516 research outputs found
Mechanochemically Synthesized CIGS Nanocrystalline Powder for Solar Cell Application
Copper Indium Gallium Diselenide (CIGS) is a compound semiconductor material from the group of I-III-VI. The material is a solid solution of copper, indium and selenium (CIS) and copper, gallium and selenium with an empirical formula of CuIn(1 – x)GaxSe2, where 0 x 1. CIGS has an exceptionally high absorption coefficient of more than 105 cm – 1 for 1.5 eV. Solar cells prepared from absorber layers of CIGS materials have shown an efficiency higher than 20 %. CuIn(1 – x)GaxSe2 (x 0.3) nanocrystalline compound was mechanochemically synthesized by high-energy milling in a planetary ball mill. The phase identification and crystallite size of milled powders at different time intervals were carried out by X-ray diffraction (XRD). The XRD analysis indicates chalcopyrite structure and the crystallite size of about 10 nm of high-energy milled CIGS powder after two and half hours of milling. An attempt for preparing the thin film from CIGS nanocrystalline powder was carried out using the flash evaporation technique. Scanning electron microscopy (SEM) reveals uniform distribution of CIGS particles in thin film.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3100
Barrier inhomogeneities of Al/p-In2Te3 thin film Schottky diodes
The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of p-In2Te3/Al thin films Schottky diodes papered by Flash Evaporation technique were measured in the temperature range 303-335 K have been interpreted on the basis of the assumption of a Gaussian distribution of barrier heights (φbo) due to barrier height inhomogeneities that prevail at the interface. It has been found that the occurrence of Gaussian distribution of BHs is responsible for the decrease of the apparent BH (φbo) and increase of the ideality factor (η). The inhomogeneities are considered to have a Gaussian distribution with a mean barrier height of (φbm) and standard deviation (σs) at zero-bias. Furthermore, the activation energy value (φb) at T = 0 and Richardson constant (A**) value was obtained as 0.587 eV and 3.09 Acm– 2 K– 1 by means of usual Richardson plots. Hence, it has been concluded that the temperature dependence of the I-V characteristics of p-In2Te3/Al Schottky Diodes can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the BHs.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2790
Magnetron sputtered Al-ZnO Thin films for photovoltaic applications
The optimization process of the RF magnetron sputtered Al - doped ZnO (AZO) thin films was carried out by studying its structural, optical, electrical, and morphological
properties at different RF power and different working pressures for its use as a front-contact for the copper indium diselenide (CIS) based thin film solar cell. The structural study suggests that the preferred orientation of grains along the ( 002)
plane having a hexagonal structure of the grains. The optical and electrical properties suggest that the films show an average transmission of 85 % and a resistivity of the order of 10-4 Wcm. The morphology analysis suggests the formation of packed grains
having a homogeneous surface.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2210
Inter-study reproducibility of arterial spin labelling magnetic resonance imaging for measurement of renal perfusion in healthy volunteers at 3 Tesla
Background:
Measurement of renal perfusion is a crucial part of measuring kidney function. Arterial spin labelling magnetic resonance imaging (ASL MRI) is a non-invasive method of measuring renal perfusion using magnetised blood as endogenous contrast. We studied the reproducibility of ASL MRI in normal volunteers.<p></p>
Methods:
ASL MRI was performed in healthy volunteers on 2 occasions using a 3.0 Tesla MRI scanner with flow-sensitive alternating inversion recovery (FAIR) perfusion preparation with a steady state free precession (True-FISP) pulse sequence. Kidney volume was measured from the scanned images. Routine serum and urine biochemistry were measured prior to MRI scanning.<p></p>
Results:
12 volunteers were recruited yielding 24 kidneys, with a mean participant age of 44.1 ± 14.6 years, blood pressure of 136/82 mmHg and chronic kidney disease epidemiology formula estimated glomerular filtration rate (CKD EPI eGFR) of 98.3 ± 15.1 ml/min/1.73 m2. Mean kidney volumes measured using the ellipsoid formula and voxel count method were 123.5 ± 25.5 cm3, and 156.7 ± 28.9 cm3 respectively. Mean kidney perfusion was 229 ± 41 ml/min/100 g and mean cortical perfusion was 327 ± 63 ml/min/100 g, with no significant differences between ASL MRIs. Mean absolute kidney perfusion calculated from kidney volume measured during the scan was 373 ± 71 ml/min. Bland Altman plots were constructed of the cortical and whole kidney perfusion measurements made at ASL MRIs 1 and 2. These showed good agreement between measurements, with a random distribution of means plotted against differences observed. The intra class correlation for cortical perfusion was 0.85, whilst the within subject coefficient of variance was 9.2%. The intra class correlation for whole kidney perfusion was 0.86, whilst the within subject coefficient of variance was 7.1%.<p></p>
Conclusions:
ASL MRI at 3.0 Tesla provides a repeatable method of measuring renal perfusion in healthy subjects without the need for administration of exogenous compounds. We have established normal values for renal perfusion using ASL MRI in a cohort of healthy volunteers.<p></p>
Mechanochemically Synthesized CIGS Nanocrystalline Powder for Solar Cell Application
Copper Indium Gallium Diselenide (CIGS) is a compound semiconductor material from the group of I-III-VI. The material is a solid solution of copper, indium and selenium (CIS) and copper, gallium and selenium with an empirical formula of CuIn(1 – x)GaxSe2, where 0 x 1. CIGS has an exceptionally high absorption coefficient of more than 105 cm – 1 for 1.5 eV. Solar cells prepared from absorber layers of CIGS materials have shown an efficiency higher than 20 %. CuIn(1 – x)GaxSe2 (x 0.3) nanocrystalline compound was mechanochemically synthesized by high-energy milling in a planetary ball mill. The phase identification and crystallite size of milled powders at different time intervals were carried out by X-ray diffraction (XRD). The XRD analysis indicates chalcopyrite structure and the crystallite size of about 10 nm of high-energy milled CIGS powder after two and half hours of milling. An attempt for preparing the thin film from CIGS nanocrystalline powder was carried out using the flash evaporation technique. Scanning electron microscopy (SEM) reveals uniform distribution of CIGS particles in thin film.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3100
Alternaria and Cercospora leaf spot diseases of Niger (Guizotia Abyssinica Cass.) – a traditional tribal crop of South Gujarat, India, with cost benefit ratio in relation to different fungicides
Niger (Guizotia abyssinica Cass.) is an important minor oil seed crop grown in dry areas grown mostly by tribal and interior places as life line of tribal segment. Tribal people mainly use its oil for cooking purpose, above than that there were also other uses. Hence, the niger crop should be protected from the infection. The crop is affected by number of fungal diseases. Therefore, a field experiment was formulated for three years with the four replications at the Niger Research Station (NRS) at Navsari Agricultural University (NAU), Vanarasi, Navsari (Gujarat) on the foliar diseases of GN-1 variety of niger crop. In this experiment, six different fungicides along with one control have been evaluated to control the Alternaria and Cercospora leaf spot diseases, out of which all the fungicidal treatments were significantly superior over the control. Here, foliar spray on the incidence of diseases was compared with the control (without any treatment). All the fungicidal treatments were significantly superior over the control to reduce Alternaria and Cercospora leaf spot diseases of Niger crop. Treatment of Carbendazim + Mancozeb (0.2 %) with two sprays first from the initiation of the disease and second after the interval of 15 days recorded the lowest incidence of Alternaria (14.56) and Cercospora (14.94) leaf spot diseases of niger and recorded the highest seed yield 337 seed yield kg/ha along with the net return with cost benefit ratio graph
Relationship of bacterial leaf blight disease of cotton with different weather parameters under South Gujarat condition of India
Cotton is a soft, fluffy staple
fiber that grows in a boll, around the seeds
of the cotton plants of the genus Gossypium
in the family Malvaceae. Bacterial blight of
cotton, also know as angular leaf spot, boll
rot, and black leg, is a potentially
destructive bacterial disease of cotton
production. The disease caused by
Xanthomonas campestris pv. malvacearum
(Smith) Dye (synonyms Xanthomonas
malvacearum (E.F. Sm) Dowson) is one of
the most important and serious disease in
cotton crop. Main objective of present
research is to study the progress of the
bacterial blight disease of cotton (BLB),
caused by Xanthomonas campestris pv.
malvacearum (Smith) Dye, with relation to
the environmental parameters. This is a
common disease affecting the growth,
development and yield of cotton. A field
trial was conducted to determine the
influence of environmental factors, viz.
rainfall periods, temperature, sun shine
hours and humidity on the development of
disease. Bacterial blight disease was
recorded with its appearance and
subsequently at weekly interval till it
prevailed on G. Cot. Hy.12 (Non Bt). The
incidence of bacterial blight disease (BLB)
was noticed during 28 to 49th standard week
with the maximum disease intensity in third
week of September (23.5% PDI). None of
the abiotic factors had significant influence
on bacterial blight disease progress and
development
Efficacy of different fungicides against dry rot pathogen of potato caused by Fusarium sp. under in vitro condition
Potato crop is affected by
numerous diseases in field, as well as in
storage conditions, particularly in cold
storage. Dry rot of potato is caused by
Fusarium sp. Dry rot of seed tubers can
reduce crop establishment by killing
developing potato sprouts, and crop losses
can be up to 25%, while more than 60% of
tubers can be infected in storage. It is a rich
source of energy, which supplement food
source of a country. In this experiment, four
systemic and four non-systemic fungicides
were tested at different concentrations in
vitro for their comparative efficacy against
inhibition of the growth of Fusarium sp.
through poisoned food technique. To
manage these diseases effectively, different
concentrations of fungicides were tested.
Results revealed against Fusarium sp. that
carbendazim and benomyl significantly
inhibited the fungal growth even at its lower
concentration (100 ppm) and proved
statistically superior over the rest of the
fungicides tested at different concentrations
and among non-systemic fungicides,
MEMC significantly inhibited the fungal
growth even at its lower concentration
(1000 ppm)
Structure and collective dynamics of liquid sodium
The temperature variation of the longitudinal and transverse phonon frequencies of liquid sodium is investigated
using the approach by Hubbard Beeby. The molecular dynamics simulation is used to generate the pair
correlation function of liquid sodium at various temperatures viz. T = 378 K, 473 K, 573 K, and 723 K, with
672 particles. To describe the electron-ion interaction our own model potential is employed along with a recent
local field correction function due to Sarkar et al. To evaluate the parameter of the potential the zero pressure
condition has been applied. The present results of g(r) are in good agreement with available experimental
findings. The computed g(r) are used to investigate the temperature variation of the collective dynamics of
liquid sodium. The amplitudes of the peaks of the longitudinal and transverse frequencies are suppressed
while the width of the propagation gap for the transverse sound waves decreases with an increase in temperature.
The computed longitudinal and transverse sound velocities at these temperatures are found to be
encouraging.За допомогою методу Габбарда-Бiбi дослiджувалась температурна залежнiсть повздовжньої та поперечної фононних частот рiдкого натрiю. Парна кореляцiйна функцiя рiдкого натрiю була запропонована при рiзних температурах, а саме T = 378 K, 473 K, 573 K та 723 K, застосовуючи метод
молекулярної динамiки для 672 частинок. Опис електрон-iонної взаємодiї здiйснювався за допомогою запропонованого авторами модельного потенцiалу, доповненого функцiєю Серкара та iн., що
описує поправку на локальне поле. Щоб оцiнити параметр потенцiалу, була застосована умова нульового тиску. Отриманi результати для g(r) добре узгоджуються з експериментальними даними.
На основi обчисленої g(r) вивчалась температурна залежнiсть колективної динамiки рiдкого натрiю.
Показано, що з пiдвищенням температури амплiтуди максимумiв повздовжньої i поперечної частот
понижуються, а ширина пропагаторної щiлини для поперечних акустичних хвиль звужується
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