Filtry
wszystkich: 3162
wybranych: 1297
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: CYCLIC CARBONATE
-
Electrochemical detection of bacterial endotoxin lipopolysaccharide (LPS) on gold electrode modified with DAL-PEG-DK5-PEG-OH - Antimicrobial peptide conjugate
PublikacjaThis work describes fabrication of gold electrodes modified with peptide conjugate DAL-PEG-DK5-PEG-OH that enables ultra-sensitive detection of lipopolysaccharide (LPS) isolated from the reference strain of Escherichia coli O26:B6. The initial step of the established procedure implies immobilization of the fully protected DAL-PEG-DK5-PEG-OH peptide on the surface of the gold electrode previously modified by cysteamine. Then side...
-
Tailoring diamondised nanocarbon-loaded poly(lactic acid) composites for highly electroactive surfaces: extrusion and characterisation of filaments for improved 3D-printed surfaces
PublikacjaA new 3D-printable composite has been developed dedicated to electroanalytical applications. Two types of diamondised nanocarbons - detonation nanodiamonds (DNDs) and boron-doped carbon nanowalls (BCNWs) - were added as fillers in poly(lactic acid) (PLA)-based composites to extrude 3D filaments. Carbon black served as a primary filler to reach high composite conductivity at low diamondised nanocarbon concentrations (0.01 to 0.2...
-
Stereoselective Alkylation of Indole with 5-Arylidene-Meldrum’s Acids in the Presence of Organocatalysts
PublikacjaBackground: Indole motif is frequently present in biologically active compounds. Enantiomerically pure or enriched 2,2-dimethyl-5-(aryl(1H-indol-3-yl)methyl)-1,3-dioxane-4,6-diones can be considered as a convenient starting point for the synthesis of a indole ring fused with cyclic ketones with biological activity. Preparation of chiral 2,2-dimethyl-5-(aryl(1H-indol-3-yl)methyl)-1,3-dioxane- 4,6-diones requires the reaction of...
-
The optimization of enzyme immobilization at Au-Ti nanotextured platform and its impact onto the response towards glucose in neutral media
PublikacjaThe market of non-invasive glucose sensors is drastically growing due to increasing number of people suffering from diabetes. Therefore, there is a significant need for any improvement in the field of biosensors that can be used for monitoring glucose level in human body. In recent years the emphasis is put onto the modification of electrode material with enzymes possessing recognition centre specific towards particular molecules....
-
Operational causes of fatigue failures within the passages of gas turbine engines
PublikacjaThe short profile of a fatigue wear process of gas turbine engine's constructional elements has been introduced in the article. The primary causes of a fatigue cracks formation within the mechanical system as well as within the passages of the engine have been showed. Especial attention was devoted to the low-cycle fatigue, what is associated with unsteady thermal-flow processes being worked out in the passages.The selected damages...
-
The analysis of turbine propulsion systems in nuclear submarines
PublikacjaThe article systematises submarines, which are presently in service, according to their propulsion types (both conventional and nuclear), power output, and submersion depth. Contemporary types of propulsion systems installed and used in submarines are discussed. Calculations were performed for the PWR (Pressurized Water Reactor) type nuclear propulsion system and the supercritical turbine propulsion system (supercritical reactor...
-
On-line measurement of cell impedance during charging and discharging process
PublikacjaW pracy przedstawiono założenia metody pomiaru impedancji, która w przeciwieństwie do dotychczasowych technik impedancyjnych stosowanych w badaniach ogniw, umożliwia pracę on-line. W celu zaprezentowania możliwości metody wykonano eksperyment polegający na cyklicznym ładowaniu i rozładowywaniu elektrody ołowianej w 4.8M H2SO4 z jednoczesnym pomiarem impedancji. Zmiany parametrów elektrycznych otrzymanych w wyniku analizy widm impedancyjnych...
-
Kinetyka formowania się tlenku miedzi(I) na elektrodzie Cu w oparciu o badania impedancyjne
PublikacjaWykorzystano technikę Dynamicznej Elektrochemicznej Spektroskopii Impedancyjnej (DEIS) do wyznaczenia chwilowych widm impedancyjnych w zakresie potencjałów formowania się warstwy pasywnej tlenku miedzi (I) w roztworze 0.1M NaOH. Autorzy skupili się na określeniu charakteru zmian parametrów impedancyjnych towarzyszących powstawaniu monowarstwy Cu-OHads. Do analizy zastosowano elektryczny obwód zastępczy R(CR)(COR). Zmiany tych parametrów...
-
Mesoscopic impedance analysis of solid materials surface
PublikacjaSeveral techniques have been developed in order to characterize electrical properties of surfaces in micrometer/nanometer scale. Obtaining of the spatial distribution of sample resistance, capacitance or potential requires separate measurements performed in different scanning modes. On the other hand, analysis of the frequency response of investigated system enables determination of several physical quantities in single measurement...
-
Cykl życia wyrobu a ochrona środowiska
PublikacjaW nienijszym rozdziale poruszono zagadnienia zwiazane z ochrona srodowiska- przedsatwiono genezę i rozwój koncepcji zarządzania środowiskiem. Przedstawiona została rózwnież problematyka wzajemnych oddziaływań przedsiebiorstwa i jego produktów na środowisko naturalne w aspekcie zarządzania środowiskowego i metody LCA(Life Cycle Assessment). Omówiono również zagadnienie związane z Zadsadą Przedłuzonej odpowiedzialności Producenta...
-
Metoda określania spawalniczych pól temperatur.Krajowa Naukowo-Techniczna Konferencja Spawalnicza ''Postęp i innowacje w spawalnictwie''.
PublikacjaPrzedstawiono opracowanie i weryfikację modelu wykorzystującego metodę bilansów elementarnych (MBE), w układzie przestrzennym z ruchomą siatką, niestacjonarnych zagadnień przepływu ciepła w płycie podczas spawania. Zakres pracy obejmuje, analizę i wykonanie obliczeń cykli cieplnych na przykładzie napawania i spawania. Weryfikację i modyfikację opracowanych modeli dokonano w oparciu o istniejące wyniki badań doświadczalnych. Pokazano...
-
Styrene Oxidation by Copper(II) Complexes Salen-Type Encapsulated into Nay Zeolite
PublikacjaThe copper(II) complex with a Schiff-base salen-type ligand has been encapsulated in the nanopores of a NaY zeolite by using two different methodologies, the flexible ligand and in situ complex preparation methods. The encapsulated and non-encapsulated copper(II) complexes were screened as catalysts for styrene oxidation by using TBHP as the oxygen source in acetonitrile solvent. Under the optimized conditions, the catalysts exhibited...
-
Red Kale (Brassica oleracea L. ssp. acephala L. var. sabellica) Induces Apoptosis in Human Colorectal Cancer Cells In Vitro
PublikacjaThis article presents the results of studies investigating the effect of red kale (Brassica oleracea L. ssp. acephala L. var. sabellica) extract on cancer cells (HT-29). The cytotoxicity of the red kale extract was assessed using MTT and LDH assays, while qRT-PCR was employed to analyze the expression of genes associated with the p53 signaling pathway to elucidate the effect of the extract on cancer cells. Furthermore, HPLC-ESI-QTOF-MS/MS...
-
An application for a new type of pneumatic engine concept
PublikacjaHeavy trucks are often equipped with loading and unloading systems like dock levellers with swing lip or telescopic lip. Most of these devices require hydro-electrical energy supply systems (eg. the pump that presses the working substance to the actuators must be propelled by electric engine.) The space taken by pump with electric engine can be reduced on condition that a new type of pneumatic drive will be considered. It is possible...
-
Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition
PublikacjaAmines are important biological compounds, and so their analysis and monitoring in various matrices is worthy of investigation and development.Due to the polar nature of amines, chromatographic analysis of free amines is generally unsatisfactory owing to adsorption and decomposition of the solute on the column, resulting in peak tailing and losses. Therefore, many derivatization reactions are employed to reduce the polarity, improve...
-
The hat problem on a union of disjoint graphs
PublikacjaThe topic is the hat problem in which each of n players is randomly fitted with a blue or red hat. Then everybody can try to guess simultaneously his own hat color by looking at the hat colors of the other players. The team wins if at least one player guesses his hat color correctly, and no one guesses his hat color wrong; otherwise the team loses. The aim is to maximize the probability of winning. In this version every player...
-
POMERANIAN LANDSCAPES OF MODERNIST ZASPA. CONCEPTS OF REVITALISATION OF THE HOUSING ESTATE
PublikacjaZaspa is a neighbourhood in Gdansk with a long locational history and numerous build-ups. It is situated in a complex landscape between the coastal strip and moraine hills. The housing estates built here in the 1970s followed the postulates of modernist urbanism, ignoring the topographical and natural specifics and the regional heritage. The result was an ergonomic but anonymous space with many current strengths...
-
In vitro biodegradation of bacterial nanocellulose under conditions simulating human plasma in the presence of selected pathogenic microorganisms
PublikacjaThe Biodegradability of bacterial nanocellulose (BNC) was assessed based on a change in its properties under conditions simulating human plasma in the presence or absence of the pathogens Staphylococcus aureus, Candida albicans and Aspergillus fumigatus. It was shown that the dry mass of BNC did not change during 6 months of incubation, except for samples stored in the presence of moulds, where the dry mass reduced by 40 %. The...
-
Preliminary estimation of groundwater recharge on Brda river outwash plain
PublikacjaEstimation of groundwater recharge is one of the most challenging subjects in hydrogeology. It is a critical factor influencing the pollution migration, assessment of aquifer vulnerability to contamination, small-scale groundwater budget calculation, modeling of nutrient cycling and detailed flow path calculations. In Poland an infiltration rate method is widely used, which depends on a system of rate coefficients referring to...
-
Degradation of the Concrete Railway Track Bed Located in the Vicinity of the Loading Wharf
PublikacjaThe following article describes the damages of the concrete railway track bed at the place of unloading petroleum products located in the immediate vicinity of the cargo berth. The concrete of the track bed has been a subject to degradation as a result of many years of exploitation resulting, inter alia, in its cyclical flooding of petroleum products during the unloading and loading of rail tankers. Repairs carried out in the previous...
-
Structure and the Biochemical Potential of the Bacterial Community in Wastewater Treatment Plant Effluent and in Receiving Waters: Northern Poland Case Study
PublikacjaWastewater treatment processes are monitored mainly in terms of biogenic substance removal efficiency. Little is known about the treated wastewater microbiome and its influence on the recipient. In this study, a wide range of methods (cultivation, microscopic analysis, New Generation Sequencing and Real Time PCR) were employed to determine the bacterial community composition of the treated wastewater and its receiver. Preliminary...
-
Single-step grown boron doped nanocrystalline diamond-carbon nanograss hybrid as an efficient supercapacitor electrode
PublikacjaDirect synthesis of nano-structured carbon hybrid consisting of vertically aligned carbon nanograss on top of boron-doped nanocrystalline diamond is demonstrated and the carbon hybrid is further applied as an electrode material for the fabrication of supercapacitor. The hybrid film combines the dual advantages of sp2 (carbon nanograss) and sp3 (nanocrystalline diamond) bonded carbon, possessing not only the excellent electrical...
-
Projekt kotła rusztowego na biomasę dla układu ORC 100 kW
PublikacjaCelem pracy było stworzenie projektu kotła rusztowego na biomasę współpracującego z układem Organic Rancine Cycle (ang. ORC) o mocy 100 kW. Ze względu na niską sprawność turbozespołu w tym układzie, celem uzyskania 100 kW mocy elektrycznej, należy dostarczyć czynnikowi chłodzącemu 600kW mocy cieplnej. W niniejszej pracy przedstawiono układ kotłowy składający się z komory spalania, komory wymiennikowej, ekonomizera oraz podgrzewacza...
-
Estimation of interior-permanent-magnet-synchronous-motor rotor position by analysis of phase-current derivatives
PublikacjaThis paper describes an algorithm for estimation of IPMSM rotor angular position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Calculation of the motor position is performed in every PWM cycle. The standard SV-PWM method is used to determine...
-
Design analysis of Tesla micro-turbine operating on a low-boiling medium
PublikacjaThis paper presents results of the design analysis of a Tesla bladeless turbine intended for a co-generating micro-power plantof heat capacity 20 kW, which operates in an organic Rankine cycle on a low-boiling medium. Numerical calculations of flowin several Tesla turbine models were performed for a range of design parameters. Results of investigations exhibit interestingfeatures in the distribution of flow parameters within the...
-
Optymalizacja parametrów pracy siłowni osiągającej zaawansowane super ultrandkrytyczne parametry pary świeżej oraz modyfikacje obiegu parowego pozwalające zwiększyć jego sprawność
PublikacjaW niniejszym artykule przedstawiono metody optymalizacji parametrów siłowni osiągającej zaawansowane super ultranadkrytyczne parametry pary. Stworzono modele obliczeniowe trzech nadkrytycznych obiegów parowych: z pojedynczym przegrzewam międzystopniowym, z podwójnym przegrzewem międzystopniowym oraz „Master Cycle". Zaprezentowano wpływ dodatkowego przegrzewu międzystopniowego i konfiguracji Master Cyde na sprawność obiegu parowego....
-
Carbon Dioxide Recovery Skid
PublikacjaIn the face of tightening climate regulations, the adoption of carbon dioxide recovery systems is inevitable. Modular process skid units have been widely adopted across the industry. The gas-steam power plant skid unit with the carbon dioxide recovery system was described. The proposed skid module consists of the compact cycle with the oxy-combustion and the carbon dioxide capture skid unit producing pure compressed CO2. The compactness...
-
Supervisory fuzzy control system for biological processes in sequencing wastewater batch reactor
PublikacjaThe paper proposes the design of the supervisory heuristic fuzzy control system applied to a Sequencing Batch Reactor (SBR) in the Wastewater Treatment Plant (WWTP). Based on real data records and the biological process and aeration system models, a control system for biological processes has been designed. The supervisory control system performs management of the reactor work cycle, determines the phase length, controls the sludge...
-
Insights into the microbial community of treated wastewater, its year-round variability and impact on the receiver, using cultivation, microscopy and amplicon-based methods
PublikacjaApart from chemical constituents, wastewater treatment plant (WWTP) effluents also release microorganisms that can be important to the receiving water bodies either from a sanitary point of view, or taking to the account the biogeochemical potential of the recipients. However, little is known about the treated wastewater microbial community, its composition, seasonal changes, functions and fate in the waters of the receiver. Thus,...
-
Photocatalytic activity of nitrogen doped TiO2 nanotubes prepared by anodic oxidation: The effect of applied voltage, anodization time and amount of nitrogen dopant
PublikacjaNitrogen doped TiO2 nanotube arrays were prepared by anodizing Ti foils in an organic electrolyte containing specified amounts of urea as nitrogen precursor. The photocatalytic activity of the samples was evaluated by analyzing the degradation kinetics of phenol in water. The influence of tubes’ length, tubes’ surface morphology and amount of nitrogen in the TiO2 lattice on hydroxyl radical formation efficiency, photocatalytic...
-
Superimposed ice as nutrient storage
PublikacjaNutrient cycling in the glacial environment is known from the perspective of meltwater release and snowpack elution processes, but the superimposed ice temporary storage remains poorly understood. In this study, the enrichment of superimposed ice in nutrient ions: nitrite, nitrate and ammonium was studied in more detail. The release of these ions from superimposed ice into a supraglacial stream was considered also, additionally...
-
Application of microturbines in CHP systems with reciprocating engines
PublikacjaThe analysis was carried out for Combined Heat and Power generation systems with micro-turbines power plants working on heat rejected from the reciprocating engine. The calculations were performed for GE Jerbacher engines of J320 GS- C05, J320 GS- C25 and J416 GS- B05 types. We considered different working media (both wet and dry fluids): water, ammonia, ethanol, methanol, methylacetylene (propyne), dimethyloether, sulphur dioxide,...
-
The Magnetic Fluid Seals Research Results vs. Kelvin-Helmholtz (K-H) instability and Preliminary Conclusions
PublikacjaIn the article a magnetic-fluid seals durability research and the tests results are presented. The tests were made with three magnetic fluids using various magnets quantity in magnetic assemblies. If values obtained in the repeated test deviated by more than 10 % from results of the first test an additional control test was made for final characteristics. The characteristics are: critical pressure, critical motion velocity and...
-
Healthy financial system of local government on the example of Poland
Publikacjahealthy local government financial system lays the foundation for the ability of local government units (LGUs) to carry out public tasks at the current qualitative and quantitative level and to meet their obligations in the short and long term. A healthy financial system of local government is a system that is adequate, stable, unified, consistent, transparent, diversified, counter-cyclical, guarantees the financial independence...
-
Corrigendum to “Fatigue life improvement using low transformation temperature weld material with measurement of residual stress” [Int. J. Fatigue 164 (2022) 107137]
PublikacjaWelding processes often produce high levels of tensile residual stress. Low transformation temperature (LTT) welding wires utilise phase transformation strains to overcome the thermal contraction of a cooling weld. In this paper, the residual stress within each weld was quantified using the milling/strain gauge method, being the strain change measured as the weldment was milled away. The fatigue tests were conducted under uniaxial...
-
Composites of tin oxide and different carbonaceous materials as negative electrodes in lithium-ion batteries
PublikacjaAbstract Tin and tin oxide have been considered as suitable materials with high theoretical capacity for lithium ion batteries. Their low cost, high safety and other technical benefits placed them as promising replacements for graphite negative electrodes. The problem to overcome with tin oxide, as well as with other metallic materials, is high volume changes during alloying/dealloying, subsequent pulverization, delamination from...
-
Synthesis and properties of porous Sr 0.96 Y 0.04 Ti 1−x Nb x O 3
PublikacjaA series of porous, single phase Sr0.96Y0.04Ti1-xNbxO3 samples was obtained using a wet synthesis method (modified citrate sol-gel) method. Temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPO) measurements have shown high stability of the obtained material in variable (oxidizing/reducing) atmospheres. All samples exhibit high conductivity in hydrogen atmosphere with the highest value (around 1S/cm)...
-
Dynamic characteristics of the proton exchange membrane fuel cell module
PublikacjaThe paper describes a fuel cell based system and its performance. The system is based on two fuel cell units, DC/DC converter, DC/AC inverter, microprocessor control unit, load unit, bottled hydrogen supply system and a set of measurement instruments. In the study presented in the paper a dynamic response of the proton exchange membrane (PEM) fuel cell system to unit step change load as well as to periodical load changing cycles...
-
Application of Barycentric Coordinates in Space Vector PWM Computations
PublikacjaThis paper proposes the use of barycentric coordinates in the development and implementationof space-vector pulse-width modulation (SVPWM) methods, especially for inverters with deformed space-vector diagrams. The proposed approach is capable of explicit calculation of vector duty cycles, independentof whether they assume ideal positions or are displaced due to the DC-link voltage imbalance. The use ofbarycentric coordinates also...
-
Electrochemical behavior of a composite material containing 3D-structured diatom biosilica
Publikacja3D-structured diatom biosilica mixed with conducting carbon black was investigated as an active electrode material for lithium-ion batteries. Diatom biosilica was obtained by cultivation of the selected diatom species under laboratory conditions. Several instrumental techniques (XRD, FTIR, Raman, SEM-EDX, TGA) were used to characterize the physicochemical properties of applied biosilica. It was evidenced that the prepared new composite...
-
Scaled agile framework. Dealing with software process‐related challenges of a financial group with the action research approach
PublikacjaThis article reports on a domain-specific software development venture at Nordea. We explore organizational constraints, challenges, and corrective actions undertaken when scaling the agile development approach of their Core Banking Platform program. The fit and required customizations of the rather complex and rigid SAFe framework in a policy-heavy financial institution are audited against the organic growth of the program. In...
-
Hydrological Dry Periods versus Atmospheric Circulations in the Lower Vistula Basin (Poland) in 1954–2018
PublikacjaThe paper discusses the impact of atmospheric circulation on the occurrence of droughts. The research in-cludes mean monthly discharges for 7 rivers in 1954-2018. Dry periods were determined with Standardised Streamflow Indices (SSI-12). Additionally, the circulation type calendar for Central Poland was used to determine the atmospheric circulation indices: western zonal (W), southern meridional (S) and cyclonicity (C). The analyses...
-
Highly sensitive large strain cellulose/multiwalled carbon nanotubes (MWCNTs)/thermoplastic polyurethane (TPU) nanocomposite foams: From design to performance evaluation
PublikacjaAerogel-based polymer composite foams are promising for large strain piezoresistive sensors, but their aerogel skeleton is partially destroyed during the foaming process, limiting their sensitivity. Herein, the thermoplastic polyurethane was synthesized on the aerogel skeleton to obtain cellulose/multiwalled carbon nanotubes (MWCNTs)/thermoplastic polyurethane (TPU) nanocomposite materials foamed with the aid of supercritical carbon...
-
Fatigue life improvement using low transformation temperature weld material with measurement of residual stress
PublikacjaWelding processes often produce high levels of tensile residual stress. Low transformation temperature (LTT) welding wires utilise phase transformation strains to overcome the thermal contraction of a cooling weld. In this paper, the residual stress within each weld was quantified using the milling/strain gauge method, being the strain change measured as the weldment was milled away. The fatigue tests were conducted under uniaxial...
-
Molecular Umbrella as A Nanocarrier for Antifungals
PublikacjaA molecular umbrella composed of two O‐sulfated cholic acid residues was applied for the construction of conjugates with cispentacin, containing a “trimethyl lock” (TML) or o‐dithiobenzylcarbamoyl moiety as a cleavable linker. Three out of five conjugates demonstrated antifungal in vitro activity against C. albicans and C. glabrata but not against C. krusei, with MIC90 values in the 0.22–0.99 mM range and were not hemolytic. Antifungal...
-
Low temperature processed MnCo2O4 and MnCo1.8Fe0.2O4 as effective protective coatings for solid oxide fuel cell interconnects at 750 °C
PublikacjaIn this study two materials, MnCo2O4 and MnCo1.8Fe0.2O4 are studied as potential protective coatings for Solid Oxide Fuel Cell interconnects working at 750 °C. First powder fabrication by a modified Pechini method is described followed by a description of the coating procedure. The protective action of the coating applied on Crofer 22 APU is evaluated by following the area specific resistance (ASR) of the scale/coating for 5500...
-
Nano Tin/Tin Oxide Attached onto Graphene Oxide Skeleton as a Fluorine Free Anode Material for Lithium-Ion Batteries
PublikacjaHerein, we show a composite formation method of tin/tin oxide nanoparticles with graphene oxide and CMC based on laser ablation technique as an electrode material for energy storage devices. The material exhibited a three-dimensional conducting graphene oxide network decorated with tin or tin oxide nanoparticles. The structure, homogeneous distribution of nanoparticles, and direct contact between inorganic and organic parts were...
-
Electrochemical oxidation of sulphamerazine at boron-doped diamond electrodes: Influence of boron concentration
PublikacjaThe boron-doped diamond (BDD) electrodes with different boron concentrations have been tested as electrode material for sulphamerazine (SRM) oxidation in water solution. An investigation of the electrode morphology and molecular structure was carried out using high resolution scanning electron microscopy (SEM) and Raman spectroscopy. Electrochemical results showed clearly that the kinetics and efficiency of SRM oxidation were dependent...
-
High Temperature Air Combustion and Gasification (HTAC; HTAG)
PublikacjaCombustion and gasification technology utilizing high-cycle regenerative air/steam preheater has drawn increased attention in many application areas. The process is to be realized at temperature level above ash melting point using highly preheated agent. The use of highly preheated media above 900oC provides additional energy in to conversion processes and results in considerable changes to the design of combustion and gasification...
-
Uniform Model Interface for Assurance Case Integration with System Models
PublikacjaAssurance cases are developed and maintained in parallel with corresponding system models and therefore need to reference each other. Managing the correctness and consistency of interrelated safety argument and system models is essential for system dependability and is a nontrivial task. The model interface presented in this paper enables a uniform process of establishing and managing assurance case references to various types...