Evaluation of 976 nm Multimode Single Emitter Laser Diodes for Efficient Pumping of 100 W+ Yb-doped Fiber Laser

Experimental evaluation of spectral and power-current (P-I) characteristics of fiber coupled single emitter multimode laser diodes used for development of efficient pumping assembly is reported. Fiber coupled laser diodes emitting around 976 nm are best suited for pumping Yb-doped fiber lasers because of excellent coupling efficiency and reduced thermal load. We have experimentally investigated emission spectrum of fiber coupled multimode laser diodes at different temperatures and drive currents. It is found that peak emission wavelength shifts towards the longer wavelength with increase in temperature and drive current. P-I characteristics of fiber coupled laser diodes have been obtained and presented for drive current from 0.4 A to 11.5 A. Based on experiment, we have constructed spectrally matched laser diode assembly for efficient pumping of 100 W fiber laser. It requires very precise control of temperature and drive current to maintain the emission spectrum. Total 162 W power is pumped in to the Yb-doped fiber laser cavity through multi-mode pump combiners and we have obtained 110 W fiber laser output power @1070 nm. The achieved optical-to-optical efficiency is 68 per cent

In-vitro antibacterial activity of Zingiber officinale (ginger) against bacteria isolated from reproductive tract of clinical endometritic Murrah buffaloes

Endometritis, an inflammation of the innermost uterine layer, is caused by a variety of bacteria, including Gram- positive and Gram-negative aerobes and anaerobes. This study aimed to identify the active compounds in Zingiber officinale (ginger) and assess its effectiveness against common bacterial pathogens found in Murrah buffaloes suffering from endometritis. The infrared spectrum of ginger powder displayed a range of wavelengths from 3361.89/cm to 664.26/cm, indicating the presence of eight functional groups. In the hydro-ethanolic ginger extract, the spectrum ranged from 3402.8/cm to 765.35/cm, revealing 12 functional groups. A total of 42 vaginal mucus samples were collected, with E. coli being the most prevalent in 23 samples, followed by S. aureus in 21 samples, Pseudomonas spp. in 12 samples, and Campylobacter spp. in 11 samples. To evaluate the in vitro antibacterial activity of ginger extracts, antimicrobial susceptibility tests were conducted at concentrations of 2.5, 5, 10, 20, 30, 40, and 50 mg/ml. Staphylococcus aureus exhibited the highest sensitivity to the ginger extract, while E. coli showed substantial resistance. In conclusion, ginger demonstrates potent antibacterial activity against multidrug-resistant uterine pathogens and could serve as an alternative therapy to mitigate the risk of drug resistance in treating uterine infections

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Search for long-lived particles decaying to photons and missing energy in proton-proton collisions at sqrt(s) = 7 TeV

Results are presented from a search for long-lived neutralinos decaying into a photon and an invisible particle, a signature associated with gauge-mediated supersymmetry breaking in supersymmetric models. The analysis is based on a 4.9 inverse femtobarn sample of proton-proton collisions at sqrt(s) = 7 TeV, collected with the CMS detector at the LHC. The missing transverse energy and the time of arrival of the photon at the electromagnetic calorimeter are used to search for an excess of events over the expected background. No significant excess is observed, and lower limits at the 95% confidence level are obtained on the mass of the lightest neutralino, m(neutralino) > 220 GeV (for c tau 6000mm (for m(neutralino) < 150 GeV)

Search for the standard model Higgs boson produced in association with WW and ZZ bosons in pppp collisions at s=7\sqrt{s}=7 TeV

A search for the Higgs boson produced in association with a W or Z boson in proton-proton collisions at a center-of-mass energy of 7 TeV is performed with the CMS detector at the LHC using the full 2011 data sample, from an integrated luminosity of 5 inverse femtobarns. Higgs boson decay modes to tau tau and WW are explored by selecting events with three or four leptons in the final state. No excess above background expectations is observed, resulting in exclusion limits on the product of Higgs associated production cross section and decay branching fraction for Higgs boson masses between 110 and 200 GeV in these channels. Combining these results with other CMS associated production searches using the same dataset in the H to gamma gamma and H to b b-bar decay modes, the cross section for associated Higgs boson production 3.3 times the standard model expectation or larger is ruled out at the 95% confidence level for a Higgs boson mass of 125 GeV

Search for heavy resonances in the W/Z-tagged dijet mass spectrum in pp collisions at 7 TeV

A search has been made for massive resonances decaying into a quark and a vector boson, qW or qZ, or a pair of vector bosons, WW, WZ, or ZZ, where each vector boson decays to hadronic final states. This search is based on a data sample corresponding to an integrated luminosity of 5.0 inverse femtobarns of proton-proton collisions collected in the CMS experiment at the LHC in 2011 at a center-of-mass energy of 7 TeV. For sufficiently heavy resonances the decay products of each vector boson are merged into a single jet, and the event effectively has a dijet topology. The background from QCD dijet events is reduced using recently developed techniques that resolve jet substructure. A 95% CL lower limit is set on the mass of excited quark resonances decaying into qW (qZ) at 2.38 TeV (2.15 TeV) and upper limits on the cross section for resonances decaying to qW, qZ, WW, WZ, or ZZ final states

Cervical trauma : subaxial cervical spine

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