Mg2+ doped Copper Cadmium oxalate (MCuCO) single crystals were grown by a single diffusion method in silica hydrogel at room temperature. Powder X-ray diffraction (XRD) studies show the triclinic ...nature of the crystals. The dielectric constant, ac resistivity and ac conductivity have been measured as a function of frequency. The dielectric constant of MCuCO crystal decreases as the frequency of applied field increases; at the end it gives the diminishing value of dielectric constant. AC conductivity increases with the increase of frequency. Absorbance, transmittance, reflectance, refractive index, and energy gap of MCuCO crystal were determined by UV-Visible spectroscopy. A high bandgap corresponds to the dielectric behavior of the crystal.
Rural and urban areas of eight selected districts in the eastern zone of India.
To estimate the annual risk of tuberculous infection (ARTI).
A community-based, cross-sectional tuberculin survey was ...conducted among children aged 1-9 years residing in a sample of rural and urban areas. Stratified two-stage cluster sampling was adopted for selection of rural and urban clusters. A total of 40964 children in 515 clusters underwent tuberculin testing and reading with 1TU PPD RT23 with Tween 80; the maximum transverse diameter of induration was measured about 72 h after the test.
A bacille Calmette-Gúerin (BCG) scar was observed in 51.5% of the test-read children. The frequency distribution of tuberculin reaction size among 19332 children without BCG scar was found to be bimodal, with the mode of reactions attributable to infection with tubercle bacilli at 20 mm. The prevalence of infection was estimated as 6.9%. The ARTI computed from the estimated prevalence was 1.3%. Children residing in the urban areas were found to be at a significantly higher risk of infection than those residing in rural areas.
The high rate of ARTI in the eastern zone of India suggests a need for committed, sustained action in provision of quality tuberculosis control services.
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•ZnO:Eu nanopowders have been synthesized by simple low cost SCS method.•SEM and TEM images reveal quasi-hexagonal morphology of the samples.•ZnO:Eu nanopowders show PL peaks ...corresponding to both Eu2+ and Eu3+ ions.•EPR spectrum exhibits a broad resonance signal attributed to Eu2+ ions.•EPR and TL studies reveal native defects. The trap parameters are discussed.
ZnO:Eu (0.1mol%) nanopowders have been synthesized by auto ignition based low temperature solution combustion method. Powder X-ray diffraction (PXRD) patterns confirm the nanosized particles which exhibit hexagonal wurtzite structure. The crystallite size estimated from Scherrer’s formula was found to be in the range 35–39nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies reveal particles are agglomerated with quasi-hexagonal morphology. A blue shift of absorption edge with increase in band gap is observed for Eu doped ZnO samples. Upon 254nm excitation, ZnO:Eu nanopowders show peaks in regions blue (420–484nm), green (528nm) and red (600nm) which corresponds to both Eu2+ and Eu3+ ions. The electron paramagnetic resonance (EPR) spectrum exhibits a broad resonance signal at g=4.195 which is attributed to Eu2+ ions. Further, EPR and thermoluminescence (TL) studies reveal presence of native defects in this phosphor. Using TL glow peaks the trap parameters have been evaluated and discussed.
Rural areas in Uttar Pradesh, the most populous state in India.
1) To estimate the average annual risk of tuberculous infection (ARI), 2) to study ARI trends with age, and 3) to compare tuberculin ...reactions among children with and without BCG scar.
A cross-sectional tuberculin survey was conducted among children aged 1-9 years residing in Rae Bareli, Hardoi and Jaunpur districts, Uttar Pradesh. Tuberculin testing was performed using 1TU of PPD RT23 with Tween 80, and indurations were measured 72 hours later. Prevalence of infection was estimated in children without BCG scar based on the cut-off point identified on the frequency distribution of reaction sizes. The ARI was computed from the estimated prevalence.
The proportion of children with BCG scar varied from 25% to 31% in the study districts. Using a cut-off of 14 mm among children without BCG scar, the ARI was estimated at 2.3% in Rae Bareli, 1.9% in Hardoi and 1.5% in Jaunpur, and was observed to increase with age. Tuberculin test results among children with BCG scar suggest that they may be included in tuberculin surveys to estimate ARI.
High rates of transmission of tuberculous infection suggest that tuberculosis control measures need to be intensified.
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► ZnO:Fe nanopowders were prepared by LSC method. ► PXRD, SEM, TEM, FTIR, UV–Vis, Raman, EPR, PL and TL studies were carried out. ► Single well resolved TL glow peak at ∼368°C was ...observed. ► The trap parameters have been evaluated and discussed.
Zn(1−x)Fe(x)O(1+0.5x) (x=0.5–5mol%) nanoparticles were synthesized by a low temperature solution combustion route. The structural characterization of these nanoparticles by PXRD, SEM and TEM confirmed the phase purity of the samples and indicated a reduction in the particle size with increase in Fe content. A small increase in micro strain in the Fe doped nanocrystals is observed from W–H plots. EPR spectrum exhibits an intense resonance signal with effective g values at g≈2.0 with a sextet hyperfine structure (hfs) besides a weak signal at g≈4.13. The signal at g≈2.0 with a sextet hyperfine structure might be due to manganese impurity where as the resonance signal at g≈4.13 is due to iron. The optical band gap Eg was found to decrease with increase of Fe content. Raman spectra exhibit two non-polar optical phonon (E2) modes at low and high frequencies at 100 and 435cm−1 in Fe doped samples. These modes broaden and disappear with increase of Fe dopant concentration. TL measurements of γ-irradiated (1–5kGy) samples show a main glow peak at 368°C at a warming rate of 6.7°Cs−1. The thermal activation parameters were estimated from Glow peak shape method. The average activation energy was found to be in the range 0.34–2.81eV.
Rural and urban areas of eight selected districts of Orissa State, India.
To estimate the average annual risk of tuberculous infection (ARTI) in the state.
A community-based, cross-sectional ...tuberculin survey was conducted among children aged 1-9 years residing in a sample of rural and urban areas of eight districts of Orissa State. A stratified sampling was adopted for selection of clusters. Highly trained designated tuberculin testers administered 0.1 ml (1 TU) of PPD RT 23 with Tween 80 by the Mantoux method to 10 626 children. Transverse tuberculin reaction sizes were measured about 72 h later by trained designated tuberculin readers. The number of children satisfactorily test-read was 10 191.
Based on the frequency distribution of tuberculin reaction sizes, the average ARTI in the state was estimated at 1.7-1.8%. The children residing in urban areas were observed to be at a significantly higher risk of infection than those in rural areas.
The study in Orissa State suggests high rates of transmission of tuberculous infection and calls to attention the need for intensification of concerted and sustained tuberculosis control efforts.
Composites reinforced with natural fibres have gained popularity compared to synthetic fibre-reinforced polymer composites due to their environmental sustainability, despite their reduced stiffness ...and load-bearing capability. In this work, the biocomposites reinforced with sisal and jute fibres which are made by hand layup technique were investigated for mechanical and water absorption characteristics. The effect of a 4 percent NaoH treatment concentration on the aforementioned properties was investigated. The specimens’ tensile and flexural broken surfaces were morphologically characterized to investigate microstructural failures. The experimental results show that, compared to untreated fibre-reinforced composites, the biocomposites reinforced with 4 percent NaoH-treated fibre exhibit higher tensile, flexural, and impact strengths, as well reduced water absorption rate. These composites are aimed to be used for strengthening existing civil structures as a retrofitting element.
•Single crystals of SrC4H4O6·5H2O and CuSrC4H4O6·5H2O are grown by gel method.•Grown crystals are characterized using various standard techniques.•Studies unveil interesting and useful structural ...features of the crystals.•Results show the usefulness of crystals both as thermal isolators and NLO devices.
Single crystals of intrinsic strontium L(+) tartrate (IST) and Cu2+ doped strontium L(+) tartrate (CuDST) are synthesized using single test tube gel diffusion technique. At ambient temperature, specific gravities of 1.050 and 1.055 and gel pH of 4.0 and 4.2 (with 0.5 M inner and upper reactants) are found to ensure optimized growth and quality of IST and CuDST crystals, respectively. These crystals show maximum sizes of 4.2 × 1.7 × 1.3 mm3 (for IST) and 5.1 × 0.9 × 0.8 mm3 (CuDST). Doping is observed to change the morphology of IST crystal. The stoichiometric composition and cationic distribution of the grown crystals are determined using Energy Dispersive X-Ray Analysis (EDAX) technique. The functional groups present in the crystals are identified by Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectral studies. Thermal studies confirm the presence of five water molecules in the IST and CuDST crystals.
Optical studies reveal that the crystals are transparent to visible and near Infrared (IR) wavelengths. Doping is observed to cause an increase in the peak absorbance in Ultraviolet (UV) region. Both IST and CuDST crystals show low absorbance in the entire visible region, indicating their usefulness in Nonlinear Optical (NLO) applications. The optical transmittance of the IST crystal is seen to increase on doping. Both IST and CuDST crystals show bandgap energies suggestive of their insulating nature, indicating their usefulness in electronic applications. The Voltage-Current (V-I) characteristics of the crystals show that the electrical conductivity of CuDST crystals is larger than the conductivity of IST crystals.
Paucity of epidemiological data on tuberculosis in India prompted the National Tuberculosis Institute, Bangalore to embark upon a nation-wide survey to estimate the Annual Risk of Tuberculosis ...Infection in different parts of the country. The survey in Junagadh district, one of the 26 districts drafted under the nation-wide survey is reported here. The prevalence of infection from the analysis of 3164 children not displaying scars of the BCG vaccination was 4.16% (CI: 3.17-5.14) and from this data the ARI was computed as 0.73% (CI: 0.55-0.91). The inclusion of vaccinated children into the study group yielded similar results. The estimate of the ARI in Junagadh district is lesser than that in several other parts of India which is probably in consonance with its better socio-economic development.
Existing buildings are retrofitted to formulate them to be more resistant to seismic activity, earth motion, and other natural disasters. Many available reinforced concrete buildings across the globe ...are in desperate need of rehabilitation, repair, or replacement owing to degradation caused by a variety of reasons such as corrosion, lack of detailing, and failure of beam-column bonding, among others. In the construction sector, fibre reinforced polymer (FRP) composites have been recognized as a potential option for repairing and increasing the strength of existing structures. In this study, comparisons are done in terms of load bearing capability of the beams for configurations between FE model predictions and field data (experimental). To assess the FRP retrofit, structural responses for strengthened and control post tensioned concrete (PTC) beams are compared, with strengthening using various wrapping methods. The load bearing capacities of the beams retrofitted with sisal and jute fibre employing strip and full wrapping procedures around all four sides is increased by 35.55 percent and 42.85 percent for sisal FRP and 7.14 percent and 12.01 percent for jute FRP, respectively, as compared to the control specimen. The FRP retrofit model is expected to result in a considerable increase in structural performance.
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