The Light and Period Variations of the Eclipsing Binary AA Ursae Majoris

We present new multiband CCD photometry for AA UMa made on 8 nights between January and March 2009; the $R$ light curves are the first ever compiled. Historical light curves, as well as ours, display partial eclipses and inverse O'Connell effects with Max I fainter than Max II. Among possible spot models, a cool spot on either of the component stars and its variability with time permit good light-curve representations for the system. A total of 194 eclipse timings over 81 yrs, including our five timings, were used for ephemeris computations. We found that the orbital period of the system has varied due to a periodic oscillation overlaid on an upward parabolic variation. The continuous period increase at a fractional rate of $+$1.3$\times$10$^{-10}$ is consistent with that calculated from the W-D code and can be interpreted as a thermal mass transfer from the less to the more massive secondary star at a rate of 6.6$\times$10$^{-8}$ M$_\odot$ yr$^{-1}$. The periodic component is in satisfactory accord with a light-time effect due to an unseen companion with a period of 28.2 yrs, a semi-amplitude of 0.007 d, and a minimum mass of $M_3 \sin i_3$=0.25 $M_\odot$ but this period variation could also arise from magnetic activity.Comment: 23 pages, including 5 figures and 8 tables, accepted for publication in PAS

The Motion of Slender Particles in Shear Flow

A model was developed for calculating the motion of dilute suspensions of rigid, slender particles in a uniformly sheared viscous liquid, taking into ac count interactions between particles. The model was applied to the plane Couette flow problem in which particles are suspended in a liquid moving parallel to a plane with a uniform, shearing motion. The results of the model were compared to existing data, and good agreement was found between the calculated and experimental results. Using the model, results were also ob tained which illustrate the major effects of particle-particle interactions on the angular motion of the particles.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68541/2/10.1177_073168448200100401.pd

Heat of Reaction, Degree of Cure, and Viscosity of Hercules 3501-6 Resin

The heat of reaction, degree of cure, and viscosity of Hercules 3501-6 resin were measured using a differential scanning calorimeter and a disc and plate type viscometer. Expression were developed for correlating the rate of degree of cure and the viscosity with the degree of cure. Viscosities calculated by these ex pressions were compared with data reported previously, and good agreement was found between the present results and the previous data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68202/2/10.1177_002199838201600605.pd

Low-frequency noise in junctionless multigate transistors

Low-frequency noise in n-type junctionless multigate transistors was investigated. It can be well understood with the carrier number fluctuations whereas the conduction is mainly limited by the bulk expecting Hooge mobility fluctuations. The trapping/release of charge carriers is related not only to the oxide-semiconductor interface but also to the depleted channel. The volume trap density is in the range of 6-30 x 10(16) cm(-3) eV(-1), which is similar to Si-SiO2 bulk transistors and remarkably lower than in high-k transistors. These results show that the noise in nanowire devices might be affected by additional trapping centers. (C) 2011 American Institute of Physics. (doi:10.1063/1.3569724

Modelling and Simulation of a River-Crossing Operation via Discrete Event Simulation with Engineering Details

From a military standpoint, a river is an area that should be avoided in a potential engagement because of lack of cover and the necessity of dividing the unit while crossing. Thus, a key point of a river-crossing operation is speed. Many efforts have been made to enable faster river crossing by improvement of tactics, techniques, and procedures (TTP). However, improvements in TTP are evaluated by modelling and simulation much less frequently than are the toe-to-toe engagements between two opposing forces, and to our knowledge, this is the first simulation model of brigade-level river crossing with engineering details. This study presents a simulation model of the river-crossing operation, applies real world parameters, and evaluates which tactics are preferable in a particular operational environments. This analysis has led to new operational methods of river crossing that have been suggested by experienced subject-matter experts. For instance, the current Republic of Korea Army Field Manual dictates to rotate river-crossing rafts in all situations, but our experiment suggests that no rotation is preferable when the width of river is less than 400 m based on the statistical analyses, which includes the regression-based meta-modelling and the ANOVA, of our simulation model that embodies the engineering details of river-crossing equipment.Defence Science Journal, Vol. 65, No. 2, March 2015, pp.135-143, DOI:http://dx.doi.org/10.14429/dsj.65.814

Intracorporeal Anastomosis Using Linear Stapler in Laparoscopic Distal Gastrectomy: Comparison between Gastroduodenostomy and Gastrojejunostomy

Purpose: Intracorporeal anastomosis during laparoscopic gastrectomy is becoming increasingly prevalent. However, selection of the anastomosis method after laparoscopic distal gastrectomy is equivocal because of a lack of technical feasibility and safety. We compared intracorporeal gastroduodenostomy with gastrojejunostomy using linear staplers to evaluate the technical feasibility and safety of intracorporeal anastomoses as well as its' minimally invasiveness. Materials and Methods: Retrospective analyses of a prospectively collected database for gastric cancer revealed 47 gastric cancer patients who underwent laparoscopic distal gastrectomy with either intracorporeal gastroduodenostomy or gastrojejunostomy from March 2011 to June 2011. Perioperative outcomes such as operation time, postoperative complication, and hospital stay were compared according to the type of anastomosis. Postoperative inflammatory response was also compared between the two groups using white blood cell count and high sensitivity C-reactive protein. Results: Among the 47 patients, 26 patients received gastroduodenostomy, whereas 21 patients received gastrojejunostomy without open conversion or additional mini-laparotomy incision. There was no difference in mean operation time, blood loss, and length of postoperative hospital stays. There was no statistically significant difference in postoperative complication or mortality between two groups. However, significantly more staplers were used for gastroduodenostomy than for gastrojejunostomy (n=6) than for gastroduodenostomy and (n=5). Conclusions: Intracorporeal anastomosis during laparoscopic gastrectomy using linear stapler, either gastroduodenostomy or gastrojejunostomy, shows comparable and acceptable early postoperative outcomes and are safe and feasible. Therefore, surgeons may choose either anastomosis method as long as oncological safety is guaranteedope