215 research outputs found
Evolution of the absorption of heavy metals in function of nutrients
The condition of an eco-system greatly depends on the different biotic and abiotic factors. The area along the river “Tisza” is highly imperiled by random appearance of heavy metal pollutants originated from mining accidents or other sources. Heavy metals are dangerous because of the bioaccumulation and they could be toxic or poisonous even at low concentration. The aim of our research was to test the reaction of a simplified soil-plant pot experiment, consists of garden cress (Lepidium sativum) for metal pollution close to the sanitary limiting value.
Garden cress is considered one of the most important agricultural vegetables and its short reaction time for various treatments makes this plant ideal object of eco-toxicological tests. Based on the results it is realistic assumption to expect decrease the above-mentioned flexibility character. Garden cress (Lepidium sativum) was chosen as a test plant to simulate the accessible pollutant uptake. Additionally, Lepidium sativum is a possible carrier of heavy metals in food chain, since it is a many-sided green vegetable consumed by humans and animals as well. The present study is undertaken to examine the level of accumulation as it is modified by a plant, if the plant growing up under other conditions. It appears how for each factor as in mobilizing heavy metals, the plant laboratory water will affect the special nutrient solution or soil pollution. Responsive changes are relevant for all of the different conditions relevant for mobile heavy metals. The accumulation levels may undergo variations in function of them. In the present study, such change is characterized by the cress garden
Microencapsulation Analysis Based on Membrane Technology: Basic Research of Spherical, Solid Precursor Microcapsule Production
The objective of the proposed investigation was to synthesis of precursor oil-carbohydrate microcapsule, suspended in water by membrane emulsification technology. To select the carrier material of precursor microcapsules, four different carbohydrates (maltodextrin, hydroxypropyl cellulose, potato starch and corn starch) were tested. Preliminary, zeta-potential, molecular weight and particle size of individual carbohydrate were estimated by Malvern Zetasizer instrument. Based on the results of the preliminary characterizations, maltodextrin was selected to carry out subsequent experiments. Maltodextrin suspended in oil and water were considered as dispersed phase and continuous phase respectively. An attempt has been made to remove the water, as well as to recover the microcapsules. It was observed that average particle size of synthesized microcapsule is 6.9 μm and stability of the microcapsule is at least 6 weeks
Vinaigrette Production by Membrane Emulsification: Process Optimization and Product Development
In present work primarily achievement in energy efficient food production were targeted. Over the last 20 years, there has been a growing interest in a technique for making emulsions known as ‘‘membrane emulsification” which allows the production of emulsion droplets under controlled conditions with a narrow size distribution. Vinaigrette is a mixture of oil and vinegar. In the present work vinaigrette was prepared in two ways. The first one was prepared by hand in the traditional way. The second sample was pr epared by membrane technology. After preparation of vinaigrette, the panel test is carried out by trained panelist in order to know the quality and customer preference. After series of experiments and data analysis it can be concluded that cross-flow ME is suitable for green production of W/O emulsions like vinaigrette, and the technology we used looks suitable for industrial applications
NyelvElő, avagy hogyan vezetjük be az idegen nyelvet gyermekkorban?
NyelvElő is a kind of school preparatory course for future pupils of our school. In our study, we would like to show how we introduce foreign languges in childhood in our school. First, we summarize the purpose, recommended topics, and methods of foreign language teaching in childhood, described in the literature. Then we present the NyelvElő session that are organised in our school as part of the school invitation program. Finally, we present the description and reflection of NyelvElő foreign language session organized for the city’s kindergarten teachers.Ebben a tanulmányban azt szeretnénk bemutatni, hogy iskolánkban hogyan vezetjük be az idegen nyelvet gyermekkorban. Először összefoglaljuk a szakirodalmakban leírt gyermekkori idegennyelv oktatás célját, ajánlott témáit, módszereit, majd az iskolánkban az iskolahívogató program keretében megvalósuló NyelvElő foglalkozásainkat mutatjuk be. A harmadik rész a város óvodapedagógusainak rendezett Szakmai Nap keretén belül megvalósuló NyelvElő idegen nyelvi foglalkozás bemutatását, leírását és reflexióját tartalmazza
A SERDÜLŐKORI DOHÁNYZÁS CSALÁDI HÁTTERE MAROS, HARGITA ÉS KOVÁSZNA MEGYEI MINTÁN
Cigarette consumption might be considered as a lifestyle model. The formation of this lifestyle model in childhood and adolescence is considerable due to the socio-cultural environment in which socialization take part. The aim of this study was to analyze adolescents’ smoking behavior, and family-related factors that may influence it. The self-reported questionnaire-based study was done in Mures, Harghita and Covasna counties among 7 th and 8 th grades students. The prevalence of smoking was 5.9% in the total sample. The results showed significant associations between smoking behavior of young people and their family background (e.g. education of parents, smoking bans at home)
A szél hatása a késő-neogén–negyedidőszaki üledékképződésre és a domborzat alakulására a Magyar-középhegységben és előterében = The effect of the wind on the late Neogene and Quaternary sedimentation and morphological evolution of the Hungarian Central Range and of its foreland
Legfontosabb kutatási eredményeink: az eolikus üledékek és felszínek elterjedésének és korának meghatározása, megayardangok és plató helyzetű eolikus képződmények leírása, valamint a defláció meghatározó szerepének kimutatása a Dunántúl mai domborzatának, így a zalai és somogyi ún. meridionális völgyrendszer kialakításában is. A szélmarta kőzetfelszínek kozmogén 10Be izotópos korát a mélységprofilok menti mintavételezési módszer alkalmazásával sikerült meghatároznunk. Ezt a módszert korábban szélcsiszolta kőzetfelszíneken még nem alkalmazták; elsőként sikerült 1,5 millió éves szélcsiszolta sziklafelszínt datálnunk Európában. A Tapolcai- és Káli-medencék negyedidőszaki deflációs alacsonyodási rátája 40-75 m/My volt, ugyanakkor a kipreparálódó kvarcittömbök csupán 2-4 m-t pusztulnak évmilliónként. A különböző korú szélmarta felszíneken mért szélkarc irányok megfeleltek a mai ÉNy-ias széliránynak. Ezzel igazoltuk az állandónak tekinthető uralkodó szélirányt a negyedidőszak során. Az OSL kormeghatározással 8-80 ezer éves üledékeket sikerült datálnunk a Vértes környezetében. Az üledékanyag szemcséit a betemetődés előtt nem érte elegendő fény ahhoz, hogy a lumineszcens szignál teljesen lenullázódjon. Ezt valószínűleg a rövid szállítási távolság okozhatta. Ezzel magyarázható, hogy a vizsgált üledékek esetében a geomorfológia és a korábbi koradatok tükrében többnyire a centrális OSL kor adja meg a betemetődés korát. | Our most important results are: determination of the distribution and age of aeolian landforms and sediments and description of megayardangs and aeolian formations in plateau position. We demonstrated that deflation played a definitive role in the formation of the topography of Transdanubia and in the development of the radial valley system of Zala and Somogy countries. Age and denudation rate of the wind-abraded rock surfaces was determined using in situ produced 10Be depth profiles. This was the first application of this method on wind-polished rock surfaces, and the first time when a 1.5 million years old wind-abraded surface was dated in Europe. Quaternary deflational surface lowering of the Tapolca and Kál Basins was 40-75 m/My, while denudation rate of the cemented quartzite rock surfaces was only 2-4 m/My. We proved long term stability of north-westerly winds by the measurement of the direction of wind striations rock surfaces of different age. OSL ages of aeolian sediments in the Vértes foreland were 8-80 ky old. The sediments were not exposed to sunlight for enough time to anneal completely the luminescence signal, most probably because of the short distance of transportation. This is the reason why the central OSL ages provide the age of sedimentation, considering the geomorphology and previous age data as well
Extensive grazing in contrast to mowing is climate-friendly based on the farm-scale greenhouse gas balance
Abstract
Livestock is both threatened by and contributing to climate change. The contribution of livestock to climate change and greenhouse gas (GHG) emission greatly vary under different management regimes. A number of mitigation options comprise livestock management, although there are a lot of uncertainties as to which management regime to use for a given pedoclimatic and farming system. Therefore, we 1) tested if an extensive cattle livestock farm is a net sink or a net source for GHG (carbon–dioxide, CO2; methane, CH4; nitrous oxide N2O) in Central‒Eastern Europe, 2) compared the annual GHG balances between the grazed and mowed treatments of the farm 3) and investigated the role of climate variability in shaping these balances. Net ecosystem exchange of CO2 (NEE) was measured with eddy covariance technique in both the grazed and mowed treatments. Estimations of lateral C fluxes were based on management data. Other GHG fluxes (CH4, N2O) were determined by chamber gas flux measurements technique (in case of soil) and IPCC guidelines (in case of manure decomposition and animal fermentation). Net greenhouse gas balance (NGHG) for the grazed treatment was 228±283 g CO2 equivalent m–2 year–1 (net sink) and –475±144 g CO2 equiv. m–2 year–1 (net source) for the mowed treatment. Net source activity at the mowed treatment was due to its higher herbage use intensity compared to the grazed treatment. At the farm scale the system was estimated to be a net sink for NGHG in a year with wet (135 g CO2 equiv. m–2 year–1), while a net source in years with dry soil moisture conditions (–267±214 g CO2 equiv. m–2 year–1). We conclude that under a temperate continental climate extended extensive grazing could serve as a potential mitigation of GHG in contrast to mowing. Our study highlights the fact that livestock farming could create a net sink for GHG under proper management regimes
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