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Search results for: hydrophobic coatings
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Synthesis, structure and properties of novel poly(hydroxyurethane)s obtained by non-isocyanate route
PublicationNon-isocyanate polyurethanes (NIPUs) can be synthesized by polyaddition of five-membered bis(cyclic carbonate)s and primary diamines. NIPUs are an alternative for the commonly used (in the form of foams, elastomers, coatings or fibers) in the industry polyurethanes obtained using toxic and moisture sensitive diisocyanates, polyols and low-molecular weight chain extenders. The main aim of this work was to synthesize non-isocyanate...
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Determination of Surfactants in Environmental Samples. Part III. Non-Ionic Compounds
PublicationNon-ionic surface active agents are a diverse group of chemicals which have an uncharged polar head and a non-polar tail. They have different properties due to amphiphilic structure of their molecules. Commercial available non-ionic surfactants consist of the broadest spectrum of compounds in comparison with other types of such agents. Typically, non-ionic compounds found applications in households and industry during formulation...
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Trustworthiness and Subversion in Large Service- Oriented Multi-Agent Systems under Virtual Anonymity and Blind Provider Selection
PublicationTo promote honest service provision in multi-agent systems, a Computational Trustworthiness and Rating scheme collects service ratings and computes agents' trustworthiness levels (TLs). Studies of existing schemes fail to reflect closed-loop dynamics of TLs arising from the mutual influence of agents' behavior and TLs, and to capture relevant properties. Recent simulative and analytical models produce results tied to a particular...
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Multi-domain and Context-Aware Recommendations Using Contextual Ontological User Profile
PublicationRecommender Systems (RS) became popular tools in many Web services like Netflix, Amazon, or YouTube, because they help a~user to avoid an information overload problem. One of the types of RS are Context-Aware RS (CARS) which exploit contextual information to provide more adequate recommendations. Cross-Domain RS (CDRS) were created as a response to the data sparsity problem which occurs when only few users can provide reviews or...
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Treatment of landfill leachate by constructed wetlands: three case studies
PublicationThe performance of three CW systems treating landfill leachate, two located in northern Poland (Szadółki near Gdańsk and Gatka near Miastko) and one in southern Sweden (Örebro), is discussed. The CWs differ in size, hydraulic regime, type of hydrophytic plants and type of leachate pre-treatment before discharging to the CW. The CW in Szadółki consists of two parallel beds with sub-surface, horizontal flow of leachate (HSSF) planted...
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PLA–Potato Thermoplastic Starch Filament as a Sustainable Alternative to the Conventional PLA Filament: Processing, Characterization, and FFF 3D Printing
PublicationThe growing popularity of the fused filament fabrication (FFF) 3D printing technology in science, industry, and in-home use is associated with an increased demand for high-quality polymer filaments. This study presents an in-depth characterization and analysis of a self-made bio-based polylactide (PLA)/thermoplastic potato starch (TPS) filament dedicated for the FFF 3D printing technology. The obtained results were compared with...
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Physicochemical and Mechanical Performance of Freestanding Boron-Doped Diamond Nanosheets Coated with C:H:N:O Plasma Polymer
PublicationThe physicochemical and mechanical properties of thin and freestanding heavy boron-doped diamond (BDD) nanosheets coated with a thin C:H:N:O plasma polymer were studied. First, diamond nanosheets were grown and doped with boron on a Ta substrate using the microwave plasma-enhanced chemical vapor deposition technique (MPECVD). Next, the BDD/Ta samples were covered with nylon 6.6 to improve their stability in harsh environments and...
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Phospholipids as potential prevention factor in carcinogenesis
PublicationPhospholipids are a group of complex lipids, which can be used in cancer chemoprevention. Glicerophospholipids are composed of fatty acids esterified to a glycerol backbone, a phosphate group and a hydrophilic residue such as: cho- line, ethanoloamine, serine or inositol. In the sn-2 position of glicerophospholipid usually there are unsaturated fatty acids, i.e. linolenic acid, while in the sn-1 position more typi- cal are saturated...
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Microporous Polyurethane Thin Layer as a Promising Scaffold for Tissue Engineering
PublicationThe literature describes that the most efficient cell penetration takes place at 200–500 µm depth of the scaffold. Many different scaffold fabrication techniques were described to reach these guidelines. One such technique is solvent casting particulate leaching (SC/PL). The main advantage of this technique is its simplicity and cost efficiency, while its main disadvantage is the scaffold thickness, which is usually not less than...
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Qualitative analysis of phospholipids and their oxidised derivatives – used techniques and examples of their applications related to lipidomic research and food analysis
PublicationPhospholipids (PLs) are important biomolecules that not only constitute structural building blocks and scaffolds of cell and organelle membranes, but also play a vital role in cell biochemistry and physiology. Moreover, dietary exogenous PLs are characterized by high nutritional value and other beneficial health effects, which are confirmed by numerous epidemiological studies. For this reason, PLs are of high interest in lipidomics...
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Nanostructuring of thin Au films deposited on ordered Ti templates for applications in SERS
PublicationIn this work the results on thermal nanostructuring of the Au films on Ti templates as well as morphology and optical properties of the obtained structures are reported. The bimetal nanostructures are fabricated in a multi-step process. First, the titania nanotubes are produced on the surface of Ti foil by anodization in an ethylene glycol-water solution containing fluoride ions. This is followed by chemical etching in oxalic acid...
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Biological and mechanical properties of bone cement with nanoparticles - in vivo and in vitro research
PublicationDespite antibiotics preventive treatment, before and after an implant implementation, risk of infection are real. These infections at the implant surface develop in a few months after applying them into the body. To prevent the development of bacteria and to reduce the risk of infection, implants coated with nanoparticles come into use. The Mechanical Department of the Technical University of Gdańsk carried out a research with...
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Determination of the active ingredient in pharmaceutical gel formulation by NIR spectroscopy
PublicationPharmaceuticals of their intended must be thoroughly controlled. The traditional analytical methods are very costly and time consuming. NIR spectroscopy allows to analyze pharmaceutical materials very quickly and with very low costs. First pharmaceutical applications of the NIR spectroscopy appeared with some incuriosity in the late 1960s. Application of NIR in the contemporary pharmaceutical industry is very large. The most common...
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Enhanced electrochemical performance of partially amorphous La0.6Sr0.4CoO3-δ oxygen electrode materials for low-temperature solid oxide cells operating at 400 °C
PublicationThis work evaluates partially amorphous La0.6Sr0.4CoO3-δ (LSC) as a potential oxygen electrode for lowtemperature solid oxide cells. LSC was deposited using the spin-coating technique onto Ce0.8Gd0.2O2-δ (CGO) substrates. The optimal oxygen electrode thickness was determined as 500 nm. The electrochemical impedance spectroscopy (EIS) study showed a significant improvement in oxygen reduction/oxidation reaction kinetics when annealing...
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Enhanced photocatalytic, electrochemical and photoelectrochemical properties of TiO2 nanotubes arrays modified with Cu, AgCu and Bi nanoparticles obtained via radiolytic reduction
PublicationTiO2 nanotubes arrays (NTs), obtained via electrochemical anodization of Ti foil, were modified with monometallic (Cu, Bi) and bimetallic (AgCu) nanoparticles. Different amounts of metals’ precursors were deposited on the surface of NTs by the spin-coating technique, and the reduction of metals was performed via gamma radiolysis. Surface modification of titania was studied by EDS and XPS analysis. The results show that AgCu nanoparticles...
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Laser-Induced Graphitization of Polydopamine on Titania Nanotubes
PublicationSince the discovery of laser-induced graphite/graphene, there has been a notable surge of scientific interest in advancing diverse methodologies for their synthesis and applications. This study focuses on the utilization of a pulsed Nd:YAG laser to achieve graphitization of polydopamine (PDA) deposited on the surface of titania nanotubes. The partial graphitization is corroborated through Raman and XPS spectroscopies and supported...
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Multi-functional monodispersed SiO2-TiO2 core-shell nanostructure and TEOS in the consolidation of archaeological lime mortars surfaces
PublicationArchaeological traditional lime mortars are susceptible to many environmental conditions such as the impact of water (rain, humidity, groundwater, etc.), variation of temperatures' degrees, wind and/or pollution. Accordingly, this research aims to provide newly assessed multifunctional Nano-coating for the purpose of archaeological lime mortar protection. For this, the study combined physicochemical and mechanical characterizations...
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Modification of cellulosic filler with diisocyanates – volatile organic compounds emission assessment and stability of chemical structure over time
PublicationThis paper investigated the impact of type and content of diisocyanate on the structure of modified cellulose fillers. Four the most popular isocyanates were applied – isophorone, hexamethylene, toluene and methylene diphenyl diisocyanate – at loadings of 1–15 wt%. Chemical structure, and its short-term storage stability, were investigated for eight weeks. Moreover, the main volatile organic compounds detected during modification,...
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Thermal decomposition kinetics of dynamically vulcanized polyamide 6-acrylonitrile butadiene rubber-halloysite nanotube nanocomposites
PublicationThermally stable thermoplastic elastomer nanocomposites based on polyamide 6 (PA6), acrylonitrile butadiene rubber (NBR), and halloysite nanotubes (HNTs) were dynamically vulcanized, and their nonisothermal decomposition kinetics were examined. The Friedman, Kissinger–Akahira–Sunose (KAS), Ozawa–Wall–Flynn (FWO), and modified Coats–Redfern (m‐CR) isoconversional models were used to obtain information about the kinetics of the thermal...
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Cross-linking of sodium caseinate-structured emulsion with transglutaminase alters postprandial metabolic and appetite responses in healthy young individuals
PublicationThe physico-chemical and interfacial properties of fat emulsions influence lipid digestion and may affect postprandial responses. The aim of the present study was to determine the effects of the modification of the interfacial layer of a fat emulsion by cross-linking on postprandial metabolic and appetite responses. A total of fifteen healthy individuals (26·5 (sem 6·9) years and BMI 21·9 (sem 2·0) kg/m2) participated in a cross-over...
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Nanokrystaliczne warstwy ceramiczne otrzymywane metodą pirolizy aerozolowej w tlenkowych ogniwach paliwowych
PublicationNiniejsza rozprawa doktorska dotyczy badań materiałów wytwarzanych w postaci cienkich, nanokrystalicznych warstw ceramicznych metodą pirolizy aerozolowej dla zastosowań w tlenkowych ogniwach paliwowych (SOFC). Badane są trzy możliwe obszary zastosowań wytwarzanych warstw tj. osadzanie powłok ochronnych na stalowych interkonektorach dostarczających gazy do elektrody tlenowej, wytwarzanie bariery ochronnej zapobiegającej dyfuzji...
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Top k Recommendations using Contextual Conditional Preferences Model
PublicationRecommender systems are software tools and techniques which aim at suggesting to users items they might be interested in. Context-aware recommender systems are a particular category of recommender systems which exploit contextual information to provide more adequate recommendations. However, recommendation engines still suffer from the cold-start problem, namely where not enough information about users and their ratings is available....
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation...
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Electrodes criticality: the impact of CRMs in the leachate electrochemical oxidation
Publication. Landfill leachate possesses high concentrations of ammonia, micropollutants, and heavy metals, and are characterised for low biodegradability. For this reason, conventional treatment technologies may result ineffective for complete pollutant removal. Electrochemical oxidation allows most of the of recalcitrant pollutants to be oxidised effectively within an easy operational and acceptable retention time, without the need to provide...
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation threshold...
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New nanoadsorbent based on magnetic iron oxide containing 1,4,7,10-tetraazacyclododecane in outer chain (Fe3O4@SiO2-cyclen) for adsorption and removal of selected heavy metal ions Cd2+, Pb2+, Cu2+
PublicationMagnetic Fe3O4@SiO2-cyclen nanoparticles were prepared and used as adsorbent for Cd2+, Pb2+ and Cu2+ from aqueous solution removal process controlled with differential pulse anodic stripping voltammetry (DPASV) and hanging mercury drop electrode (HDME). Nanomaterial was synthesised in three-step process co-precipitation of Fe3O4 core, coating with silane and N-(3-(triethoxysilyl)propyl)-1,4,7,10-tetraazacyclododecane-1-carboxamide...
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Simple synthesis route for fabrication of protective photo‐crosslinked poly(zwitterionic) membranes for application in non‐enzymatic glucose sensing
PublicationThis work focuses on the fabrication of non-enzymatic glucose sensing materials based on laser-formed Au nanoparticles embedded in Ti-textured substrates. Those materials possess good catalytic activity toward glucose oxidation in 0.1 × phosphate buffered saline as well as resistance to some interferants, such as ascorbic acid, urea, and glycine. The electrodes are further coated with three different polymers, that is, Nafion,...
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Cadmium complex possessing simultaneously silanethiolato- and dithiocarbamato-ligands. A novel single-source precursor of cadmium sulfide
PublicationThermal decomposition of suitable coordination compounds may be used as efficient route for fabrication of semiconducting layers. A new potential CdS precursor—a cadmium complex with all-sulfur Cd-coordination sphere [Cd{l-SSi(OBut)3}(S2CNC4H8)]2 (1) —has been prepared and its properties are investigated. The complex was obtained in the reaction between dimeric bis(tri-tert-butoxysilanethiolato) cadmium(II) [Cd{SSi(OBut)3}2]2 and...
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Development of novel optoelectronic sensory structures utilising colour centres in nanodiamonds and their interactions with analytes
PublicationThe goal of this dissertation was to develop and assess surface modifications of fluorescent nanodiamonds (NDs) for optical sensing. Three modification routes were tested, each aimed at a different application. Modification with poly-L-lysine (pLys) was verified for optical sensing of pH via an interrelationship between electrically negative (NV¯) and neutral (NV0) nitrogen-vacancy centres. Immobilisation of Ochratoxin A (OTA),...
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Determination of antifreeze substances in the airport runoff waters by solid-phase microextraction and gas chromatography–mass spectrometry method
PublicationA new method has been developed for the determination of antifreeze agents such as ethylene glycol (EG), propylene glycol (PG), and diethylene glycol (DEG) in the samples of airport runoff water. The method is based on headspace solid–phase microextraction (HS–SPME) of target analytes, which is coupled with gas chromatography–mass spectrometry (GC–MS). Until now, there was a lack of appropriate methodology for collecting reliable...
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Impedimetric sensing of α-amino acids driven by micro-patterned 1,8-Diazafluoren-9-one into titania- boron- doped maze-like nanocarbons
PublicationThe development of impedimetric, non-faradaic label-free sensors for the detection of α-amino acids constitutes a trailblazing technology for the fast and inexpensive quantification of such biomarkers. Since α-amino acids, such as glycine and sarcosine, are basic constituents in biological processes, a variation in their concentration may be an indicator of cardiovascular diseases and metabolic disorders or neurological conditions....
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Tailoring Diffusional Fields in Zwitterion/Dopamine Copolymer Electropolymerized at Carbon Nanowalls for Sensitive Recognition of Neurotransmitters
PublicationThe importance of neurotransmitter sensing in the diagnosis and treatment of many psychological illnesses and neurodegenerative diseases is non-negotiable. For electrochemical sensors to become widespread and accurate, a long journey must be undertaken for each device, from understanding the materials at the molecular level to real applications in biological fluids. We report a modification of diamondized boron-doped carbon nanowalls...
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Chicken feather keratin as a source of bioactive peptides useful in prevention of metabolic disorders – in silico and in vitro hydrolysis
PublicationProtein derived bioactive peptides not only serve as nutrients but can also exert drug-like activity, e.g. antidiabetic, antihypertensive, or antimicrobial, to name a few. Most biopeptides have beneficial effects on health that make them attractive for nutraceutical applications. The majority of bioactive peptides have been obtained from food proteins, but protein-rich by-products generated by agriculture...
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Pilicides effectively hinder chaperone-usher interactions in all Gram-negative bacteria
PublicationThe chaperone-usher pathway of adhesive structures biogenesis is highly conserved in all Gram-negative bacteria. Pili are polymers of thousands protein subunits that possess conserved immunoglobuline-like structure denoted by lack of the seventh G strand. The effect of this structural defect is a hydrophobic acceptor cleft. The folding of protein subunits is strictly dependent on the action of specific periplasmic chaperone protein...
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Self-standing Nanoarchitectures
PublicationDespite there are structures invisible for the human eye, they mastered the world of advanced electronic devices, sensors, novel cosmetics or drugs. When the dimensions of the materials go down to the nanometres scale, their properties change dramatically comparing to the observable objects. Because of their tiny size, they gained the name of nanomaterials but simultaneously their importance has significantly grown up. Nanomaterials...
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Biomechanical properties of 3D-printed bone models
PublicationBone lesions resulting from large traumas or cancer resections can be successfully treated by directly using synthetic materials or in combination with tissue engineering methods (hybrid). Synthetic or hybrid materials combined with bone tissue’s natural ability for regeneration and biological adaptation to the directions of loading, allow for full recovery of its biological functions. Increasing interest in new production methods...
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Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder
PublicationInvestigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry),...
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Plasma-Based Deposition and Processing Techniques for Optical Fiber Sensing
PublicationPlasma-based techniques are widely applied for well-controlled deposition, etching or surface functionalization of a number of materials. It is difficult to imagine fabrication of novel microelectronic and optoelectronic devices without using plasma-enhanced deposition of thin films, their selective etching or functionalization of their surfaces for subsequent selective binding of chemical or biological molecules. Depending on...
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The Effect of Openings’ Size and Location on Selected Dynamical Properties of Typical Wood Frame Walls
PublicationThe wooden frame constructions are now popular in many developed countries of the world. Many of these locations where such buildings are constructed are exposed to seismic and other shocks which are generated by human activities. This paper discusses the effect of the size and location of openings in the wooden frame walls under dynamic loadings. Natural frequencies of such frames with and without openings have been determined....
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Fracture Areas Quantitative Investigating of Bending-Torsion Fatigued Low-Alloy High-Strength Steel
PublicationIn this study, the impact of pseudo-random non-proportional bending-torsion fatigue loadings proportion on the fatigue life and the fracture surface topography was analyzed. Investigation was carried out for 24 specimens made of S355J2 steel with 11 different ratios of maximum stresses λ. For these cases, after the fatigue tests, the surface topography measurements were carried out using an optical profilometer, using the focus...
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Investigation of interaction between xanthene dye rhodamine B and metagenomic-derivated methylthioadenosine phosphorylase RSFP
PublicationIn the previous study we found that the expression of the metagenomic - derived methylthioadenosine phosphorylase gene (rsfp) in E. coli cells and the presence of rhodamine B in the growth medium were crucial for the pink fluorescence of one E. coli colony from Antarctic soil metagenomic library (Cieśliński et al., 2009). In this study, rsfp gene expression was induced by an arabinose promoter in an LMG194 E. coli strain and the...
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Defected Ag/Cu-MOF as a modifier of polyethersulfone membranes for enhancing permeability, antifouling properties and heavy metal and dye pollutant removal
PublicationIn this study, a novel bimetallic metal-organic framework (MOF) i.e. Ag/Cu-MOF was synthesized using a solvothermal method and later incorporated at different concentrations (0.1–2 wt%) using a phase inversion method for modification and antifouling property improvement of polyethersulfone (PES) membranes. The resulting Ag/Cu-MOF characteristics were investigated using different techniques, such as FTIR, XRD, FE-SEM and EDX. The...
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Facilitated water transport in composite reduced graphene oxide pervaporation membranes for ethanol upgrading
PublicationHigh purity ethanol is one of the most sought-after renewable energy sources. However, standard production methods yield ethanol of insufficient quality. Membrane processes such as pervaporation are recognized as a viable method for upgrading ethanol. Their performance and selectivity depend solely on membrane employed. Hydrophilic polyvinyl alcohol (PVA) membranes are used industrially for this purpose, but there is a trade-off...
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A new multi-process collaborative architecture for time series classification
PublicationTime series classification (TSC) is the problem of categorizing time series data by using machine learning techniques. Its applications vary from cybersecurity and health care to remote sensing and human activity recognition. In this paper, we propose a novel multi-process collaborative architecture for TSC. The propositioned method amalgamates multi-head convolutional neural networks and capsule mechanism. In addition to the discovery...
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Non-Linear Analysis of Structures Utilizing Load-Discretization of Stiffness Matrix Method with Coordinate Update
PublicationThis paper proposes a stiffness method based structural analysis algorithm for geometrically non-linear structures. In this study, the applied load on the joints has been discretized to a sequence of a few loadings applied. Each loading step produces incremental external nodal displacements, which are added to the corresponding coordinates to get a new geometrical shape of the structure. This process is iteratively repeated until...
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Nano-particle doped hydroxyapatite material evaluation using Spectroscopic Polarization Sensitive Optical Coherence Tomography
PublicationBio-ceramics such as hydroxyapatite (HAp) are widely used materials in medical applications, especially as an interface between implants and living tissues. There are many ways of creating structures from HAp like electrochemical assisted deposition, biomimetic, electrophoresis, pulsed laser deposition or sol-gel processing. Our research is based on analyzing the parameters of the sol-gel method for creating thin layers of HAp....
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Diamond-based protective layer for optical biosensors
PublicationOptical biosensors have become a powerful alternative to the conventional ways of measurement owing to their great properties, such as high sensitivity, high dynamic range, cost effectiveness and small size. Choice of an optical biosensor's materials is an important factor and impacts the quality of the obtained spectra. Examined biological objects are placed on a cover layer which may react with samples in a chemical, biological...
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Lipopolysaccharides: regulated biosynthesis and structural diversity
PublicationThe cell envelope of Gram-negative bacteria contains two distinct membranes, an inner (IM) and an outer (OM) membrane, separated by the periplasm, a hydrophilic compartment that includes a thin layer of peptidoglycan. The most distinguishing feature of such bacteria is the presence of an asymmetric OM with phospholipids located in the inner leaflet and lipopolysaccharides (LPSs) facing the outer leaflet. The maintenance of this...
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A Microwave Sensor with Operating Band Selection to Detect Rotation and Proximity in the Rapid Prototyping Industry
PublicationThis paper presents a novel sensor for detecting and measuring angular rotation and proximity, intended for rapid prototyping machines. The sensor is based on a complementary split-ring resonator (CSRR) driven by a conductor-backed coplanar waveguide. The sensor has a planar topology, which makes it simple and cost-effective to produce and accurate in measuring both physical quantities. The sensor has two components, a rotor, and...
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Process layout planning and optimised product range selection in manufacture of wooden construction sets
PublicationThis paper introduces a systematic deterministic framework for planning and the analysis of facility layouts aimed at manufacturing a variety of parts, as components of specific end products. The essence of the proposed approach lies in the decomposition of a traditional job-shop into layout modules of generic material flow patterns, that inherently yields improved efficiency of the entire system. It entails the use of a relevant...