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Wyniki wyszukiwania dla: ELECTROMAGNETIC (EM) EXPOSURE
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FDTD Simulations on Disjoint Domains with the Use of Discrete Green's Function Diakoptics
PublikacjaA 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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Bezczujnikowe sterowanie trakcyjnym silnikiem IPMSM małej mocy
PublikacjaThis paper describes an algorithm for estimation of IPMSM angular rotor position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. Control of the IPMSM electromagnetic torque requires a precise estimation of the rotor angular position throughout the wide speed range. This involves using a set of estimation methods switched with the dependence on the actual rotor...
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Properties of ordered titanium templates covered with Au thin films for SERS applications
PublikacjatCurrently, roughened metal nanostructures are widely studied as highly sensitive Raman scattering sub-strates that show application potential in biochemistry, food safety or medical diagnostic. In this workthe structural properties and the enhancement effect due to surface enhanced Raman scattering (SERS) ofhighly ordered nano-patterned titanium templates covered with thin (5–20 nm) gold films are reported.The templates are formed...
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Multitaper-Based Post-processing of Compact Antenna Responses Obtained in Non-anechoic Conditions
PublikacjaThe process of developing antenna structures typically involves prototype measurements. While accurate validation of far-field performance can be performed in dedicated facilities like anechoic chambers, high cost of construction and maintenance might not justify their use for teaching, or low-budget research scenarios. Non-anechoic experiments provide a cost-effective alternative, however the performance metrics obtained in such...
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Miniaturized Inline Bandpass Filters Based on Triple-Mode Integrated Coaxial-Waveguide Resonators
PublikacjaThis work presents a design technique to implement miniaturized cross-coupled bandpass filters in inline physical configurations based on triple-mode resonators. Triple-mode resonances are obtained by using integrated coaxial-waveguide cavity resonators. They consist of two coaxial conducting posts placed in the sidewalls of a rectangular waveguide cavity. In the proposed triplet, a transmission zero (TZ) can be positioned at any...
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Expedited Feature-Based Quasi-Global Optimization of Multi-Band Antenna Input Characteristics with Jacobian Variability Tracking
PublikacjaDesign of modern antennas relies—for reliability reasons—on full-wave electromagnetic simulation tools. In addition, increasingly stringent specifications pertaining to electrical and field performance, growing complexity of antenna topologies, along with the necessity for handling multiple objectives, make numerical optimization of antenna geometry parameters a highly recommended design procedure. Conventional algorithms, particularly...
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Jednoelektronowy atom Diraca w słabym polu magnetycznym
PublikacjaW rozprawie przedstawiono opis wpływu zewnętrznego stałego, słabego, jednorodnego pola magnetycznego na jednoelektronowy atom Diraca. Wykorzystując funkcje gęstości ładunku elektrycznego oraz gęstości prądu elektrycznego, rozważono procesy indukowania się w atomie dodatkowych elektromagnetycznych momentów multipolowych. Dokonano analizy indukowanego momentu dipolowego, w wyniku której uzyskano wyrażenie dla magnetyzowalności atomu....
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Distribution and bioavailability of mercury in the surface sediments of the Baltic Sea
PublikacjaThe study aimed to determine the level of mercury (Hg) and its labile and stable forms in the surface sediments of the Baltic Sea. The work considers the impact of current and historical sources of Hg on sediment pollution, together with the influence of different environmental parameters, including water inflows from the North Sea. Surface sediments (top 5 cm) were collected in 2016–2017 at 91 stations located in different...
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Typology of the Black Tents Architecture between Iranian nomad tribes
PublikacjaEvidence of the past shows variation in human settlements. Nomadic house the” Black Tent” shows relationship between humans and the natural environment surrounding them. Black Tents are made of natural materials consistant with environmental conditions. This paper discusses nomadic living space of some Iranian tribes located in different regions to show their unique architecture and culture. Rediscovering different architecture...
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Active Site Architecture and Reaction Mechanism Determination of Cold Adapted beta-D-galactosidase from Arthrobacter sp. 32cB
PublikacjaArthbetaDG is a dimeric, cold-adapted beta-D-galactosidase that exhibits high hydrolytic and transglycosylation activity. A series of crystal structures of its wild form, as well as its ArthbetaDG_E441Q mutein complexes with ligands were obtained in order to describe the mode of its action. The ArthbetaDG_E441Q mutein is an inactive form of the enzyme designed to enable observation of enzyme interaction with its substrate. The...
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Tuning of the Electrochemical Properties of Transparent Fluorine-doped Tin Oxide Electrodes by Microwave Pulsed-plasma Polymerized Allylamine
PublikacjaWe report here the dry, one-step, and low-temperature modification of FTO surfaces using pulsed plasma polymerization of allylamine (PPAAm). PPAAm/FTO surfaces were characterized by X-ray photoelectron spectroscopy, spectroscopic ellipsometry, and contact angles to understand the morphological, structural, and optical properties. FTO were coated with a very thin layer of adherent cross-linked, pinhole-, and additive-free allylamine...
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Multifrequency Nanoscale Impedance Microscopy (m-NIM): A novel approach towards detection of selective and subtle modifications on the surface of polycrystalline boron-doped diamond electrodes
PublikacjaIn this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a combination of contact-mode atomic force microscopy with local impedance measurements. The postulated approach is based on the application of multifrequency voltage perturbation instead of standard frequency-by-frequency analysis, which among others offers more time-efficient and accurate determination of the resultant impedance spectra...
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Determination of polybrominated diphenyl ethers (PBDEs) in dust samples collected in air conditioning filters of different usage – method development
PublikacjaThis study presents the results of studies aimed at the development of an analytical procedure for separation, identification, and determination of PBDEs compounds in dust samples collected from automotive cabin air filters and samples collected from filters installed as part of the air purification system in academic facilities. Ultrasound-assisted dispersive solid phase extraction (UA-dSPE) was found to perform better in terms...
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Biological responses to environmental contamination. How can metal pollution impact signal honesty in avian species?
PublikacjaEnvironmental pollution, for example with metals, can significantly affect the ecosystem balance leading to severe changes. Biologically active pigments are relevant for the appearance and condition of birds. Melanin and carotenoid particles are the most frequently deposited pigments in avian integument. They are responsible for the majority of colors of bird plumage. The phenotypic expression can be affected by metal contamination....
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Utilizing Morphological and Physiological Parameters of Lemna minor for Assessing Tetracyclines’ Removal
PublikacjaAntibiotics with significant environmental toxicity, e.g., tetracyclines (TCs), are often used in large quantities worldwide, with 50–80% of the applied dose ending up in the environment. This study aimed to investigate the effects of exposure to tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN) on L. minor. Our research evaluated the phytotoxicity of the TCs by analyzing plant growth and biomass and evaluating...
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Enhanced stability of electrochemical performance of few-layer black phosphorus electrodes by noncovalent adsorption of 1,4-diamine-9,10-anthraquinone
PublikacjaIn this paper, the novel noncovalent functionalisation strategy of few-layer black phosphorus by 1,4-diamine-9,10-anthraquinone electrode was proposed and studied. The degradation of few-layer black phosphorus under exposure to oxygen and water is a significant obstacle to its use as an electroanalytical electrode. The anthraquinone compound adsorbed at black phosphorus flakes results in improved prevention of the phosphorus surface...
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Real-time monitoring of the emission of volatile organic compounds from polylactide 3D printing filaments
PublikacjaEstablishing the emission profile of volatile organic compounds generated during fused deposition modeling 3D printing using polymer filaments is important in terms of both understanding the processes taking place during thermal degradation of thermoplastics, and assessing the user's exposure to potentially harmful volatiles. However, obtaining detailed, real-time qualitative and quantitative results poses a challenge. In this...
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High resolution X-ray diffractometry and reflectometry of semiconductor nano- and micro- structures based on X-ray refractive optics
PublikacjaIn this thesis proposed, discussed and studied novel synchrotron X-ray diffractometry and reflectometry methods based on a refractive optics. The experimental results obtained from the ID06 beamline at ESRF, Grenoble, France are presented and analyzed in this work to demonstrate a high angular and space resolution in addition to the opportunity to manage in situ and on operando experiments with the help of proposed X-ray optical...
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Antibacterial properties of laser-encapsulated titanium oxide nanotubes decorated with nanosilver and covered with chitosan/Eudragit polymers
PublikacjaTo provide antibacterial properties, the titanium samples were subjected to electrochemical oxidation in the fluoride-containing diethylene glycol-based electrolyte to create a titanium oxide nanotubular surface. Afterward, the surface was covered by sputtering with silver 5 nm film, and the tops of the nanotubes were capped using laser treatment, resulting in an appearance of silver nanoparticles (AgNPs) of around 30 nm in diameter...
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A Surrogate-Assisted Measurement Correction Method for Accurate and Low-Cost Monitoring of Particulate Matter Pollutants
PublikacjaAir 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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Low-cost and reliable geometry scaling of compact microstrip couplers with respect to operating frequency, power split ratio, and dielectric substrate parameters
PublikacjaA technique for rapid re-design of miniaturised microstrip couplers with respect to operating conditions as well as material parameters of the dielectric substrate is proposed. The dimension scaling process is based on a set of pre-optimised reference designs, obtained for an equivalent circuit model of the coupler at hand. The reference designs are utilised to construct an inverse surrogate model which – upon suitable correction...
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Numerical Simulation of Catastrophic Flood: the Case Study of Hypothetical Failure of the Bielkowo Hydro–Power Plant Reservoir
PublikacjaThe numerical modeling of flood wave propagation following the hypo-thetical breaks of the embankments of the Bielkowo hydro–power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland have been presented. The results of computations were used to estimate the parameters of the flood waves, which are indispensable for the flood zone determination and mapping and then for the flood risk analysis. When estimating...
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Technologie komputerowego wspomagania projektowania BIM w procesie kształcenia inżyniera branży sanitarnej
PublikacjaRozwiązanie, którego początków należy szukać pod koniec lat 80, a które na przełomie XX i XXI wieku zostało nazwane BIM-em, będące innowacyjną technologią parametrycznego modelowania informacji o budynku (z ang. Building Information Modeling), jest do dzisiaj intensywnie rozwijane we wszystkich etapach projektowania inżynierskiego. Uczelnie techniczne, chcąc dostosować program kształcenia współczesnego inżyniera branży sanitarnej...
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Zero-pole approach to computer aided design of in-line siw filters with transmission zeros
PublikacjaThis paper presents a design of a new type of in-line pseudo-elliptic filters implemented in substrate integrated waveguide(SIW) technology. To realize transmission zeros in in-line topology,frequency-dependent couplings were used. Such dispersive couplingswere implemented as shorted stubs. The design process startswith the generation of a suitable starting point. To this end, anapproximation of SIW as a rectangular waveguide is...
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A Wideband Rotary-Joint-Free H-Plane Horn Antenna With 360° Steerable Radiation Pattern Using Gap Waveguide Technology
PublikacjaConsidering the limitations of electronically steerable antennas such as limited steering span, gain degradation for large steering angles, complexity, and cost, this article is focused on the design of a simple mechanically steerable H-plane horn antenna. It is shown that since there is no need for an electrical connection between the top and bottom sections of a gap waveguide (GWG), if a sectoral horn is properly designed and realized...
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Cost-Efficient Design Methodology for Compact Rat-Race Couplers
PublikacjaIn this article, a reliable and low-cost design methodology for simulation-driven optimization of miniaturized rat-race couplers (RRCs) is presented. We exploit a two-stage design approach, where a composite structure (a basic building block of the RRC structure) is first optimized using a pattern search algorithm, and, subsequently, the entire coupler is tuned by means of surrogate-based optimization (SBO) procedure. SBO is executed...
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Propagation Characteristics of Partial Discharges in an Oil-Filled Power Transformer
PublikacjaPower transformers are among the most important assets in the power transmission and distribution grid. However, they suffer from degradation and possible faults causing major electrical and financial losses. Partial discharges (PDs) are used to identify the insulation health status and their degradation level. PDs are incipient, low-magnitude faults caused by localized dielectric breakdown. Those activities emit signals in many...
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Windowing of the Discrete Green's Function for Accurate FDTD Computations
PublikacjaThe paper presents systematic evaluation of the applicability of parametric and nonparametric window functions for truncation of the discrete Green's function (DGF). This function is directly derived from the FDTD update equations, thus the FDTD method and its integral discrete formulation can be perfectly coupled using DGF. Unfortunately, the DGF computations require processor time, hence DGF has to be truncated with appropriate...
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Diagnostics of induction motor bearings - possibility of measurements
PublikacjaIn induction motors damage in the elements of electromagnetic system, for example in the wiring of stator, rotor or in the magnetic circuit can appear as well as damage of mechanical parts (bearings, rotor, shaft). Bearing diagnostics is so important in supervision of motor condition, because extensive research shows that the bearings arethe elements most susceptible to damage. This paper presents the research which the author...
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Analysis of nonlinear eigenvalue problems for guides and resonators in microwave and terahertz technology
PublikacjaThis dissertation presents developed numerical tools for investigating waveguides and resonators' properties for microwave and terahertz technology. The electromagnetics analysis requires solving complex eigenvalue problems, representing various parameters such as resonant frequency or propagation coefficient. Solving equations with eigenvalue boils down to finding the roots of the determinant of the matrix. At the beginning, one...
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Problems of Measuring Gas Content in Oil in a Two-Phase Flow: A Review
PublikacjaIn view of the necessity of measuring the air content in oil in two-phase flows in the context of general industry, a review of the most popular methods of measuring the air content in oil was carried out. This review includes an assessment of their advantages and disadvantages and of whether they meet criteria such as the degree of filling, the size and number of bubbles, verification, the absence of additional pressure drops,...
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Design of Frequency-Reconfigurable Branch-Line Crossover Using Rectangular Dielectric Channels
PublikacjaThis paper presents an efficient yet straightforward passive reconfiguration technique to tune the operating frequency of a branch-line crossover (BLCO). The underlying principle is to fill rectangular dielectric channels (RDCs) prepared beforehand with either air or materials of different relative permittivity. Two configurations (one RDC and three RDCs in each arm) of the branch-line crossover are employed to estimate the tunability...
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Thermomagnetic behavior of a semiconductor material heated by pulsed excitation based on the fourth-order MGT photothermal model
PublikacjaThis article proposes a photothermal model to reveal the thermo-magneto-mechanical properties of semiconductor materials, including coupled diffusion equations for thermal conductivity, elasticity, and excess carrier density. The proposed model is developed to account for the optical heating that occurs through the semiconductor medium. The Moore–Gibson–Thompson (MGT) equation of the fourth-order serves as the theoretical framework...
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Application of the Monte Carlo algorithm for solving volume integral equation in light scattering simulations
PublikacjaVarious numerical methods were proposed for analysis of the light scattering phenomenon. Important group of these methods is based on solving the volume integral equation describing the light scattering process. The popular method from this group is the discrete dipole approximation (DDA). DDA uses various numerical algorithms to solve the discretized integral equation. In the recent years, the application of the Monte Carlo (MC)...
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Reprezentacje architektury w filmach science fiction jako symboliczny wyraz wizji przyszłości
PublikacjaW filmach gatunku science fiction z II poł. XX i początku XXI w. zawartych zostało wiele wizji przyszłości, które były jednocześnie refleksją nad osiągnięciami i mankamentami współczesności. W latach 60. XX w. w dziełach kinematografii dominował optymizm i wiara w możliwość nigdy nie kończącego się postępu. Przewidywano zanik podziałów politycznych między blokami państw i wspólną eksplorację kosmosu. Scenografowie podejmowali...
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Czy e-demokracja i rozwiązania znane ze świata biznesu są właściwymi kierunkami zmian politycznych w Polsce?
PublikacjaCEL NAUKOWY: Celem artykułu jest przedstawienie wybranych problemów systemu demokratycznego w Polsce oraz zaproponowanie kierunków rozwoju, poprawiających jego działanie. PROBLEM i METODY BADAWCZE: Problem badawczy dotyczył sprawdzenia czy wdrożenie założeń nowoczesnych koncepcji organizacyjnych i rozwiązań teleinformatycznych może przyczynić się do sprawniejszego sprawowania demokratycznej władzy, a także podwyższenia...
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Consequences of New Approach of Chemical Stability Tests of Active Pharmaceutical Ingredients (APIs)
PublikacjaThere is a great need of broaden look on stability tests of active pharmaceuticalingredients (APIs) in comparison with current requirements contained in pharmacopeia.By usage of many modern analytical methods the conception of monitoring the changesof APIs during initial stage of their exposure to harmful factors has been developed. Newknowledge must be acquired in terms of identification of each degradation...
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Chromium (III) removal by perennial emerging macrophytes in floating treatment wetlands
PublikacjaFloating treatment wetlands (FTWs) are a sustainable solution to treat polluted water, but their role in chromium (Cr(III)) removal under neutral pH conditions remains poorly understood. This study evaluated the potential of FTWs planted with two perennial emergent macrophytes, Phragmites australis and Iris pseudacorus, to remove Cr(III) and nutrients (N and PO4-P) from water containing 7.5 mg/L TN, 1.8 mg/L PO4-P, and Cr(III)...
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Visual content representation and retrieval for Cognitive Cyber Physical Systems
PublikacjaCognitive Cyber Physical Systems have gained significant attention from academia and industry during the past few decade. One of the main reasons behind this interest is the potential of such technologies to revolutionize human life since they intend to work robustly under complex visual scenes, which environmental conditions may vary, adapting to a comprehensive range of unforeseen changes, and exhibiting prospective behavior...
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Electrophoretic deposition (EPD) of nanohydroxyapatite - nanosilver coatings on Ti13Zr13Nb alloy
PublikacjaTitanium and its alloys are the biomaterials most frequently used in medical engineering, especially as parts of orthopedic and dental implants. The surfaces of titanium and its alloys are usually modified to improve their biocompatibility and bioactivity, for example, in connection with the deposition of hydroxyapatite coatings. The objective of the present research was to elaborate the technology of electrophoretic deposition...
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Mercury contamination, a potential threat to the globally endangered aquatic warbler Acrocephalus paludicola
PublikacjaMercury (Hg) contamination is considered a global concern for humans and wildlife, and although the number of studies dealing with that issue continues to increase, some taxonomic groups such as small passerine birds are largely understudied. In this paper, concentration of mercury in the aquatic warbler (Acrocephalus paludicola) feathers, a globally threatened passerine species, was examined. The concentration differences between...
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Toward Mechanosynthesis of Diamondoid Structures: IX Commercial Capped CNT Scanning Probe Microscopy Tip as Nowadays Available Tool for Silylene Molecule and Silicon Atom Transfer
PublikacjaAccording to K. E. Drexler, advanced mechanosynthesis will employ advanced nanomachines, but advanced nanomachines will themselves be product of advanced mechanosynthesis. This circular relationship must be broken in SPM technology development. In the article, the possibility of use easy available commercial CNT tips to assembly silicon-based intermediate generations of nano-devices is considered. Mechanosynthesis of a target class...
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Porównanie cystouretrografii mikcyjnej i sonocystografii mikcyjnej z użyciem ultrasonograficznego środka kontrastującego drugiej generacji w badaniu prospektywnym
PublikacjaThe invasiveness and exposure to radiation in voiding cystourethrography led to the introduction of alternative methods of diagnosis of vesicoureteral reflux, including contrast enhanced voiding urosonography. While there is a limited number of studies comparing these methods using new generation ultrasound contrast agents, none of them compared both methods simultaneously. This study is aimed at assessing agreement between contrast...
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S-scheme heterojunction Bi2O3-ZnO/Bentonite clay composite with enhanced photocatalytic performance
PublikacjaThe industrial waste water is always a bottleneck problem in the modern civilization of the present era. In a quest to develop effective methods for the elimination of lethal pollutants from the waste water and water remediation, this work is focused on the development of a rapid and proficient approach for preparing supported binary metal oxide catalyst for photocatalytic advance oxidation process used in waste water treatment...
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Evaluation of mercury content in combustible tobacco products by employing cold vapor atomic absorption spectroscopy and considering the moisture content: a comprehensive study
PublikacjaPlants are mainly made up of water, which constitutes between 80 and 90% of their weight. Moisture factor comes across as one of the most important in tobacco products. Rapid determination of moisture content in tobacco products comes at neces- sity in any tobacco management plants (before and after production). Therefore, the concern has been raised in this study to evaluate the moisture content in four kinds of combustible tobacco...
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Monitoring Lead Concentration in the Surrounding Environmental Components of a Lead Battery Company: Plants, Air and Effluents—Case Study, Kenya
PublikacjaLead (Pb) pollution from smelters and lead–acid battery has become a serious problem worldwide owing to its toxic nature as a heavy metal. Stricter regulations and monitoring strategies have been formulated, legislated and implemented in various parts of the world on heavy metal usage. Developed countries such as the USA and in Europe largely operate within the set standards, however, developing countries such as Kenya, Nigeria...
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Time-Gating method with automatic calibration for accurate measurements of electrically small antenna radiation patterns in Non-Anechoic environments
PublikacjaNon-anechoic sites represent a cheap alternative to measurements of antennas in dedicated facilities. However, due to a high noise—from the external EM signal sources and multipath interferences—the quality of radiation patterns obtained in non-anechoic conditions is poor. The characteristics can be corrected using a time-gating method (TGM), which involves filtering of the noise based on temporal analysis of the measured signals....
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A Geometrically Simple Compact Wideband Circularly Polarized Antenna
PublikacjaA compact broadband wide-slot circular polarization (CP) antenna is proposed. An inverted L-shape parasitic strip at the open end of a microstrip line extension and a slot modification is applied to attain wideband CP. The advantage of this technique is simplicity which makes it readily re-designable for different frequency bands. To demonstrate the concept, three designs working at different frequencies are obtained. The redesign...
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A Broadband Circularly Polarized Wide-Slot Antenna with a Miniaturized Footprint
PublikacjaThis letter presents a novel and simple feeding technique for exciting orthogonal components in a wide-slot antenna. In this technique, a rectangular bracket-shape parasitic strip is placed at the open end of the straight microstrip line to excite the fundamental horizontal and vertical components of the circular polarization (CP). The proposed technique—when employed in conjunction with the asymmetrical geometry of coplanar waveguide...
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Theory versus experiment for vacuum Rabi oscillations in lossy cavities. II. Direct test of uniqueness of vacuum
PublikacjaThe paper continues the analysis of vacuum Rabi oscillations we started in part I [Phys. Rev. A 79, 033836 (2009)]. Here we concentrate on experimental consequences for cavity QED of two different classes of representations of harmonic-oscillator Lie algebras. The zero-temperature master equation, derived in part I for irreducible representations of the algebra, is reformulated in a reducible representation that models electromagnetic...