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Number of results: 32
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Abstract

This work presents an application possibility of sorption refrigerators driven by low temperature fluid for air conditioning of buildings. Thermodynamic models were formulated and absorption LiBr-water chiller with 10 kW cooling power as well as adsorption chiller with silica gel bed were investigated. Both of them are using water for desorption process with temperature Tdes = 80 °C. Coefficient of performance (COP) for both cooling cycles was analyzed in the same conditions of the driving heat source, cooling water Tc = 25 °C and temperature in evaporator Tevap = 5 °C. In this study, the computer software EES was used to investigate the performance of absorption heat pump system and its behaviour in configuration with geothermal heat source.
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Abstract

Thermodynamic analysis of car air cooler is presented in this paper. Typical refrigerator cycles are studied. The first: with uncontrolled orifice and non controlled compressor and the second one with the thermostatic controlled expansion valve and externally controlled compressor. The influence of the refrigerant decrease and the change of the air temperature which gets to exchangers on the refrigeration efficiency of the system; was analysed. Also, its effectiveness and the power required to drive the compressor were investigated. The impact of improper refrigerant charge on the performance of air conditioning systems was also checked.
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Abstract

Temporal differentiation of the air thermal conditions in SW part of Spitsbergen has been presented in this paper. Daily meteorological records of the Polish Polar Station of the Polish Academy of Sciences in Hornsund have been used for the period of 1978—1986. Distributions of basic thermal indices based on mean, maximum, minimum air temperatures and minimum temperature at a ground surface have been given. Annual patterns of the above elements of various occurrence probabilities have been also presented and thermal periods have been distinguished.
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Abstract

Multidisciplinary research was carried on in 1978/79 in the region of Admiralty Bay and Arctowski Station. This area is representative of the near-shore Antarctic ecosystem. It is characterized by a number of local traits such as climate, ice conditions, hydrology, hydrochemistry and hydrodynamics. Estimates were made of primary production and abundance of zooplankton in Admiralty Bay and of the biomass and quantity of food taken by avi-fauna and pinnipeds. Main routes and directions of transport of mineral and organic matter are shown; some of them have been estimated quantitatively. A continuous inflow of organic matter from Bransfield Strait is necessary for the summer functionning of Admiralty Bay.
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Abstract

The aim of this article is to defi ning problems occurring in the spatial management system, including those independent of subsequent legislative changes. The process of adopting decisions to be viable and socially equitable and execute the requirements of spatial order and sunstainable development requires fundamental changes. The study draws a conclusion – important in the context of subsequent research activities – that the varied application of development decisions in diff erent municipalities is also the result of not preparing a large part of the representatives of municipalities for specifi c spatial activities.
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Abstract

Ground temperature measurement results in main ecotopes of the Kaffiöyra coastal plain (Oscar II Land, northwestern Spitsbergen): sea beach, tundra and morainic plateau, are presented and discussed in the paper. The spatial distribution of thermal conditions is discussed with particular regard to temperature of the active surface and vertical gradients of temperature dependent on daytime and weather conditions.
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Abstract

Managing human consumption has a major impact on the functioning of societies, and – even more importantly – on the condition of our planet. What does the future hold?
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Abstract

An investigation of cyanobacterial microflora in the northern, deglaciated part of James Ross Island in the NW part of the Weddell Sea, Antarctica , was conducted during the Antarctic summer season 2005-2006. Five main types of habitats with dominant cyanobacterial assemblages were analyzed (soils, seepages, streams, wetted rocky walls and lakes), and main ecological variables were measured (pH, temperature, intensity of global radiation, conductivity and nutrients), as a background for further ecological and ecophysiological studies. The definable traditional cyanobacterial morphospecies were identified.
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Abstract

This paper describes the spatial differentiation of topoclimatic conditions in the vicinity of the Arctowski Station (King George Island, Antarctica) during the summer season of the 2006/2007. The measurement stations were located in the Point Thomas oasis as well as on the Ecology Glacier and Warszawa Icefield. The paper analyses meteorological elements such as air temperature, air humidity (eight sites) and wind direction and velocity (three sites). Significant topoclimatic diversities resulting from denivelation, exposure, ground properties and local air circulation were recorded in the study area.
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Abstract

Soil-plant conditions in selected valleys typical for Bellsund Region are varying from hardly favourable (Skilvika), to favourable (Calypsostranda) and medium (Lyellstranda). Plant growth and development of a soil cover are favoured by grain size composition (loamy sands and light loams), quick warming-up of a soil, relative stability of a ground, location and shape of valleys, etc. Unfavourable soil-plant conditions result from too light or too heavy grain size composition, considerable dynamics of ground mechanical features and high compactness of a soil. Varying contents of carbonates and alkaline reaction (except for almost neutral reaction in organic horizons) were typical for the studied soils. Thickness of humus horizons as well as contents of organic C vary at the three studied sites. Significant is high concentration of easily available Ca and Mg, sometimes also of Na.
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Abstract

With reference to the situation experienced in several Polish collieries where the risk of occurrence of gas-geodynamic phenomena is increasing and decisions to start the mining activities need to take numerous constraints associated with previous mining into account, this paper addresses certain geo-mechanical aspects of longwall mining in the zones of excavation edge interactions giving rise to major changes in the conditions of the deposit and rock strata, as a consequence of previous mining operations in adjacent coalbeds. Starting from the analytical description of displacements and stresses in the proximity of longwall mining systems, the paper summarizes the results of model tests and investiga-tions of the influence that the excavation edge has on the behavior and structural continuity of a portion of the coal body in the coalbed beneath or above an old excavation. Based on selected nonlinear functions emulating the presence of edges in the rock strata, a comparative study is carried out by investigating two opposite directions of workface advance, from the gob area towards the coal body and from the coal body towards the gobs. The discussion of the results relies on the analysis of roof deformation and the concentration factor of the vertical stress component at the workface front.
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Abstract

In the Accession Treaty of 16 April 2003, Poland agreed to adopt euro as its national currency, but the date of this adoption was not specified. The financial crisis in several countries of the Eurozone, in response to the world financial crisis in 2008, reduced drastically the public support in Poland for the replacement of the zloty by the euro. This article has two objectives. One is to assess the net costs, economic and political, for Poland remaining long outside the Eurozone. In this assessment the analysis includes also two official reports by National Bank of Poland, the country’s central bank, published in 2009 and 2014. The other objective is to note and assess the reforms which have been undertaken by member states of the Eurozone in response to this crisis, in order to maintain and enhance financial stability and economic effectiveness of the rules adopted at the start of the Eurozone on 1 January 1999. The author suggests to consider and adopt additional reforms. Discussed is also the USA experience with its own monetary union, and the potential influence on policy developments in the EU of increasing global competitive pressures from China and India.
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Abstract

As a kind of mass transfer process as well as the basis of separating and purifying mixtures, interfacial adsorption has been widely applied to fields like chemical industry, medical industry and purification engineering in recent years. Influencing factors of interfacial adsorption, in addition to the traditional temperature, intensity of pressure, amount of substance and concentration, also include external fields, such as magnetic field, electric field and electromagnetic field, etc. Starting from the point of thermodynamics and taking the Gibbs adsorption as the model, the combination of energy axiom and the first law of thermodynamics was applied to boundary phase, and thus the theoretical expression for the volume of interface absorption under electric field as well as the mathematical relationship between surface tension and electric field intensity was obtained. In addition, according to the obtained theoretical expression, the volume of interface absorption of ethanol solution under different electric field intensities and concentrations was calculated. Moreover, the mechanism of interfacial adsorption was described from the perspective of thermodynamics and the influence of electric field on interfacial adsorption was explained reasonably, aiming to further discuss the influence of thermodynamic mechanism of interfacial adsorption on purifying air-conditioning engineering under intensification of electric field.
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Abstract

Adsorption refrigeration systems are able to work with heat sources of temperature starting with 50°C. The aim of the article is to determine whether in terms of technical and economic issues adsorption refrigeration equipment can work as elements that produce cold using hot water from the district heating network. For this purpose, examined was the work of the adsorption air conditioning equipment cooperating with drycooler, and the opportunities offered by the district heating network in Warsaw during the summer. It turns out that the efficiency of the adsorption device from the economic perspective is not sufficient for production of cold even during the transitional period. The main problem is not the low temperature of the water supply, but the large difference between the coefficients of performance, COPs, of adsorption device and a traditional compressor air conditioning unit. When outside air temperature is 25°C, the COP of the compressor type reaches a value of 4.49, whereas that of the adsorption device in the same conditions is 0.14. The ratio of the COPs is 32. At the same time ratio between the price of 1 kWh of electric power and 1 kWh of heat is only 2.85. Adsorption refrigeration equipment to be able to compete with compressor devices, should feature COPads efficiency to be greater than 1.52. At such a low driving temperature and even changing the drycooler into the evaporative cooler it is not currently possible to achieve.
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Abstract

This study presents the rheological properties of sewage sludge after conditioning with the application of biomass ash. The impact of sewage sludge pre-treatment on its viscosity, flow curves and thixotropy was investigated. The increase of shear stress and the decrease of viscosity were observed with the increase of shear rate. Obtained results were compared with raw sewage sludge and the sludge after modification by means of polyelectrolyte in the dosage of 1.5 g (kg d.m.)-1. The findings proved that samples of raw and conditioned sewage sludge had thixotropic characteristics. The correlation between moisture content and capillary suction time reduction as well as selected rheological parameters were also determined. On the basis of the obtained results it was stated that the Ostwald de Vaele model best fits the experimental data.
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Abstract

Mid-winter rapid rise of temperature in the vicinity of Arctowski Station, King George Island (West Antarctica) was studied in 1991. Depending on circumantarctic migration of cyclones, sudden drop in air pressure and foehn-like phenomenon intensified by local topography occurred. Two such events are described on May 13 and June 28, against meteorological conditions during autumn and winter. Extreme intensification of morphogenetic processes caused degradation of a snow cover, immense meltwater discharge, radical transformation of slopes, effective aeolian activity and dynamic modifications in a sea-shore zone.
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Abstract

Due to unfavorable factors, dangerous conditions occurred in the delivery of electric energy in Poland. This was the most serious incident of its kind since the 1980’s. Such a serious incident raised concern about the safety of the electric power system in the summer and led to the formulation of conclusions for the future. In this article, the author analyses the conditions, which caused that situation. Poland was experiencing a doubt in August 2015, which along with an extremely high maximum daily temperature created remarkably unfavorable conditions for power plants and decreased the capacity of overhead power lines. Such unfavorable metrological conditions occurred not only in Poland, but also in Central-Eastern and Western Europe. It is worth emphasizing that the safety of electric energy delivery was endangered only in Poland. The improper renovation and upkeep policies, as well as unplanned outages in power plants caused a significant decrease of available power in the National Electric Power System. Unscheduled flows between Germany and Poland ruled out the possibility of importing electric energy at such a critical time. The author presents the correlation between the maximum daily air temperature in the sweltering heat and an increase in the demand for electric energy. Overall, unfavorable conditions posed a threat in the delivery of electric energy in Poland. In this article, the author draws attention to the report from the Supreme Audit Office (Najwyższa Izba Kontroli – NIK) from 2014, which predicted such a dangerous situation. Unfortunately, that report remained unnoticed. The author formulated appropriate solutions in order to increase the safety of electric energy delivery in the summer and to prevent such occurrences in the future.
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Abstract

The paper presents the results of assessment studies of the time course for technical wear in masonry buildings located in the area of mining-induced ground deformations. By using fuzzy inference system (FIS) and the “if-then” rule, corresponding language labels describing actual damage recorded in structure components were translated into scalar outputs describing the degree of damage to the building. Adopting this approach made it possible to separate damage resulting from additional effects coming from mining-induced ground deformations and the natural wear and tear of masonry structure. By using statistical analysis an exponential function for the condition of building damage and the function of natural wear and tear were developed. Both phenomena were subject to studies as a function of time regarding the technical age of building structure. The results obtained were used to develop a model for the course of technical wear of traditionally constructed buildings used within mining areas. In the course of natural wear and tear buildings located in mining areas are additionally exposed to forced ground deformations. The increase of internal forces in structure components induced by those effects results in creating an additional stress factor and damage. The hairline cracks and cracks of building structure components take place when the intensity value of mining effects becomes higher than the component stress resistance and repeated effects result in the decrease of structure rigidity. The observations of building behaviour in mining areas show that the intensity of mining activity and the multiplicity of its effect play a substantial role in the course of technical wear of buildings. The studies show that the level of damage resulting from mining effects adds up to natural wear and tear of the building and impairs the global technical condition as compared to similar buildings used outside mining areas.
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Abstract

The debate between Ludwik Fleck (microbiologist and philosopher of science) and Tadeusz Bilikiewicz (historian and philosopher of medicine) took place shortly before the outbreak of World War II and remained virtually unnoticed until 1978. A wider recognition of their exchange was possible only after the English and German translations appeared. Basically, the polemics concerned understanding of the concept of style and influence that the environment exerted on scientific activity and its products. The polemic started with the review of Bilikiewicz’s book Die Embryologie im Zeitalter des Barock und des Rokoko (1932) where the historical account of the development of embryology in the early and late Baroque period was interwoven with bold sociological remarks. The commentators of the debate were quick to notice that the claims made by Fleck at that time were crucial for understanding of his position, especially because they let to interpret his views in a non-relativist way. While the importance of the controversy was univocally acknowledged, its assessment so far has been defective for two reasons. First, for decades the views of Bilikiewicz were known only from the short and rather critical presentation given by Fleck and this put their discussion into an inadequate perspective. Second, for over 40 years it remained a complete puzzle what prompted their exchange of views. This paper closes these gaps. Thus, on the one hand, I reconstruct the central issue of the disputation between Fleck and Bilikiewicz and situate it within the context of Bilikiewicz’s views. On the other hand – and this is more important – I try to explain the origin of their debate by quoting some recently discovered and unpublished archival materials. A review of their correspondence gives me an opportunity to advance some hypotheses about the aims and hopes connected with their project but also possible reasons for its failure.
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Abstract

The Bulletin of the Polish Academy of Sciences: Technical Sciences (Bull.Pol. Ac.: Tech.) is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred: Artificial and Computational Intelligence, Biomedical Engineering and Biotechnology, Civil Engineering, Control, Informatics and Robotics, Electronics, Telecommunication and Optoelectronics, Mechanical and Aeronautical Engineering, Thermodynamics, Material Science and Nanotechnology, Power Systems and Power Electronics. Journal Metrics: JCR Impact Factor 2018: 1.361, 5 Year Impact Factor: 1.323, SCImago Journal Rank (SJR) 2017: 0.319, Source Normalized Impact per Paper (SNIP) 2017: 1.005, CiteScore 2017: 1.27, The Polish Ministry of Science and Higher Education 2017: 25 points. Abbreviations/Acronym: Journal citation: Bull. Pol. Ac.: Tech., ISO: Bull. Pol. Acad. Sci.-Tech. Sci., JCR Abbrev: B POL ACAD SCI-TECH Acronym in the Editorial System: BPASTS.
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Abstract

The flat horizontal polymer loop thermosyphon with flexible transport lines is suggested and tested. The thermosyphon envelope consists of a polyamide composite with carbon based high thermal conductive micro-, nanofilaments and nanoparticles to increase its effective thermal conductivity up to 11 W/(m°C). Rectangular capillary mini grooves inside the evaporator and condenser of thermosyphon are used as a mean of heat transfer enhancement. The tested working fluid is R600. Thermosyphon evaporator and condenser are similar in design, have a long service life. In this paper three different methods (transient, quasi-stationary, and stationary) have been used to determine the thermophysical properties of polymer composites used as an envelope of thermosyphon, which make it possible to design a wide range of new heat transfer equipment. The results obtained contribute to establish the viability of using polymer thermosyphons for ground heat sinks (solar energy storage), gas-liquid heat exchanger applications involving seawater and other corrosive fluids, efficient cooling of superconductive magnets impregnated with epoxy/carbon composites to prevent wire movement, enhance stability, and diminish heat generation.
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Abstract

This paper presents the parameters of the reference oxy combustion block operating with supercritical steam parameters, equipped with an air separation unit and a carbon dioxide capture and compression installation. The possibility to recover the heat in the analyzed power plant is discussed. The decision variables and the thermodynamic functions for the optimization algorithm were identified. The principles of operation of genetic algorithm and methodology of conducted calculations are presented. The sensitivity analysis was performed for the best solutions to determine the effects of the selected variables on the power and efficiency of the unit. Optimization of the heat recovery from the air separation unit, flue gas condition and CO2 capture and compression installation using genetic algorithm was designed to replace the low-pressure section of the regenerative water heaters of steam cycle in analyzed unit. The result was to increase the power and efficiency of the entire power plant.
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Abstract

According to The European Commission’s regulation numbers 842/2006 and 517/2014, refrigerants whose Global Warming Potential ratio is more than 150, have been prohibited in mobile air conditioning (MAC) since January 2017. Therefore, the commonly used R-134 gas has been banned. The search for a new refrigerant, which grants all the required criteria, has begun. In accordance with new European standards, the gas should have environmentally friendly properties and should not be noxious to human life while operating. In this paper, two alternative substances, which can substitute the banned R134a, have been compared. This is synthetic R1234yf, which belongs to the HFO group, and carbon dioxide, which exists in the natural environment. The chemical build, physical and thermodynamic properties have been described. Scientific articles, which present and compare the technical results of testing both refrigerants, have been discussed. Comparison results, tools used and research methodology have been described in these articles. Alternative gases have been analyzed for their environmental impact and have been checked on the toxic, flammable, impact on ozone depletion and global warming. The threats to human life due to the use of the new refrigerants have been reviewed. The thesis also comprises an economical comparison between the two gases. A short review and conclusions have been presented at the end of the article.
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Abstract

In these remarks I make an attempt to understand and present the functioning of authorities in science. I do use in the first place the earlier claims which present this issue in a historical perspective. This allows to grasp the social process of emergence of the authorities as well the changing of their position in the way they are functioning. Especially the thoughts of Max Weber are being considered by my as useful in this matter. I do share his general thesis saying that even the greatest of scientific authorities – called by me in these remarks ”centennial” – couldn't occur and function without their social and cultural ”background”. This had led in large extent to the situation where these authorities fist played a significant role in the development of science and then went over to a more or less dignified ”retirement”. In this and other issues I present some of my own remarks and sugestions.
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