Non isolated and non-invertingcockcroft-walton multiplier based hybrid 2Nx interleaved boost converterfor renewable energy applications

Abstract: In this paper hybrid non isolated and noninvertingCockcroft- Walton multiplier based 2Nx InterleavedBoost converter (2Nx IBC) for renewable energy applications is presented. The presented hybrid boost converter topology is derived from non-invertingNx Multilevel Boost Converter (Nx MBC) and inverting Nx Multilevel Boost Converter (Nx MBC). In renewable energy applications, generated voltage needs to be stepped up with high conversion ratio using a DC-DC converter at voltage levels as per the application requirement. The advantages of the presentedtopology of interleaved converter are high voltage conversion ratio, reduce ripple, low voltage stress, non-inverting output voltage without utilizing the high duty cycle, coupled inductors and transformer. The main advantage of presented topology consists in increasing voltage gain by adding capacitor and diode into circuitry without disturbing the main circuit.Moreover, the presented topologyis compared with several recent non isolated high gainDC-DC converters. The proposed topology is simulated in MATLAB/SIMULATION andobtained results verify the validity of the design and operation of converter

Development of SSR markers for Robusta coffee (Coffea canephora)

Coffee has long been bred with the view of improving important agronomic characteristics such as yield, bean size, cup quality, caffeine content, disease, drought resistance etc. However, the progress in coffee breeding using conventional approaches has been slow due to the narrow genetic base of cultivated coffee and the long generation time. The use of modern tools of molecular biology holds great promise for the faster development of improved varieties. A primary prerequisite is the availability of suitable marker systems. Co-dominant maker systems like SSRs provides comprehensive genome coverage, are locus specific and multi allelic. However, the number of SSR markers available for coffee is limited and there is an urgent need for generating large number of microsatellite markers. Aim of the study was to develop and characterize a comprehensive set of genomic and genic SSR markers for Robusta coffee by pre-cloning enrichment strategy and also by annotating Robusta specific unigene sequences. The pre-cloning enrichment (selective hybridization) strategy followed in the study resulted in identification of 405 SSRs in 267 sequences. The 405 SSRs isolated consisted of more of mono-nucleotide repeats (40.2%) followed by penta (33.3%), di (12.1%), tri (10.6%) and tetra (3.7%) nucleotide repeats. Among the genic SSRs identified, 43.7 per cent contained penta-repeat motifs followed by 22.5 per cent and 22.5 per cent sequences with hexa and mono repeat motifs respectively. The remaining identified motifs consisted of 5.5 per cent tri nucleotide repeat motifs, 3.5 per cent di repeat motifs and 2.2 per cent tetra repeat motifs. The study resulted in development of 31 genomic SSRs and 86 genic SSRs which were validated for locus specific amplification

Signals for Lorentz Violation in Electrodynamics

An investigation is performed of the Lorentz-violating electrodynamics extracted from the renormalizable sector of the general Lorentz- and CPT-violating standard-model extension. Among the unconventional properties of radiation arising from Lorentz violation is birefringence of the vacuum. Limits on the dispersion of light produced by galactic and extragalactic objects provide bounds of 3 x 10^{-16} on certain coefficients for Lorentz violation in the photon sector. The comparative spectral polarimetry of light from cosmologically distant sources yields stringent constraints of 2 x 10^{-32}. All remaining coefficients in the photon sector are measurable in high-sensitivity tests involving cavity-stabilized oscillators. Experimental configurations in Earth- and space-based laboratories are considered that involve optical or microwave cavities and that could be implemented using existing technology.Comment: 23 pages REVTe

Exploring unusual metastasis in carcinoma breast: Divulging vulval metastasis

Regional lymph nodes, bones, brain, lung, and liver are the most common sites of the breast carcinoma metastases. Nodular or ulcerated lesions over the vulva are ignored for a long time as benign lesions by the patient and there is a lot of hesitance to undergo the examination. Here, we report the case of a 41-year-old female with an isolated, asymptomatic vulval metastasis of Invasive ductal carcinoma of the breast. The purpose of reporting this case is to make the clinicians aware of this rare site of metastasis of breast cancer and the importance of pelvic examination in follow-up patients

United classification of cosmic gamma-ray bursts and their counterparts

United classification of gamma-ray bursts and their counterparts is established on the basis of measured characteristics: photon energy E and emission duration T. The founded interrelation between the mentioned characteristics of events consists in that, as the energy increases, the duration decreases (and vice versa). The given interrelation reflects the nature of the phenomenon and forms the E-T diagram, which represents a natural classification of all observed events in the energy range from 10E9 to 10E-6 eV and in the corresponding interval of durations from about 10E-2 up to 10E8 s. The proposed classification results in the consequences, which are principal for the theory and practical study of the phenomenon.Comment: Keywords Gamma rays: burst

Thermoluminescence, photoluminescence and optically stimulated luminescence characteristics of CaSO4:Eu phosphor: experimental and density functional theory (DFT) investigations

The CaSO4:Eu phosphor in nanocrystalline form was obtained by chemical method. The sample was annealed at various temperatures and quenched. The structural, electronic and optical properties are studied using various experimental techniques. As synthesized CaSO4:Eu particles have nanorod shapes with diameter of ~15 nm and length of ~250 nm. After annealing (at around 900 °C) a significant increase in their size (~2–4 μm) with phase transformation from hexagonal to orthorhombic was observed. Thermoluminescence (TL) and optically stimulated luminescence (OSL) intensities were found to increase with temperature up to 900 °C and decrease thereafter for 1 Gy of test dose of β-rays from 90Sr-90Yr source. However, the maximum OSL sensitivity was found to be more than that of CaSO4:Eu microcrystalline phosphor (prepared by acid recrystallization method) contrary to the usually found in the literature but much less than that of commercially available α-Al2O3:C phosphor. The activation energy for thermally assisted OSL process was found to be 0.0572 ± 0.0028 eV. The dose ranges of TL and OSL response was found from 0.04 Gy to 100 Gy and 0.02 Gy–100 Gy, respectively. The experimental results are also correlated with computational calculations based on density functional theory (DFT). The crystal structures and electronic structures of both hexagonal and orthorhombic CaSO4 and CaSO4:Eu materials show that they are direct band gap (5.67–5.86 eV) insulators, with Ca2+ substitution by Eu2+ found to introduce donor states in the band gap near Fermi level and the valence band edge of CaSO4 on doping with Eu2+ impurity ions

The Importance of Incorporating At-Home Testing Into SARS-CoV-2 Point Prevalence Estimates: Findings From a US National Cohort, February 2022

Background: Passive, case-based surveillance underestimates the true extent of active infections in the population due to undiagnosed and untested cases, the exclusion of probable cases diagnosed point-of-care rapid antigen tests, and the exclusive use of at-home rapid tests which are not reported as part of case-based surveillance. The extent in which COVID-19 surveillance may be underestimating the burden of infection is likely due to time-varying factors such as decreased test-seeking behaviors and increased access to and availability of at-home testing. Objective: The objective of this study is to estimate the prevalence of SARS-CoV-2 based on different definitions of a case to ascertain the extent to which cases of SARS-CoV-2 may be underestimated by case-based surveillance. Methods: A survey on COVID-19 exposure, infection, and testing was administered to calculate point prevalence of SARS-CoV-2 among a diverse sample of cohort adults from February 8, 2022, to February 22, 2022. Three-point prevalence estimates were calculated among the cohort, as follows: (1) proportion positives based on polymerase chain reaction (PCR) and rapid antigen tests; (2) proportion positives based on testing exclusively with rapid at-home tests; and (3) proportion of probable undiagnosed cases. Test positivity and prevalence differences across booster status were also examined. Results: Among a cohort of 4328, there were a total of 644 (14.9%) cases. The point prevalence estimate based on PCR or rapid antigen tests was 5.5% (95% CI 4.8%-6.2%), 3.7% (95% CI 3.1%-4.2%) based on at-home rapid tests, and 5.7% (95% CI 5.0%-6.4%) based on the case definition of a probable case. The total point prevalence across all definitions was 14.9% (95% CI 13.8%-16.0%). The percent positivity among PCR or rapid tests was 50.2%. No statistically significant differences were observed in prevalence between participants with a COVID-19 booster compared to fully vaccinated and nonboosted participants except among exclusive at-home rapid testers. Conclusions: Our findings suggest a substantial number of cases were missed by case-based surveillance systems during the Omicron B.1.1.529 surge, when at-home testing was common. Point prevalence surveys may be a rapid tool to be used to understand SARS-CoV-2 prevalence and would be especially important during case surges to measure the scope and spread of active infections in the population

C-axis lattice dynamics in Bi-based cuprate superconductors

We present results of a systematic study of the c axis lattice dynamics in single layer Bi2Sr2CuO6 (Bi2201), bilayer Bi2Sr2CaCu2O8 (Bi2212) and trilayer Bi2Sr2Ca2Cu3O10 (Bi2223) cuprate superconductors. Our study is based on both experimental data obtained by spectral ellipsometry on single crystals and theoretical calculations. The calculations are carried out within the framework of a classical shell model, which includes long-range Coulomb interactions and short-range interactions of the Buckingham form in a system of polarizable ions. Using the same set of the shell model parameters for Bi2201, Bi2212 and Bi2223, we calculate the frequencies of the Brillouin-zone center phonon modes of A2u symmetry and suggest the phonon mode eigenvector patterns. We achieve good agreement between the calculated A2u eigenfrequencies and the experimental values of the c axis TO phonon frequencies which allows us to make a reliable phonon mode assignment for all three Bi-based cuprate superconductors. We also present the results of our shell model calculations for the Gamma-point A1g symmetry modes in Bi2201, Bi2212 and Bi2223 and suggest an assignment that is based on the published experimental Raman spectra. The superconductivity-induced phonon anomalies recently observed in the c axis infrared and resonant Raman scattering spectra in trilayer Bi2223 are consistently explained with the suggested assignment.Comment: 29 pages, 13 figure

Global Search for New Physics with 2.0/fb at CDF

Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak-scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with the standard model prediction. A model-independent approach (Vista) considers gross features of the data, and is sensitive to new large cross-section physics. Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distributions for "bumps" that could indicate resonant production of new particles; and the Sleuth procedure scans for data excesses at large summed transverse momentum. This combined global search for new physics in 2.0/fb of ppbar collisions at sqrt(s)=1.96 TeV reveals no indication of physics beyond the standard model.Comment: 8 pages, 7 figures. Final version which appeared in Physical Review D Rapid Communication