Development of Geometrical Models of Hard-Alpha Inclusions for Ultrasonic Analysis in Titanium Alloys

The engine titanium consortium is currently conducting an extensive study of the ultrasonic response and detectability of a number of naturally occurring hard-alpha defects found in titanium billets. These naturally occurring defects appear to be highly irregular in shape and inhomogeneous in composition, and we would like to access the extent to which their responses can be predicted by available ultrasonic scattering models [1]. Three dimensional geometrical (surface and solid) models of the hard-alpha defects are needed in order to obtain the geometrical and material properties to drive the ultrasonic model calculations and the subsequent probability-of-detection evaluation [2]

The nascent coffee ring with arbitrary droplet contact set: an asymptotic analysis

We consider the effect of droplet geometry on the early-stages of coffee ring formation during the evaporation of a thin droplet with an arbitrary simple, smooth, pinned contact line. We perform a systematic matched asymptotic analysis of the small-capillary number, large-solutal Peclet number limit for two evaporative models: a kinetic model, in which the evaporative flux is constant across the droplet, and a diffusive model, in which the evaporative flux is singular at the contact line. For both evaporative models, solute is transported to the contact line by a capillary flow while, local to the contact line, solute diffusion counters advection. The resulting interplay leads to the formation of the nascent coffee ring. By exploiting a coordinate system embedded in the contact line, we solve explicitly the local leading-order problem, deriving a similarity profile (in the form of a gamma distribution) that describes the coffee ring profile in its early stages. Notably, the ring characteristics change due to the concomitant asymmetry in the shape of the droplet free surface, the evaporative flux (in the diffusive evaporative regime) and the mass flux into the contact line. We utilize the asymptotic model to determine the effects of geometry on the growth of the coffee ring for a droplet with an elliptical contact set. Our results offer mechanistic insight into the effect of contact-line curvature on the development of the coffee-ring from deposition up to jamming of the solute; moreover our model predicts when finite concentration effects become relevant

A Benchmark of GW Methods for Azabenzenes: Is the GW Approximation Good Enough?

Many-body perturbation theory in the GW approximation is a useful method for describing electronic properties associated with charged excitations. A hierarchy of GW methods exists, starting from non-self-consistent G0W0, through partial self-consistency in the eigenvalues (ev-scGW) and in the Green function (scGW0), to fully self-consistent GW (scGW). Here, we assess the performance of these methods for benzene, pyridine, and the diazines. The quasiparticle spectra are compared to photoemission spectroscopy (PES) experiments with respect to all measured particle removal energies and the ordering of the frontier orbitals. We find that the accuracy of the calculated spectra does not match the expectations based on their level of self-consistency. In particular, for certain starting points G0W0 and scGW0 provide spectra in better agreement with the PES than scGW

A Comparison of the Effects of Moderate-Intensity Continuous Cycling and High-Intensity Interval Cycling on Postprandial Lipemia and Glycemia

Both moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) has been reported to reduce the magnitude of postprandial lipemia and glycemia. It is unclear if performing MICE or HIIE of similar duration and work would have a comparable effect on postprandial lipemia or glycemia. PURPOSE: Examine the postprandial lipemic and glycemic response following the completion of high-intensity interval cycling (HIIC) and moderate-intensity continuous cycling (MICC) that is of equal duration and comparable work output. METHODS: Participants were mildly active males (n = 12; age = 21.9 ± 1.8 yrs; body mass = 90.1 ± 16.8 kg; BF% = 25.9 ± 8.6). Each participant completed a graded exercise test on a cycle ergometer to determine their maximal work rate (WRmax). For the study, each participant completed a bout of 1) REST, 2) MICC, and 3) HIIC in a randomized order. Each bout was performed for 20 minutes on the afternoon of Day 1. Each bout was separated by at least 1 week. Rest involved sitting quietly in the laboratory. MICC required continuous cycling at 60% WRmax. HIIC involved 15-second cycling sprints at 120% WRmax followed with 45 seconds of cycling at 40% WRmax. A mixed meal (50% carbohydrate (CHO), 35% fat, 6.4 ± 1.2 kcal/kgBW) was provided 30 minutes following the completion of each bout. Blood samples were acquired just prior to each bout and at 0, 0.5, 1, and 2 hours following the completion of the meal (post-meal). The next morning (Day 2), following a 10-hour fast, a 2nd mixed meal was provided. Blood samples on Day 2 were acquired at 0, 2, and 4 hours post-meal. Blood samples were analyzed for glucose, insulin, and triglyceride (TG) concentration. The postprandial (PP) response was quantified via the total (AUCT)and incremental area under the curve (AUCI) using the trapezoidal method. Significant differences (pRESULTS: The average heart rate was significantly higher (p=.037, ES = 1.1) during HIIC (163.3 ± 7.3) compared to MICC (154.4 ± 8.5). Average work output (Watts) was similar between MICC (122.5 ± 25.4) and HIIC (110.3 ± 14.7) (p = .091, ES = .51). On Day 1, there was no significant difference in the PP glucose, insulin, or TG response between the 3 bouts. On Day 2, there was no significant difference in the PP glucose or insulin response. On Day 2, MICC did reduce the TG AUCT (442.9 ± 76.4mg·dl-1·4hr-1) when compared to rest (487.4 ± 104.4mg·dl-1·4hr-1) (p = .02, ES = .43). HIIC did not reduce the TG AUCT on Day 2 (454.8 ± 72.3mg·dl-1·4hr-1), (p = .076, ES = .31). There was no difference in the AUCI between the 3 bouts for any of the postprandial measurements on Day 1 or Day 2. CONCLUSION: A brief bout of MICC and HIIC does not influence the PP response when completed just prior to a mixed meal. There may be a delayed response to exercise as MICC reduced the postprandial triglyceride (PPTG) concentration when completed approximately 16 hours prior to a mixed meal. While HIIC did not reduce PPTG on Day 2 there was a trend towards a significant reduction. The delayed reduction in the PPTG concentration may be associated with a delayed increase in lipoprotein lipase activity which may occur 4 – 18 hours following the completion of exercise. The lack of change in the PP glucose and insulin response might be explained by a wide inter-individual variance as half of the participants appeared to have responded to the exercise bouts based on their PP glucose and insulin concentration

Efficient adenovirus-mediated gene transfer into primary T cells and thymocytes in a new coxsackie/adenovirus receptor transgenic model

BACKGROUND: Gene transfer studies in primary T cells have suffered from the limitations of conventional viral transduction or transfection techniques. Replication-defective adenoviral vectors are an attractive alternative for gene delivery. However, naive lymphocytes are not readily susceptible to infection with adenoviruses due to insufficient expression of the coxsackie/adenovirus receptor. RESULTS: To render T cells susceptible to adenoviral gene transfer, we have developed three new murine transgenic lines in which expression of the human coxsackie/adenovirus receptor (hCAR) with a truncated cytoplasmic domain (hCARΔcyt) is limited to thymocytes and lymphocytes under direction of a human CD2 mini-gene. hCARΔcyt.CD2 transgenic mice were crossed with DO11.10 T cell receptor transgenic mice (DO11.hCARΔcyt) to allow developmental studies in a defined, clonal T cell population. Expression of hCARΔcyt enabled adenoviral transduction of resting primary CD4(+) T cells, differentiated effector T cells and thymocytes from DO11.hCARΔcyt with high efficiency. Expression of hCARΔcyt transgene did not perturb T cell development in these mice and adenoviral transduction of DO11.hCARΔcyt T cells did not alter their activation status, functional responses or differentiative potential. Adoptive transfer of the transduced T cells into normal recipients did not modify their physiologic localization. CONCLUSION: The DO11.hCARΔcyt transgenic model thus allows efficient gene transfer in primary T cell populations and will be valuable for novel studies of T cell activation and differentiation

Cylindrical surface profile and diameter measuring tool and method

A tool is shown having a cross beam assembly made of beams joined by a center box structure. The assembly is adapted to be mounted by brackets to the outer end of a cylindrical case. The center box structure has a vertical shaft rotatably mounted therein and extending beneath the assembly. Secured to the vertical shaft is a radius arm which is adapted to rotate with the shaft. On the longer end of the radius arm is a measuring tip which contacts the cylindrical surface to be measured and which provides an electric signal representing the radius of the cylindrical surface from the center of rotation of the radius arm. An electric servomotor rotates the vertical shaft and an electronic resolver provides an electric signal representing the angle of rotation of the shaft. The electric signals are provided to a computer station which has software for its computer to calculate and print out the continuous circumference profile of the cylindrical surface, and give its true diameter and the deviations from the ideal circle

Theoretical Analysis of STM Experiments at Rutile TiO_2 Surfaces

A first-principles atomic orbital-based electronic structure method is used to investigate the low index surfaces of rutile Titanium Dioxide. The method is relatively cheap in computational terms, making it attractive for the study of oxide surfaces, many of which undergo large reconstructions, and may be governed by the presence of Oxygen vacancy defects. Calculated surface charge densities are presented for low-index surfaces of TiO$_2$, and the relation of these results to experimental STM images is discussed. Atomic resolution images at these surfaces tend to be produced at positive bias, probing states which largely consist of unoccupied Ti 3$d$ bands, with a small contribution from O 2$p$. These experiments are particularly interesting since the O atoms tend to sit up to 1 angstrom above the Ti atoms, so providing a play-off between electronic and geometric structure in image formation.Comment: 9 pages, Revtex, 3 postscript figures, accepted by Surf. Scienc

Code Blue Emergencies: A Team Task Analysis and Educational Initiative

Introduction: The objective of this study was to identify factors that have a positive or negative influence on resuscitation team performance during emergencies in the operating room (OR) and post-operative recovery unit (PAR) at a major Canadian teaching hospital. This information was then used to implement a team training program for code blue emergencies. Methods: In 2009/10, all OR and PAR nurses and 19 anesthesiologists at Vancouver General Hospital (VGH) were invited to complete an anonymous, 10 minute written questionnaire regarding their code blue experience. Survey questions were devised by 10 recovery room and operation room nurses as well as 5 anesthesiologists representing 4 different hospitals in British Columbia. Three iterations of the survey were reviewed by a pilot group of nurses and anesthesiologists and their feedback was integrated into the final version of the survey. Results: Both nursing staff (n = 49) and anesthesiologists (n = 19) supported code blue training and believed that team training would improve patient outcome. Nurses noted that it was often difficult to identify the leader of the resuscitation team. Both nursing staff and anesthesiologists strongly agreed that too many people attending the code blue with no assigned role hindered team performance. Conclusion: Identifiable leadership and clear communication of roles were identified as keys to resuscitation team functioning. Decreasing the number of people attending code blue emergencies with no specific role, increased access to mock code blue training, and debriefing after crises were all identified as areas requiring improvement. Initial team training exercises have been well received by staff