7,468 research outputs found
Improving efficiency (optimization) of CIGS thin film solar cell using absorbent layer profile change
CIGS thin film solar cell of solid solution combination of Copper-indium-selenide (CIS) and copper -Gallium – selenide CGS is an I-III-VI2 semiconductor which is one of the options to replace silicon solar cell due to high stability and direct band gap, it also has higher yields and lower price compared to other thin film solar cells. In this article, we will initially evaluate the effect of three major factors of thickness, impurity density and band gap of absorber layer which is the most important layer in solar cells on the output parameters including efficiency using AMPS (Analysis of Microelectronic and Photonic Structures) software. Then, for the first time we will provide two important strategies to improve the efficiency of CIGC thin film solar cell. Layers of this type of solar cell are: 1-TCO made of ZnO (zinc oxide) 2- CdS layer gate (cadmium sulphate) with impurities of n 3-CIGS absorber layer with the impurity of p, 4- 5 glass substrate molybdenum layer made of soda. Reduced thickness of the absorbent layer makes the back connection to be closer to the discharge area. Jsc ,Voc , FF and Quantum efficiency (QE) decrease due to absorption of electrons of electrons to the surface of back connection and their participation in recomposition.Efficiency increases from 20.3399% to 21.3721% by increasing impurity density of absorbent layer and efficiency increases to 28.9266% and the quantum efficiency (QE) doubles by increasing the band gap of absorber layer which is a result of increasing the amount of gallium in CIGS cell. Then, we will achieve the efficiency of 34.1512% which has improved by 5.2246% compared to previous state by providing a way to reduce recombination at the intersection of absorbent / final connection by adding an extra layer made of absorbent layer with more impurities. In the final step, we improved the efficiency by 3.8581% (38.0093%) for the first time by increasing the band gap of CIGS layer. The solar cell used in this cellular thesis has characteristics such as Jsc = 36.7059&, Voc = 0.6721%, FF = 82.4422% and η = 20.3393%.Keywords: CIGS thin film solar cell, absorbent layer, improving efficiency, quantum efficiency QE, and recombinatio
Growth responses and accumulation of heavy metals by fungus Agaricus bisporus
Ectomycorrhizal fungi are able to form symbiotic associations with tree roots, and therefore, plants gain different benefits. On metal-contaminated soils, these fungi may improve plant fitness through an enhanced nutrition or by reducing toxicity of the metals. Agaricus bisporus, an edible fungus has been noted to grow in large numbers under Pistacia vera plantations in orchards of Kerman, Iran, indicating that it may form ectomycorrhiza with the tree. This research describes the responses of this fungus to heavy metals in solid and liquid MMN media. The fungus was grown in vitro in liquid and solid cultures for 3 weeks on five different concentrations (0, 15, 30, 45, 60 ppm) of five heavy metals (Cu, Zn, Ni, Co, Mn) as sulphate and the effect of these metal on radial growth, biomass production and metal content of fungal biomass were determined. The result showed there was a strong variation in metal tolerance, so that Agaricus bisporus was more tolerant to Mn than other metals, while the reverse was true for Ni, so that the fungus had an increased growth in the presence of low concentrations of Co, Mn, and Zn, but Ni greatly inhibited increase in biomass and colony diameter even at concentrations as low as 15 mg/l
The effect of Fe2Nio4 and Fe4Nio4Zn nanoparticles on hepatic, renal and spleen tissues in male wistar rat
Background and aims: Nanoparticles in a wide range of consumer products (cosmetics, health, industrial, ...) is used. The aim of this study is to evaluate the effect of the nanoparticle Fe2NiO4 and Fe4NiO4Zn on the Hepatic, Renal and Spleen Tissues.
Methods: This study of experimental was conducted on 40 male Wistar rats. The average weight was between 200-250g and divided into 5 groups. Group I: control group received 0.5ml saline. Respectively it was injected 0.5ml from second to fifth group with concentration 100 and 200 ppm of Fe4Nio4Zn and Fe2Nio4 nanoparticles. These injections were performed for 7 consecutive days with intraperitoneally injection.
Results: Results of H and E showed that Fe4NiO4Zn nanoparticles (200nm) had effect on the hepatic tissue and caused to damage tissues. Also, upper doze of (200nm) damaged to spleen tissue. Fe2NiO4 nanoparticle with doze (200nm) damaged the renal tissue, but, Fe2NiO4 nanoparticle with doze (100nm) had not no effect on hepatic, renal, and spleen tissues. The results of iron stain in the current study showed that iron has deposited on the spleen tissue in all of groups, but this iron sediment in the spleen in Fe4NiO4Zn treatment group (100, 200nm) was more compared with the control group (groups that contain zinc nanoparticles).
Conclusion: Both of Fe2NiO4 and Fe4NiO4Zn nanoparticles damage on Hepatic, renal and spleen tissues, but, damage in both of them was more in an upper doze, and iron stain showed that Fe4NiO4Zn caused more damage on spleen
نگاهی به رفتارهای نامحترمانه در محیط های آموزشی از دیدگاه اساتید و دانشجویان A Glance at Students and Faculty Members Perceptions of Incivil Behavior in Educational Setting
رفتارهای نامحترمانه در محیط های آموزشی می تواند به شدت یاددهی و یادگیری را مختل نماید و به ایجاد تناقض و اضطراب بین استاد و دانشجو منجر گردد. هدف از این مقاله بررسی دیدگاه دانشجویان و اساتید دانشگاه علوم پزشکی گلستان در مورد رفتارهای نامحترمانه و تهدید آمیز در محیط های آموزشی می باشد
Systematic Projected Shell Model Study of Even-Even Dysprosium Isotopes
Back-bending phenomenon is one of the important phenomena usually seen at high spin states of even - even heavy nuclei. As a result, any changes in the behavior of nuclear rotation, such as increase in moment of inertia versus rotational frequency can be shown in the usual back-bending plots which have been studied in many papers before. In this paper we show for the first time that these changes can be seen in the ratio of electromagnetic reduced transition probabilities B (E2) and B (M1) in even - even 152-164Dy isotopes using the Projected Shell Model (PSM) theory. The electric quadrupole transition probability B (E2) and the magnetic dipole transition probability B (M1) moments are sensitive to nuclear shape deformation and nuclear charge distribution, respectively. Our findings confirm the well-known back-bending previously seen and are in good agreement with experimental results. While intrinsic quadrupole moments are constant for each Dy isotope, the new findings show that spectroscopic quadrupole moments are increasing with spin
Isolation of keratinophilic fungi and aerobic actinomycetes from park soils in Gorgan, North of Iran
Background: Keratinophilic fungi are a group of fungi that colonize in various keratinous substrates and degrade them to the components with low molecular weight. This study was conducted to determine the prevalence of keratinophilic fungi and aerobic Actinomycetes in soil of city parks in Gorgan. Objectives: In this study, we surveyed the city park soils of Gorgan (a northern province of Iran) to determine the identities and diversity of soil aerobic Actinomycetes, keratinophilic and non-keratinophilic fungi. Materials and Methods: A total of 244 soil samples were collected from 22 diferent parks of Gorgan, North of Iran. The samples were collected from the superfcial layer with depth not exceeding than 0-10 cm in sterile polyethylene bags. We used hair bait technique for isolation keratinophilic fungi. The colonies identifed by macroscopic and microscopic characterization after slide culturing. Actinomycetes were isolated by antibiotic dilution methods and detected by using physiological tests such as Lysozyme, Casein, Xanthine, Hypoxanthine, Gelatin, Urea Broth, and modifed acid-fast stain. Results: Totally, 75 isolates of aerobic Actinomycetes were detected that Actinomadura madurae and Nocardia asteroides were the most prevalent strains, with 14.66 and 28% prevalence respectively. Microsporum gypseum was more frequent than other keratinophilic fungi (22.96%) and Aspergillus spp. was the most species of saprophyte fungi (15.92%). Conclusions: This study showed that the collected soil from studied areas was rich of keratinophilic fungi and Actinomycetes, therefore hygiene protocol should be taken to prevent the spread of pathogenic and saprophytes fungi in the environment of susceptible person. © 2013, Ahvaz Jundishapur University of Medical Sciences
Effect of exercise on Mesencephalic astrocyte derived neurotrophic factor levelsin the striatum of rats suffering from Parkinsons
Background and aims: The aim of this study, regarding the results of the previous researches and the effects of voluntary exercise on neurotrophic factors in treating PD, was to evaluate changes MANF level of rats` stratum exposed to neurotoxin injected by the stereotaxic surgery following the four weeks of treadmill running.
Methods: Twenty four rats were divided into four groups: Sham, Parkinson control, Parkinson exercise, and healthy control. Exercise group exercised for 4 weeks, 5 days per week and 2
15-minute sessions having at least 1 h interval. The purpose of injecting 6-OHDA into the brain striatum was to create an experimental model of PD. Three weeks after the injection of
6-hydroxydopamine (6-OHDA), Apo morphine rotational test was carried out in order to verify the rats with Parkinson latest. MANF levels in the striatum were measured by ELISA. Data was analyzed by one-way analysis of variance (ANOVA) and Tukey post-hoc test.
Results: The findings showed that there is a significant difference in the striatum MANF level of Parkinson control group (26.91±9 pg/mg) compared to the healthy control group (45.22±2 pg/mg) (P≤0.05). Furthermore, the striatum MANF level in Parkinson exercise group (29.35±2 pg/mg) had an increase in comparison with the Parkinson control group (26.91±9 pg/mg), but the difference was not significant (P=0.997).
Conclusion: This research has shown that performing treadmill running program cannot increase the MANF level of striatum. Therefore, we cannot decisively consider a neural protective role for this training protocol and it necessitates further studies
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