Search
Filters
total: 2183
filtered: 1810
-
Catalog
Chosen catalog filters
displaying 1000 best results Help
Search results for: SECONDARY ELECTRON YIELD
-
Comparison of Properties of the Hybrid and Bilayer MWCNTs—Hydroxyapatite Coatings on Ti Alloy
PublicationCarbon nanotubes are proposed for reinforcement of the hydroxyapatite coatings to improve their adhesion, resistance to mechanical loads, biocompatibility, bioactivity, corrosion resistance, and antibacterial protection. So far, research has shown that all these properties are highly susceptible to the composition and microstructure of coatings. The present research is aimed at studies of multi-wall carbon nanotubes in three different...
-
Automatic classification and mapping of the seabed using airborne LiDAR bathymetry
PublicationShallow coastal areas are among the most inhabited areas and are valuable for biodiversity, recreation and the economy. Due to climate change and sea level rise, sustainable management of coastal areas involves extensive exploration, monitoring, and protection. Current high-resolution remote sensing methods for monitoring these areas include bathymetric LiDAR. Therefore, this study presents a novel methodological approach to assess...
-
Hybrid SONIC: joint feedforward–feedback narrowband interference canceler
PublicationSONIC (self-optimizing narrowband interference canceler) is an acronym of a recently proposed active noise control algorithm with interesting adaptivity and robustness properties. SONIC is a purely feedback controller, capable of rejecting nonstationary sinusoidal disturbances (with time-varying amplitude and/or frequency) in the presence of plant (secondary path) uncertainty. We show that although SONIC can work reliably without...
-
Biosynthetic and synthetic access to amino sugars.
PublicationAmino sugars are important constituents of a number of biomacromolecules and products of mi crobial secondary metabolism, including antibiotics. For most of them, the amino group is located at the positions C1, C2 or C3 of the hexose or pentose ring. In biological systems, amino sugars are formed due to the catalytic activity of specific aminotransferases or amidotransferases by introducing an amino functionality derived from L-glutamate...
-
Bone healing under different lay‐up configuration of carbon fiber‐reinforced PEEK composite plates
PublicationSecondary healing of fractured bones requires an application of an appropriate fixa-tor. In general, steel or titanium devices are used mostly. However, in recent years,composite structures arise as an attractive alternative due to high strength to weightratio and other advantages like, for example, radiolucency. According to Food andDrug Administration (FDA), the only unidirectionally reinforced composite allowed tobe implanted...
-
Chapel at St. Joseph's Church in Gdańsk
PublicationThe subject of this article is the chapel located in the former Gdańsk Carmelite monastery complex. The results of the architectural research carried out in it in 2014–2015 are presented. As a result, the time and purpose of the building’s construction were established. The original appearance and traces of later alterations were also recognised. The recesses found on the longitudinal walls, of similar dimensions, not reaching...
-
Initial Investigation of Wave Interactions During Simultaneous Valve Closures in Hydraulic Piping Systems
PublicationThe effects of interference of pressure waves in simple piping systems were studied. A freeware computer code Allievi developed at the University of Valencia was used to simulate dynamic waveforms in simple and complex networks. The tests were carried out according to three scenarios. No pressure increases significantly exceeding the Joukowsky pressure in simple cases were noticed. When the effects of the simultaneous closing of...
-
Innovative Bidirectional Isolated High-Power Density On-Board Charge for Vehicle-to-Grid
PublicationThis paper deals with developing and implementing a bidirectional galvanically isolated on-board charger of a high-power density. The power density of the new charger was 4 kW/kg and 2.46 kW/dm3, and the maximum efficiency was 96.4% at 3.4 kW. Due to the requirement to achieve a high-power density, a single-stage inverter topology was used. Regarding switching losses, due to the topology of the circuit with so-called hard switching,...
-
Profiling and Qualitative Assessment of Enzymatically and Thermally Oxidized Egg Yolk Phospholipids using a Two‐Step High‐Performance Liquid Chromatography Protocol
PublicationA two‐step high‐performance liquid chromatography (HPLC) method for the profiling and qualitative assessment of oxidized phospholipids (oxPL) present in foods was developed. The applicability of the investigated two‐step HPLC protocol was verified for separation of enzymatically and thermally oxidized hen egg yolk phospholipids (PL) as a relevant food model. In the first step, seven individual PL classes were separated using hydrophilic...
-
Rola i znaczenie zbiornika sieciowego w kształtowaniu hydrauliki i jakości wody w systemie wodociągowym
PublicationEksploatacja zbiornika sieciowego powinna zapewniać cykliczną wymianę wody w jego komorach. Koniecznym warunkiem prawidłowej eksploatacji zbiornika jest zgodność założeń projektowych ze stanem faktycznym. Praktyka eksploatacyjna wskazuje na szereg nieprawidłowości w tym względzie. Z powodu lokalizacji zbiornika sieciowego za nisko lub za wysoko albo wskutek błędów popełnionych w ustaleniu jego parametrów obserwuje się niestabilność...
-
Cavitation wearing of the SUPERSTON alloy after laser treatment at cryogenic conditions
PublicationThe purpose of this paper is to demonstrate the method of laser remelting at cryogenic conditions of the SUPERSTON alloy and its influence on microstructure and cavitation wearing. The cavitation test was performed using the rotating disc facility in IPM PAN Gdansk. During the cavitation test, the mass loss of the material with different parameters of laser remelting was determined. Surface and cross-section microstructure of the...
-
Investigation of corrosion behavior of 6060 and 6082 aluminum alloys under simulated acid rain conditions
PublicationInstantaneous impedance changes of 6060 and 6082 type aluminum alloys in pure water, and simulated acid rain poured into the pure water was investigated by dynamic electrochemical impedance spectroscopy (DEIS). In this way, the influence of aluminum content on the corrosion behavior of 6060 and 6082 type aluminum alloys immersed in simulated acid rain was determined. The corrosion rate of the alloy decreased with increasing Al...
-
Long-working-distance Raman system for monitoring of uPA ECR CVD process of thin diamond/DLC layers growth
PublicationW artykule przedstawiono konstrucję systemu optoelektronicznego do monitoringu ramanowskiego in-situ procesu μPA ECR CVD (ang.: Microwave Plasma Assisted Electron Cyclotron Resonance Chemical Vapour Deposition), stosowanego do osadzania cienkich warstw diamentowych i diamentopodobnych DLC. System ma budowę modułową i wyposażony jest w dedykowane sondy optyczne. Przedstawiono wyniki pomiarów testowych, potwierdzjące, że system posiada...
-
A Method and Device for 3D Recognition of Cutting Edge Micro Geometry
PublicationA very useful method was successfully applied in the investigation of tools for machining wood and wood based composites. It allows scanning of the cutting edge micro geometry in three dimensions and reproducing it in a virtual space as a 3D surface. The application of the method opens new possibilities of studying tool wear by scanning, including the calculation of volume loss and other analysis of tool wedge geometry along and...
-
Sharp transitions in low-number quantum dots Bayesian magnetometry
PublicationWe consider Bayesian estimate of static magnetic field, characterized by a prior Gaussian probability distribution, in systems of a few electron quantum dot spins interacting with infinite temperature spin environment via hyperfine interaction. Sudden transitions among optimal states and measurements are observed. Usefulness of measuring occupation levels is shown for all times of the evolution, together with the role of entanglement...
-
Cytotoxic and Antioxidant Activities of Benzohydroxamic Acid Analogues
Publication20 benzohydroxamic acid analogues were synthesized and evaluated for their in vitro cytotoxicities against mouse mammary tumor cells as well as antioxidant activities against DPPH radical and superoxide anion. It was found that benzothiohydroxamic acids exhibit greater cytotoxicities than benzohydroxamic acids and N-isopropyl derivatives are more active than N-methyl ones. On the other hand, benzothiohydroxamic acids show more...
-
Interactions between components of SrTi0.98 Nb0.02O3-δ-YSZ and SrTi0.98 Nb0.02O3-δ -CeO2 composites
PublicationComposites consisting of SrTiO3-based perovskite and either yttria-stabilized zirconia or ceria were investigated. The mechanical compatibility and possible inter-diffusion between phases were characterized by scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. A gradual disappearance of Ce-containing phases with an increase in the temperature of reduction in hydrogen was noticed. Moreover,...
-
Electrical conductivity and relaxation processes in V2O5 nanorods prepared by sol–gel method
PublicationProperties of high purity V2O5 nanorods prepared by a sol – gel method are presented. The studied materials were characterized by: X-ray diffractometry (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrical impedance was measured as a function of temperature and frequency. The obtained results show that the electrical conductivity increases with increasing temperature. The d.c. conductivity...
-
Instantaneous impedance monitoring of AA 7075 aluminum alloy corrosion in borate buffer with admixed chloride ions
PublicationThe study presents a research capabilities of Dynamic Electrochemical Impedance Spectroscopy (DEIS) as a tool used for instantaneous on-line monitoring of corrosion processes on the example of AA 7075 aluminum alloy. A borate buffer with admixed chloride ions in a quantity ranging from 0.05 to 25 mM was used to represent different types of corrosion attack. The surface of samples specimens was evaluated before and after the tests...
-
Superconductivity in Bismuth Pyrochlore Lattice Compounds RbBi2 and CsBi2: The Role of Relativistic Effects
PublicationSuperconducting properties of two bismuthide intermetallic compounds, RbBi2 and CsBi2, were studied by means of experimental measurements and ab initio calculations. We show that in both compounds, the superconductivity emerges from the pyrochlore Bi lattice and its formation is heavily influenced by relativistic effects. Based on our analysis of the effect of spin–orbit coupling on the electron–phonon coupling, we suggest a possible...
-
Effect of carbazole and pyrrolidine functionalization of phenanthroline ligand on ground- and excited-state properties of rhenium(I) complexes. Interplay between 3MLCT and 3IL/3ILCT
PublicationNew rhenium(I) tricarbonyl complexes based on the phenanthroline ligand were designed and synthesized to investigate the role of carbazole (cbz) and pyrrolidine (pyrr) substituents in determining thermal, electrochemical and optoelectronic properties. Both pyrr and cbz are electron-releasing substituents, but they differ in the steric hindrance and electron delocalization ability. The impact of pyrr and cbz on ground- and excited-state...
-
Scattering of electrons by a 1,2-butadiene (C4H6) molecule: measurements and calculations
PublicationWe present the results of experimental and theoretical study on electron collisions with a 1,2-butadiene (H2C=C=CHCH3) molecule. Absolute grand-total cross sections (TCSs) were measured using a linear electron-transmission method for collision energies in the 0.5–300 eV range. Two distinct features in the TCS energy curve were detected: a narrow peak located at 2.3 eV and a broad enhancement centered around 9 eV. We attributed...
-
Perovskite-type KTaO3–reduced graphene oxide hybrid with improved visible light photocatalytic activity
PublicationNovel rGO–KTaO3 composites with various graphene content were successfully synthesized using a facile solvothermal method which allowed both the reduction of graphene oxide and loading of KTaO3 nanocubes on the graphene sheets. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), Fourier...
-
The influence of small intestinal mucus structure on particle transport ex vivo
PublicationMucus provides a barrier to bacteria and toxins while allowing nutrient absorption and waste transport. Unlike colonic mucus, small intestinal mucus structure is poorly understood. This study aimed to provide evidence for a continuous, structured mucus layer and assess the diffusion of different sized particles through it. Mucus structure was assessed by histology and immunohistochemistry. Ultra-structure was assessed by scanning...
-
Chlorine-free extraction and structural characterization of cellulose nanofibers from waste husk of millet (Pennisetum glaucum)
PublicationThis study aims to extract cellulose nanofibers (CNFs) from a sustainable source, i.e. millet husk, which is an agro-waste worthy of consideration. Pre-treatments such as mercerisation, steam explosion, and peroxide bleaching (chlorine-free) were applied for the removal of non-cellulosic components. The bleached millet husk pulp was subjected to acid hydrolysis (5% oxalic acid) followed by homogenization to extract CNFs. The extracted...
-
Cu-HKUST-1 and Hydroxyapatite–The Interface of Two Worlds toward the Design of Functional Materials Dedicated to Bone Tissue Regeneration
PublicationA novel composite based on biocompatible hydroxyapatite (HA) nanoparticles and Cu-HKUST-1 (Cu-HKUST-1@HA) has been prepared following a layer-by-layer strategy. Cu-HKUST-1 was carefully selected from a group of four Cu-based metal−organic frameworks as the material with the most promising antimicrobial activity. The formation of a colloidal Cu- HKUST-1 layer on HA nanoparticles was confirmed by various techniques, e.g., infrared...
-
Chemically reduced graphene oxide based aerogels - Insight on the surface and textural functionalities dependent on handling the synthesis factors
PublicationEfficient adjusting of reduced graphene oxide aerogels properties requires information about experimental factor-aerogel property relationship. In this work, the reduced graphene oxide aerogels surface and textural functionalities in relation to precursor concentration, gelation time and hydrogel freezing temperature were studied in detail, with the use of dynamic adsorption method of gaseous organic probes and experimental design....
-
Relationship between GIX, SIDX, and ROTI ionospheric indices and GNSS precise positioning results under geomagnetic storms
PublicationIonospheric indices give information about ionospheric perturbations, which may cause absorption, diffraction, refraction, and scattering of radio signals, including those from global navigation satellite systems (GNSS). Therefore, there may be a relationship between index values and GNSS positioning results. A thorough understanding of ionospheric indices and their relationship to positioning results can help monitor and forecast...
-
A method for the production of D-tagatose using a recombinant Pichia pastoris strain secreting beta-D-galactosidase from Arthrobacter chlorophenolicus and a recombinant L-arabinose isomerase from Arthrobacter sp. 22c
PublicationD-Tagatose is a natural monosaccharide which can be used as a low-calorie sugar substitute in food, beverages and pharmaceutical products. It is also currently being tested as an anti-diabetic and obesity control drug. D-Tagatose is a rare sugar, but it can be manufactured by the chemical or enzymatic isomerization of D-galactose obtained by a beta-D-galactosidase-catalyzed hydrolysis of milk sugar lactose and the separation of...
-
The Application of the Thermal Stabilization Prompted by the Ice Cover Expansion Considering the Energy Production Optimization in the Dam-Reservoir Coupled Systems on the Vistula River
PublicationIn this study, the thermal stabilization of a water resource together with an energy production optimization in the power plant of the dam–reservoir coupled system is conducted. This coupled dam system is designed to consist of a primary (Włocławek) and secondary (Siarzewo) dam due to the erosion control aspect. The other beneficial aspect of this coupled dam design is to have an additional power plant, with the aim of achieving...
-
Closed-Loop Control System Design for Wireless Charging of Low-Voltage EV Batteries with Time-Delay Constraints
PublicationThis paper presents an inductive power transfer system on the basis of a double single- phase three-level T-type inverter and two split transmitting coils for constant current and constant voltage wireless charging of low-voltage light electric vehicle batteries with closed-loop control, considering time-delay communication constraints. An optimal control structure and a modified control strategy were chosen and implemented to...
-
Bis(diisopropylammonium) thiosulfate and bis(tert-butylammonium) thiosulfate
PublicationTwo new dialkylammonium thiosulfates, namely bis(diisopropylammonium) thiosulfate, 2C6H16N+S2O3 2-, (I), and bis(tert-butylammonium) thiosulfate, 2C4H12N+S2O3 2-, (II), have been characterized. The secondary ammonium salt (I) crystallizes with Z = 4, while the primary ammonium salt (II), with more...
-
Economic significance of initial public offerings in China and India
PublicationRapid economic growth in China and India has attracted attention of many researchers, focusing on various social and economic factors underlying the success of these countries. One of the key components of country’s economy is financial system which consists of segments such as banking sector and equity market. The topic of initial public offerings (IPOs), one of the corporate financing sources, involving raising funds through...
-
Galvanostatic impedance measurements for the efficient adsorption isotherm construction in corrosion inhibitor studies
PublicationWe present an approach towards an accurate and time-efficient adsorption isotherm determination to evaluate the corrosion inhibitor interaction in electrolytic environments. The approach is based on dynamic impedance spectroscopy measurements in galvanostatic mode (g-DEIS). The studied corrosion inhibitor is continuously injected between the secondary cell and the corrosion cell. The efficiency corresponding to instantaneous inhibitor...
-
New procedure for the control of the treatment of industrial effluents to remove volatile organosulfur compounds
PublicationWe present a new procedure for the determination of volatile organosulfur compounds in samples of industrial effluents using dispersive liquid–liquid microextraction and gas chromatography with flame photometric detection. Initially, the extraction parameters were optimized. These included: type and volume of extraction solvent, volume of disperser solvent, salting out effect, pH, time and speed of centrifugation as well as extraction...
-
Effective method of treatment of industrial effluents under basic pH conditions using acoustic cavitation – a comprehensive comparison with hydrodynamic cavitation processes
PublicationThe use of acoustic cavitation in advanced oxidation processes (AOPs) is a promising trend in research for treatment of industrial effluents. The paper presents the results of investigations on the use of acoustic cavitation aided by additional oxidation processes (ozonation/H2O2 oxidation/Peroxone/UV-C) for the treatment of effluents from the production of bitumens. Under these conditions, the total contaminant load, expressed...
-
Biopolymer-based composites for tissue engineering applications: A basis for future opportunities
PublicationBiomimetic scaffolds supporting tissue regeneration are complex materials with multifunctional characteristics. The unique biocompatibility and biodegradability of biopolymers make them excellent candidates for tissue engineering and regenerative medicine. Biopolymers, which have a wide range of properties, can be obtained from different natural sources. Depending on the target tissue, biopolymers can be engineered to meet a series...
-
Multi-transformer primary-side regulated flyback converter for supplying isolated IGBT and MOSFET drivers
PublicationThis paper presents primary-side voltage regulated multi-transformer quasi-resonant flyback converter (MTFC) for supplying isolated power switch drivers. The proposed topology offers distinct advantages over frequently used flyback converter possessing one high frequency transformer with isolated multiple outputs. Particularly, when a large number of separate dc supply units is required, then MTFC enables improved regular distribution...
-
Recycling of Polyurethanes Containing Flame-Retardants and Polymer Waste Transformed into Flame-Retarded Polyurethanes
PublicationThe growing number of polyurethanes (PUs) produced every year has developed methods for their mechanical and chemical recycling which yield valuable products like substitutes for commercial polyols or flame-retardants. PUs can be produced in different shapes and forms (i.e., elastomers, flexible or rigid foams, coatings, etc.) using several different components (i.e., di- or polyisocyanates, ester- or ether-based polyols, low-molecular...
-
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...
-
Non-linear strain rate analysis of earthquake-induced pounding between steel buildings
PublicationPast and recent earthquakes have shown that ground motions may cause severe structural damage to civil engineering structures. Earthquake-induced pounding between adjacent buildings has been identified as one of the reasons which intensifies damages. The aim of this paper is to show the results of the detailed nonlinear FEM analysis of earthquake-induced pounding between two steel buildings. The elastic – perfectly plastic material...
-
Influence of Bingham fluid viscosity on energy performances of a vortex chamber pump
PublicationOne of the problems in the development of coal-water technologies is the use of reliable and long-lasting pumps. To date, classic pumps, due to the use of mechanical moving parts and seals, are subject to rapid abrasive wear. The solution to this problem can lie in the creation of new vortex chamber pumps developed by the authors. They are highly reliable, simple in design and have no moving parts. The object of this paper consists...
-
Synthesis of thiol derivatives of azobenzocrown ethers. The preliminary studies on recognition of alkali metal ions by gold nanoparticles functionalized with azobenzocrown and lipoic acid
PublicationThe article presents the synthesis of novel 13- and 16-membered azobenzocrown derivatives with peripheral thiol moieties and preliminary studies assessing their possible application in plasmonic sensors based on gold nanoparticles. The effect of the length of the chain connecting the macrocycle with the thiol group and the effect of the presence of the additional functional compound,...
-
Ammonia amendment promotes high rate lactate production and recovery from semi-continuous food waste fermentation
PublicationIn this study, a reliable approach using ammonia nitrogen was proposed to increase lactate production during semi-continuous food waste (FW) fermentation under mesophilic conditions. Both free ammonia nitrogen (FAN) and ammonium ion (NH4+-N) were present in mesophilic reactors, with a wide FAN/NH4+-N ratio variation due to the intermittent pH control. The investigation of responsible mechanisms revealed that the increased production...
-
Application of Fracture Mechanics for Energetic Effects Predictions While Wood Sawing
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, cutting forces (or power - more interesting from energetic point of view) could be considered from a point of view of modern fracture mechanics. Cutting...
-
Selected issues related to the toxicity of ionic liquids and deep eutectic solvents—a review
PublicationGreen Chemistry plays a more and more important role in implementing rules of sustainable development to prevent environmental pollution caused by technological processes, while simultaneously increasing the production yield. Ionic liquids (ILs) and deep eutectic solvents (DESs) constitute a very broad group of substances. Apart from many imperfections, ILs and DESs have been the most promising discoveries in the world of Green...
-
Experimental study and numerical optimization of tensegrity domes – A case study
PublicationThe paper deals with the design, experimental analysis and numerical optimization of tensegrity dome models. Two structures are analyzed – a Geiger system dome (preliminary dome), with PVC-U bars and PA6/PP/PET tendons and a Fuller system dome (target dome), with wooden bars and steel cables as tendons. All used materials are experimentally tested in terms of Young's modulus and yield stress values, the compressed bars are also...
-
Reduction of road traffic noise by source measures — present and future strategies
PublicationThe current trend worldwide is less focused on reducing road traffic noise. This is in strong contrast to the severe impact of traffic noise to the general health and quality of life. A more holistic and combined strategy is needed. Current international rules and regulations regarding vehicles and tyres are not sufficient to reduce traffic noise levels in an effective way. Calculations show that these regulations will only yield...
-
M-BDC (M = Co and/ or Fe) MOFs as effective catalysts for hydrogen generation via hydrolysis of sodium borohydride
PublicationMono- (Co-BDC, Fe-BDC) and bimetallic FeCo-BDC Metal-Organic Frameworks are successfully synthesized by the solvothermal method in DMF at 150 °C within 15 h and tested as catalysts for sodium borohydride hydrolysis. The materials are characterized by FTIR, PXRD, TGA, ICP-OES, H2-TPR, BET model, and SEM-EDS. The catalytic activity of these materials is studied for dehydrogenation of sodium borohydride in water at various temperatures...
-
Modelization of Nutrient Removal Processes at a Large WWTP Using a Modified ASM2d Model
PublicationThe biodegradation of particulate substrates starts by a hydrolytic stage. Hydrolysis is a slow reaction and usually becomes the rate limiting step of the organic substrates biodegradation. The objective of this work was to evaluate a novel hydrolysis concept based on a modification of the activated sludge model (ASM2d) and to compare it with the original ASM2d model. The hydrolysis concept was developed in order to accurately...