Properties of Al-doped ZnS films grown by chemical bath deposition

Zinc sulphide (ZnS) buffer layers are a cadmium free, wider energy band gap, alternative to the cadmium sulphide(CdS) buffer layers commonly used in copper indium gallium diselenide (CuInGaSe2)-based solar cells. However extrinsic doping of the ZnS is important to lower the resistivity of the layers and to improve flexibility of device design. In this work, Al-doped ZnS nanocrystalline films have been produced on glass substrates using a chemical bath deposition (CBD) method. The Al- concentration was varied from 0 at. % to 10 at. %, keeping other deposition parameters constant. The elemental composition of a typical sample with 6 at. % ‘Al’ in ZnS was Zn=44.9 at. %, S=49.8 at. % and Al=5.3 at.%. The X-ray diffraction data taken on these samples showed a broad peak corresponding to the (111) plane of ZnS while the crystallite size varied in the range, 8 – 15 nm, depending on the concentration of Al in the layers. The films with a Al-doping content of 6 at. % had an optical transmittance of 75 % in the visible range and the energy band gap evaluated from the data was 3.66 eV. The films n-type electrical conductivities and the electrical resistivity varied in the range, 107-103 Ωcm, it decreasing with an increase of the Al-concentration in the solution

A cross-sectional study of post-vaccination anti-HBs titer and knowledge of hepatitis B infection amongst medical students in a metropolitan city

Background: Medical students are at risk of acquiring hepatitis B virus infection due to occupational contact with patients’ blood or other body fluids. This study was conducted to determine knowledge of hepatitis B virus infection and anti-HBS antibody titer amongst medical students.Methods: This cross-sectional observational study was conducted on medical students who satisfied the intake criteria and gave written informed consent to participate in the study. After Institutional Ethics Committee clearance, written informed consent was obtained and a structured, pre-validated questionnaire (pre-test) was administered to the participants. After an educational session, an identical questionnaire was administered (post-test). For determining anti-HBs titer (vaccinated participants) and HBsAg (non-vaccinated participants), blood was aseptically collected by cubital venepuncture. HBsAg and anti-HBs antibody levels were determined by immuno-chromatographic assay and enzyme-linked immunosorbent assay, respectively.Results: 140 healthy, HBsAg-negative medical students (79 males; 61 females) participated in the present study. There was increased median correct response in the post-test with increased minimum and first quartile. 91 (65%) who were vaccinated against Hepatitis B were enrolled for anti-HBs titer estimation. There was no significant gender difference in mean antibody titer. 19 (20.9%) had inadequate levels of anti-HBS antibodies. 50% seroconversion was seen after single dose of hepatitis B vaccine.Conclusions: It is essential to delve into the logistic aspects of evaluating all medical students for hepatitis B infection, procuring and offering free vaccination and assessing anti-HBS titer of vaccinated individuals

Retrospective record based study of maternal and fetal outcome in induction of labour at 40 and 41 weeks of gestation in uncomplicated primigravida women

Background: The objective of the study was to compare maternal and foetal outcome after induction in two groups: women who were induced at 40-weeks and at 41-weeks.Methods: This was a retrospective study conducted over period of one year from 1 January 2018 to 31 December 2018 in the obstetrics and gynaecology department. A total of 200 uncomplicated primigravida women were included in the study. The data was collected and comparative analysis was done between two groups: control group (group A), women with induction at 40 weeks; study group (group B), women with induction at 41 weeks. The outcome was then analysed in terms of mode of delivery, oligohydramnios, meconium-stained liquor, Apgar score, need of NICU, perinatal death. The data was collected, analysed and statistical analysis was done using the Chi square test.Results: Out of total 200 women, 104 women were of 40 weeks and 96 women had completed 41 weeks. The LSCS rate was reduced from 25.96% to 17.7%, when the labour was induced at 41 weeks, the instrumental delivery rate was low in the study group compared to the control group. Even though the meconium staining of liquor was high but NICU admission and perinatal mortality was comparatively lower in the study group.Conclusions: Induction of labour done at 41weeks is associated with reduced maternal morbidity and no adverse effect on the perinatal outcome as compare to induction at 40 weeks

Annealing study and thermal investigation on bismuth sulfide thin films prepared by chemical bath deposition in basic medium

This is a post-peer-review, pre-copyedit version of an article published in Applied Physics A 124.2 (2018): 166. The final authenticated version is available online at: http://doi.org/10.1007/s00339-018-1584-7Bismuth sulfide thin films were prepared by chemical bath deposition using thiourea as sulfide ion source in basic medium. First, the effects of both the deposition parameters on films growth as well as the annealing effect under argon and sulfur atmosphere on as-deposited thin films were studied. The parameters were found to be influential using the Doehlert matrix experimental design methodology. Ranges for a maximum surface mass of films (3 mg cm-2) were determined. A well crystallized major phase of bismuth sulfide with stoichiometric composition was achieved at 190°C for 3 hours. The prepared thin films were characterized using Grazing Incidence X-ray diffraction (GIXRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDX). Second, the band gap energy value was found to be 1.5 eV. Finally, the thermal properties have been studied for the first time by means of the electropyroelectric (EPE) technique. Indeed, the thermal conductivity varied in the range of 1.20 - 0.60 W m-1 K-1 while the thermal diffusivity values increased in terms of the annealing effect ranging from 1.8 to 3.5 10-7 m2s-1This work was financially supported by the Tunisian Ministry of Higher Education and Scientific Research and by the WINCOST (ENE2016-80788-C5-2-R) project funded by the Spanish Ministry of Economy and Competitivenes

Robust Detection of Text in Natural Scene Images

Detection of text and identification in natural scene images has applications in computer vision systems such as license plate detection, automatic street sign translation, image retrieval and help for visually challenged people. The text images has complex background, blur, occluded text, different font-styles, and noises in image and variation in illumination. Hence, scene text recognition puts forth challenges in computer vision. Hence, a potent method based on Maximally Stable External Regions (MSER) has been used as described in this paper. Here, the text characters are clustered, separating them from high probable non-text characters with the help of text categorizer. The algorithm is then verified by testing it on images based on the predefined rules