Transient Heat Partition Factor for a Sliding Railcar Wheel

During a wheel slide the frictional heat generated at the contact interface causes intense heating of the adjacent wheel material. If this material exceeds the austenitising temperature and then cools quickly enough, it can transform into martensite, which may ultimately crack and cause wheel failure. A knowledge of the distribution of the heat partitioned into the wheel and the rail and the resulting temperature fields is critical to developing designs to minimize these deleterious effects. A number of theoretical solutions have appeared in the literature to model the thermal aspects of this phenomenon. The objective of this investigation was to examine the limitations of these solutions by comparing them to the results of a finite element analysis that does not incorporate many of the simplifying assumptions on which these solutions are based. It was found that these simplified solutions can produce unrealistic results under some circumstances

An Investigation Of The Relationships Between Motivation, Worker Role Conflicts And Worker Outcomes

This study investigated the relationships between several work motivational process variables and work-life-conflict (WLC) and how these variables contribute to job related outcomes such as work performance, job satisfaction and life satisfaction. This survey study identified several correlations which suggest that a more comprehensive model of motivation should include variables such as energy pool and direction toward organizational objectives. Results also suggest that WLC contributes to the amount of energy pool available to workers and the amount of motivation exhibited by workers. WLC also impacts important job and life attitudes directly and through the above mentioned motivation process variables. The basis for a comprehensive work motivation model will be posited and theoretical and practical implications will be discussed

The relation between the frequency distributions of sieve diameters and fall velocities of sediment particles

A relation between the frequency distributions of sieve diameters and fall velocities is developed. The relation shows that if the sieve diameters of a sediment are log-normally distributed, the fall velocities will also have this distribution, but with a different standard deviation which can be calculated. The results of detailed measurements of the fall velocities of two different natural sands are presented, and the distributions of fall velocities are found to be in good agreement with the predicted distributions. The sedimentation diameters determined from the measured fall velocities agree very well with those predicted from the sieve diameters by the Inter-Agency Committee on Water Resources [1957]

Uncleared Homicides: A Canada/United States Comparison

Beginning in the 1960s, there has been a marked decline in clearance rates of homicides, a finding that has generated little interest among criminological researchers. This article presents a comparative analysis of homicide clearance in Canada and the United States using data generated by the Canadian Centre of Justice Statistics and the U.S. Federal Bureau of Investigation\u27s Supplementary Homicide Reports. Using logistic regression, homicide clearance is predicted on the basis of specific victim and offense characteristics for cases in Canada versus the United States and in Ontario versus New York State. The results indicate that the model is a good fit for homicide clearance in both countries as a whole. Whereas the homicide weapon, circumstances surrounding the offense, age, and gender of the victim were found to be significant homicide clearance predictors in New York State, only the circumstances surrounding the offense emerged as an important predictor in Ontario

Professional guideline versus product label selection for treatment with IV thrombolysis: an analysis from SITS registry

Introduction: Thrombolysis usage in ischaemic stroke varies across sites. Divergent advice from professional guidelines and product labels may contribute. Patients and methods: We analysed SITS-International registry patients enrolled January 2010 through June 2016. We grouped sites into organisational tertiles by number of patients arriving ≤2.5 h and treated ≤3 h, percentage arriving ≤2.5 h and treated ≤3 h, and numbers treated ≤3 h. We assigned scores of 1–3 (lower/middle/upper) per variable and 2 for onsite thrombectomy. We classified sites as lower efficiency (summed scores 3–5), medium efficiency (6–8) or higher efficiency (9–11). Sites were also grouped by adherence with European product label and ESO guideline: ‘label adherent’ (>95% on-label), ‘guideline adherent’ (≥5% off-label, ≥95% on-guideline) or ‘guideline non-adherent’ (>5% off-guideline). We cross-tabulated site-efficiency and adherence. We estimated the potential benefit of universally selecting by ESO guidance, using onset-to-treatment time-specific numbers needed to treat for day 90 mRS 0–1. Results: A total of 56,689 patients at 597 sites were included: 163 sites were higher efficiency, 204 medium efficiency and 230 lower efficiency. Fifty-six sites were ‘label adherent’, 204 ‘guideline adherent’ and 337 ‘guideline non-adherent’. There were strong associations between site-efficiency and adherence (P < 0.001). Almost all ‘label adherent’ sites (55, 98%) were lower efficiency. If all patients were treated by ESO guidelines, an additional 17,031 would receive alteplase, which translates into 1922 more patients with favourable three-month outcomes. Discussion: Adherence with product labels is highest in lower efficiency sites. Closer alignment with professional guidelines would increase patients treated and favourable outcomes. Conclusion: Product labels should be revised to allow treatment of patients ≤4.5 h from onset and aged ≥80 years

The environment power system analysis tool development program

The Environment Power System Analysis Tool (EPSAT) is being developed to provide space power system design engineers with an analysis tool for determining system performance of power systems in both naturally occurring and self-induced environments. The program is producing an easy to use computer aided engineering (CAE) tool general enough to provide a vehicle for technology transfer from space scientists and engineers to power system design engineers. The results of the project after two years of a three year development program are given. The EPSAT approach separates the CAE tool into three distinct functional units: a modern user interface to present information, a data dictionary interpreter to coordinate analysis; and a data base for storing system designs and results of analysis

Rapid Stereomicroscopic Imaging of HER2 Overexpression in Ex Vivo Breast Tissue Using Topically Applied Silica-Based Gold Nanoshells

Tumor margin detection for patients undergoing breast conservation surgery primarily occurs postoperatively. Previously, we demonstrated that gold nanoshells rapidly enhance contrast of HER2 overexpression in ex vivo tissue sections. Our ultimate objective, however, is to discern HER2 overexpressing tissue from normal tissue in whole, nonsectioned, specimens to facilitate rapid diagnoses. Here, we use targeted nanoshells to quickly and effectively visualize HER2 receptor expression in intact ex vivo human breast tissue specimens. Punch biopsies of human breast tissue were analyzed after a brief 5-minute incubation with and without HER2-targeted silica-gold nanoshells using two-photon microscopy and stereomicroscopy. Labeling was subsequently verified using reflectance confocal microscopy, darkfield hyperspectral imaging, and immunohistochemistry to confirm levels of HER2 expression. Our results suggest that anti-HER2 nanoshells used in tandem with a near-infrared reflectance confocal microscope and a standard stereomicroscope may potentially be used to discern HER2-overexpressing cancerous tissue from normal tissue in near real time and offer a rapid supplement to current diagnostic techniques

Seasonal Variation in Diurnal Atmospheric Grass Pollen Concentration Profiles

In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods of the pollen season. Pollen concentrations are also influenced by meteorological factors – directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season in Aarhus – a twin peak profile during the early season, a single evening profile during the middle of the season, and a single midday peak during the late season. Whilst this variation could not be explained by meteorological factors, no inconsistencies were found with the theory that it was driven by a succession of different grass species with different diurnal flowering patterns dominating atmospheric pollen loads as the season progressed. The potential for exposure was found to be significantly greater during the late-season period than during either the early- or mid-season periods

Effect of ventricular function on the exercise hemodynamics of variable rate pacing

AbstractTo determine the effect of ventricular function on the exercise hemodynamics of variable rate pacing, 16 selected patients underwent paired, double-blind, randomized exercise tests in single rate demand (VVI) or variable rate (VVIR) pacing modes. Ejection fraction and cardiac index were determined by two-dimensional and Doppler echocardiography at baseline and during peak exercise.Baseline ejection fraction ranged from 14 to 73% and was < 40% in 6 patients (Group 1) and ≥ 40% in 10 patients (Group 2). Duration of exercise was longer during the VVIR mode (502 s) than during the VVI mode (449 s) (p < 0.01) and unrelated to baseline ejection fraction. Heart rate during exercise increased 9% in the VVI mode and 35% in the VVIR mode (p < 0.005). Cardiac index increased 49% in the VVI mode and 83% in the VVIR mode. Analysis of variance for repeated measures showed a significant effect of pacing mode (p < 0.01) and exercise (p < 0.001), but not baseline ejection fraction, on cardiac index. Baseline ejection fraction did not correlate with the increase in cardiac index in either pacing mode or with the difference in increase between modes. There was no significant difference between Groups 1 and 2 in exercise duration, peak heart rate-blood pressure (rate-pressure) product, baseline or peak heart rate or baseline or peak cardiac index.Therefore, in selected patients, VVIR pacing during exercise results in an increase in heart rate, duration of exercise and cardiac index that is unrelated to the degree of baseline left ventricular dysfunction. These data have clinical implications for the use of variable rate pacemakers in patients with abnormalities of ventricular function