Electronic band structure and optical properties of titanium dioxide

In this work the Fritz-Haber Institute ab initio Molecular Simulation (FHI-aims) code was used to investigate and obtain the band energies and linear dielectric functions of the three naturally occurring phases of TiO2 (Rutile, Anatase and Brookite). The exchange-correlation interactions are treated by the PBE. The results of the band gap were obtained to be 1.76 eV for Rutile, 2.07 eV for Anatase and 2.33 eV for Brookite with Rutile having a direct band gap and indirect band gaps for both Anatase and Brookite. The obtained band gaps are in agreement with other theoretical work, especially on the rutile phase. The linear dielectric function was calculated using Random Phase Approximation (RPA) where the average static dielectric function at ω= 0 was obtained as 5.61 for Rutile TiO2, 4.29 for Anatase TiO2 and 2.23 for Brookite TiO2

Preparation and characterization of nanocrystalline Ba(Ti0.96SnxZr0.04-x)O3 ceramic

Nanocrystalline powders of Barium titanate (BaTiO3 or BT) and Ba(Ti0.96SnxZr0.04-x)O3 (BTSZ1, BTSZ2, and BTSZ3) [x=0.02, 0.03 and 0.04] have been synthesized by a combination of solid-state reaction and high energy ball- milling technique (HBM). The effect of increasing Sn content on the microstructure and dielectric properties of the ceramics were studied. X-ray diffraction patterns show cubic and tetragonal symmetry without secondary phase. Sn4+ and Zr4+ ions entered the perovskite-type cubic structure and led to an increase in the lattice parameters. The average crystallite size has been calculated using Scherrer formula. Using Scherrer, the crystallite size of the (110) peaks of the pure BT is 31.2 nm and that of BTSZ1, BTSZ2, and BTSZ3 are 42.7, 37.9 and 42.3 nm respectively. The FESEM results indicated a variation of grain size from 144.53, to 89.28 nm for the pure BT, BTSZ1, BTSZ2, and BTSZ3, which show a decrease in grain size as Sn doping increases. Frequency dependence of dielectric permittivity and loss studied in the range temperature and frequency range 30-400oC and 40 Hz–1 MHz, respectively, for BT, BTSZ1, BTSZ2, and BTSZ3 show a normal ferroelectric phase transition behavior. The corresponding dielectric constant and loss at room temperature show that BTSZ2 has the highest dielectric constant and loss of 1671 and 1.6 respectively. The high dielectric constants and relatively lower loss tangent values meet the current demand for device miniaturization in the electronics industry.Keywords: BT-BTSZ ceramics; high energy ball milling; XRD; FESEM; dielectric propertie

Depositional Behaviour of Highly Macro-Crystalline Waxy Crude Oil Blended with Polymer Inhibitors in a Pipe with a 45-Degree Bend

Abstract Production, transportation and storage of highly waxy crude oil is very challenging. This is because they are usually characterised by high content of macro-crystalline waxes, predominantly consisting of n-alkanes (C18 to C36) that which could cause costly deposition within the wellbore and production equipment. The accumulation of deposited wax can decrease oil production rates, cause equipment breakdown, and clog the transport and storage facilities. Currently, different polymeric inhibitors have been utilised in the oil and gas field to mitigate and prevent wax deposition. However, as of today, there is no distinctive wax inhibitor that could work effectively for all oil fields. One of the objectives of this work is to study the efficacy of a blended commercial wax inhibitor - pour point depressant on wax deposition mitigation in a flow rig designed with 0 and 45-degree bends in the pipeline. Standard laboratory techniques using high-temperature gas chromatography (HTGC), rheometer rig, polarized microscope and elution chromatography were employed to obtain n-paraffin distribution, oil viscosity, WAT, pour point and SARA fractions. Series of experimentation were carried out with and without the inhibitor in a straight pipe test section. The severity of wax deposition in the pipeline built-in with a 45-degree bend is compared with a straight pipe. The blended inhibitor was tested at concentrations of 500, 1000, and 1500-ppm, under laminar and turbulent conditions. The crude oil sample was found to be naturally waxy with wax content of 19.75wt%, n-paraffin distributions ranges from C15-C74, WAT and pour point of 30°C and 25°C respectively. The severity of wax deposition in the test section is 43% higher in 45-degree bend compared to straight pipe. However, the severity of the deposition was reduced to 12.3% at extremely low temperature and flow rate. Nonetheless, better inhibition performance was achieved at 25 and 30°C. The wax thickness was reduced from δwax ≈ 0.36mm at 5 l/min to δwax ≈ 0.132mm at 7 l/min at constant coolant temperature (25°C) and 1500-ppm, whereas, no wax deposition was observed at 11 l/min. Mechanisms such as molecular diffusion due to frictional pressure losses, shear dispersion and gravity settling due to momentum change and hydrostatic, alongside with thermal difference are the main drivers for wax deposition in both straight and bend pipe. Whereas, the interaction mechanisms such as the nucleation, alongside with adsorption, co-crystallization, and solubilisation between the new blended inhibitor and the wax crystals provide an improved inhibition performance in the system even at extreme cases

Strategy on Hepatitis B prevention among African undergraduate students of health sciences in Davangere, Karnataka India

Background: Hepatitis B is an inflammatory disease of the liver which is caused by Hepatitis B Virus. It is a global problem, with 66% of all the population living in areas where there are high levels of infections. Hepatitis B infection are due to lapses in the sterilization of instruments as well as improper waste management. Knowledge regarding Hepatitis B and safety precautions is needed to minimize the health care setting’s acquired infections among health personnel and students of health Sciences. Aim: The study was aimed at assessing the knowledge regarding the prevention of Hepatitis B among African Undergraduate students of Health Sciences in Davangere. Methodology: A cross sectional design was used for the study were 50 students were selected using purposive sampling. A validated structured questionnaire was used for data collection. The data were analyzed using median score and correlations. Results: The results indicated that majority (52%) of the respondents were between 22- 24years of age. The students of B.Pharm were 25 (50%), 38% MBBS and 12% B.Sc. Nursing. The overall median score on knowledge regarding hepatitis B Prevention was 13.0 out of maximum score of 29. The association between the knowledge on hepatitis B prevention strategy with level of study and course specialty was 0.74 P>0.05. Conclusion: The study concluded that the knowledge regarding Hepatitis B prevention among students was inadequate hence, recommends a similar study on a larger scale. Keywords: Knowledge; Prevention; Hepatitis B; Infection; African

Structural and dielectric properties of Ba(Ti0.96Sn0.01Zr0.03)O3 perovskite nanoparticles fabricated by mechanochemical synthesis route

Lead free Nanocrystalline BaTiO3 doped with Sn and Zr is prepared by a combination of solid-state reaction and high energy ball milling (HBM) technique in a temperature range 30–150 °C, over a frequency range 40 Hz – 1 MHz. A single-phase nanocrystalline sample with ABO3 type of perovskite structure with cubic symmetry was confirms by XRD diffraction. The crystallite and grain size determined from Scherrer equation and intercept method are 38.2 nm and 46.13 nm respectively. FE-SEM images show samples are dense and have different microstructures with certain amount of porosity. A grain size of 46.13 nm is obtained by using linear intercept method. Room temperature (RT) variation of ′and tan as a function of frequency of the modified BT system has also been studied. Variation of dielectric properties with frequency shows the usual behaviour of dielectric materials i.e decrease of the value of ′ with the increase of frequency. A dielectric anomalies is observed corresponding to phase transitions viz tetragonal to cubic (− ) at 70oC. These effect can guide to design the nanostructure for various practical applications of MLCC

Karakteristik Roti Bebas Gluten Berbahan Dasar Pati Ganyong Termodifikasi

Modified canna starch by Heat Moisture Treatment (HMT) and xanthan gum (GX) showed had potential used in the formulation of gluten-free breads. This study aimed to explore the phyiscals and sensory caharacteristics of gluten-free breads from some types of modified canna starch. The main material was some types of modified canna starch. The study was applied Completely Randomized Design with one treatment factor of starches type (HMT-GX and HMT modified canna starches, natural canna starch with and without 1.5% of xanthan gum addition, corn starch, and wheat flour). While the characteristics of bread determined include: specific volume, color, texture, ratio between height and diameter of bread, and sensory. The results showed that the best treatment based on physical and sensory characteristics was produced using HMT-GX modified canna starch. The characteristics of gluten free bread produced have a specific volume of 2.85 ± 0.017 cm3/g, color (L *, a *, b * 75.13, +9.370; +29.40, respectively), texture of 109.03 ± 7.50 gf, bread high and diameter ratio of 0.74, hedonic score for taste, color, texture and aroma respectively 5.34; 5.46; 5.56, and 5.80 repectively (range of hedonic values from 1 = very dislike to 7 = very like)

Development and Performance Evaluation of a Castor Seed (Ricnus Communis) Shelling Machine with a Winnowing System

This study reports the development and performance evaluation of a castor seed shelling with a winnowing system using locally available materials. The winnowing unit does the cleaning of the castor seed after shelling with the help of fan. The machine consists of a hopper, shelling cylinder, concave, bearing, bolt and nuts, cleaning unit, pulley, grain outlet, shaft, prime mover seat and frame. The developed machine was evaluated using variety of (IAR) castor seed in a factorial experiment with five levels of cylinder speed (220, 20, 260, 280 and 300 rpm), three levels of concave clearance (15, 20, and 28 mm) and three cylinder types (metal, rubber and wood) in a completely randomized design (CRD). Data collected for shelling efficiency, cleaning efficiency, mechanical grain damage, scattered losses and output capacity were analyzed using a statistical analysis software (SAS), where analysis of variance (ANOVA) and the Duncan multiple range test (DMRT) were computed at 1 and 5% levels of significance. The results showed that the best cylinder types in descending order were metal, rubber and wood while cylinder speed of 220 rpm was optimum for all the cylinder types. However, the optimum concave clearance varies with the cylinder types as 15, 20, and 28 mm respectively. While the corresponding optimum values for output capacity, cleaning and scattered seeds were17.90 kg/h, 97.26, 78.20 and 0.51%;12.19 kg/h, 78.91 and 0.36%; 14.78 kg/h, 67.96, and 1.67%, respectively.Keywords—Keyword: Castor seed shelling machine, winnower, castor seed, and machine design

N′-[1-(5-Bromo-2-hydroxy­phen­yl)ethyl­idene]-3,4,5-trihydroxy­benzohydrazide dimethyl sulfoxide solvate trihydrate

The benzohydrazide mol­ecule in the title compound, C15H13BrN2O5·C2H6OS·3H2O, is almost planar with an r.m.s. deviation for the non-H atoms of 0.078 Å. The organic mol­ecules, water and dimethyl sulfoxide solvent mol­ecules are linked by N—H⋯O, O—H⋯O and O—H⋯S inter­molecular hydrogen bonds, forming zigzag chains along the a axis. Intra­molecular O—H⋯O and O—H⋯N hydrogen bonds also occur

Toxicity of imidacloprid gel bait against laboratory strain of Periplaneta americana (L.) (Dictyoptera : Blattidae) and Blattella germanica (L.)(Dictyoptera : Blattellidae)

The efficacy of a 2.15% imidacloprid gel bait against laboratory strain Periplaneta americana and Blattella germanica was evaluated under laboratory conditions. The susceptibility trend of both species towards imidacloprid was: adult male < adult female < nymphs. All stages of both species were dead within 10 days in primary poisoning testing. Periplaneta americana adult male (LT50 = 0.47 h; LT95 = 5.24 h) died fastest, while nymphs of B. germanica took the longest time to reach 95% mortality (LT95 = 43.84 h). In indirect exposure via secondary poisoning, only adult males of P. americana (LT50 = 100.63 h) and B. germanica (LT50 = 54.66 h) obtained 50% mortality before the testing ended. No complete mortalities were achieved in any stages of both species within 10 days of secondary poisoning testing. Therefore, imidacloprid gel bait used in this study was able to cause complete mortalities within less than 2 days of 10-day primary poisoning testing but less effective in the 10-day secondary poisoning testing