2,651 research outputs found
Natural Dye Extracts of Areca Catechu Nut as dye Sensitizer for Titanium dioxide Based Dye Sensitized Solar Cells
A dye sensitized solar cell was fabricated using titanium dioxide nano particles sensitized by a new natural dye extracted from areca catechu nut. The natural dye extract contains tannin which is rich in gallotannic acid. The pure titanium dioxide nano particles in anatase phase were synthesized by sol-gel technique and were sensitized by the natural dye to yield photo anode material. The Powder X-Ray Diffraction, UV-vis spectra, Fourier Transform Infra Red spectroscopy, Energy Dispersive X- Ray spectroscopy and Scanning Electron Microscopy studies of pure and natural dye sensitized TiO2 were carried out to analyze their structural, optical, functional group, compositional and morphological details. The dye sensitized solar cell was fabricated using TiO2 nano particles coated on FTO glass plate which is sensitized by the natural dye as photo anode and platinum coated FTO as counter electrode. The natural dye sensitized solar cell showed a solar light energy to electron conversion efficiency of 0.76 %.
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STABILITY INDICATING RP HPLC METHOD FOR THE ESTIMATION OF ARMODAFINIL IN TABLET DOSAGE FORM
Objective: To develop simple reverse phase HPLC method for the estimation of Armodafinil in tablet dosage form.
Methods: Chromatography was performed by isocratic elution on a Stainless steel Hibar C18 column with dimensions 4.6 x 250 mm, packed with octadecylsilane bonded to porous silica (C18) with particle size 5 micron. Acetonitrile and water in the ratio of 50:50 v/v is used as mobile phase. The flow rate is 1.0 ml/ min and effluent is monitored at 220 nm. Armodafinil was eluted at a retention time of 3.8 minutes.
Results: The standard curve of Armodafinil was linear over a working range of 1–700 µg/ml and gave an average correlation coefficient of 0.999. The limit of quantitation (LOQ) of the drug is 0.1 µg/ ml. Recovery studies were carried out by standard addition method and the recoveries are found satisfactory within the range of 99.3 to 101.5 %. The method is precise with % RSD below
Conclusion: The method is validated in terms of robustness and forced degradation studies were carried out and this method can be applied for routine degradation studies ans quantification in regular laboratories
Variability of Low-ionization Broad Absorption Line Quasars Based on Multi-epoch Spectra from The Sloan Digital Sky Survey
We present absorption variability results for 134 bona fide \mgii\ broad
absorption line (BAL) quasars at 0.46~~2.3 covering days
to 10 yr in the rest frame. We use multiple-epoch spectra from the Sloan
Digital Sky Survey, which has delivered the largest such BAL-variability sample
ever studied. \mgii-BAL identifications and related measurements are compiled
and presented in a catalog. We find a remarkable time-dependent asymmetry in EW
variation from the sample, such that weakening troughs outnumber strengthening
troughs, the first report of such a phenomenon in BAL variability. Our
investigations of the sample further reveal that (i) the frequency of BAL
variability is significantly lower (typically by a factor of 2) than that from
high-ionization BALQSO samples; (ii) \mgii\ BAL absorbers tend to have
relatively high optical depths and small covering factors along our line of
sight; (iii) there is no significant EW-variability correlation between \mgii\
troughs at different velocities in the same quasar; and (iv) the EW-variability
correlation between \mgii\ and \aliii\ BALs is significantly stronger than that
between \mgii\ and \civ\ BALs at the same velocities. These observational
results can be explained by a combined transverse-motion/ionization-change
scenario, where transverse motions likely dominate the strengthening BALs while
ionization changes and/or other mechanisms dominate the weakening BALs.Comment: 24 pages, accepted for publication in ApJ
A Randomized Controlled Trial of Glucose versus Amylase Resistant Starch Hypo-Osmolar Oral Rehydration Solution for Adult Acute Dehydrating Diarrhea
Background: Reduction of gross diarrhea rate in excess of that seen over time with intravenous therapy and appropriate antibiotics is not usually achieved by oral glucose-electrolyte rehydration therapy for cholera and cholera-like diarrheas. Methodology and Principal Findings: This prospective randomized clinical trial at a tertiary referral hospital in southern India was undertaken to determine whether amylase resistant starch, substituting for glucose in hypo-osmolar oral rehydration solution, would reduce diarrhea duration and weight in adults with acute severe dehydrating diarrhea. 50 adult males with severe watery diarrhea of less than three days' duration and moderate to severe dehydration were randomized to receive hypo-osmolar ORS (HO-ORS) or HO-ORS in which amylase resistant high amylose maize starch 50g/L substituted for glucose (HAMS-ORS). All remaining therapy followed standard protocol. Duration of diarrhea (ORS commencement to first formed stool) in hours was significantly shorter with HAMS-ORS (median 19, IQR 10-28) compared to HO-ORS (median 42, IQR 24-50) (Bonferroni adjusted P, P-adj < 0.001). Survival analysis (Kaplan-Meier) showed faster recovery from diarrhea in the HAMS-ORS group (P < 0.001, log rank test). Total diarrhea fecal weight in grams (median, IQR) was not significantly lower in the HAMS-ORS group (2190, 1160-5635) compared to HO-ORS (5210, 2095-12190) (P-adj = 0.08). However, stool weight at 13-24 hours (280, 0-965 vs. 1360, 405-2985) and 25-48 hours (0, 0-360 vs. 1080, 55-3485) were significantly lower in HAMS-ORS compared to HO-ORS group (Padj = 0.048 and P = 0.012, respectively). ORS intake after first 24 hours was lower in the HAMS-ORS group. Subgroup analysis of patients with culture isolates of Vibrio cholerae indicated similar significant differences between the treatment groups. Conclusions: Compared to HO-ORS, HAMS-ORS reduced diarrhea duration by 55% and significantly reduced fecal weight after the first 12 hours of ORS therapy in adults with cholera-like diarrhea
X-ray and multi-epoch optical/UV investigations of BAL to non-BAL quasar transformations
We report on an X-ray and optical/UV study of eight Broad Absorption Line
(BAL) to non-BAL transforming quasars at 1.7-2.2 over 0.29-4.95
rest-frame years with at least three spectroscopic epochs for each quasar from
the SDSS, BOSS, , and ARC 3.5-m telescopes. New observations
obtained for these objects show their values of and
, as well as their spectral energy distributions, are
consistent with those of non-BAL quasars. Moreover, our targets have X-ray
spectral shapes that are, on average, consistent with weakened absorption with
an effective power-law photon index of . The newer and ARC 3.5-m spectra reveal
that the BAL troughs have remained absent since the BOSS observations where the
BAL disappearance was discovered. The X-ray and optical/UV results in tandem
are consistent with at least the X-ray absorbing material moving out of the
line-of-sight, leaving an X-ray unabsorbed non-BAL quasar. The UV absorber
might have become more highly ionized (in a shielding-gas scenario) or also
moved out of the line-of-sight (in a wind-clumping scenario).Comment: 14 pages, 5 figures, Accepted for publication in MNRA
Incidence of cetonid beetles, Protaetia alboguttata (Vigors) on karonda, Carissa carandas
Severe infestation of cetonid beetles, Protaetia alboguttata (Vigors) has been noticed on karonda at the experimental station of Indian Institute of Horticultural Research, Bengaluru during the year 2013. The mean damage on the ripe fruits was found to be 22.40+2.50% with a range of 15.00 – 30.00%. Considering the polyphagy of cetoniids, these beetles can pose direct threat to the cultivation of karonda
Ocular doppler imaging: opening a new window in decoding glaucoma
Background: In the aetiopathogenesis of multifactorial glaucoma autoregulation of ocular blood flow plays an important role as failure of autoregulation may lead to progression of disease. Aim of this study to understand this better this study was designed to investigate the quantum of these abnormalities and their likely role in pathogenesis and prognosis of primary open angle glaucoma(POAG).Methods: This is a case control study design which involved 67 POAG patients and 67 matched controls. The parameters assessed includes peak systolic velocity(PSV), end diastolic velocity(EDV) and resistive index(RI) of ophthalmic artery(OA) and central retinal artery(CRA) of patients having POAG with age and sex matched healthy subjects. The data obtained was statistically analysed using IBM SPSS 21.Results: The study showed decreased PSV of 31.7 cm/s vs 42.7 cm/s(p=0.0001) and EDV11.7 cm/s vs 19.8 cm/s(p=0.002) with increased RI 0.63 vs 0.53(p=0.000) in OA and PSV of 15.2 cm/s vs 21.4 cm/s(p=0.001) and EDV4.7 cm/s vs 11.7 cm/s(p=0.003) with increased RI 0.69 vs 0.45(p=0.000) in CRA in both eyes in POAG patients as compared to healthy controls.Conclusion: The study has shown the promising application of ocular Doppler in evaluating POAG patients. However, more such studies are needed with larger study sample and on follow up basis for better understanding glaucoma hemodynamics and applicability of ocular Doppler in management of glaucoma
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