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1
Content available remote Pilot study of patient and phantom breast dose measurements in Bulgaria
100%
EN
A pilot study of breast dose measurements on two mammography units in Bulgaria was conducted. The mean glandular doses (MGDs) to samples of approximately 60 women per unit were measured. MGD with a standard PMMA phantom was measured as well. The MGDs were calculated according to the European protocol on dosimetry in mammography as well as to the European protocol for the quality control of the physical and technical aspects of mammography screening. The measured women's MGDs were divided into three groups depending on the compressed breast thicknesses. The results for the group of thicknesses in the interval 40-60 mm were compared with the results from the measurements on the standard 45 mm PMMA phantom. Some differences were found which could be due to errors in breast thickness measurements, differences in breast and phantom densities and other factors. A standardized procedure was elaborated for patient dose measurement and calculation both from patient and phantom studies.
2
Content available remote Sewage Sludge Combustion – Experimental and Theoretical Analysis
100%
EN
Whereas the use of biofuels has attracted increasing attention, the aim of this paper is to investigate the possibility of using sewage sludge as biofuel. Preparation of untreated and stabilised sludge with natural additives is described, as well as combusting method applied and experimental results of combusting are presented based on the assessment of composition of emitted pollutants and their concentrations in the exhaust gas. NOx formation in the exhaust gas has been analysed in depth. The results of investigations have shown that the use of dried sewage sludge possesses a positive energy balance. Therefore, the sludge may be used as fuel. The obtained experimental results demonstrate that during combustion, pollutant concentrations vary depending on oxygen content (O2), while formation of nitrogen oxides is strongly influenced by fuel-bound nitrogen. Also, a generalized equation of calculating fuel bound nitrogen conversion into NOx is presented.
EN
To characterize the dynamic behavior of typical asphalt pavements, which is induced by a complex loading system coupled with environmental effects, full-scale field tests were conducted on instrumented sections with embedded sensors. The impacts of vehicular loading factors and pavement temperature on strains at the bottom of asphalt layers were analyzed in the presence of in situ dynamic loading. According to orthogonal array tests, the impact levels of loading factors were quantified through analysis of variance. Furthermore, the temperature conversion factors of measured strain were explored using regression analysis. These results show that the measured strains present an asymmetry over time. The strain response goes up with increasing axle load and decreases with growing speed. Compared to the speed and the tire inflation pressure, the axle load plays a dominant role in strain responses. The estimated temperature conversion factor facilitates the strain conversion between non-standard temperature conditions and a required reference temperature.
Karbo
|
2002
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tom Nr 3
101-102
PL
Przedstawiono, jak w prosty sposób na podstawie pomiaru zmian gęstości pozornej można określić stopień przereagowania materiału węglowego. Podczas karbonizacji i utleniania takich materiałów zmienia się ich gęstość, dlatego też właściwość ta może być wskaźnikiem postępu reakcji. Ponieważ pozwala ona również ocenić rozwój struktury porowatej, poszukiwano zależności pomiędzy stopniem przereagowania, a gęstością pozorną aktywa-tów węglowych. Stopień przereagowania (x) aktywatów obliczono jako iloraz różnicy masy próbki przed i po aktywacji do masy próbki przed procesem. Gęstość pozorną p (pa) oznaczano metodą porównawczą, która może być stosowana dla materiałów zmieniających skład ziarnowy w trakcie reakcji. Pomiędzy omawianymi wielkościami znaleziono liniową zależność p = -1,464 x + 1,484, tym samym stwierdzono możliwość stosowania gęstości pozornej do oceny stopnia przereagowania substancji węglowej w procesie aktywacji.
EN
In this paper the authors present the simple way of the determination of the conversion of the carbonaceous material basing on the measurement of the apparent density. The density may be the progress index of reaction because this property is changing during the carbonization and oxidation. Researched the functional dependence between the apparent density and conversion, because the first one is the property, which enables us to determine of the development of the porous structure. The conversion of the carbonaceous materials B1- B5 was calculated as a ratio of the difference of the mass of the sample before and after activation and of the mass of its before this process. The apparent density (Ppa) was measured by the comparative method, which may be apply for materials changing the grain composition during reaction. It was found the linear dependence p ap=-1,464 x + 1,484 (where: x - conversion) between these two properties and state that the apparent density can be used to estimate the conversion of carbonaceous material in the activation process.
PL
W pracy przeanalizowano wpływ stosowanej metody uśredniania arytmetycznego wartości ciepła spalania na błędy w przeliczaniu zużycia paliwa gazowego do celów grzewczych w gospodarstwach domowych. W analizie wykorzystano metodę stopniodni, uwzględniając rzeczywiste wartości współczynnika konwersji paliwa gazowego dla kilku Obszarów Rozliczeniowych Ciepła Spalania. Wyznaczono względne błędy rozliczenia zużycia paliwa gazowego dla rocznego okresu rozliczeniowego, w porównaniu do przeliczania na podstawie średniej ważonej. Na podstawie przeprowadzonej analizy stwierdzono, że błąd względny stosowanej metody, z wykorzystaniem średniej arytmetycznej wartości ciepła spalania w okresie rozliczeniowym, jest na bardzo niskim poziomie, co sprawia że metoda ta jest właściwa do stosowania w określaniu zużycia gazu ziemnego w gospodarstwach domowych.
EN
Influence of arithmetic averaging method of heat of combustion on errors in gas consumption for households were analyzed in the paper. The analysis uses day degrees method, taking into account real values of the gas conversion factor for several localities. Relative errors of gas consumption compared to the conversion based on the weighted average were determined for annual period. On basis of the analysis carried out, it was found that the relative error of the applied method using the arithmetic mean of heat of combustion is a very low, which makes this method appropriate for use in determining the consumption of natural gas in households.
EN
The authors have developed an improved version of the vapor compression system for heating and cooling civil buildings on the basis of the soil and ventilation air integrated energy. It is characterized by increased energy efficiency and the possibility of redistribution with automatic regulation of generated heat in subsystems. The results of the analytical study of the system established a multifactorial dependence of the actual conversion factor and led to greater efficiency in the transformation of the extracted heat from the soil and ventilation air. It simulates the multifactorial effect of the initial parameters and operating conditions on the possibility of highly efficient use of integrated energy in cold, warm and transitional periods of the year. The integrated use of soil energy and air flows in heat pump heating systems is distinguished by the possibility of its controlled redistribution with a decrease in the intensity of heat extraction via a ground heat exchanger, as well as the possibility of reducing the depth of the wells and the corresponding costs for the arrangement and operation of probe heat exchangers.
EN
Whereas the use of biofuels has attracted increasing attention, the aim of this paper is to investigate the possibility of using sewage sludge as biofuel. Preparation of untreated and stabilised sludge with natural additives is described, as well as combusting method applied and experimental results of combusting are presented based on the assessment of composition of emitted pollutants and their concentrations in the exhaust gas. NOx formation in the exhaust gas has been analysed in depth. The results of investigations have shown that the use of dried sewage sludge possesses a positive energy balance. Therefore, the sludge may be used as fuel. The obtained experimental results demonstrate that during combustion, pollutant concentrations vary depending on oxygen content (O2), while formation of nitrogen oxides is strongly influenced by fuel-bound nitrogen. Also, a generalized equation of calculating fuel bound nitrogen conversion into NOx is presented.
PL
Przedmiotem artykułu jest analiza możliwych usprawnień projektu budynku wielorodzinnego pozwalających na spełnienie wymagań standardu niemal zeroenergetycznego (NZEB), które wejdą w życie w 2021 roku. W ramach analizy w programie Audytor OZC stworzono model 3D dziewięciokondygnacyjnego budynku mieszkalnego. Charakterystykę energetyczną budynku obliczono dla 18 lokalizacji w całej Polsce, reprezentujących różne warunki klimatyczne i źródła ciepła. Uzyskane wyniki pozwoliły sprawdzić, czy budynek spełnia wymagania NZEB (WT 2021) w odniesieniu do współczynnika zapotrzebowania na energię pierwotną (EP ≤ 65 kWh/(m2rok)). W miejscach, w których wskaźnik EP został przekroczony, zaproponowano ulepszenia dotyczące głównie systemów technicznych i wykorzystania OZE (kolektory słoneczne lub fotowoltaika). Rezultatem obliczeń jest „Przewodnik inwestora” pokazujący zalecane usprawnienia w zależności od źródła ciepła i lokalizacji w Polsce. Przedstawiono również stopień trudności spełnienia kryteriów NZEB. Wnioski z artykułu mogą być przydatne dla projektantów i inwestorów planujących budowę budynków wielorodzinnych po 2020 roku. Wyraźnie pokazują, jaki rodzaj konwencjonalnego i odnawialnego źródła ciepła, a także systemów, warto zastosować.
EN
The main objective of this paper is to propose possible improvements of an apartment building design allowing its adaptation to nearly zero-energy (NZEB) requirements, entering into force in the year 2021. Within the research the 3D model of the nine-storey, residential building was created with the help of Audytor OZC software. The energy performance of building was calculated for 18 locations in whole Poland representing different climate conditions and heat sources. The results obtained allowed to check if the building meets the NZEB requirements in regard to primary energy demand factor (EP ≤ 65 kWh/(m2rok)). In the locations where the EP factor was exceeded improvements were proposed including mainly building systems and the use of RES (solar collectors or photovoltaic) for the domestic hot water heating. As a result of the research “Investor’s Guide” was created, demonstrating the recommended solutions depending on the heat source and the location in Poland. The degree of difficulty in meeting the NZEB criteria was presented as well. The paper conclusions can be very useful for designers and investors planning to build multi-family buildings after 2020. They clearly show what kind of conventional and renewable heat source as well as systems to use.
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