Parametrizacija funkcije raspodjele elektronske energije u tinjavom izboju u RF elektromagnetskom polju

A set of twenty four plasma glow discharge experiments using radio-frequency electromagnetic fields were carried out. The discharge pressure was 27 Pa. Dried air was used as the discharge gas. Axial radio-frequency fields between 0.6-1.2 MHz were applied. Four different values of the RF field intensity were used. For each case, the plasma Langmuir probe characteristics were measured. A computational method was used to extract the electron energy distribution function in each case. Values of the plasma density and plasma temperature were obtained directly from the fits. They compare well with values obtained using the conventional logarithmic method. The Maxwellian behaviour of the distribution function was established to hold in many but not in all cases.Izveli smo 24 mjerenja u plazmi u tinjavom izboju pod djelovanjem radiofrekventnog (RF) elektromagnetskog polja. Tlak u izboju bio je 27 Pa. Izbojni plin bio je suhi zrak. Rabili smo osna RF polja u području 0.6 do 1.2 MHz. Primijenili smo četiri jakosti RF polja. U svakom mjerenju odredili smo značajku Langmuirove probe. Računalnom smo metodom izveli funkciju elektronske raspodjele energije za svako mjerenje. Izravno iz prilagodbi izveli smo vrijednosti gustoć i temperature plazme. Te se vrijednosti dobro uspoređuu s vrijednostima dobivenim uobičajenom logaritamskom prilagodbom. Maxwellova funkcija raspodjele se pokazuje dobrom u mnogim, ali ne svim slučajevima

Parametrizacija funkcije raspodjele elektronske energije u tinjavom izboju u RF elektromagnetskom polju

A set of twenty four plasma glow discharge experiments using radio-frequency electromagnetic fields were carried out. The discharge pressure was 27 Pa. Dried air was used as the discharge gas. Axial radio-frequency fields between 0.6-1.2 MHz were applied. Four different values of the RF field intensity were used. For each case, the plasma Langmuir probe characteristics were measured. A computational method was used to extract the electron energy distribution function in each case. Values of the plasma density and plasma temperature were obtained directly from the fits. They compare well with values obtained using the conventional logarithmic method. The Maxwellian behaviour of the distribution function was established to hold in many but not in all cases.Izveli smo 24 mjerenja u plazmi u tinjavom izboju pod djelovanjem radiofrekventnog (RF) elektromagnetskog polja. Tlak u izboju bio je 27 Pa. Izbojni plin bio je suhi zrak. Rabili smo osna RF polja u području 0.6 do 1.2 MHz. Primijenili smo četiri jakosti RF polja. U svakom mjerenju odredili smo značajku Langmuirove probe. Računalnom smo metodom izveli funkciju elektronske raspodjele energije za svako mjerenje. Izravno iz prilagodbi izveli smo vrijednosti gustoć i temperature plazme. Te se vrijednosti dobro uspoređuu s vrijednostima dobivenim uobičajenom logaritamskom prilagodbom. Maxwellova funkcija raspodjele se pokazuje dobrom u mnogim, ali ne svim slučajevima

EDTA as a corrosion inhibitor for Al in 0.5 M HCl: adsorption, thermodynamic and theoretical study

In this study; EDTA is used in very small amount (10-10 M) as an inhibitor for the Al corrosion in 0.5 M HCl. Thermodynamic and adsorption parameters are calculated. The result shows that, in this range of concentrations, EDTA is chemisorbed at the Al surface, forming a stable complex with Al and give inhibition efficiency up to 89 %. For more con-centration, unstable complex is formed and acceleration of corrosion occurs. The adsorp-tion fit well to Langmuir, Temkin isotherms and El-awady model. Density functional theory (DFT) is used to study the geometrical optimizations of EDTA. From the obtained optimized structure, The highest occupied molecular orbital (EHOMO), the lowest unoccupied molecular orbital (ELUMO and their energy difference (ΔE), the total energy (TE), electronegativity (χ), dipole moment (μ), global hardness (η), global softness (σ), electron affinity (A), ionization potential (I), the fraction of electrons transferred (ΔN) and were determined using B3LYP/6-31G(d,p) basis set

Electrosynthesis and characterization of adherent poly(2-aminobenzothiazole) on Pt-electrode from acidic solution

AbstractThe electrochemical oxidation of 2-aminobenzothiazole, 2-ABT, on Pt-electrode has been investigated using CV in HCl solutions under nitrogen atmosphere at different temperatures, different monomer concentrations and different Na2SO4 concentrations. The experimentally obtained kinetic equation was RP,E=kE [monomer]1.19 [acid]1.32 [electrolyte]1.08, which was deduced from values of the first anodic current density (ipI). A simplified mechanism for the electrochemical oxidation of 2-ABT is proposed. Activation energy, which was obtained from the experimental data, was almost same in studied parameters. This means the electrochemical oxidation mechanism for 2-ABT must be the same. The obtained polymer films are found to be thermally stable and have tubular or fibrillar elongated crystals. Different tools have been used to characterized P(2-ABT) as: 1H NMR, Uv–vis, IR spectroscopy and elemental analysis

Nitrogen availability and economic returns of various crop rotations with forage and annual crops

Non-Peer Reviewe

A Logarithmic Formula to Describe the Relationship between the Increased Radiosensitivity at Low Doses and the Survival at 2 Gray

Objectives: Intrinsic radiosensitivity at doses used in radiotherapy is linked to hypersensitivity (HRS) and increased radio resistance (IRR) at low doses. The aim of this study was to explore this relationship. Methods: Survival curves for 18 human tumour cell lines were analysed, using two models to fit the data points in order to extract the necessary parameters relevant for this study. Results: The IRR ratio αs/αr versus the survival at 2 gray (Gy) can be described by a logarithmic relation which leads to a series of straight lines. Conclusion: The relationship obtained implies that there is a direct link between HRS/IRR and survival at clinically relevant doses of 2 Gy

Nitrogen availability and economic returns of various crop rotations with forage and annual crops

Non-Peer Reviewe

Les arbres de Tunis peuvent-ils devenir un patrimoine urbain ? Pour qui ? Pourquoi ?

En s’appuyant sur des observations in situ et des résultats d’entretiens avec les citadins, nous avons d’abord tenté de définir en premier lieu le statut de l’arbre de Tunis. Puis, en second lieu, nous avançons quelques hypothèses quant à la perception de l’arbre par les Tunisois. Nous avançons que la perception sociale des arbres de Tunis est construite et nourrie surtout par l’identité personnelle des habitants de la ville. Mais il faut néanmoins souligner que l’arbre contribue aussi à forger l’identité des citadins en marquant leur espace public de vie. La perception de l’arbre devient ainsi un mélange complexe de goûts personnels et de possibilités pratiques, mais surtout de traditions, de croyances religieuses et d’expériences individuelles.For our case which is Tunis, we’ve been relied on in-situ observations and results of interviews with the citizens to attempt to define; first, the status of the tree of Tunis. Then, second, we do a few assumptions about the perception of the tree by the citizens. We advance the following thesis: the social perception of the tree of Tunis is built on the personal identity of the inhabitants of the city. Nevertheless, the tree helps also to forge the identity of the urban public space by marking their life. The perception of the tree becomes a complex mix of practicality, traditions, religious beliefs and personal experiences

Evidence of Global Warming from Zakho Precipitation Data

Analysis of available precipitations data for Zakho area supports the argument that global warming has affected this region. Results shows that monthly and yearly rain fall have been decreasing systematically since the thirties of the last century until now. Based on linear correlation model, some future estimations of the reduction in precipitation as related to the global atmospheric carbon dioxide concentrations are made