29 research outputs found
Recommended from our members
Ionic Liquids for Utilization of Waste Heat from Distributed Power Generation Systems
The objective of this research project was the development of ionic liquids to capture and utilize waste heat from distributed power generation systems. Ionic Liquids (ILs) are organic salts that are liquid at room temperature and they have the potential to make fundamental and far-reaching changes in the way we use energy. In particular, the focus of this project was fundamental research on the potential use of IL/CO2 mixtures in absorption-refrigeration systems. Such systems can provide cooling by utilizing waste heat from various sources, including distributed power generation. The basic objectives of the research were to design and synthesize ILs appropriate for the task, to measure and model thermophysical properties and phase behavior of ILs and IL/CO2 mixtures, and to model the performance of IL/CO2 absorption-refrigeration systems
Reduction of Pollution Emission by Using Solar Energy in Eastern Poland
The present work is devoted to the analysis of electric energy production in photovoltaic power plant located in eastern part of Poland and to the estimation of pollution avoided due to the use of solar radiation energy. Photovoltaic power plant consists mainly of silicon polycrystalline modules but in its experimental part thin film modules of three different technologies are also installed giving the total power of 1.4 MWp. In 2015 the PV plant produced above 1.5 MWh of electric energy. Benefits of renewable energy use result in a significant reduction of emissions that are harmful to people and other living species too
Wpływ wybranych czynników na wskaźniki oddziaływania na środowisko instalacji fotowoltaicznych
Rosnąca świadomość zagrożeń dla środowiska naturalnego i klimatu powodowanych przez działalność człowieka stała się motorem zmian w sposobie eksploatacji zasobów naturalnych. Wiele porozumień międzynarodowych, począwszy od Deklaracji podsumowującej konferencję Narodów Zjednoczonych z 1972 roku, a skończywszy na Porozumieniu Paryskim (2015) zostało podpisanych w celu minimalizacji negatywnego oddziaływania na środowisko, związanego w szczególności z energetyką. Jednym z podstawowych celów stawianych przed tą branżą jest spełnienie kryteriów rozwoju zrównoważonego. Instalacje fotowoltaiczne są jednym z odnawialnych źródeł energii, dotowanym z budżetu organizacji międzynarodowych oraz poszczególnych państw jako zmniejszające potencjalne oddziaływanie sektora energetycznego na środowisko. Jednakże produkcja, użytkowanie i zagospodarowanie końcowe modułów fotowoltaicznych nie są obojętne dla środowiska, istnieje więc konieczność porównania pozytywnych i negatywnych efektów powodowanych przez wymienione procesy. Bilans środowiskowy tego rodzaju instalacji może zostać oceniony za pomocą Oceny Cyklu Życia (Life Cycle Assessment). Celem pracy jest porównanie aspektów środowiskowych wybranych systemów fotowoltaicznych pracujących w różnych lokalizacjach
The content of phenolic acids in the edible parts of selected varieties of apples
Owoce i warzywa są cennym źródłem wielu substancji odżywczych, niezbędnych do prawidłowego funkcjonowania organizmu.
Do najchętniej spożywanych owoców w wielu krajach Europy, w tym także w Polsce, należą jabłka. Prozdrowotne
właściwości jabłek związane są między innymi z zawartością w nich związków polifenolowych, w tym kwasów fenolowych
wykazujących właściwości antyoksydacyjne. Stężenie tych związków zależy od wielu czynników, w tym: odmiany, klimatu,
dojrzałości, warunków glebowych i zabiegów agrotechnicznych. Celem przeprowadzonych badań było porównanie stężenia
kwasów fenolowych i epikatechiny w odmianach jabłek Szampion i Jonica, zebranych w różnych sadach na terenie Lubelszczyzny.
Analizę związków fenolowych przeprowadzono za pomocą wysokosprawnej chromatografii cieczowej (HPLC),
dokonując ich rozdziału na kolumnie RP C18 Symmetry (Waters). Dominującym kwasem fenolowym w jabłkach odmiany
Szampion był kwas chlorogenowy. W miąższu jabłek odmiany Jonica, zebranych w sadach w Puławach i Lublinie w najwyższym
stężeniu występował kwas chlorogenowy, zaś w pozostałych próbach (sad Stryjno i Góra Markuszowska) - kwas
homowanilinowy. Spośród odmian Jonica i Szampion pochodzących z różnych sadów z terenu Lubelszczyzny najwyższą
zawartość epikatechiny stwierdzono w miąższu odmiany Szampion zebranej w sadzie w Puławach oznaczono – 13,12 mg/kg
s.m epikatechiny. Generalnie, niezależnie od miejsca zbioru, jabłka odmiany Szampion uznano za lepsze źródło kwasów
fenolowych i epikatechiny niż jabłka odmiany Jonica.Fruits and vegetables are essential sources of many nutritive substances which are necessary for normal function of
the organism. One of the mostly consumed fruits in many European countries, including Poland is apples. The prohealthy
properties of apples are associated with the contents of polyphenolic compounds, thus including in parts phenolic acids
which have antioxidant properties. The concentration of these compounds depends on many factors such as variety climate
and soil conditions, maturity as well as agro technical operations. The aim of this investigation was to compare the concentrations
of phenolic acids and epicatechin in the varieties of apple Champion and Jonica, which were collected from
different orchards around Lublin. The phenolic compounds were assayed using a Symmetry column carrier RP-C18 (Waters)
integrated with a high pressure liquid chromatography apparatus. The dominant phenolic acids found in the Champion
variety was chlorogenic acid, whereas in the Jonica variety, chlorogenic and homovanilic acids were the dominate once.
The highest concentrations of chlorogenic acid was detected in the pulp of an apple (Jonica variety) collected from the
orchards around the cities of Puławy and Lublin, whereas homovanilic acid was the highest in the other samples collected
from the orchards in the vicinity of Stryjno and Góry Markuszowskie. Among the Jonica and Champion varieties of apples
collected from various orchards in the vicinity of Lublin, the highest content of epicatechin (13,12 mg/kg) was found in the
pulps of Champions variety colected in Puławy. In general, the Champion variety was the best source of phenolic acids and
epicatechin compared to the Jonica variety independent of the harvest zone
The analysis of the solar power plant performance in temperate climate
Due to gradual depletion of fossil fuels resources and emission of harmful chemicals accompanying the combustion process, the interest in alternative energy sources still increases. Among many kinds of alternative sources, solar radiation is very special because of its wide availability and large technical potential. Photovoltaic systems providing the electric energy are used in many countries. The most important part of photovoltaic system is a module, which parameters (e.g. efficiency, rated power, temperature coefficients of power and efficiency, short circuit current, open circuit voltage) are determined in laboratory tests under Standard Test Conditions (STC: 25°C, 1,000 W/m2 , air mass 1.5). However, in real outdoor conditions the modules exhibit lower efficiency since local climate influences their performance and different external factors generate energy losses in the whole system. The aim of this work is the performance analysis of a solar power plant connected to the grid, which total rated power is 2.985 MW and it works in temperate climate in eastern Poland. Insolation in the location was estimated according to Solargis data and the role of the modules tilt angle, of which the value is non-typical for the considered location was studied. The tilt angle smaller than optimal angle allows increasing the amount of the solar radiation collected in the summer period. The electric energy production based on the inverters data in 2016 and 2017 as well as yearly yield are presented. The results are compared to data coming from other solar power plants, also located at high latitude
Characterization of ZnO:Al layers for applications in thin film solar cells
Thin films of zinc oxide doped with aluminium were obtained by using the magnetron sputtering technique on glass substrates. The changes in magnetron power influence the structural, optical and electrical properties of the ZnO:Al layers. The deposited films are characterized by very good homogeneity and high optical transmission. Thicker films with larger agglomerates on the surface exhibit lower resistivity with the remaining good transparency
New approach to the determination of phase equilibrium in the Zn-Te system
The polyassociative model of the liquid phase was applied to describe the phase equilibrium in the Zn-Te system. The thermodynamic functions describing the formation of liquid associates were obtained, taking into account the experimental data on the p-T-x equilibrium in the system. The model of polyassociative solutions with the parameters obtained in this work satisfactorily describes the p-T-x diagram of the system. The numerical results of the analysis of the phase equilibrium confirmed the possibility of applying the polyassociative model to the Zn-Te system in a wide temperature range
Polyassociative model of A2B6 semiconductor melt and p-T-x phase equilibria in Zn-Cd-Te system
This work presents a numerical analysis of p-T-x phase equilibrium in the Zn-Cd-Te ternary system in the framework of the polyassociative solution model. On the basis of the experimental data on p-T-x phase equilibrium in the ternary system, thermodynamic functions describing the formation of liquid associates were found. It was shown that the results of the mixing of components in the Zn-Cd-Te ternary melt are related to the occurrence of ZnCdTe and ZnCdTe3 associates. Dissociation parameters of these complexes were calculated and subsequently used in order to efficiently describe p-T-x phase equilibrium of the system in a wide temperature range