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Search results for: PWM MODULATION
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PROBABILISTIC ANALYSIS OF A SPACE TRUSS BY MEANS OF A MULTIDIMENSIONAL VARIABLE DESCRIPTION
PublicationThe objective of this paper is to present a variant of the point estimate method (PEM) to determine mean values and standard deviations of limit loads of engineering structures. This approach is illustrated by limit state analysis of a space truss, considering geometric and material imperfections. The calculations were performed for different random models, so the influence of random parameters on the limit load of the truss can...
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Wpływ parametrów eksploatacyjnych oraz przecieków na wartość skoków ciśnienia w pompie tłoczkowej z rozrządem krzywkowym
PublicationPublikacja stanowi kontynuację artykułu "Analiza zjawisk dynamicznych w komorze cylindrowej pompy PWK o zmiennej wydajności" z monografii Cylinder 2010. Praca stanowi uszczegółowienie wcześniejszej publikacji oraz jej rozszerzenie o wyniki badań oraz symulacji, a także szczegółowo porusza temat przecieków w oknie rozrządu, który we wcześniejszych publikacjach był tylko wspomniany.
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Resistance noise in tio2-based thin film gas sensors underultraviolet irradiation
PublicationBadano możliwości wykorzystania fluktuacji rezystancji w cienkich warstwach TiO2 do wykrywania gazów. Pomiary przeprowadzono, gdy próbka była oświetlona promieniowaniem ultrafioletowym o długości 370nm, w obecności gazu H2S. Stwierdzono, że fluktuacje rezystancji są indukowane promieniowaniem ultrafioletowym i pozwalają na wykrycie obecności H2S w stężeniu do 1.5 ppm.
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Distance measurement errors in silent FM-CW sonar with matched filtering
PublicationThe secretiveness of sonar operation can be achieved by using continuous frequency-modulated sounding signalswith reduced power and significantly prolonged repeat time. The application of matched filtration in the sonarreceiver provides optimal conditions for detection against the background of white noise and reverberation, and avery good resolution of distance measurements of motionless targets. The article shows that target...
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Studies on removal of Zn(II), Cd(II) and Pb(II) ions in polymer inclusion membrane transport with calix[4]-crown-6 derivatives
PublicationZbadano selektywność procesu wydzielania jonów cynku(II), kadmu(II) i ołowiu(II) z wodnych roztworów azotanowych zawierających równomolową mieszaninę tych trzech metali (cMe= 0,01 M) w procesie transportu przez polimerowe membrany inkluzyjne (PIM) przy użyciu w roli przenośników jonów pochodnych kaliks[4]-korony-6. Membrany typu PIM syntezowano z trójoctanu celulozy (nośnik), eteru o?nitrofenylopentylowego (pastyfikator) i pochodnych...
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Ekspertyza w zakresie dostępności kolejowych obiektów obsługi podróżnych z niepełnosprawnościami oraz ograniczoną możliwością poruszania
PublicationEkspertyza dotyczy oceny dostosowania zintegrowanych węzłów przesiadkowych do potrzeb osób z ograniczoną sprawnością, w tym osób z niepełnosprawnościami. Węzły komunikacyjne stanowią ważny element zwiększania niezależności osób z ograniczoną sprawnością i poprzez możliwość skorzystania z różnych środków transportu zwiększa się obszar do którego mogą dotrzeć. W ekspertyzie wskazano, aby wypełnić wymagania wytycznych TSI PRM, a także...
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A Surrogate-Assisted Measurement Correction Method for Accurate and Low-Cost Monitoring of Particulate Matter Pollutants
PublicationAir pollution involves multiple health and economic challenges. Its accurate and low-cost monitoring is important for developing services dedicated to reduce the exposure of living beings to the pollution. Particulate matter (PM) measurement sensors belong to the key components that support operation of these systems. In this work, a modular, mobile Internet of Things sensor for PM measurements has been proposed. Due to a limited...
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Preparation of silver nanoparticles in reverse micelles and antibacterial activity of silver modified-paints
PublicationW publikacji została opisana metoda otrzymywania nanocząstek srebra oraz farb modyfikowanych srebrem i ich wpływ na zahamowanie rozwoju wybranych bakterii i grzybów. Podjęto również próbę porównania wpływu rodzaju prekursora srebra oraz substancji powierzchniowo czynnej na stabilność otrzymanych nanocząstek srebra. Przygotowane mikroemulsje zawierały od 500 do 2000 ppm srebra
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ADOPTED ISOCHRONE METHOD IMPROVING SHIP SAFETY IN WEATHER ROUTING WITH EVOLUTIONARY APPROACH
PublicationThe paper is focused on adaptation of an isochrone method necessary for application to a weather routing system with evolutionary approach. Authors propose an adaptation of the isochrone method with area partitioning assuring that the route found by the adopted method would not cross land. In result, when applied to a weather routing system with evolutionary approach, this proposal facilitates creation of initial population, resulting...
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Bezczujnikowe sterowanie maszyną indukcyjną zasilaną z falownika prądu
PublicationW układach napędowych przez nazwę bezczujnikowe sterowanie rozumie się sterowanie maszyną bez pomiaru prędkości kątowej wirnika. Prędkość kątową oblicza się wykorzystując model maszyny lub cechy fizykalne maszyny, w niniejszej pracy wykorzystano obserwator prędkości kątowej wirnika opracowany na podstawie modelu matematycznego maszyny indukcyjnej klatkowej. Układy napędowe z falownikiem napięcia znalazły powszechne uznanie ze względu...
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Hybrid‐mode single‐slope ADC with improved linearity and reduced conversion time for CMOS image sensors
PublicationIn the paper, a single‐slope analog‐to‐digital converter (ADC) for integrated CMOS image sensor applications with an improved technique of conversion has been proposed. The proposed hybrid‐mode ADC automatically uses one of the following conversion techniques: time based (i.e. PWM) or voltage based (i.e. single‐slope). During the ADC operation, the clock frequency and reference voltage are modified in order to reduce the conversion...
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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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Prototypowy czujnik do oznaczania lotnych związków opganicznych w powietrzu
PublicationW pracy zaprezentowano prototypowy elektrochemiczny czujnik zbudowany na bazie cieczy jonowej do oznaczania związków z grupy lotnych związków organicznych (LZO). W czujniku zostały użyte komercyjne elektrody firmy DropSens. w postaci pasków z nadrukowanymi elektrodami na ceramicznym podłożu. Jako elektrolit i środowisko reakcji redox wykorzystano następujące ciecze jonowe: dicyjanoamid 1-butylo-3-metyloimidazoliowy ([BMIM][N(CN2)]),...
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Heat transfer enhancement of modular thermal energy storage unit for reversible heat pump cooperation
PublicationThe following article presents experimental comparison research on a hexagonal shelland-tube latent thermal energy storage (TES). Such shape of a shell was deliberately chosen instead of a cylindrical one due to its high modularity and with intent for future applications in automobiles (EV and PHEV) air conditioning systems (HVAC). Two geometries of helical coils, acting as tubes, were studied in this article. One was a simple...
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CURRENT SITUATION ON THE POLAND REAL ESTATE MARKET
PublicationIn recent years the polish real estate market has been characterised by a significant increase in supply and demand. This was facilitated by a number of macroeconomic factors. In recent years, housing has been commissioned as 30 years ago. Therefore, the depth analysis issue of the causes and consequences for the Polish economy of these trends is now relevant. Among the reasons are significant economic growth, low interest rates...
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Nowoczesne rozwiązania stosowane w kontekście ograniczenia strat energetycznych w budynkach oraz poprawy komfortu cieplnego
PublicationW artykule zaprezentowano nowoczesne rozwiązania pozwalające na zmniejszenie energochłonności budynków oraz ograniczenie wpływu warunków atmosferycznych na komfort cieplny. Omówiono metodologię optymalizacji kształtu oraz rodzaju materiałów wykorzystywanych w procesie powstawania budynków użytkowych. Zaprezentowano tu metody oparte o najnowsze zdobycze techniki takie jak materiały budowlane z domieszką PCM (ang. Phase change materials)
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A comprehensive evaluation of mimosa extract as a corrosion inhibitor on AA6060 alloy in acid rain solution: part I. Electrochemical AC methods
PublicationThe inhibition effect of mimosa extract on the corrosion of AA6060 aluminum alloy in acid rain solution was investigated by electrochemical impedance spectroscopy and dynamic electrochemical impedance spectroscopy (DEIS). All the studied electrochemical parameters showed good corrosion inhibitive characteristics with respect to the aluminum alloy in the tested solution. Inhibitor efficiency increased with the concentration and...
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QUASI-DISTRIBUTED NETWORK OF LOW-COHERENCE FIBER-OPTIC FABRY-PÉROT SENSORS WITH CAVITY LENGTH-BASED ADDRESSING
PublicationDistributed measurement often relies on sensor networks. In this paper, we present the construction of low coherent fiber-optic Fabry-Pérot sensors connected into a quasi-distributed network. We discuss the mechanism of spectrum modulation in this type of sensor and the constraints of assembly of such sensors in the network. Particular attention was paid to separate the signals from individual sensors, which can be achieved by...
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Method of selecting the LS-SVM algorithm parameters in gas detection process
PublicationIn this paper we showed the method of resistive gas sensors data processing. The UV irradiation and temperature modulation was applied to improve gas sensors’ selectivity and sensitivity. Noise voltage across the sensor’s terminals (proportional to its resistance fluctuations) was recorded to estimate power spectral density. This function was an input data vector for LS-SVM (least squares – support vector machine) algorithm, which...
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PHONEME DISTORTION IN PUBLIC ADDRESS SYSTEMS
PublicationThe quality of voice messages in speech reinforcement and public address systems is often poor. The sound engineering projects of such systems take care of sound intensity and possible reverberation phenomena in public space without, however, considering the influence of acoustic interference related to the number and distribution of loudspeakers. This paper presents the results of measurements and numerical simulations of the...
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Detection of gaseous compounds with different techniques
PublicationSensing technology has been developed for detection of gases in some environmental, industrial, medical, and scientific applications. The main tasks of these works is to enhance performance of gas sensors taking into account their different applicability and scenarios of operation. This paper presents the descriptions, comparison and recent progress in some existing gas sensing technologies. Detailed introduction to optical sensing...
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Measurement of Impulse Response of Shallow Water Communication Channel by Correlation Method
PublicationPerformances of underwater acoustic communication (UAC) systems are strongly related to specific propagation conditions of the underwater channel; conditions that can additionally change in time due to the movement of the acoustic system transmitter and receiver or to reflection by underwater objects of the transmitted signal. The time-varying impulse response is a comprehensive description of dynamically changing transmission...
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The Role of Inflammatory Cytokines in the Pathogenesis of Colorectal Carcinoma-Recent Findings and Review
PublicationThe inflammatory process plays a significant role in the development of colon cancer (CRC). Intestinal cytokine networks are critical mediators of tissue homeostasis and inflammation but also impact carcinogenesis at all stages of the disease. Recent studies suggest that inflammation is of greater importance in the serrated pathway than in the adenoma-carcinoma pathway. Interleukins have gained the most attention due to their...
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Measurements of transmission properties of Acoustic Communication Channels
PublicationTough transmission properties of shallow water acoustic channels (SWAC) highly limit the use of underwater acoustic communication (UAC) systems. An adaptive matching of modulation and signaling schemes to instantaneous channel conditions is needed for reliabledata communications. This creates, however, unique challenges for designers when compared to radio transmission systems. When communication system elements are in move, the...
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A 1-nS 1-V Sub-1-µW Linear CMOS OTA with Rail-to-Rail Input for Hz-Band Sensory Interfaces
PublicationThe paper presents an operational transconductance amplifier (OTA) with low transconductance (0.62–6.28 nS) and low power consumption (28–270 nW) for the low-frequency analog front-ends in biomedical sensor interfaces. The proposed OTA implements an innovative, highly linear voltage-to-current converter based on the channel-length-modulation effect, which can be rail-to-rail driven. At 1-V supply and 1-Vpp asymmetrical input driving,...
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RCDs Tripping in the Range from DC to AC 50 kHz for Slowly Rising Residual Current
PublicationThe wide use of power electronic converters means that in many low-voltage systems earth fault currents containing components from DC to AC of various frequencies have to be taken into account. Due to the tendency to increase the modulation frequency in converters, components of higher frequencies may be in the order of several tens of kilohertz. Therefore, it is very important to verify the behavior of devices for protection against...
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Trace Elements in Aquatic Environments
PublicationA trace element is defined as a chemical element whose the average concentration is less than 100 ppm (mg/kg, mg/L – in the case of a water matrix). In aquatic environments the concentrations of trace elements are usually at the level of picomoles per liter and lower. This causes extreme analytical problems, especially in situations where low content is in the range of background levels. Taking into account the role of trace elements...
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NOBLE METAL MODIFIED TiO2 FOR PHOTOCATALYTIC AIR PURIFICATION
PublicationTiO2 was surface modified with silver, gold, palladium and platinum ion clusters to improve its photocatalytic activity. The effect of metal content, the kind of dopant used during preparation procedure on the photoactivity were investigated. in toluene removal which was used as a model volatile organic compound. Toluene, at the concentration of about 100 ppm, was irradiated over noble metal modified TiO2 using light-emitting diodes...
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A study of the photoelectron spectra of α-tetrahydrofurfuryl alcohol over the outer valence energy region (9–25 eV)
PublicationPhotoelectron spectra of α-tetrahydrofurfuryl alcohol (THFA) molecules, the threshold spectrum and spectra for constant photoelectron energies, have been measured over the photon energy range 9–25 eV. Analysis of the photoelectron spectra has allowed overlapping photoionization bands to be separated, tentatively assigned and their vertical photoionization energies to be determined. These energies are compared with existing theoretical...
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Biophilic Design: A Trend Watch
PublicationDuring the 20th century, many people migrated to cities for employment and economic opportunities, abandoning farming and natural landscapes so their direct connection to the countryside and nature was lost. This process continues to this day with unprecedented urban growth, in fact, it’s estimated 68% of the world population will live in urban areas by 2050. Due to the evolutionary disposition of humans, when people live in an...
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Changing Attitudes in Cross Cultural Diversity through International Senior Capstone Projects
PublicationIn this global world, today’s engineer is likely to have to work in global international teams with colleagues from other nationalities. The challenge for many engineering curricula is how to include, in a realistic way, this global dimension and increase the student’s awareness of the issues that are encountered. In the Purdue University Engineering Technology program, an international capstone project was created to increase...
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Prototype of electrochemical sensor for measurements of volatile organic compounds in gases
PublicationThe paper presents a laboratory prototype of an electrochemical sensor for measurements of volatile organic compounds (VOCs) in gases, utilizing ionic liquids and commercial screen printed electrodes by DropSens. The following ionic liquids have been tested as the electrolyte and redox reaction environment: 1-butyl, 3-methylimidazolium dicyanoamide ([BMIM][N(CN)2]), 1-octyl, 3-methylimidazolium tetrafluoroborate ([OMIM][BF4]),...
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Female entrepreneurship in Kazakhstan
PublicationWomen constitute the majority of the Kazakh population and, even though they live almost 10 years longer than men on average, they are far less economically active. Less than half of the female population take up employment. Women’s wages are often as much as 30% lower than men’s. The subjective reasons for undertaking economic activity as mentioned by women included: independence from the husband, low earnings of the husband and...
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Trimethylamine N-oxide and the reverse cholesterol transport in cardiovascular disease: a cross-sectional study
PublicationThe early atherosclerotic lesions develop by the accumulation of arterial foam cells derived mainly from cholesterol-loaded macrophages. Therefore, cholesterol and cholesteryl ester transfer protein (CETP) have been considered as causative in atherosclerosis. Moreover, recent studies indicate the role of trimethylamine N-oxide (TMAO) in development of cardiovascular disease (CVD). The current study aimed to investigate the association...
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Analiza nowoczesnych siłowni jądrowych
PublicationW pracy analizowano obiegi termodynamiczne siłowni wykorzystujących reaktory jądrowe IV generacji. Obliczano sprawność obiegów siłowni jądrowych z nowoczesnymi reaktorami, a wyniki obliczeń porównano z tradycyjnym układem obecnie stosowanym typu PWR. Każdy z badanych układów optymalizowano ze względu na maksymalną sprawność dla zadanych parametrów początkowych. Układ nadkrytyczny wodny SCWR okazał się najkorzystniejszy ze względów...
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Stochastic equivalence scales in log-normal distributions of expenditures
PublicationIn the paper, the properties of the stochastic equivalence scales (SES) are analysed when expenditure distributions are log-normal. The SES provides the equivalent distribution of expenditures when the population of households is heterogeneous with respect to such attributes as household size, demographic cpmposition, etc. For log-normal expenditure distributions, the non-parametric SES deflators are proportional to the ration...
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An assessment of Islamic banking in Bosnia and Herzegovina – a comparative analysis using the CAMELS approach
PublicationThis paper examines the phenomenon of Islamic banking in Bosnia and Herzegovina. Although almost half of the Bosnian population is recognized as Islamic, there is only one bank purely based on Sharia operating in this country. The aim of the article is to conduct a comparative analysis of the financial standing of this bank and the banking sector in this country and region. The chosen method of analysis is CAMELS which examines...
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"Srebrni przedsiębiorcy" w świetle badań europejskich
PublicationArtykuł poświęcony jest przedsiębiorczości ludzi w wieku dojrzałym. Stanowi próbę przybliżenia tej tematyki głównie poprzez pryzmat teorii i dotychczas przeprowadzonych badań empirycznych, głównie europejskich. Szczególnie dużo miejsca poświęcono w nim motywacjom „srebrnych przedsiębiorców”, dokonano również podziału tej populacji na różne profile, wynikające z czynników jakie miały wpływ na ich decyzje przedsiębiorcze.
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Discrete random variables in reliability calculations of a reticulated shell
PublicationImplementation of the Point Estimation Method (PEM) in the reliability analysis of a three-dimensional truss structure is presented in the paper. The influence of geometric and material random parameters on the truss load-carrying capacity was investigated. The analysis was performed for different combinations of basic variables. Symmetric and asymmetric cases of snow load were taken to assess the structural reliability. Sensitivity...
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Future of medicine: personalized oncology
PublicationUnderstanding genetic and epigenetic mechanisms of tumorigenesis allows identifying many vital mutations affected the formation of various malignancies. This led to the discovery of a new therapeutic approach, based on molecular mechanisms in the world of medicine, which is called personalized medicine (PM). This review aims to outline the state of the art of the personalized medicine in treatment, taking into account anti-cancer...
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Sex contribution to average age at onset of Huntington's disease depends on the number of (CAG)n repeats
PublicationHuntington’s disease (HD) is a hereditary neurodegenerative disorder caused by the extension of the CAG repeats in exon 1 of the HTT gene and is transmitted in a dominant manner. The present study aimed to assess whether patients’ sex, in the context of mutated and normal allele length, contributes to age on onset (AO) of HD. The study population comprised a large cohort of 3723 HD patients from the European Huntington’s Disease...
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Personalized nutrition in ageing society: redox control of major-age related diseases through the NutRedOx Network (COST Action CA16112)
PublicationA healthy ageing process is important when it is considered that one-third of the population of Europe is already over 50 years old, although there are regional variations. This proportion is likely to increase in the future, and maintenance of vitality at an older age is not only an important measure of the quality of life but also key to participation and productivity. So, the binomial “nutrition and ageing” has different aspects...
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Approval of an Arrangement in the Restructuring Proceedings and the Financial Condition of Companies Listed on the Stock Exchanges in Warsaw. Is There Any Relationship?
PublicationThis paper attempts to identify the financial indicators differentiating companies that are insolvent or at risk of insolvency and have successfully entered into an arrangement with their creditors from those that have not. In addition, a two-factor model for predicting the odds of an arrangement has been proposed. The research was conducted using a population of companies listed on stock exchanges in Warsaw that initiated restructuring...
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Study of ZrS3-based field-effect transistors toward the understanding of the mechanisms of light-enhanced gas sensing by transition metal trichalcogenides
PublicationExtending knowledge of the properties of low-dimensional van der Waals materials, including their reactivity to the ambiance, is important for developing innovative electronic and optoelectronic devices. Transition metal trichalcogenides with tunable optical band gaps and anisotropic conductivity are an emerging class among low- dimensional structures with the possibility of gate tunability and photoreactivity. These properties...
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Testing OFDM Transmission Schemes for Shallow Water Acoustic Communications
PublicationLarge variability of communication properties of underwater acoustic channels, and especially strongly varying instantaneous conditions in shallow waters, is a tough challenge for the designers of underwater acoustics communication (UAC system. There is a need for developing adaptive signaling schemes that would dynamically optimize signal parameters in both physical and link layers of communication protocols. The orthogonal frequency...
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Analytical Estimation of Power Losses in a Dual Active Bridge Converter Controlled with a Single-Phase Shift Switching Scheme
PublicationMicro-grid solutions around the world rely on the operation of DC/DC power conver- sion systems. The most commonly used solution for these topologies is the use of a dual active bridge (DAB) converter. Increasing the efficiency and reliability of this system contributes to the improvement in the stability of the entire microgrid. This paper discussed an analytical method of energy efficiency and power loss estimation in a single...
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A Comprehensive Review of Phytonutrients as a Dietary Therapy for Obesity
PublicationObesity is a complex medical condition mainly caused by eating habits, genetics, lifestyle, and medicine. The present study deals with traditional diets like the Mediterranean diet, Nordic diet, African Heritage diet, Asian diet, and DASH, as these are considered to be sustainable diets for curing obesity. However, the bioavailability of phytonutrients consumed in the diet may vary, depending on several factors such as digestion...
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Light-Modulated Sunscreen Mechanism in the Retina of the Human Eye
PublicationThe functioning of the human eye in the extreme range of light intensity requires a combination of the high sensitivity of photoreceptors with their photostability. Here, we identify a regulatory mechanism based on dynamic modulation of light absorption by xanthophylls in the retina, realized by reorientation of pigment molecules induced by trans–cis photoisomerization. We explore this photochemically switchable system using chromatographic...
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Comparison of Ozonation and Evaporation as Treatment Methods of Recycled Water for Bioethanol Fermentation Process
PublicationThe paper compared the performance of the ethanol yield after alcoholic fermentation with samples of rejected (RW) and permeate water (PW), RW and PW treated by oxidation with ozone (O3) (5 and 15 min) and evaporation, aiming the recirculation back to the bioethanol process. RW and PW were collected after an anaerobic bioreactor (AnBR) used for stillage treatment. Nine types of fermentations were made, where one used 100% tap...
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Historia budowy i reaktywacji Kolei Kokoszkowskiej w postaci Pomorskiej Kolei Metropolitalnej
PublicationW artykule została przedstawiona historia budowy Kolei Kokoszkowskiej (otwarcie w 1914 r. i zburzenie w 1945 r.), jej znaczenie dla powiązań przestrzennych Wolnego Miasta Gdańsk i polskich Kaszub, próba jej reaktywacji w związku z rozwojem aglomeracji trójmiejskiej w II połowie XX wieku i ostatecznie budowa po jej śladzie Pomorskiej Kolei Metropolitalnej na początku XXI wieku. W artykule poruszono zagadnienia związane ze sporami...