1,814 research outputs found

    Asymptotic behavior of the average local ionization energy in finite basis sets

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    The average local ionization energy (ALIE) has important applications in several areas of electronic structure theory. Theoretically, the ALIE should asymptotically approach the first vertical ionization energy (IE) of the system, as implied by the rate of exponential decay of the electron density; for one-determinantal wavefunctions, this IE is the negative of the highest-occupied orbital energy. In practice, finite-basis-set representations of the ALIE exhibit seemingly irregular and sometimes dramatic deviations from the expected asymptotic behavior. We analyze the long-range behavior of the ALIE in finite basis sets and explain the puzzling observations. The findings have implications for practical calculations of the ALIE, the construction of Kohn–Sham potentials from wavefunctions and electron densities, and basis-set development

    Combined resonance and vibration reduction of non linear dynamical system subject to tuned excitation

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    The non-linear dynamical system subject to tuned excitation is consider, and studied . The system is represented by two degree of freedom differential equations of the system and absorber. The method of multiple scale is applied to solve the system up to 3rd order approximation. Effect of different parameters is studied numerically all resonance cases are studied numerically to obtain the worst case . Stability of the system is investigated using both phase plane and frequency response curves

    First Ionization Energy as the Asymptotic Limit of the Average Local Electron Energy

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    The first vertical ionization energy of an atom or molecule is encoded in the rate of exponential decay of the exact natural orbitals. For natural orbitals represented in terms of Gaussian basis functions, this property does not hold even approximately. We show that it is nevertheless possible to deduce the first ionization energy from the long-range behavior of Gaussian-basis-set wavefunc- tions by evaluating the asymptotic limit of a quantity called the average local electron energy (ALEE), provided that the most diffuse functions of the basis set have suitable shape and location. The ALEE method exposes subtle qualitative differences between seemingly analogous Gaussian basis sets and complements the extended Koopmans theorem by being robust in situations where the one-electron reduced density matrix is ill-conditioned

    Significance of nutrient and water sustainability: Effect of land leveling, cut off irrigation and N- fertilization on maize yield

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    A wide variety of soil, nutrient, and irrigation management practices are available to farmers, most of them concerned with the basic building block of agriculture, the soil. Soil management practices include the tillage and cropping systems and crop rotations used on a farm. Therefore, sustainable crop production should be managed to enhance soil ecosystems, improving soil health and fertility and reversing degradation and pollution of land. As well as, it should be contributed to maintaining and improving, and efficiently utilizing, water resources (quantity, access, stability and quality), especially promoting practices that minimize risks of water pollution from agrochemicals and save water. It is well documented that fertilizer N is the most costly input in maize production and its effective management is a major challenge for improving productivity and environmental sustainability. In present study, the effect of land leveling, cut off irrigation and N- fertilizer on yield and yield components of maize have been studied. The results showed that the highest yield of grain and straw of maize was obtained with using N-fertilization rate 288 kg N ha-1, land levelling rate 0.01 % of surface slope and cut off stream of irrigation rate 75%. The results of this study suggest that, irrigation application efficiency (%) increased from 71 % (for control) to 80 % for cut off 75 % of stream irrigation and land leveling with 0.01 % slope. Thus, about 20 % from the applied water for irrigation is saved by the previous treatments

    DYNAMICAL CHAOS IN 6 ï† -RAYLEIGH OSCILLATOR WITH THREE WELLS DRIVEN AN AMPLITUDE MODULATED FORCE.

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    Chaotic behavior of6 ï† -Rayleigh oscillator with three wells is investigated. The method of multiple scale method is usedto solve the system up to 3rd order approximation. Effect of parameters is studied numerically; all resonance cases arestudied numerically to obtain the worst case. Stability of the system is investigated using both phas

    Effects of feeding angles and cutting speeds of a mower knife with serrated edges on the pulverization of sweet potato vines

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    A study was conducted to test the effects of three different speeds of 1830, 2066 and 2440 rpm of a mower knife with serrated edges and two different feeding angles of 45° and 90° on the pulverization of sweet potato vines. The results indicated that all the treatments were significant at 99% significance level for the pulverized percentage of sweet potato vines remaining on the sieve. The best result was for the 45° feeding angle with lowest vine pulverized percentage of 47.20%. The second speed of 2066 rpm had the finest vine pulverized percentage of 57.47%. The best performance for overlapping effect between feeding angle and speed of mower was achieved by the 45° feeding angle and a mower speed of 1830 rpm resulting in an average percentage of 44.45 % of pulverized vines

    Efficiency of Barley Bran and Oat Bran in Ameliorating Blood Lipid Profile and the Adverse Histological Changes in Hypercholesterolemic Male Rats

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    The efficiency of oat bran and barley bran in lowering the induced hyperlipidemia and hypercholesterolemia in blood of male Albino rats (Rattus rattus) was studied. Twenty rats were divided into four groups each consisted of five rats and fed the specified test diets for eight weeks. The first group (G1) is the negative group which was fed basal diet, the second group (G2) was fed 1.0% cholesterol, was the third group (G3) fed 1.0% cholesterol and 10% oats bran, and the fourth group (G4) was fed 1.0% cholesterol and 10% barley bran. Feeding rats on 1% cholesterol significantly increased serum total cholesterol, low density lipoprotein, and very low density lipoprotein and triglyceride and decreased serum high density lipoprotein. Furthermore, enzyme activity of alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase was increased, and lipid peroxide was increased, whereas catalase and glutathione-S-transferase were decreased. Kidney functions parameters in the cholesterol supplemented group were elevated compared with the negative control. In addition, histological alteration in kidney, liver, heart, and testes was observed, compared with the negative control. Hypercholesterolemic rats supplemented with oat bran and barley bran showed significant decrease in lipid parameters, significant increase in high density lipoprotein-cholesterol, improved antioxidant enzyme, and improved histopathology of kidney, liver, heart, and testes. In conclusion, both oat bran and barley bran had protective effects against induced hyperlipidemia and improved histological alterations. Oat bran appeared more efficient than barley bran in lowering the lipid profile levels in hypercholesterolemic rats

    Synthesis and Spectroscopic Properties of Conducting Polymer Polyaniline (ES)

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    Polyaniline (PANI) was synthesized in Emaraldine salt  form by the chemical oxidation method by using Ammonium persulfate (APS) as an oxidizing factor. The XRD pattern refer to that PANI is an amorphous nature with  d-spacing 4.34 Ǻ. The FE-SEM images show that the  thin film of  polyaniline at 500nm shows  that is highly micro-porous. Similarly, the UV-Visible spectra of this polymer refer to two absorption peak at around 426nm and 805nm. These absorption bands are attributed to the transitions phase of π → π* and Benzenoid to Quinoid respectively. The FT-IR spectrum of  PANI shows strong bands  representing the surface bondings of  PANI and their vibration modes were also observed.  PL  photo-luminescent spectra of conducting  Polyaniline (ES) , one peak shows a broad spectrum with a maximum intensity at around 537nm, and the band gap energy at 2.3ev corresponds to the emission of polyaniline at solid state. Keywords: Polyaniline (PANI-ES), XRD, FE-SEM, FTIR, UV, PL

    Acetaldehyde Production by Rothia Mucilaginosa Isolates from Patients with Oral Leukoplakia.

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    Rothia mucilaginosa has been found at high abundance on oral leukoplakia (OLK). The ability of clinical isolates to produce acetaldehyde (ACH) from ethanol has not been investigated. The objective of the current study was to determine the capacity of R. mucilaginosa isolates recovered from OLK to generate ACH. Analysis of R. mucilaginosa genomes (n = 70) shows that this species does not normally encode acetaldehyde dehydrogenase (ALDH) required for detoxification of ACH. The predicted OLK metagenome also exhibited reduced ALDH coding capacity. We analysed ACH production in 8 isolates of R. mucilaginosa and showed that this species is capable of generating ACH in the presence of ethanol. The levels of ACH produced (mean = 53 µM) were comparable to those produced by Neisseria mucosa and Candida albicansin parallel assays. These levels were demonstrated to induce oxidative stress in cultured oral keratinocytes. This study shows that R. mucilaginosa can generate ACH from ethanol in vitro at levels which can induce oxidative stress. This organism likely contributes to oral ACH levels following alcohol consumption and the significance of the increased abundance of R. mucilaginosa in patients with potentially malignant disorders requires further investigation
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