Stability of a plane vortex sheet between gases exchanging heat by radiation

Stability of plane vortex sheet between gases exchanging heat by radiation applied to gas core in coaxial jet nuclear rocke

The Effects of Solar Panel Temperature on the Power Output Efficiency in Calabar, Nigeria

Background: The current push for adoption of alternative energysources necessitates research into parameters that would enhancethe optimum harvest of the benefits of such efforts.Purpose: To determine the effects of solar panel temperature on itsefficiency in Calabar, Nigeria, by determining the output currentand voltage changes due to solar panel temperature.Materials and Methods: A modern digital thermometer, Model220k type, and Alda ADV 890C digital multimeter, were used toobtain measurements of solar panel temperatures, current andvoltage, respectively, in Calabar, Nigeria. Comparisons were madeof the values of current and voltage obtained with solar paneltemperature changes, and efficiency of the output of the solarpanels determined by calculation using efficiency as given byKachhava (2003).Results: Results indicate that a maximum output current of18.4x10-1A was recorded at 42.8oC. Beyond this temperature theoutput current dropped down to 12x10-1A at 54.8oC. The voltageoutput remained relatively stable as solar panel temperatureincreased. Power output efficiency dropped from 82.3% at 42.8oCto 52.4% at 54.8oC.Conclusion: High solar panel temperatures may have adverseeffects on solar panel efficiency. The result obtained in this studysuggest a maximum operating temperature of solar panel inCalabar, Nigeria

Non-Relativistics Treatment of Schrodinger Particle under Modified Inversly Quadratic Hellmann Potential Model Via Parametric N-U Method

The non-relativistics study of particles under the modified inversely quadratic Hellmann potential has been studied. The energy eigenvalues and the corresponding wavefunction expressed in terms of the Jacobi polynomial are obtained using the parametric NU method. In obtaining the solutions for this system, we have used an approximation scheme to evaluate the centrifugal term (potential barrier). To test the accuracy of our result, we compared the approximation scheme with the centrifugal term and the result shows that there is an agreement between the centrifugal term and the approximation scheme for a very small screening parameter; showing that our potential is a short range potential. The results obtain from this work, would have many application in inner shield ionization problem, Electron core, Solid state Physics, Alkali-Hydride molecules. Three special cases of this potential have also been discussed

Optimizing Students’ Performance in English through Quality Teacher Education

Research has established significant connection between quality teacher education and student achievement. This cannot but be a concept in considering the performance of students in English language, a skill-based school subject. This paper examines the course content for language education for trainee teachers in the University of Calabar. This study appraises and validates the adequacy of the curriculum content to meet the language needs of the trainees with regard to transferring their learning to meeting the curriculum demands of secondary school English language learner. Suggestions towards optimizing quality teacher and professional education with the aim of improving performance in English language are proffered. Keywords: Student’s performance, English language, quality teacher education, curriculum content, trainee teachers

Effects of oxygen on the optical properties of phenyl-based scintillators during irradiation and recovery

Plastic scintillators are a versatile and inexpensive option for particle detection, which is why the largest particle physics experiments, CMS and ATLAS, use them extensively in their calorimeters. One of their challenging aspects, however, is their relatively low radiation hardness, which might be inadequate for very high luminosity future projects like the FCC-hh. In this study, results on the effects of ionizing radiation on the optical properties of plastic scintillator samples are presented. The samples are made from two different matrix materials, polystyrene and polyvinyltoluene, and have been irradiated at dose rates ranging from $2.2\,$Gy/h up to $3.4\,$kGy/h at room temperature. An internal boundary that separates two regions of different indices of refraction is visible in the samples depending on the dose rate, and it is compatible with the expected oxygen penetration depth during irradiation. The dose rate dependence of the oxygen penetration depth for the two matrix materials suggests that the oxygen penetration coefficient differs for PS and PVT. The values of the refractive index for the internal regions are elevated compared to those of the outer regions, which are compatible with the indices of unirradiated samples.Comment: Replaced with published version. Added journal DOI. 30 pages, 15 figures. Published in Nuclear Instruments and Methods in Physics Research Section

Reduction of light output of plastic scintillator tiles during irradiation at cold temperatures and in low-oxygen environments

The advent of the silicon photomultiplier has allowed the development of highly segmented calorimeters using plastic scintillator as the active media, with photodetectors embedded in the calorimeter, in dimples in the plastic. To reduce the photodetector's dark current and radiation damage, the high granularity calorimeter designed for the high luminosity upgrade of the CMS detector at CERN's Large Hadron Collider will be operated at a temperature of about -30$^\circ$C. Due to flammability considerations, a low oxygen environment is being considered. However, the radiation damage to the plastic scintillator during irradiation in this operating environment needs to be considered. In this paper, we present measurements of the relative decrease of light output during irradiation of small plastic scintillator tiles read out by silicon photomultipliers. The irradiations were performed using a $^{60}\mathrm{Co}$ source both to produce the tiles' light and as a source of ionizing irradiation at dose rates of 0.3, 1.3, and $1.6\,$Gy/hr, temperatures of -30, -15, -5, and 0$^\circ$C, and with several different oxygen concentrations in the surrounding atmosphere. The effect of the material used to wrap the tile was also studied. Substantial temporary damage, which annealed when the sample was warmed, was seen during the low-temperature irradiations, regardless of the oxygen concentration and wrapping material. The relative light loss was largest with 3M$^{\tiny \textrm{TM}}$ Enhanced Specular Reflector Film wrapping and smallest with no wrapping, although due to the substantially higher light yield with wrapping, the final light output is largest with wrapping. The light loss was less at warmer temperatures. Damage with $3\%$ oxygen was similar to that in standard atmosphere. Evidence of a plateau in the radical density was seen for the 0$^\circ$C data

Can Taxpayers Stand Discrimination?: Lack of Standing and the Religious Freedom Restoration Act Permits the Executive Branch to Fund Discrimination Within Religious Organizations

The Density Functional Theory (DFT) and ab initio (HF and MP2) calculations were performed on the quinoline molecule (QL) and its derivatives, namely quinaldine (QLD) and quinaldic acid (QLDA) to investigate their possible role as corrosion inhibitors for mild steel in acidic medium. Calculations were done for non-protonated and protonated forms in vacuo and in water. Some quantum chemical parameters were calculated and discussed in order to provide insight into the reactivity and selectivity of the molecules. The performance of the different calculation methods were also compared with available experimental data. The results show that DFT/B3LYP basis set is adequate in describing the geometry and quantum chemical parameters of the studied systems. Both experimental and theoretical results established that QLDA has the highest inhibition efficiency. A comparison in the trends of the quantum chemical parameters in water solution and in vacuo shows minimal influence of the solvent effects

Metathesis of Fatty Acid Ester Derivatives in 1,1-Dialkyl and 1,2,3-Trialkyl Imidazolium Type Ionic Liquids

The self-metathesis of methyl oleate and methyl ricinoleate was carried out in the presence of ruthenium alkylidene catalysts 1–4 in [bmim] and [bdmim][X] type ionic liquids (RTILs) (X = PF6−, BF4− and NTf2−) using the gas chromatographic technique. Best catalytic performance was obtained in [bdmim][X] type ionic liquids when compared with [bmim][X] type ionic liquids. Catalyst recycling studies were also carried out in the room temperature ionic liquids (RTILs) with catalysts 1–4 in order to explore their possible industrial application

Limits on WWgamma and WWZ Couplings from W Boson Pair Production

The results of a search for W boson pair production in pbar-p collisions at sqrt{s}=1.8 TeV with subsequent decay to emu, ee, and mumu channels are presented. Five candidate events are observed with an expected background of 3.1+-0.4 events for an integrated luminosity of approximately 97 pb^{-1}. Limits on the anomalous couplings are obtained from a maximum likelihood fit of the E_T spectra of the leptons in the candidate events. Assuming identical WWgamma and WWZ couplings, the 95 % C.L. limits are -0.62<Delta_kappa<0.77 (lambda = 0) and -0.53<lambda<0.56 (Delta_kappa = 0) for a form factor scale Lambda = 1.5 TeV.Comment: 10 pages, 1 figure, submitted to Physical Review

A Quasi-Model-Independent Search for New Physics at Large Transverse Momentum

We apply a quasi-model-independent strategy ("Sleuth") to search for new high p_T physics in approximately 100 pb^-1 of ppbar collisions at sqrt(s) = 1.8 TeV collected by the DZero experiment during 1992-1996 at the Fermilab Tevatron. Over thirty-two e mu X, W+jets-like, Z+jets-like, and 3(lepton/photon)X exclusive final states are systematically analyzed for hints of physics beyond the standard model. Simultaneous sensitivity to a variety of models predicting new phenomena at the electroweak scale is demonstrated by testing the method on a particular signature in each set of final states. No evidence of new high p_T physics is observed in the course of this search, and we find that 89% of an ensemble of hypothetical similar experimental runs would have produced a final state with a candidate signal more interesting than the most interesting observed in these data.Comment: 28 pages, 17 figures. Submitted to Physical Review