Search
displaying 1000 best results Help
Search results for: EFFICIENCY
-
Energy Efficiency
Journals -
Journal on Efficiency and Responsibility in Education and Science
Journals -
PAYMENT TRANSACTIONS’ ENERGY EFFICIENCY
PublicationThe payment system and infrastructure is a sector that is not given enough attention today in the context of energy efficiency. This sector plays a big role in organizing and ensuring money circulation and funds. It has its value consisting on the one hand of the cost of payment equipment, infrastructure, payment instruments. On other hand, its value consists of the cost of energy for their manufacture and maintenance. The European...
-
The effect of different accelerators on the reclaiming efficiency of ground tire rubber
Open Research DataThe presented results concern the influence of different accelerators on the reclaiming efficiency of ground tire rubber (GTR). All the specimens were prepared using a two-roll mill and each sample was prepared in the same manner. Samples were submitted to curing analysis via Rheometer Monsanto 100S after 24 hours of aging. The attached data are related...
-
ANALYSIS OF ENERGY EFFICIENCY IN ELECTRIC DRIVES
PublicationIn this paper energy efficiency in electric drives is analysed. This factor strongly depends on energy parameters - efficiency n and power factor k (in special case cos fi)
-
On a Method of Efficiency Increasing in Kaplan Turbine
PublicationThis paper presents a method of increasing efficiency in Kaplan-type turbine. The method is based on blade profile optimisation together with modelling the interaction between rotor and stator blades. Loss coefficient was chosen as the optimisation criterion, which is related directly to efficiency. Global optimum was found by means of Genetic Algorithms, and Artificial Neural Networks were utilised for approximations to reduce...
-
Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
-
Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
-
Diversification of investment efficiency in selected economies
PublicationAn assessment of the effectiveness of investments is a key element of investment processes. In order to be comprehensive and exhaustive, it should go beyond the scope of the microeconomic assessment and take into account the macroeconomic calculation of effectiveness. The prerequisite for the effectiveness of investment decisions implemented by private companies is the maximization of the return on the investments. When attempting...
-
Lightning impulse efficiency of horizontal earthings
PublicationSystem uziemień współczesnych obiektów jest zwykle bardzo rozległy, a na łączenie poszczególnych elementów uziemiających za pomocą głównej szyny wyrównania potencjałów uwzględnia także uziemienia stacji transformatorowej. Ocena przydatności takiego systemu uziemień do celów ochrony odgromowej nie jest prosta, bo tylko jego część określana, jako długość efektywna bierze udział w odprowadzaniu do gruntu prądu piorunowego. Praca zawiera...
-
The efficiency of turbomachinery in the zero-and three-dimensional approaches
PublicationEfficiency of turbomachinery is usually defined using an isentropic process. This approach provides a reliable reference point only when pressure and temperature measurements are available, e.g. at the casing inlet and outlet. In the case of a single stage internal efficiency determination the reference point is difficult. Computational fluid dynamics allows for an exact calculation of values of losses occurring in a turbine...
-
Losses and energy efficiency of drive motors and systems
PublicationLosses and energy efficiency of every drive motor must be presented as functions of physical quantities independent of losses in the motor. Such quantities are speed and load required by the machine or device driven by the motor, changing in the drive operating field. Speed and load of the motor decide of the instantaneous useful power of the motor and also in a differentiated way of kinds and values of losses occurring in the...
-
Losses and energy efficiency of drive motors and systems
PublicationLosses and energy efficiency of every drive motor must be presented as functions of physical quantities independent of losses in the motor. Such quantities are speed and load required by the machine or device driven by the motor, changing in the drive operating field. Speed and load of the motor decide of the instantaneous useful power of the motor and also in a differentiated way of kinds and values of losses occurring in the...
-
Rational method of grit chamber efficiency determination
PublicationAlthough grot chambers are designed with utmost care, they still remain difficuly to control. As concentration of grit is non-uniform, representative measurements of the sand concentration is a very complex issue. In the paper the results of measure,ents performed at WTP in Gdańsk and Gdynia were analyzed. The proposed method to determine grit chambers efficiency is based on comparison of suspension flow in the inlet and flux of...
-
EVALUATION OF THE EFFICIENCY OF FLEXICURITY IMPLEMENTATION IN OECD COUNTRIES
PublicationFlexicurity is a policy of flexible and secure labour market. It has been the subject of many analyses, however, a coherent evaluation methodology is difficult to specify. The purpose of this paper is to propose a Data Envelopment Analysis based model for the evaluation of the efficiency of flexicurity implementation in OECD countries. The results will be used to create the ranking of countries, to determine changes in time, and...
-
Urban dew formation efficiency and chemistry in Poland
PublicationThe measurements of dew formation efficiency and chemistry were performed in Poland in September 2009, as a part of a longer, two-year sampling campaign. Pairs of sites, representing centers of major Polish cities and rural conditions in three different regions, were compared. With the aim to get more detailed landuse-oriented characteristics of dew, two additional sites were set close to Wroclaw. Collection of dew at each site...
-
The Efficiency of Post‐Communist Countries’ Health Systems
PublicationHealth‐care costs are a major financial burden for the transition economies, which have experienced rapidly increasing demand for health‐care services. The former communist countries of the Central and Eastern Europe and Central Asia needed to reform the financing of their health‐care systems and make efforts to strengthen the role of primary care while limiting the role of hospital care. The growing health needs and, consequently,...
-
Considerations of Computational Efficiency in Volunteer and Cluster Computing
PublicationIn the paper we focus on analysis of performance and power consumption statistics for two modern environments used for computing – volunteer and cluster based systems. The former integrate computational power donated by volunteers from their own locations, often towards social oriented or targeted initiatives, be it of medical, mathematical or space nature. The latter is meant for high performance computing and is typically installed...
-
Partial Admission Stages of High Efficiency for a Microturbine
PublicationThe paper presents the results of a design analysis of a micro-turbine for a co-generation 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 3kW. After the design analysis, the axial turbine with partial admission in all stages was built and tested experimentally. Special attention was...
-
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...
-
Method for assessing the dynamics and efficiency of diving fins
Publication -
Impact of Advanced Oxidation Products on Nanofiltration Efficiency
Publication -
Efficiency evaluation of public hospitals – DEA method
Publication -
Efficiency of interactive terrain visualization with a PC-cluster
PublicationW artykule przedstawiono wyniki jednego z zadań krajowego projektu CLUSTERIX, poświęconego opracowaniu wydajnej aplikacji do interaktywnej wizualizacji terenu z rzeczywistych danych przestrzennych. Szczególną uwagę poświęcono praktycznym aspektom wykorzystania klastrów obliczeniowych w zastosowaniach ściśle graficznych.
-
The efficiency of tram articulations compared to vibroacoustic emissions
Publication -
Biosurfactants - Biodegradability, toxicity, efficiency in comparison with synthetic surfactants
PublicationBiosurfactants are natural surface active agents produced by variety of bacteria yeast and fungi. A review of their biodegradability, toxicity and efficiency is presented in order to compare their properties with synthetic surfactants. Due to their high efficiency in many applications and environmentally friendly character we tried to apply them in oil refining process. The efficiency of biosurfactants in this application was very...
-
The Efficiency and Productivity Evaluation of National Innovation Systems in Europe
PublicationPurpose: An efficient innovation system currently plays a crucial role in creating competitive prevalence, contributing to the economic growth of individual states. The innovation system is influenced by many socioeconomic factors, including in international rankings of innovativeness of economies. These classifications have some limitations. Primarily, they do not examine the efficiency, which means they do not analyze the...
-
Efficiency comparison of selected endoscopic video analysis algorithms
PublicationIn the paper, selected image analysis algorithms were examined and compared in the task of identifying informative frames, blurry frames, colorectal cancer and healthy tissue on endoscopic videos. In order to standardize the tests, the algorithms were modified by removing from them parts responsible for the classification, and replacing them with Support Vector Machines and Artificial Neural Networks. The tests were performed in...
-
The Efficiency of Public and Private Higher Education Institutions in Poland
PublicationChanges introduced to Poland’s education system in 2011 and 2014 amid efforts to adjust it to the needs of the labour market had an effect on the country’s institutions of higher learning. This paper provides an analysis of the efficiency of public and private Polish universities and examines the impact of selected factors in the years that followed. To estimate this efficiency, a Banker, Charnes and Cooper (BCC) model of the...
-
On the internal efficiency of a turbine stage: classical and CFD definitions
PublicationAlmost entire fleet of steam turbines in Poland was designed between 1950 – 1980 with the use of the so-called zero dimensional (0D) calculation tools. For several years, design and modernization of the turbines occur in assistance with the state of the art methods that describe working fluid flow field based on 3D models and CFD codes. This cooperation between 0D and 3D codes requires exchange of overall, integral information...
-
Efficiency evaluation of graduation process in Australian public universities
PublicationFirst-year attrition and on-time graduation are key challenges for contemporary universities, which determine their efficiency. Based on the benefit of the doubt approach, this study reports the efficiency of the graduation process in 37 Australian public universities. The super-efficiency model extended by restrictions on virtual weights is used. The proposed model considers the attrition rate and the on-time graduation rate separately...
-
Estimation of the Regenerative Braking Process Efficiency in Electric Vehicles
PublicationIn electric and hybrid vehicles, it is possible to recover energy from the braking process and reuse it to drive the vehicle using the batteries installed on-board. In the conditions of city traffic, the energy dissipated in the braking process constitutes a very large share of the total resistance to vehicle motion. Efficient use of the energy from the braking process enables a significant reduction of fuel and electricity consumption...
-
Decrease in Photovoltaic Module Efficiency Due to Deposition of Pollutants
PublicationThe deposition of pollutants on the surface of photovoltaic (PV) modules reduce the efficiency that can be achieved in given climatic conditions. This results in the loss of energy yield obtained from the solar installation. A number of factors determine the scale of this problem. The first of these is the amount of impurities deposited, the associated amount of precipitation, and the speed and direction of the wind. A second aspect...
-
Analysis of energy efficiency of suburban railway transport network
PublicationRising numbers of agglomeration residents cause increased need for people movement on daily basis. Because of congestion of local roads, air pollution and limited parking space, providing mass transit based on electric traction is reasonable. While the electric rail vehicles are considered highly efficient in themselves, they need to be analyzed as a part of a transport network, because energy consumption depends on operating conditions...
-
Evaluation of technical efficiency of heat and electric power generation
PublicationThis paper presents an evaluation of technical efficiency and time-dependent changes in productivity of Polish professional electric power and heat&electric power stations by using Data Envelopment Analysis non-parametric method. The research covered the enterprises whose total available electric power amounted to about 98% of that of all professional thermal electric power stations in this country. The analysis has concerned...
-
Energy efficiency of electric multiple units in suburban operation
PublicationThis thesis presents approach to analysis of energy efficiency of a suburban rail network, using novel models developed on the Matlab/Simulink basis. Necessary features and requirements for such models were determined thru in-depth review of the source literature in all applicable fields: electrified transportation systems, electric multiple units construction, vehicle drivetrains and finally, existing simulation methods. Existing...
-
Simple design criteria and efficiency of hydrodynamic vortex separators
PublicationVortex separators are locally applied for waste water treatment in different systems - from storm waste water sewerage to water treatment in fish ponds. However, the methods for separator design presented in the literature are questionable. The paper presents two simple and functional criteria that were employed to construct a laboratory test stand. The test results gave positive feed back on the efficiency of vortex separators.
-
INFLUENCE OF INLET GEOMETRY ON THE EFFICIENCY OF 1MW STEAM TURBINE
PublicationThe process of the design of the 1MW steam turbine includes designing the stator and rotor blades, the steam turbine inlet and exit, the casing and the rotor. A turbine that operates at rotation speeds other than 3000 rpm requires a gear box and generator with complex electronic software. This paper analyses the efficiency of eight turbine variants, including seven inlet geometries and three stages of stator as well as an eight...
-
Effect of organic nitrogen concentration on the efficiency of trickling filters
PublicationThe study was conducted in Poland at six selected wastewater treatment plants (WWTP) based on the trickling filters Bioclere® technology. The aim of the study was to find the relationship between the influent organic nitrogen concentration and the purification efficiency expressed as effluent COD concentration. In the tests performed, the COD to BOD5 relationship was close to 2 and the ratio of BOD5 to TN was lower than 4. The...
-
Experimental test of nonclassicality with arbitrarily low detection efficiency
PublicationWe theoretically introduce and experimentally demonstrate the realization of a nonclassicality test that allows for arbitrarily low detection efficiency without invoking an extra assumption of independence of the devices. Our test and its implementation is set in a prepare-and-measure scenario with an upper limit on the classical communication capacity of the channel through which the systems are communicated. The essence for our...
-
The impact of environmentally friendly refrigerants on heat pump efficiency
PublicationThis paper discusses the issue of heat pump simulation. Lower operating costs can be achieved through good equipment design and appropriate operation. Detailed technical and economic analysis inform the selection of system components with the highest possible efficiency and lower energy demand. The use of systems based on environmentally friendly refrigerants can deliver long product life, which is associated with a shorter payback...
-
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...
-
Evaluation of time-efficiency of disjoint paths calculation schemes
PublicationThe concept of alternate paths has been shown in the literature to provide fast response of a network to failures of its elements (nodes/links) affecting flows along the primary communication paths. Various approaches have been proposed to reduce the time necessary to redirect the respective flows onto the alternate paths. In this paper, we focus on another important objective, that so far has not received much attention, i.e.,...
-
The study of influence of a rotating magnetic field on mixing efficiency
Publication -
Comparison of the Efficiency of Hetero- and Homogeneous Catalysts in Cellulose Liquefaction
PublicationBiomass liquefaction is a well-known and extensively described process. Hydrothermal processes are well understood and can be used in the fuel industry. The use of organic solvents can result in full-fledged products for use in the synthesis of polyurethanes. The plastics industry, including polyurethanes, is targeting new, more environmentally friendly solutions. One of these is the replacement of petrochemical polyols with compounds...
-
Theoretical studies of nonlinear generation efficiency in a bubble layer
PublicationCelem pracy jest teoretyczna analiza propagacji fal o dużym natężeniu w warstwie z pęcherzykami. Przedstawiono model matematyczny zjawiska w tym omówiono problem wyznaczania prędkości fazowej, współczynnika tłumienia i częstotliwości rezonansowej pęcherzyków. Badano zmiany amplitud pierwszej i drugiej harmonicznej ciśnienia fali odbitej i bieżącej w funkcji grubości warstwy oraz względnej koncentracji pęcherzyków. Rozważano pęcherzyki...
-
Enhancement of the Brayton cycle efficiency by water or steam utilization
PublicationIn the paper, thermodynamic analysis of two modifications of a Brayton cycle into enhancement cycles with water/steam injection are discussed. The first one deals with a STIG modified system with both interstage compressed air cooling and air heating (heat regeneration) before combustion chamber. The second one, mainly devoted to higher steam/air ratio, is connected with separate steam production in a HRSG. The analysis has been...
-
Efficiency of gas mixtures detection by resistive gas sensors
PublicationResistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Theeir main disadvantage is very limited selectivity. Practical use of gas sensors in environenmental applications requires determination of concentration of a few mixed gases at the same time. We would like to present recent results of gas detection improvement by utilizing a single gas sensor and additional measurements to...
-
EFFICIENCY OF GAS MIXTURES DETECTION BY RESISTIVE GAS SENSORS
PublicationResistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Their main disadvantage is very limited selectivity. Practical use of gas sensors in environmental applications (e.g., in sewage systems to protect workers, in air conditioning systems to monitor atmosphere quality) requires determination of concentration of a few mixed gases at the same time. We would like to present recent...
-
The Conditions of Measuring Local Government Units Expenditure Efficiency
Publication