Rotating Machine Technologies for Integration of Pulsed and High Power Loads in Naval Electric Power Systems

Advanced electric sensors and weapons are placing increasing demands on the electric power distribution systems of future naval vessels and energy storage is viewed as a critical technology for effective integration of IPS architectures in these platforms. This paper shows that kinetic energy storage, i.e. stored in the angular momentum of a rotating mass, can be applied in differing topologies to address a range of ship power system applications. Rotating machine technologies are presented for UPS and load leveling applications as well as for high cycle rate pulsed power applications.Center for Electromechanic

Effect of Pt doping on the critical temperature and upper critical field in YNi2-xPtxB2C (x=0-0.2)

We investigate the evolution of superconducting properties by doping non-magnetic impurity in single crystals of YNi2-xPtxB2C (x=0-0.2). With increasing Pt doping the critical temperature (Tc) monotonically decreases from 15.85K and saturates to a value ~13K for x>0.14. However, unlike conventional s-wave superconductors, the upper critical field (HC2) along both crystallographic directions a and c decreases with increasing Pt doping. Specific heat measurements show that the density of states (N(EF)) at the Fermi level (EF) and the Debye temperatures (Theta_D) in this series remains constant within the error bars of our measurement. We explain our results based on the increase in intraband scattering in the multiband superconductor YNi2B2C.Comment: ps file with figure

Temperature dependence of transport spin polarization in NdNi5 measured using Point Contact Andreev reflection

We report a study in which Point contact Andreev reflection (PCAR) spectroscopy using superconducting Nb tip has been carried out on NdNi5, a ferromagnet with a Curie temperature of TC~7.7K. The measurements were carried out over a temperature range of 2-9K which spans across the ferromagnetic transition temperature. From an analysis of the spectra, we show that (i) the temperature dependence of the extracted value of transport spin polarization closely follows the temperature dependence of the spontaneous magnetization; (ii) the superconducting quasiparticle lifetime shows a large decrease close to the Curie temperature of the ferromagnet. We attribute the latter to the presence of strong ferromagnetic spin fluctuations in the ferromagnet close to the ferromagnetic transition temperature.Comment: pdf file including figures-Typographical error and errors in references correcte

Reduction of Cd(II)-Itaconate & Cd(II)-Oxalate-Itaconate Complexes at d.m.e.

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Vortex matching effect in engineered thin films of NbN

We report robust vortex matching effects in antidot arrays fabricated on thin films of NbN. The near absence of hysteresis between field sweep directions indicates a negligible residual pinning in the host thin film. Owing to the very small coherence length of NbN thin films ($\xi < 5 nm$), the observations suggests the possibility of probing physics of vortices at true nanometer length scales in suitably fabricated structures.Comment: Submitted to Appl. Phys. Let

Forest hardening and Hirth lock during grinding of copper evidenced by MD simulations

Through the use of molecular dynamics (MD) simulation, grinding process of a single crystal copper with two scratch configurations (i) near spacing (NS) between adjacent scratches, and (ii) far spacing (FS) between adjacent scratches were simulated and compared to the control sample i.e., a single scratch (SS). FS configuration revealed the highest material removal, whereas NS configuration showed that the material removal is affected by various types of defects in the sub-surface which include FCC intrinsic stacking fault, a coherent twin boundary next to an intrinsic stacking fault and two adjacent intrinsic stacking faults. The formation of a Stair-rod 1/6 due to the reaction between two Shockley partial dislocations 1/6 was seen as a distinct feature of the NS configuration which forms the onset of hardening

Nutritional Status of School Children Aged 8-12 Years in Deprived Areas of Mauritius

This study investigated the nutritional status of school children in deprived areas of Mauritius and determined whether specific socio-economic factors were associated with poor nutritional status among children. A cross-sectional survey was conducted among 240 primary school children aged 8-12 years old. Out of 27 schools located in the deprived regions of Mauritius, eight of them were selected for the study. The data collection tools included a questionnaire, anthropometric measurements (weight and height) and a 24-hour dietary recall. A questionnaire was used to gather information on the socioeconomic profile of the children and their eating patterns. The Centre for Disease Control (CDC) BMI-for-age and stature-for-age percentiles were used to identify children who were stunted (&lt;5th percentile stature-for-age), underweight (&lt; 5th BMI-for age percentile), overweight (85th to 95th percentile BMI-for age) or obese (≥95th percentile BMI-for-age). Findings revealed that the main meals taken by the children included breakfast, lunch and dinner. Ninety two percent of the children mentioned taking breakfast in the morning; the most commonly consumed food commodities being bread, margarine, cheese, jam and tea; milk, yoghurt, fruits or fruit juice were rarely consumed. Packed lunches consisted mainly of eggs and convenience foods such as sausages without any vegetables. Poor snacking habits, that is, high consumption of salty corn-based snacks, were identified among these children. Age of school children was significantly associated (p&lt;0.05) with the amount of money spent on snacks at school. Anthropometric measurements revealed the prevalence of both undernutrition and overnutrition among the children. Thirty seven per cent of the children were underweight, four per cent were overweight, three per cent were obese and there were no cases of stunting. The study findings indicate that the children are being fed the wrong kinds of foods or the wrong proportions. Thus, there is a need for local education and health authorities to develop nutrition education programmes that are contextually sensitive to specifically target school children and parents in deprived areas of Mauritius.Key words: Nutritional status, deprived children, Mauritiu