1,407 research outputs found

    Potassium Nutrition in Plants and Its Interactions with Other Nutrients in Hydroponic Culture

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    Potassium is an essential major nutrient for plant growth and development. Plants absorb more K (potassium) than any other element, with the exception of N. Most plant-available forms of essential plant nutrients are ionic. Among the many plant mineral nutrients, K stands out as a cation having the strongest influence on quality attributes. Potassium ions are involved in many processes that result from ionic activity in the hydroponic nutrient solution and often provide positive contributions. Due to the presence of potassium cation ions, some elements increase in nutrient solution, whereas others decrease

    Interaction with Matter of Ionizing Radiation and Radiation Damages (Radicals)

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    Interaction of matter with “ionizing radiation,” that is, high-energy electromagnetic radiation (X- or gamma rays) or α- or β-particles, can promote chemical change which commonly involves free radicals. Free radicals formed by high-energy radiation in solids can then be identified by analysis of their EPR spectra

    Biomedical EPR

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    Free radicals may participate in biological processes. An enzymatic dehydrogenation involved free radical intermediates. The oxidations of organic molecules, although they are bivalent, proceed in two successive steps, the intermediate state being a free radical. In an attempt to correlate the action of such a variety of carcinogenic agents as sodium hydroxide, ultraviolet and ionizing radiations and thousands of organic compounds, a free radical intermediate always suggests itself. Electron paramagnetic resonance (EPR) has brought sufficient sensitivity and discrimination to observe free radical intermediates directly in many of these reactions. EPR is aided by an increased sensitivity in many cases and has made a much greater contribution by distinguishing among paramagnetic ions, odd molecules and free radicals

    Dipolar Interactions: Hyperfine Structure Interaction and Fine Structure Interactions

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    The interaction between the nuclear spin and the electron spin creates a hyperfine structure. Hyperfine structure interaction occurs in paramagnetic structures with unpaired electrons. Therefore, hyperfine structure interaction is the most important of the fundamental parameters investigated by electron paramagnetic resonance (EPR) spectroscopy. For EPR spectroscopy the two effective Hamiltonian terms are the hyperfine structure interaction and the electronic Zeeman interaction. The hyperfine structure interaction has two types as isotropic and anisotropic hyperfine structure interactions. The zero-field splitting term (electronic quadrupole fine structure), the nuclear Zeeman term, and the nuclear quadrupole interaction term are among the Hamiltonian terms used in EPR. However, their effects are not as much as the term of the hyperfine structure interaction. The zero-field splitting term and the nuclear quadrupole interaction term are the fine structure terms. The interaction of two electron spins create a zero-field splitting, the interaction between the two nucleus spins form the nuclear quadrupole interaction. Hyperfine structure interaction, zero-field interaction, and nuclear quadrupole interaction are subclasses of dipolar interaction. Interaction tensors are available for all three interactions

    Magnetic Resonance

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    Magnetic resonance is divided into electron spin resonance (ESR) [electron paramagnetic resonance (EPR)] and nuclear magnetic resonance (NMR) according to the working region in the electromagnetic spectrum. If the studied region is in the microwave region, this resonance type is electron spin resonance. If the region studied is the radio frequency region, then nuclear magnetic resonance is mentioned. ESR and NMR are similar in terms of their basic theorem

    EPR Analysis of Antioxidant Compounds

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    A free radical is a molecular species having an unpaired electron and it is a highly reactive entity and unstable. A free radical is a molecule with one or more unpaired electrons in its outer shell. Free radicals can be formed by chemical bond breakage from molecules or by redox reactions. When cells use oxygen, the oxidative stress occurs. The oxidative stress causes free radical formation. Free radicals can also be generated from ionizing radiations, ozone, heavy metal poisoning, cigarette smoking, and chronic alcohol intake. These free radicals are highly reactive and oxidize biomolecules leading to tissue injury and cell death. They also cause toxic effects and diseases. Antioxidants neutralize free radicals resulting from oxidative stress. Antioxidants play an important role in the treatment of diseases. The most suitable method for the analysis of free radicals is the electron paramagnetic resonance (EPR) spectroscopy method. The EPR method detects a paramagnetic center with a single electron. It gives information about the interactions with other nuclei around one electron. It provides information on the structure and environment of radicals

    Planiranje okolišno prihvatljive trase šumske ceste pomoću GIS & S-MCDM

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    Forest roads are basic precondition for the sustainable management of forest resources. These roads entail a complex engineering effort because they can cause substantial environmental damage to forests and include a high-cost construction. Therefore, the design of forest road routes should have taken into account in terms of environmental impacts. In order to do this, the Geographical Information System (GIS) with Spatial Multi Criteria Decision Making (S-MCDM) techniques is a useful tool for creating a model. One such S-MCDM is the Spatial-integrated Technique for Order Preference by Similarity to Ideal Solution (S-TOPSIS). In this study, S-TOPSIS was applied to integrate environmental impacts into the design of a forest road route. Using the current forest road route (CFOR) and the GIS-based S-TOPSIS method, an environmentally sound forest road route (ESFOR) was determined according to environmental criteria. Five environmental criteria (avalanche, river, soil, geology and slope) were used for analysis to compare with. The results obtained from the analyses, are compared to the current forest road route. The CFOR 15.385 km in length, while the ESFOR found by S-TOPSIS was 14.385 km. If the differences in length between two roads multiplied by the width of the road (1km X 5m), the result would be 0.5 ha. The results showed that this methodology can provide environmentally sound road network also help to design quickly and less costly. These results suggest that spatial multi criteria decision making method can be more accurate in terms of environmentally sensitive forest road designing in mountainous area.Šumske ceste su osnovni preduvjet za održivo upravljanje šumskim resursima. Te ceste uključuju složene inženjerske napore, jer mogu izazvati znatnu ekološku štetu šumama i uključuju vrlo skupu izgradnju. Stoga pri izrada trasa šumskih cesta, treba uzeti u obzir i utjecaj na okoliš. Da bi se to i napravilo, geografski informacijski sustav (GIS) s tehnikama prostornog višekriterijskog donošenja odluka (S-MCDM) koristan je alat za izradu modela. Jedan takav S-MCDM je prostorno-integrirana tehnika preferiranja sličnosti do idealnog rješenja (S-TOPSIS). U ovoj studiji S-TOPSIS primijenjen je za integriranje ekoloških učinaka u izradu trase šumske ceste. Korištenjem sadašnje trase šumske ceste (CFOR) te S-TOPSIS metode na temelju GIS-a, utvrđena je ekološki osjetljiva trasa šumske ceste (ESFOR) prema ekološkim kriterijima. Za usporedbu korišteno je pet ekoloških kriterija (lavina, rijeka, tlo, geologija, nagib). Rezultati dobiveni iz analiza uspoređeni su sa sadašnjom trasom šumske ceste. Dužina CFOR-a je 15.385 km dok je ESFOR utvrđen S-TOPSIS-om bio 14.385 km. Da se razlike u dužini između dviju cesta pomnože sa širinom ceste (1 km x 5 m) rezultat bi bio 0,5 ha.Rezultati su pokazali da ova metodologija može pružiti ekološki osjetljivu mrežu cesta, te može pomoći u bržoj izradi i biti jeftinija. Ovi rezultati sugeriraju da metoda prostorne procjene višestrukim kriterijima može biti točnija u smislu izrade ekološki osjetljivih šumskih cesta u planinskim područjima

    Changing Perspectives on the Planning of Ankara (1924-2007) and Lessons for a New Master-Planning Approach to Developing Cities

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    As one of the newly planned capitals in the 20th century – like Islamabad, Canberra and Brazil –, Ankara represents an original case in planning history: from shaping a new town under the influence of early European urbanism to the control of a dynamic metropolitan form by structural planning approaches. Forming its urban core according to the initial planning perspectives between the beginning of 1930s and the mid-1970s, the city has entered a rapid phase of space production in its extensions for about the last thirty years.In the current period of development, highly fragmented urban peripheral formation has being occurred in Ankara. Since the existing trend on the dispersion of urban form lacking spatial coherence at different scale-levels causes the dominance of the private domain and a loss of urbanity, this trend might at first glance be considered as a break with the European tradition and the emergence of Anglo-Americanization in Turkish planning system in terms of looser development control approach on urban form.Before, coming to such a critical end-point, the paper prefers a closer look into the changing dynamics of master plans of the city. It is aimed to reveal the developmental logic of the city by means of master plan analysis. The comprehensive outlook – called plan matrix – is integrated into each master plan schema by correlating the basic components like main policy directions, depth of control, settlement typology, and city structure and form. Such a framework has a potential to be utilized for any kind of plan analysis at metropolitan scale for different cases. At the end of the analysis, the paper tends to address an alternative master planning approach for the similar types of developing cities striving for keeping its urban character within a fragmented urban body

    Waste Identification Lean Approach in effective education system - Case of Albania

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    The continuing growth and expansions incorporated with technology, has generated variations in tastes, behavior and demand. Thus the changes need management restructures to reduce the costs of adaptation. Lean principles as cost reduction orientated possess the sufficient elements to fix problems in order to reduce wastes and increase the values. The theory application can be used also in education sector in order to increase the quality and reduce the costs. Thus, the aim is to identify the improvidences (waste) and propose several applicable solutions. It is based on interviews and researches to the teachers working in private schools for at least 5 years. This study is being conducted in Private high school in Albania

    Effect of Nutrient, Light Intensity and Temperature on the Growth Rates and Metabolism of a Stress-Resistant Bacillariophyta – Entomoneis sp. - in Izmir Bay (Aegean Sea)

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    A unicellular marine microalga, Entomoneis sp. was isolated and studied as had become the dominant species according to other bacillariophyta species in different environmental fluctuations in Izmir Bay. Because of our effort to better understand the dynamics of this microalga that facilitates unprecedented domination, we conducted on a monoculture isolation study.In this study, experiments were planned with the annual range of the Izmir Bay temperature, and the demonstrated behavior of the species in light and nutrient conditions. The stock culture medium was illuminated by approximately 50μmol photons m-2s-1 of illumination with 14/24 daylight. The temperature of the climate chamber was set on the summer (T1 (21±1oC)), spring (T2 (17±1oC)) and winter (T3 (13±1oC)) of Izmir Bay. Experiments were also applied with four different light intensities (L1 (50 μmol photons m-2s-1), L2 (25 μmol photons m-2s-1), L3 (5 μmol photons m-2s-1) and L4 (dark)). In this context, nutrient measurements were made on samples of the exponential, stationary and death phase of the culture and nutrient analyses were carried out. The results, which were designed according to ceteris paribus assumptions, were adapted to Michaelis-Menten kinetics. Consequently, considering the lifetime of the diatom at different temperature conditions, T3 was determined as an optimum temperature. Maximum growth rate and process time were observed at this temperature. This is the evidence why these diatoms are available in the winter. Once the light intensity was increased, the growth rate was increased at the T1 and T2 temperatures. However, T3 had a high growth rate in the nearly L1 light intensity. Considering the consumption and transformation of different nutrient conditions, different results for both types of microalgae were obtained.
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