High frequency losses in induction motors, part 2

The following subject areas are covered: high frequency losses in induction motors; stray losses in induction motors; and high frequency time harmonic losses in induction motors

Reducing numerical diffusion for incompressible flow calculations

A number of approaches for improving the accuracy of incompressible, steady-state flow calculations are examined. Two improved differencing schemes, Quadratic Upstream Interpolation for Convective Kinematics (QUICK) and Skew-Upwind Differencing (SUD), are applied to the convective terms in the Navier-Stokes equations and compared with results obtained using hybrid differencing. In a number of test calculations, it is illustrated that no single scheme exhibits superior performance for all flow situations. However, both SUD and QUICK are shown to be generally more accurate than hybrid differencing

Antennal Responses of the Two Host Races of the Larch Bud Moth, Zeiraphera diniana , to Larch and Cembran Pine Volatiles

The larch bud moth (LBM) Zeiraphera diniana Guenée causes defoliation on larch in the Alps at 8- to 10-year intervals, after which populations crash. There are two LBM host races, one on larch and the other on cembran pine. These host races are morphologically indistinguishable as adults but they differ genetically in larval color types. Furthermore, females of each host race produce distinct pheromone blends and show oviposition preferences for their respective hosts. It is not clear to what extent host choice contributes to assortative mating in the LBM. Here, we compare the olfactory sensitivities of the two host races to the odors of fresh foliage of the host plants using the electroantennogram (EAG) technique, and the responses of the two host races to volatiles collected from the two host plants as analyzed by gas-chromatography-linked antennographic detection (GC-EAD). Both sexes of the larch and cembran host races show the same EAG responses to vapors of fresh larch and cembran pine foliage. Fifteen plant volatiles identified as chemostimuli by GC-EAD from larch and cembran pine odors elicited the same antennogram responses from the two host races. However, the GC-EAD analyses indicate that the number and quantity of chemostimuli emanating from each host plant is different. It is, therefore, most probably the array of olfactory receptors responding to the bouquet of volatiles unique to each host plant that underlies the host preferences of the two races. What remains open is the extent to which the similarity of the olfactory systems may contribute to cross-attraction. The fact that LBM individuals with intermediate characteristics between the two host races exist, suggests that olfactory perception does not hinder gene flow and contributes to sustained genetic diversity within the species Z. dinian

Island Size Selectivity during 2D Ag Island Coarsening on Ag (111)

We report on early stages of submonolayer Ag island coarsening on Ag(111) surface at room temperature ($300$ K) carried out using realistic kinetic Monte Carlo (KMC) simulations. We find that during early stages, coarsening proceeds as a sequence of selected island sizes creating peaks and valleys in the island size distribution. We find that island-size selectivity is due to formation of kinetically stable islands for certain sizes because of adatom detachment/attachment processes and large activation barrier for kink detachment. In addition, we find that the ratio of number of adatom attachment to detachment processes to be independent of parameters of initial configuration and also on the initial shapes of the islands confirming that island-size selectivity is independent of initial conditions.These simulations were carried out using a very large database of processes identified by their local environment and whose activation barriers were calculated using the embedded-atom method

MPEG-4 video transmission using distributed TDMA MAC protocol over IEEE 802.15.4 wireless technology

The issues of green technology nowadays give an inspiration to the researcher to make all the future design to be energy efficient. Medium Access Control (MAC) layer is the most effective layer to provide energy efficient due to its ability to control the physical radio directly. One of the important applications in the future is a video transmission that can be transmitted with low-cost and low power consumption. MPEG-4 is one of the international standards for moving video. MPEG-4 provide better compression and primarily design at low bit rate communication. In order to achieve good quality for video application, the design at MAC layer must be strong. Therefore, to increase the performance of the MPEG-4 in IEEE 802.15.4, in this paper we propose a cross layer design between MAC layer and Application layer. A priority queue will be implemented at MAC scheduling depends on the level of frame important in MPEG-4 format frame. A distributed Time division Multiple Access (TDMA) will be used for MAC protocol to provide reliable data transmission for high priority frame

Traversal of 3D AI Objects in Virtual Game Worlds

This paper aims to highlight the underlying problem of AI traversal in virtual game worlds. AIrsquos self-awareness as an entity, solely depends on the programmer and hence can run into problems if itrsquos not coded properly. The purpose of this research is to eliminate the various factors involved in the traversal of AI and provide a simple solution to the problem that even a novice would be able to code their AI to move around the terrain of the virtual world or in-game world. By using collisions, objective markers and virtual invisible points, the AI can not only move in a 360-degree direction, but cover sufficient in-game mileage and abstain from traversing in to the lsquodanger zonesrsquo which are aptly titled due to them being inaccessible or missing the collision feature. The medium of choice to depict the virtual world is Unreal Engine 4. The reason for choosing UE4 is because it has a similar layout to other game engines like Unity and hence migration of code is possible though not without its own trials

Biomarkers of systemic inflammation and growth in early infancy are associated with stunting in young Tanzanian children

Stunting can afflict up to one-third of children in resource-constrained countries. We hypothesized that low-grade systemic inflammation (defined as elevations in serum C-reactive protein or alpha-1-acid glycoprotein) in infancy suppresses the growth hormone–insulin-like growth factor (IGF) axis and is associated with subsequent stunting. Blood samples of 590 children from periurban Dar es Salaam, Tanzania, were obtained at 6 weeks and 6 months of age as part of a randomized controlled trial. Primary outcomes were stunting, underweight, and wasting (defined as length-for-age, weight-for-age and weight-for-length z-scores < −2) between randomization and endline (18 months after randomization). Cox proportional hazards models were constructed to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of time to first stunting, underweight, and wasting as outcomes, with measures of systemic inflammation, insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) as exposures, adjusting for numerous demographic and clinical variables. The incidences of subsequent stunting, underweight, and wasting were 26%, 20%, and 18%, respectively. In multivariate analyses, systemic inflammation at 6 weeks of age was significantly associated with stunting (HR: 2.14, 95% CI: 1.23, 3.72; p = 0.002). Children with higher levels of IGF-1 at 6 weeks were less likely to become stunted (HR: 0.58, 95% CI: 0.37, 0.93; p for trend = 0.019); a similar trend was noted in children with higher levels of IGF-1 at 6 months of age (HR: 0.50, 95% CI: 0.22, 1.12; p for trend = 0.07). Systemic inflammation occurs as early as 6 weeks of age and is associated with the risk of future stunting among Tanzanian children.This research was funded by the National Institutes of Health (R01 HD048969, 2P30 DK040561, K24 DK104676-Dr. Duggan) and the Bill and Melinda Gates Foundation (OPP1066203-Dr. Duggan). (R01 HD048969 - National Institutes of Health; 2P30 DK040561 - National Institutes of Health; K24 DK104676 - National Institutes of Health; OPP1066203 - Bill and Melinda Gates Foundation)Accepted manuscrip

Frequency Control of Multi-Pulse 2-micron Laser Transmitter for Atmospheric Carbon Dioxide Measurement

Laser sources with highly stabilized emission wavelength is of paramount importance for a long term atmospheric carbon dioxide (CO2) measurement from a space platform. Integrated Path Differential Absorption (IPDA) lidar is a promising instrument for such a task. The design of a laser transmitter, with emphasis on the method used to control and select several wavelengths, is presented. This multi-pulsed, injection seeded, 2-m transmitter uses a Ho:Tm:YLF laser crystal which has matching emission to the absorption of CO2 in the R30 spectroscopic area. The injection seeded laser produces triple single longitudinal mode transform limited line width pulses with a total of 80 mJ at a repetition rate of 50 Hz