkich, smół ciężkich, wody oraz gazu pirolitycznego. Wykonano także analizy ciepła spalania poszczególnych frakcji w zależności od temperatury prowadzenia procesu. Eksperymenty wykonano przy pomocy...
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Koncepcja międzynarodowej konkurencyjności makrootoczenia przedsiębiorstw
PublikacjaCelem badań przedstawionych w niniejszym artykule jest opracowanie koncepcji konkurencyjności międzynarodowej (IC) krajów, której podstawą jest makroekonomiczne otoczenie przedsiębiorstw. Motywem podjęcia tych badań były poważne wady metodologii pomiaru IC gospodarek stosowanej przez Światowe Forum Ekonomiczne (WEF). WEF rekomenduje Globalny Indeks Konkurencyjności (GCI) jako globalną miarę produktywności kraju. WEF utrzymuje,...
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Amphotericin B and Its New Derivatives - Mode of Action
PublikacjaAmphotericin B (AmB) is a well known antifungal and antiprotozoal antibiotic used in the clinic for several decades. Clinicalapplications of AmB, however, are limited by its nephrotoxicity and many other acute side effects which are not acceptable by patientswhen their life is not threaten. In order to improve the therapeutic index of this drug, lipid formulations have been introduced and manyefforts have been made to obtain less...
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ESG investing during the Covid-19 crisis. Evidence from Central European Stock Exchanges
PublikacjaAs COVID-19 turned into a global pandemic, world markets gradually began to recover after initial dynamic declines. Restrictions, and their subsequent loosening, were, and are, not without significance for the financial markets. These particular circumstances provide a unique opportunity to contribute to the literature by focusing on the potential resilience of ESG (environmental, social and governance) investing in an era of crisis....
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Export diversification and dependence on natural resources
PublikacjaLow export diversification is a risk-augmenting factor for many countries dependent on natural resources. The literature tends to focus on the growth effects of resource dependence (‘resource curse’ debate) while not much is known on how it affects the variety of non-resource exports. To quantify this effect we decompose the relative Theil index using product-level export data from 160 countries over the time period 1996–2018....
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Miniaturized, green salting-out liquid–liquid microextraction coupled with GC–MS used to evaluate biogenic amines in wine samples
PublikacjaMonitoring of the biogenic amines (BAs) content in food products, including wine, is important due to the health and safety of consumers and from the quality control point of view. In a given study, simultaneous derivatization and salting-out liquid–liquid microextraction (SALLME) coupled with GC–MS for BAs determination from wine samples was developed. For the optimization the Box-Behnken design was applied, where three independent...
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Direct reduction of pellets through hydrogen: Experimental and model behaviour
PublikacjaThis paper presents the hydrogen reduction behaviour of industrial pellets designed for the efficient hydrogen based direct reduction. The pellets were provided with very low non ferrous oxides percentage (0.52 of basicity index) and with the absence on TiO2 oxides. The pellets measured diameters in the range 1.14–1.72 cm and were characterized in terms of porosity, pores size, tortuosity and compression strength. The pellets were...
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Ferrofluids based analytical extractions and evaluation of their greenness
PublikacjaFerrofluids are stable dispersions of magnetic nanoparticles in a carrier liquid. They have attracted considerable attention in analytical extractions as they combine fluid-like properties with magnetic character, providing magnetic control over the extraction process. The synthesis of ferrofluids is very straightforward, and it generally involves the preparation of magnetic nanoparticles, their coating, and then mixing in a suitable...
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Application of Thin ZnO ALD Layers in Fiber-Optic Fabry-Pérot Sensing Interferometers
PublikacjaIn this paper we investigated the response of a fiber-optic Fabry-Pérot sensing interferometer with thin ZnO layers deposited on the end faces of the optical fibers forming the cavity. Standard telecommunication single-mode optical fiber (SMF-28) segments were used with the thin ZnO layers deposited by Atomic Layer Deposition (ALD). Measurements were performed with the interferometer illuminated by two broadband sources operating...
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Optically transparent boron-doped nanocrystalline diamond films for spectroelectrochemical measurements on different substrates
PublikacjaFabrication process of optically transparent boron nanocrystalline diamond (BNCD) electrode on silicon and quartz substrate was shown. The B-NCD films were deposited on the substrates using Microwave Plasma Assisted Chemical Vapor Deposition (MWPACVD) at glass substrate temperature of 475 ºC. A homogenous, continuous and polycrystalline surface morphology with high sp3 content in B-NCD films and film thickness depending from substrate...
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Mechatronic design o strongly nonlinear systems on a basis of three wheeled mobile platform
PublikacjaRemarkable grow in demand both of mobile platform operability performance and reduction of project leading time development encourage to apply modern algorithms and reliable engineering tools for the design process. The paper discusses the mechatronic design applied for the surveillance system based on the energy performance index algorithm. The exploited mechatronic techniques i.e. virtual prototyping, Hardware-In-the-Loop Simulation...
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Chitin nanowhiskers from shrimp shell waste as green filler in acrylonitrile-butadiene rubber: Processing and performance properties
PublikacjaIn this work, chitin nanowhiskers with high crystallinity index were obtained from shrimp shells waste using acid hydrolysis method and then comprehensively characterized. Subsequently, the impact of chitin nanowhisker content on processing and performance of acrylonitrile-butadiene rubber based nanocomposites was evaluated. The results showed that the addition of chitin nanowhiskers increased tensile strength and tear strength...
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Novel bio-based thermoplastic poly(ether-urethane)s. Correlations between the structure, processing and properties
PublikacjaThe main purpose of this work was to analyze the effect of the number of unreacted isocyanate groups and the [NCO]/[OH] molar ratio during the chain extension of a prepolymer during the polymerization process on the structure, processing and selected properties of thermoplastic poly(ether-urethane)s. Three series of novel thermoplastic polyurethanes were obtained via a prepolymer route. Three prepolymers were synthesized from diisocyanate...
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Gas Composition Influence on the Properties of Boron-Doped Diamond Films Deposited on the Fused Silica
PublikacjaThe main subject of this study are molecular structures and optical properties of boron-doped diamond films with [B]/[C] ppm ratio between 1000 and 10 000, fabricated in two molar ratios of CH 4 -H 2 mixture (1 % and 4 %). Boron-doped diamond (BDD) film on the fused silica was presented as a conductive coating for optical and electronic purposes. The scanning electron microscopy images showed homogenous and polycrystalline surface...
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Green Analytical Chemistry: Summary of Existing Knowledge and Future Trends
PublikacjaAnalysis of recent publications in green analytical chemistry shows the current trends and future needs in this area. The main issues are related with search for cheaper, more efficient, more accurate, greener and miniaturized alternatives. Miniaturization is perhaps, the most notable current trend in analytical chemistry. Rapid developments and improvements in instrumentation have led to impressive range of benchtop technology...
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Thermodynamic study of binary mixtures of toluene with ionic liquids, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide
PublikacjaDensities, refractive indices and viscosities at 293.15, 298.15, 303.15, 308.15 and 313.15 K of binary mixtures of toluene with 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide have been measured over the miscible region at p = 0.1 MPa. From the experimental data, values of excess molar volume,...
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ASSESSMENT OF GOLD AND/OR CRUDE OIL AS INVESTMENTS FOR PORTFOLIO DIVERSIFICATION. A WARSAW STOCK EXCHANGE CASE STUDY
PublikacjaThe purpose of the study is to assess whether the inclusion of investments in gold and/or crude oil improves an investment portfolio consisting of shares of enterprises included in the WIG20 index (traditional invest-ments). All possible combinations of investment portfolios with minimal risk and maximum efficiency were tested. The portfolios were determined based on Markowitz’s portfolio theory. All results were compared...
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Enhancing electrochemical properties of an ITO-coated lossy-mode resonance optical fiber sensor by electrodeposition of PEDOT:PSS
PublikacjaA sensor working in multiple domains may offer enhanced information about the properties of an investigated analyte, including those containing biological species. It has already been shown that a dual-domain sensing capability, i.e., in optical and electrochemical domains, can be offered by lossy-mode resonance (LMR) sensors based on indium-tin-oxide (ITO) thin film. The spectral response of the LMR sensors depends on the refractive...
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Evaluation and start-up of an electro-Fenton-sequencing batch reactor for dairy wastewater treatment
PublikacjaThis study examined the performance of an integrated wastewater (WW) treatment system, namely an electro-Fenton (EF)-sequencing batch reactor (SBR), for dairy industry WW. The EF process was used as the first stage of the SBR. It degrades bio-refractory compounds via advanced oxidation processes, thereby resulting in the formation of simple biodegradable intermediates. Several factors, including the hydraulic retention time (HRT),...
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Structural changes of bacterial cellulose due to incubation in conditions simulating human plasma in the presence of selected pathogens
PublikacjaBacterial nanocellulose (BNC) is a natural biomaterial with a wide range of medical applications. However, it cannot be used as a biological implant of the circulatory system without checking whether it is biodegradable under human plasma conditions. This work aimed to investigate the BNC biodegradation by selected pathogens under conditions simulating human plasma. The BNC was incubated in simulated biological fluids with or...
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Fracture susceptibility of high RAP content asphalt concrete in terms of aging
PublikacjaDue to the reduction of CO2 emissions during the production of asphalt mixtures and the decrease in the demand for mineral resources, the addition of reclaimed asphalt pavement (RAP) is becoming indispensable. The durability of asphalt pavements containing a high RAP content may be reduced due to a decrease in the cracking resistance of the material, especially under the influence of operational aging. The article presents the...
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Application of Diagnostic Ratios of PAHs to Characterize the Pollution Emission Sources
PublikacjaThe paper summarizes the potential of application of parent polycyclic aromatic hydrocarbons (PAHs) to identify their emission sources. Four parent PAHs diagnostic ratios are used for this purpose: anthracene/(anthracene + phenanthrene), fluoranthene/(fluoranthene + pyrene), benzo[a]pyrene/(benzo[a]pyrene + chryzene) and indeno[1,2,3-c,d]pyrene/(indeno[1,2,3-c,d]pyrene + benzo[g,h,i]perylene). The compounds of each ratio have the...
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A headspace solid-phase microextraction method development and itsapplication in the determination of volatiles in honeys by gas chromatography
PublikacjaThe first part of the paper presents the detailed optimisation of all steps of the determination procedureof volatiles from Polish honeys by headspace solid-phase microextraction (HS-SPME) as the sample preparationmethod and gas chromatography/mass spectrometry (GC-MS) as the method of final determination.The methodology of semi-quantative analysis allowed the isolation and identification of volatile fractioncompounds from popular...
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Intermolecular Hydrogen Bonding Directed by Aryl–Perfluoroaryl π–π Stacking Interactions
PublikacjaThe crystal structures of five compounds capable of forming self-complementary hydrogen bonds but crystallizing as catemers or creating more complex crystal structures were compared with their complexes prepared by cocrystallization with perfluoroaryl compounds. The results of X-ray diffraction revealed that in all the cases the π–π stacking interactions caused reorganization of hydrogen bonds and induced creation of the expected...
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1,3,4-Thiadiazole-based diamides: Synthesis and complexation properties
PublikacjaAromatic diamides, derivative of 2,6-pyridinedicarboxylic acid and isophthalic acid, bearing 1,3,4-thiadiazole residue were prepared with satisfactory yields in conventional procedures and microwave stimulated reactions. X-ray structure of N,N-bis (1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide (2) DMSO solvate (2DMSO) was described. Selective zinc(II), lanthanum(III), terbium(III) and L-tyrosine recognition was found for N,N-bis(1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide...
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Persistent organic pollutants (POPs) as an indicator of surface water quality in the vicinity of the Polish Polar Station, Horsund
PublikacjaSurface waters were collected in the vicinity of the Polish Polar Station in Hornsund (Svalbard) to determine their concentration of various persistent organic pollutants (POPs), such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). In addition, parameters such as pH, SEC and TOC were measured. In total, 15 samples of lake water from and 15 samples of stream water were analysed. The sampling took...
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Hydrogen and chalcogen bonds in crystals of chalcogenadiazolecarboxylic acids – competition or cooperation?
PublikacjaThis article presents crystal structures of chalcogenadiazolecarboxylic acids bearing both a hydrogen and a chalcogen bond donor. The selected molecules varied in the size of the aromatic unit, the chalcogen atom and/or the position of the carboxyl group in the core structure. The most common synthons in their lattice are "R" _"2" ^"2" (8) self-complementary acid dimers or four-membered [Ch···N]2 rings. Supramolecular synthons...
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H2AX phosphorylation, its role in DNA damage response and cancer therapy
PublikacjaDouble-strand breaks (DSBs) are the most deleterious DNA lesions, which, if left unrepaired, may have severe consequences for cell survival, as they lead to chromosome aberrations, genomic instability, or cell death. Various physical, chemical, and biological factors are involved in DSB induction. Cells respond to DNA damage by activating the so-called DNA damage response (DDR), a complex molecular mechanism developed to detect...
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Stopniowa chromatografia cienkowarstwowa w normalnych układach faz (NP-TLC), jako technika rozdzielania i oceny składu grupowego frakcji asfaltenowych z utleniania pozostałości próżniowej ropy naftowej
PublikacjaW pracy opisano wyniki badań nad opracowaniem metodyki oceny składu grupowego i czystości frakcji asfaltenowych techniką chromatografii cienkowarstwowej w normalnych układach faz (NP-TLC). Skupiono się na doborze takich parametrów/warunków rozdzielania, jak stężenie i masa próbki, a także skład i kolejność eluentów stosowanych podczas rozwijania chromatogramów TLC. Zastosowana trój-stopniowa metodyka polega na nałożeniu 5 µL frakcji...
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Adaptacja akustyczna pomieszczenia wykładowego - studium przypadku
PublikacjaW niniejszej pracy przedstawiono analizę rozkładu pola akustycznego sali wykładowej znajdującej się w budynku Wydziału Elektroniki i Telekomunikacji Politechniki Gdańskiej. Badania przeprowadzono metodą pomiarową oraz symulacyjną z wykorzystaniem programu Odeon. Wybór parametrów oceny akustyki wnętrz sugerowany jest wymaganiami stawianymi pomieszczeniom lekcyjnym z zaznaczeniem multimedialnego charakteru wykładów prowadzonych...
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Rigid polyurethane foams modified with selected layered silicate nanofillers
PublikacjaThe aim of this study was to investigate the effect of three different nanofillers on the properties of rigid polyurethane foams, which were prepared by a one-step, laboratory-scale method from a two-component system at the ratio of NCO groups to OH groups equaled to 2. The reaction mixture consisted of the proper amounts of the commercial oligoether polyol, catalysts, water, nanoclays, and polymeric diphenylmethane diisocyanate....
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UPDRS tests for diagnosis of Parkinson's disease employing virtual-touchpad
PublikacjaThis paper presents a new approach to diagnosing Parkinson's disease. The progression of the disease can be measured by the UPDRS (Unified Parkinson Disease Rating Scale) scale which is used to evaluate motor and behavioral symptoms of Parkinson's disease. Hitherto the evaluation of the advancement of the disease in the UPDRS scale was made by a specialist through medical observation. The authors suggest a partial automation of...
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Structural Assessment of Reinforced Concrete Beams Incorporating Waste Plastic Straws
PublikacjaThe behavior of reinforced concrete beams containing fibers made of waste plastic straws (WPSs) under the three point bending test is examined. The effect of WPS fiber addition on the compressive and split tensile strength is reported. Four concrete mixes were prepared. The control mix PS-0 had a proportion of 1 cement: 1 sand: 2 coarse aggregate and a water cement ratio of 0.4. In the other three mixes PS-0.5, PS-1.5 and PS-3,...
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Tuning of the finesse coefficient of optoelectronic devices
PublikacjaOptoelectronic devices attracted considerable attention in many branches of science and technology, which can be attributed to their unique properties. Many of them use optical cavities which parameters can be adopted to specific requirements. This thesis investigates the introduction of diamond structures (nitrogen-doped diamond film, boron-doped diamond film, undoped diamond sheet) to optical cavities to tune their finesse coefficient....
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A probabilistic-driven framework for enhanced corrosion estimation of ship structural components
PublikacjaThe work proposes a probabilistic-driven framework for enhanced corrosion estimation of ship structural components using Bayesian inference and limited measurement data. The new approach for modelling measurement uncertainty is proposed based on the results of previous corrosion tests that incorporate the non-uniform character of the corroded surface of structural components. The proposed framework's basic features are outlined,...