Search
Filters
total: 752
filtered: 642
Search results for: FREEZE/THAW CYCLE
-
Cooperation of ORC installation with a gas boiler as a perspective co-generation system for households
PublicationThis paper reports tests of an innovative micro-CHP unit prototype, consisting of a traditional gas boiler and organic Rankine cycle (ORC), which incorporates original system components such as an axial vapour microturbine, evaporator and condenser. The system co-generates heat and electricity for a single household or a group of households. Electricity is only a by-product during production of heat. While testing the prototype,...
-
Gazowa mikrosiłownia domowa z modułem ORC - doświadczenia z badania prototypu
PublicationArtykuł zawiera rozważania nad ideą wykorzystania obiegu parowego ORC (Organic Rankine Cycle) do skojarzonej produkcji ciepła i energii elektrycznej dla pokrycia potrzeb indywidualnego odbiorcy. Dokonano w nim podsumowania dotychczasowych prac prowadzonych przez Autorów, które zaowocowały budową demonstracyjno-badawczego stanowiska mikro-CHP z technologią ORC w skali „domowej”, współpracującą z komercyjnym kotłem gazowym. W publikacji...
-
Criteria for selection of working fluid in low-temperature ORC
PublicationThe economics of an ORC system is strictly linked to thermodynamic properties of the working fluid. A bad choice of working fluid could lead to a less efficient and expensive plant/generation unit. Some selection criteria have been put forward by various authors, incorporating thermodynamic properties, provided in literature but these do not have a general character. In the paper a simple analysis has been carried out which resulted...
-
Partial Admission Stages of High Efficiency for a Microturbine
PublicationThe paper presents the results of a design analysis of a microturbine for a cogeneration micro-power plant working in accordance with organic Rankine cycle. The heat power of the plant is assumed equal to 20kW and the corresponding available electric output is estimated to be about 3 kW. After the design analysis, the axial turbine with partial admission in all stages was built and tested experimentally. Special attentionwas paid...
-
The conception of energetic investigations of the multisymptom fatigue of the simple mechanical systems' constructional materials
PublicationThe article presents the basic assumptions of the research project aimed, as the main scientific purpose, an identification of the slow-changeable energy processes surrounding the high-cycle fatigue of constructional materials within the plain mechanical system, especially the marine one, for diagnostic purposes. There is foreseen an application of alternative diagnostic methods based on energetic observations of the multi-symptom,...
-
Water Footprint Assessment of Selected Polymers, Polymer Blends, Composites, and Biocomposites for Industrial Application
PublicationThis paper presents a water footprint assessment of polymers, polymer blends, composites, and biocomposites based on a standardized EUR-pallet case study. The water footprint analysis is based on life cycle assessment (LCA). The study investigates six variants of EUR-pallet production depending on the materials used. The system boundary included the production of each material and the injection molding to obtain a standardized...
-
3D Hierarchical Boron-Doped Diamond-Multilayered Graphene Nanowalls as an Efficient Supercapacitor Electrode
PublicationSynthesis of stable hybrid carbon nanostructure for high-performance supercapacitor electrode with long life-cycle for electronic and energy storage devices is a real challenge. Here, we present a one-step synthesis method to produce conductive boron-doped hybrid carbon nanowalls (HCNWs), where sp2-bonded graphene has been integrated with and over a three-dimensional curved wall-like network of sp3-bonded diamond. The spectroscopic...
-
Heavy duty vehicle fuel consumption modelling using artificial neural networks
PublicationIn this paper an artificial neural network (ANN) approach to modelling fuel consumption of heavy duty vehicles is presented. The proposed method uses easy accessible data collected via CAN bus of the truck. As a benchmark a conventional method, which is based on polynomial regression model, is used. The fuel consumption is measured in two different tests, performed by using a unique test bench to apply the load to the engine. Firstly,...
-
Effect of Pin Shape on Thermal History of Aluminum-Steel Friction Stir Welded Joint: Computational Fluid Dynamic Modeling and Validation
PublicationThis article studied the effects of pin angle on heat generation and temperature distribution during friction stir welding (FSW) of AA1100 aluminum alloy and St-14 low carbon steel. A validated computational fluid dynamics (CFD) model was implemented to simulate the FSW process. Scanning electron microscopy (SEM) was employed in order to investigate internal materials’ flow. Simulation results revealed that the mechanical work...
-
THE ESSENCE OF THE TRANSFORMATION OF SOCIO-ECONOMIC RELATIONS IN THE NATIONAL ECONOMY: THEORETICAL AND METHODOLOGICAL ASPECT
PublicationThe article is devoted to a thorough study of the theoretical and methodological foundations of the essence of the transformation of socio-economic relations of the national economy. Based on the study of scientific sources, a proper definition of the concept of "transformation of socio-economic relations" was formed. It is proposed to consider transformational processes from the point of view of their direct or indirect impact...
-
A brief note on entire fracture surface topography parameters for 18Ni300 maraging steel produced by LB-PBF after LCF
PublicationThe concept of entire fracture surface investigation is helpful in explaining fatigue phenomena. In this paper, this method has been applied for 18Ni300 maraging steel using a 3D measurement system. Before post-mortem analysis, the specimens produced by laser beam powder bed fusion (LB-PBF) were tested under low-cycle fatigue (LCF) for eight strain amplitudes in the interval 0.3% to 1.0%. The attention was placed on the relationship...
-
Negative carbon dioxide gas power plant integrated with gasification of sewage sludge
PublicationOne of the primary objectives of the negative carbon dioxide gas power plant (nCO2PP) is to develop an innovative technology confirming the possibility of the use of sewage sludge to produce electricity while having a positive impact on the environment. In this paper, a mathematical model is presented to estimate thermodynamic parameters of the system in relation to the gasification process and changes in such parameters in the...
-
The valance state of vanadium-key factor in the flexibility of potassium vanadates structure as cathode materials in Li-ion batteries
PublicationPotassium hexavanadate (K2V6O16·nH2O) nanobelts have been synthesized by the LPE-IonEx method, which is dedicated to synthesis of transition metal oxide bronzes with controlled morphology and structure. The electrochemical performance of K2V6O16·nH2O as a cathode material for lithium-ion batteries has been evaluated. The KVO nanobelts demonstrated a high discharge capacity of 260 mAh g−1, and long-term cyclic stability up to 100...
-
Comprehensive thermodynamic analysis of the CAES system coupled with the underground thermal energy storage taking into account global, central and local level of energy conversion
PublicationA key aspect of CAES is the optimal configuration of the thermodynamic cycle. In this paper, the situation of cooperation between the current conventional power plants and wind farms is analyzed, and then, based on thermodynamic models, the process of storing thermal and electrical energy in the CAES system coupled with a heat storage and recovery is developed. Therefore, three levels can be distinguished, namely: the global level...
-
Pressure drop and heat transfer during boiling and condensation at subcritical region
PublicationMost of the data presented in the literature relate to saturation temperatures in the range - 20°C to 40°C due to the application in refrigeration technology. There is necessity to extend databases to higher values of saturation temperature due to new applications such as Organic Rankine Cycle and high temperature heat pumps. Only few papers contain data for high reduced pressure for low boiling point liquids. This paper focus...
-
Hysteresis curves for some periodic and aperiodic perturbations in magnetosonic flow
PublicationA thermodynamic relation between perturbations of pressure and mass density in the magnetohydrodynamic flow is theoretically studied. Planar magnetohydrodynamic perturbations with the wave vector, which forms a constant angle with the equilibrium magnetic field, are under study. The theory considers thermal conduction of a plasma and the deviation from adiabaticity of a flow due to some kind of heating–cooling function. It also...
-
Designing Control and Protection Systems with Regard to Integrated Functional Safety and Cybersecurity Aspects
PublicationThis article addresses current problems of risk analysis and probabilistic modelling for functional safety management in the life cycle of safety-related systems. Two main stages in the lifecycle of these systems are distinguished, namely the design and operation. The risk analysis and probabilistic modelling differ in these stages in view of available knowledge and data. Due to the complexity and uncertainty involved, both qualitative...
-
LCF behavior of 2024AA under uni- and biaxial loading taking into account creep pre-deformation
PublicationThis study presents the results of experimental low-cycle fatigue (LCF) tests of aluminum 2024 alloy T3511 temper in uni- and biaxial loading states. Tests were carried out on both the as-received material (hardened extruded rods) and material with different pre-deformation histories. These deformations were carried out in the creep process at 200 °C and 300 °C for two different levels of at each temperature. The pre-deformed material’s...
-
Utilizing Genome-Wide mRNA Profiling to Identify the Cytotoxic Chemotherapeutic Mechanism of Triazoloacridone C-1305 as Direct Microtubule Stabilization
PublicationRational drug design and in vitro pharmacology profiling constitute the gold standard in drug development pipelines. Problems arise, however, because this process is often dicult due to limited information regarding the complete identification of a molecule’s biological activities. The increasing aordability of genome-wide next-generation technologies now provides an excellent opportunity to understand a compound’s diverse eects...
-
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...
-
Aspekt ekonomiczny ogrzewania wolnostojącego budynku powietrzną pompą ciepła
PublicationArtykuł poświęcony ocenie ekonomicznej ogrzewania wolnostojącego budynku mieszkalnego z wykorzystaniem powietrznej pompy ciepła pracującej w systemie biwalentnym monoenergetycznym. Podstawę analizy stanowi projekt systemu ogrzewania oparty na sprężarkowej pompie ciepła typu powietrze - woda ( P-W ) dla wolnostojącego budynku mieszkalnego o powierzchni użytkowej 140 m2. Ocenę ekonomiczną tego rozwiązania przeprowadzono w oparciu...
-
Network Graph Transformation Providing Fast Calculation of Paths for Resilient Routing
PublicationProtection of transmission against failures can be appropriately dealt with by alternative paths. However, common schemes (e.g., Bhandaris scheme) are characterized by a remarkable delay while determining the transmission paths. This in turn may have a serious impact on serving dynamic demands (characterized by relatively short duration time). As a remedy to this problem, we introduce an approach to pre-compute the sets of disjoint...
-
Organizational culture as prerequisite of proactive safety and security management in critical infrastructure systems including hazardous plants and ports
PublicationThis article addresses selected aspects of organizational culture to be considered in the context of knowledge based proactive safety and security management of plants, ports and systems of critical infrastructure. It has been often emphasized in the domain literature that business effectiveness of such plants and their resilience against hazards and threats to avoid major accidents depends substantially on human and organizational...
-
An approach to improve the time efficiency of disjoint paths calculation
PublicationFailures of network elements can be appropriately dealt with by utilization of alternate disjoint paths to provide redirection of flows affected by failures of the respective working paths. Known approaches can be broadly divided by decision on backup paths installation into proactive and reactive mechanisms, as well as based on the scope of recovery actions into local and global rerouting. There are several important scenarios...
-
CO2 EMISSION TO THE ATMOSPHERE FROM CARBONATE WATERS: THE STUDY CASE OF THE LUBLIN UPLAND AND ROZTOCZE REGIONS
PublicationThe concentration of carbon dioxide dissolved in water (CO2(aq)) was measured in consecutive phases of the hydrological cycle. Its potentially possible degassing from groundwaters to the atmosphere was also assessed. The research was conducted in the area of occurrence of carbonate rocks of the Lublin Upland and Roztocze (SE Poland). The results of the measurements of CO2(aq) concentration varied as follows (min-max/mean): precipitation...
-
A simple modification of PCR thermal profile applied to evade persisting contamination
PublicationThe polymerase chain reaction (PCR), one of the most commonly applied methods of diagnostics and molecular biology has a frustrating downside known as the false positive signal or contamination. Several solutions to avoid and to eliminate PCR contaminations have been worked out to date but the implementation of these solutions to laboratory practice may be laborious and time consuming. A simple approach to circumvent the problem...
-
High-efficiency mini and micro heat exchangers for dispersed power generation
PublicationTaking into account the dispersed systems technologies and their development, the ORC systems seem to be promising technology amongst various micro-CHP domestic units (electrical power production below 10 kWe), however practical realization of the ORC cycle in a micro-scale is technically challenging. The system consists in devices such as the vapour generation unit (boiler), expansion device and heat exchangers. Each of them should...
-
Planning optimised multi-tasking operations under the capability for parallel machining
PublicationThe advent of advanced multi-tasking machines (MTMs) in the metalworking industry has provided the opportunity for more efficient parallel machining as compared to traditional sequential processing. It entailed the need for developing appropriate reasoning schemes for efficient process planning to take advantage of machining capabilities inherent in these machines. This paper addresses an adequate methodical approach for a non-linear...
-
Novel chalcone-derived pyrazoles as potential therapeutic agents for the treatment of non-small cell lung cancer
PublicationLung cancer is considered to account for approximately one-fifth of all malignant tumor-related deaths worldwide and is therefore one of the most lethal malignancies. Pyrazole scaffold possesses a wide range of biological and pharmacological activities, which play important roles in medicinal chemistry. The present study reports the synthesis and in vitro biological characterization of nine pyrazoles derived from chalcones as potential...
-
Detection and removal of priority substances and emerging pollutants from stormwater: case study of the Kołobrzeska collector, Gdańsk, Poland
PublicationProgressive urban development affects environmental balance and disrupts the hydrologic cycle, in which rainfall plays a significant role. Since rainwater is considered a valuable resource of the environment, many technical solutions are implemented that enable effective rainwater management. On the other hand, stormwater runoff from urban areas contains numerous (also toxic) substances, and therefore should be properly treated....
-
Investigation of ecological parameters of a gas turbine combustion chamber with steam injection for the floating production, storage, and offloading vessel
PublicationThe article is dedicated to the investigation of the possibility of using the contact type gas turbine cycle with steam injection into the combustion chamber for the floating production, storage, and offloading vessel in order to increase the specific power and efficiency and reduce emissions of toxic components. A new approach is proposed, associated with the use of the two-stage injection of superheated steam into a gas turbine...
-
New insights on lithium storage in silicon oxycarbide/carbon composites: Impact of microstructure on electrochemical properties
PublicationIn this work, we study the impact of the preceramic precursor vinyltriethoxysilane (VTES) on the electrochemical performance of silicon oxycarbide (SiOC) glass/graphite composites. We apply an innovative approach based on high-power ultrasounds in order to obtain highly homogenous composites with a uniform distribution of small graphitic flakes. This procedure enhances gelation and drying of VTES-based preceramic polymer/graphite...
-
DIGITAL HYDRAULICS CIRCUIT BASED ON PWM FUNCTION FOR CONTROLLING HYDRAULIC ACTUATOR POSITION
PublicationHydraulic systems are used in many different industries, such as multi-source hydrostatic drive systems. In traditional hydraulic systems, a proportional servo valve is used to control the position of hydraulic actuators. The low energy efficiency and high cost of these control valves are two major problems with these systems. Digital hydraulics is one of the most unique ideas on how to solve these problems. Researchers like digital...
-
Tetrahydroquinolinone derivatives exert antiproliferative effect on lung cancer cells through apoptosis induction
PublicationThe anticancer properties of quinolones is a topic of interest among researchers in the scientific world. Because these compounds do not cause side effects, unlike the commonly used cytostatics, they are considered a promising source of new anticancer drugs. In this work, we designed a brief synthetic pathway and obtained a series of novel 8-phenyltetrahydroquinolinone derivatives functionalized with benzyl-type moieties at position...
-
Numerical analysis of CO2-water separation in a horizontal double T-junction
PublicationCarbon dioxide is considered one of the main factors leading to global warming. Considering the significant impacts of CO2 on climate change, various technologies have been developed in recent decades to control carbon emission, such as for example CO2 capture and storage. The developed cycle of a negative CO2 emission power plant includes some devices, out of which, separator plays an indispensable role. To this end, T-junction...
-
Modelling of heat transfer in supercritical pressure recuperators
PublicationIn the paper presented is analysis of convective flow heat transfer at supercritical pressure in channels of heat exchanger working in the thermodynamic cycle. The modelling is based on the division of the flow into three regions, namely the heavy fluid, a two phase flow consisting of the heavy and light fluids and finally the light fluid flow. Modelling is concentrated on the region of simultaneous flow of two fluids divided into...
-
Assessing ecotoxicity, synergic and antagonistic actions of commonly used components of polymerization mixture in molecularly imprinted polymers preparation process
PublicationIncreasingly, the challenge is the optimal process of developing a suitable MIP-type sorptive material (taking into account its final form and application area), which is mainly related to the efficiency/effectiveness of the polymerization process. The lack of reaction or its low efficiency generates additional waste and puts it into the environmental cycle. The main aim of the performed research was the estimation of ecotoxicity,...
-
Sphere Drive and Control System for Haptic Interaction With Physical, Virtual, and Augmented Reality
PublicationA system for haptic interaction with physical, virtual, and augmented realities, founded on drive and measurement elements (DMEs), is considered. The system consists of eight DME rolls equipped with linear actuators, able to measure their angular velocity, drive the sphere, and adjust downforce (pressing the roll against the sphere). Two modeling issues are addressed. Special effort is put in to compensate for various technical...
-
Synthesis, molecular structure, and metabolic stability of new series of N' -(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)-1-(5-phenyl-1 H -pyrazol-1-yl)amidine as potential anti-cancer agents
PublicationA series of new N'-(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)-1-(5-phenyl-1H-pyrazol-1-yl)amidine derivatives have been synthesized and evaluated in vitro by MTT assays for their antiproliferative activity against cell lines of colon cancer HCT-116, cervical cancer HeLa and breast cancer MCF-7. The studied compounds display selective activity mainly against HCT-116 and HeLa cells. Thus, five compounds show selective cytotoxic...
-
Współpraca pomp ciepła ze źródłem konwencjonalnym. Algorytmy obliczenia bilansu energetycznego i efektywności ekonomicznej
PublicationW wielu przypadkach pompy ciepła w instalacjach ogrzewania współpracują z innymi źródłami ciepła (kotły wodne opalane olejem opałowym, gazem ziemnym, biogazem, bojlery elektryczne, miejska lub osiedlowa sieć ciepłownicza) tworząc hybrydowe źródło ciepła. W każdym wariancie źródła hybrydowego odbiorcę i producenta ciepła interesuje bilans energetyczny całego obiektu oraz efektywność ekonomiczna wytwarzania ciepła w źródle hybrydowym...
-
Switched-capacitor DC-DC converters in arbitrary switching mode - topologically derived resistive models based on incremental graph approach.
PublicationIn the preceding paper we reviewed some of modeling approaches aimed at systematic formulation and solution of switched capacitor DC-DC converters. In our review, special attention was paid to computationally efficient and mathematically elegant methods. In so doing we had tried to demonstrate the virtues of unified Incremental Graph (IG) approach. Incremental Graph is, in concept, a tool originally created for analysis and synthesis...
-
H2AX phosphorylation, its role in DNA damage response and cancer therapy
PublicationDouble-strand breaks (DSBs) are the most deleterious DNA lesions, which, if left unrepaired, may have severe consequences for cell survival, as they lead to chromosome aberrations, genomic instability, or cell death. Various physical, chemical, and biological factors are involved in DSB induction. Cells respond to DNA damage by activating the so-called DNA damage response (DDR), a complex molecular mechanism developed to detect...
-
A new viscoelastic method of calculation of low-temperature thermal stresses in asphalt layers of pavements
PublicationThe paper presents a new method of calculation of thermal stresses in asphalt layers of pavements induced by cooling or heating. The method, developed by the author, is based on the analytical solution for the linear viscoelastic Burgers model extended numerically for the case of asphalt layers whose rheological parameters are strongly dependent on temperature. The coefficient of thermal expansion and Poisson’s ratio may optionally...
-
The concept of sewage-sludge management system for an individual household
PublicationThe individual farms at the rural areas often face problems with domestic sewage collection and treatment. In many cases building of sewerage systems and central wastewater treatment plants (WWTPs) brings too high costs, due to high distances from one farm to another and terrain configuration. Treatment wetlands for individual farms can solve this problem. In the article, an overview of individual treatment wetlands in Europe and...
-
Design and numerical testing of 5-box gfrp shell footbridge
PublicationThe paper formulates new design conditions for composite footbridges, taking into account the material and structural specificity of these objects, i.e. the strength condition, the serviceability condition and the frequency condition. A GFRP composite footbridge labelled with CFB2 code has been designed, with the original superstructure in the form of an opened-closed 5-box girder. The foot and cycle track bridge is simply supported,...
-
Application of Analytic Signal and Smooth Interpolation in Pulse Width Modulation for Conventional Matrix Converters
PublicationThe paper proposes an alternative and novel approach to the PWM duty cycles computation for Conventional Matrix Converters (CMC) fed by balanced, unbalanced or non–sinusoidal AC voltage sources. The presented solution simplifies the prototyping of direct modulation algorithms. PWM duty cycles are calculated faster by the smooth interpolation technique, using only vector coordinates, without trigonometric functions and angles. Both...
-
Shaping the City Responding to Climate Change – Concept of Development of the Right Bank of the Vistula River in Toruń, Poland,
PublicationThe problems of cities of the 21st century are caused by anthropogenic oppression of the environment, through the growth of economic activity and continuous urbanisation, and taking away ecologically important open areas and biologically active areas. Increasingly frequent and sudden rains, strong winds, turbulence and rising world water levels are some of the consequences of climate change that have a direct impact on the functioning...
-
The Development of a Conceptual Framework for Knowledge Sharing in Agile IT Projects
PublicationOrganizations must adapt their resources to meet the challenges associated with changes in the work environment in order to remain competitive in the information era. Several research findings identify knowledge sharing as a means for an organization to improve its competitiveness. Knowledge sharing can be defined in a variety of ways, but it essentially refers to the exchange of knowledge from an information giver to an information...
-
Reducing the Uncertainty of the Moving Object Location Measurement with the Method of Quasi-Multiple Measurement in GNSS Technology in Symmetrical Arrangement
PublicationThe article presents a solution to the problem of limited accuracy of dynamic measurements performed with GNSS receivers. The proposed measurement method is a response to the needs related to the assessment of the measurement uncertainty of the position of the track axis of the rail transport line. However, the problem of reducing the measurement uncertainty is universal for many different situations where high accuracy of positioning...
-
Leaf wettability and plant surface water storage for common wetland species of the Biebrza peatlands (northeast Poland)
PublicationWetlands play a crucial role in buffering the effects of climate change. At the same time, they are one of the most endangered ecosystems on the globe. The knowledge of the water cycle and energy exchange is crucial for the practical preservation and exploiting their capabilities. Leaf wettability is an important parameter characterising the plant's ability to retain water on its surface, and is linked to the ecosystems' hydrological...