Enhanced Room Temperature Coefficient of Resistance and Magneto-resistance of Ag-added La0.7Ca0.3-xBaxMnO3 Composites

In this paper we report an enhanced temperature coefficient of resistance (TCR) close to room temperature in La0.7Ca0.3-xBaxMnO3 + Agy (x = 0.10, 0.15 and y = 0.0 to 0.40) (LCBMO+Ag) composite manganites. The observed enhancement of TCR is attributed to the grain growth and opening of new conducting channels in the composites. Ag addition has also been found to enhance intra-granular magneto-resistance. Inter-granular MR, however, is seen to decrease with Ag addition. The enhanced TCR and MR at / near room temperature open up the possibility of the use of such materials as infrared bolometric and magnetic field sensors respectively.Comment: 22 pages of Text + Figs:comments/suggestions([email protected]

Ground-based optical transmission spectrum of the hot Jupiter HAT-P-1b

Time-series spectrophotometric studies of exoplanets during transit using ground-based facilities are a promising approach to characterize their atmospheric compositions. We aim to investigate the transit spectrum of the hot Jupiter HAT-P-1b. We compare our results to those obtained at similar wavelengths by previous space-based observations. We observed two transits of HAT-P-1b with the Gemini Multi-Object Spectrograph (GMOS) instrument on the Gemini North telescope using two instrument modes covering the 320 - 800 nm and 520 - 950 nm wavelength ranges. We used time-series spectrophotometry to construct transit light curves in individual wavelength bins and measure the transit depths in each bin. We accounted for systematic effects. We addressed potential photometric variability due to magnetic spots in the planet's host star with long-term photometric monitoring. We find that the resulting transit spectrum is consistent with previous Hubble Space Telescope (HST) observations. We compare our observations to transit spectroscopy models that marginally favor a clear atmosphere. However, the observations are also consistent with a flat spectrum, indicating high-altitude clouds. We do not detect the Na resonance absorption line (589 nm), and our observations do not have sufficient precision to study the resonance line of K at 770 nm. We show that even a single Gemini/GMOS transit can provide constraining power on the properties of the atmosphere of HAT-P-1b to a level comparable to that of HST transit studies in the optical when the observing conditions and target and reference star combination are suitable. Our 520 - 950 nm observations reach a precision comparable to that of HST transit spectra in a similar wavelength range of the same hot Jupiter, HAT-P-1b. However, our GMOS transit between 320 - 800 nm suffers from strong systematic effects and yields larger uncertainties.Comment: A&A, accepted, 16 pages, 8 figures, 5 table

Continuing reductions in HPV 16/18 in a population with high coverage of bivalent HPV vaccination in England: an ongoing cross-sectional study.

OBJECTIVES: The human papillomavirus (HPV) immunisation programme in England was introduced in 2008. Monitoring changes in type-specific HPV prevalence allows assessment of the population impact of this vaccination programme. METHODS: Residual vulva-vaginal swab specimens were collected from young sexually active women (aged 16-24 years) attending for chlamydia screening across England. Specimens were collected between 2010 and 2013 for type-specific HPV-DNA testing. HPV prevalence was compared to a similar survey conducted in 2008 prior to the introduction of HPV vaccination. RESULTS: A total of 7321 specimens collected in the postvaccination period, and 2354 specimens from the prevaccination period were included in this analysis. Among the individuals aged 16-18 years, with an estimated vaccination coverage of 67%, the prevalence of HPV16/18 infection decreased from 17.6% in 2008 to 6.1% in the postvaccination period. Within the postvaccination period, there was a trend towards lower HPV16/18 prevalence with higher vaccination coverage and increasing time since vaccine introduction from 8.5% in the period 2-3 years postvaccination to 4.0% in the period 4-5 years postvaccination. The prevalence of HPV31 reduced from 3.7% in the prevaccination period to 0.9% after vaccine introduction, although this no longer reached statistical significance after additional consideration of the uncertainty due to the assay change. Smaller reductions were seen in the individuals aged 19-21 years with lower estimated vaccination coverage, but there was no evidence of a reduction in the older unvaccinated women. Some overall increase in non-vaccine types was seen in the youngest age groups (ORs (95% CI); 1.3 (1.0 to 1.7) and 1.5 (1.1 to 2.0) for individuals aged 16-18 and 19-21 years, respectively, when adjusted for known population changes and the change in assay) although this should be interpreted with caution given the potential unmasking effect. CONCLUSIONS: These data demonstrate a reduction in the HPV vaccine types in the age group with the highest HPV vaccination coverage

Current energy resources in Kazakhstan and the future potential of renewables: a review

Kazakhstan is rich in natural resources including coal, oil, natural gas and uranium and has significant renewable potential from wind, solar, hydro and biomass. In spite of this, the country is currently dependent upon fossil fuels for power generation. Coal-fired plants account for 75% of total power generation leading to concerns over greenhouse gas emissions and impacts on human health and the environment. Recent economic growth in Kazakhstan has driven increased demand for energy services making the construction of additional generating capacity increasing necessary for enabling sustained growth. In this context, renewable energy resources are becoming an increasingly attractive option to help bridge the demand-supply gap. Despite significant wind, solar, hydro and biomass potential, these resources have not been sustainably captured and deployed due a range of technical, institutional, social and economic barriers. This article reviews the current energy situation in Kazakhstan including fossil energy and renewable resources and investigates policy drivers for the energy sector. The barriers to adoption of renewables are analysed within the context of national climate and energy goals. Recommendations are presented for the promotion, development and implementation of renewable energy resources in Kazakhstan

Role of fluorine doping on the electron transport layer of F-doped TiO2 (Titanium dioxide) for photovoltaic systems and its environmental impact

Photovoltaic (PV) systems are regarded as clean and sustainable energy sources and exhibit minimal pollution during their lifetime. The production of hazardous contaminants contaminating water resources, emissions of air pollutants during the manufacturing process, and the impact of PV installations on land use are important environmental factors to consider. The present study aimed to synthesise the F-doped Titanium dioxide (TiO2) thin films on a glass substrate employing spin coating followed by the sol-gel process ETL application purpose.  Fluorine-doped TiO2 thin films were prepared using the sol-gel spin coating technique. The X-ray diffraction (XRD) results confirmed that the most intense peak was observed at 25.37° corresponding to the crystallographic plane (101) for anatase TiO2. The average transparency of TiO2 was increased by adding the doping level of fluorine and increment in the optical bandgap. The thickness of the thin film was kept at about 300 nm. The resistance of nanocrystalline thin films of different F doped TiO2 was decreased from 1.322×1012 Ω, 9.728×1011 Ω, as the F doping concentration was increased from pristine to 7 at. %. Based on electrical measurements, it was observed that a suitable electron transport layer (ETL) of F-doped TiO2 can be synthesized for photovoltaic applications.  The present study offers a synthesis and analysis of F-doped TiO2 that can be used to improve the sustainability of PV manufacturing processes, improve its economic value, and mitigate its negative impact on the environment.

Neutral Iron Emission Lines From The Day-side Of KELT-9b -- The GAPS Programme With HARPS-N At TNG XX

We present the first detection of atomic emission lines from the atmosphere of an exoplanet. We detect neutral iron lines from the day-side of KELT-9b (Teq $\sim$ 4, 000 K). We combined thousands of spectrally resolved lines observed during one night with the HARPS-N spectrograph (R $\sim$ 115, 000), mounted at the Telescopio Nazionale Galileo. We introduce a novel statistical approach to extract the planetary parameters from the binary mask cross-correlation analysis. We also adapt the concept of contribution function to the context of high spectral resolution observations, to identify the location in the planetary atmosphere where the detected emission originates. The average planetary line profile intersected by a stellar G2 binary mask was found in emission with a contrast of 84 $\pm$ 14 ppm relative to the planetary plus stellar continuum (40 $\pm$ 5$\%$ relative to the planetary continuum only). This result unambiguously indicates the presence of an atmospheric thermal inversion. Finally, assuming a modelled temperature profile previously published (Lothringer et al. 2018), we show that an iron abundance consistent with a few times the stellar value explains the data well. In this scenario, the iron emission originates at the $10^{-3}$-$10^{-5}$ bar level.Comment: Accepted for publication on ApJL; 19 pages, 4 figures, 3 table

Comparative clinical profile of patients of Benign Prostatic Hyperplasia (BPH) with and without Metabolic Syndrome: a prospective observational study

Background: Benign Prostatic Hyperplasia (BPH) is one of common disorder in men of old age group. The pathogenesis of BPH is multi-factorial and still not been fully elucidated. There are numerous reports which suggest possible link between several metabolic alterations known as Metabolic Syndrome. In the present study, the aim was to establish relation between Benign Prostatic Hyperplasia and Metabolic Syndrome and to find out effects of therapeutic intervention of Metabolic Syndrome on prostatic parameters.Methods: 93 patients of Benign Prostatic Hyperplasia enrolled who met qualifying criteria for inclusion in study and divided into three groups on the basis of Metabolic Syndrome and its treatment administered. Administration of alpha adrenergic blocker was common to all patients of all groups. Metabolic parameters including Fasting blood glucose, High-density lipoprotein (HDL), Triglycerides (TGs), waist circumference and prostatic parameters that is prostate volume, prostate specific antigen (PSA), uroflometry, International prostate symptom score (IPSS) were assessed at baseline, after 3 and 6 months follow-up. Further appropriate statistical tests were applied for comparison of parameters among groups.Results: Patients receiving no treatment for Metabolic Syndrome were having most deranged prostatic parameters as compared to patients without Metabolic Syndrome or patients with Metabolic Syndrome receiving treatment for same. Further patients receiving treatment for Metabolic Syndrome and alpha adrenergic blocker were having better clinical profile than patients of alpha adrenergic blocker alone.Conclusions: These findings show probable link between Metabolic Syndrome and worse prostatic profile. Metabolic Syndrome must be looked for and treated in patients of Benign Prostatic Hyperplasia. Metabolic derangements must not be overlooked and must be treated accordingly

Hierarchical Control of Grid-Connected Hydrogen Electrolyzer Providing Grid Services

This paper presents the operation modes and control architecture of the grid-connected hydrogen electrolyzer systems for the provision of frequency and voltage supports. The analysis is focused on the primary and secondary loops in the hierarchical control scheme. At the power converter inner control loop, the voltage- and current-control modes are analyzed. At the primary level, the droop and opposite droop control strategies to provide voltage and frequency support are described. Coordination between primary control and secondary, tertiary reserves is discussed. The case studies and real-time simulation results are provided using Typhoon HIL to back the theoretical investigation