Elastomer Compound Developed for High Wear Applications

The U.S. Army is currently spending 300 million dollars per year replacing rubber track pads. An experimental rubber compound has been developed which exhibits 2 to 3 times greater service life than standard production pad compounds. To improve the service life of the tank track pads various aspects of rubber chemistry were explored including polymer, curing and reinforcing systems. Compounds that exhibited superior physical properties based on laboratory data were then fabricated into tank pads and field tested. This paper will discuss the compounding studies, laboratory data and field testing that led to the high wear elastomer compound

How to Use Common Technologies to Minimize Perceptual Biases When Grading Essays: A Five-Step Process

Evaluation of student performance is an important component of higher education course work and a major dimension of Ignatian pedagogy. However, the process of grading essay exams (a popular assessment method in both the liberal arts and technical programs) naturally brings the threat of several perceptual biases that harm grading validity and consistency. Thus, we sought a method to collect and organize essay tests to minimize identification bias (make student authors anonymous to the grader) and randomize grading order to minimize systematic error (related to always grading the same students first or last). Specifically, in this paper, we describe a step-by-step innovative approach that uses multiple common computer technologies (NetSupport School, Word, DOS, and Excel) to prepare, administer, and grade essay examinations submitted by students. Within the Appendix, we describe the steps and how to use these common tools, but within the paper, we offer general guidelines to apply our methods using whatever software or technologies schools are currently using. The discussion section presents limitations to our described method, offers ideas of modifications that may meet the same goals, and recommends future research directions

Examining the Perspectives and Experiences of Nutrition Educators Working with Clients in Substance Use Recovery Settings

Substance use disorder (SUD) is one of the most detrimental health, social, and economic problems in the United States. Limited studies suggest providing tailored nutrition education during SUD treatment correlates with positive recovery outcomes. The University of Kentucky Nutrition Education Program conducted two focus group sessions to explore and determine educators’ instructional and programmatic needs who deliver nutrition education to clients in substance use recovery throughout Kentucky. The study team identified four emerging themes and several subthemes related to Nutrition Education Program educators working with clientele in recovery. The four emerging themes included: (1) current experiences working with the audience, (2) relevant components in the current curriculum, (3) suggested new and expanded resources for future curriculum, and (4) guidance to assistants new to the audience. Our research findings contribute to the development of new programmatic materials that are better suited to meet clients’ needs in recovery and ultimately improve SUD recovery outcomes. With increased knowledge on this emerging research topic, the University of Kentucky Nutrition Education Program will directly benefit Kentucky residents who suffer from SUD and experience its detrimental social and health implications

X-raying the Beating Heart of a Newborn Star: Rotational Modulation of High-energy Radiation from V1647 Ori

We report a periodicity of ~1 day in the highly elevated X-ray emission from the protostar V1647 Ori during its two recent multiple-year outbursts of mass accretion. This periodicity is indicative of protostellar rotation at near-breakup speed. Modeling of the phased X-ray light curve indicates the high-temperature (~50 MK), X-ray-emitting plasma, which is most likely heated by accretion-induced magnetic reconnection, resides in dense (>~5e10 cm-3), pancake-shaped magnetic footprints where the accretion stream feeds the newborn star. The sustained X-ray periodicity of V1647 Ori demonstrates that such protostellar magnetospheric accretion configurations can be stable over timescales of years.Comment: 26 pages, 10 figure

Effect of Drought Stress on Fibre Digestibility of Corn for Silage

Limited information exists about the impact of drought stress on corn silage digestibility. The objective of this study was to determine the effect of irrigation on in situ NDF digestibility of corn tissues grown under controlled conditions in a greenhouse. Five commercial corn hybrids were planted in pots and grown in a greenhouse. Pots were subjected to an abundant or restricted irrigation regime. Leaf blades and stem internodes were collected from the upper and bottom portion of each hybrid. Tissue samples were incubated in the rumen of 3 rumen-cannulated cows for 0, 3, 6, 12, 24, 48, 96, and 240 hours. Drought stress did not affect the concentration of undigested neutral detergent fibre (uNDF) in upper or bottom internodes but slightly decreased in leaf blades (17.5 and 15.7% for abundant and restricted watering, respectively). The concentration of uNDF varied substantially among corn hybrids in upper internodes (13.4 to 28.3% uNDF), bottom internodes (21.5 to 42.3% uNDF), and blades (11.6 to 20.1% uNDF). Drought stress did not affect the fractional digestion rate (kd) of fibre in any tissue. The kd of fibre varied substantially among corn hybrids in upper (3.8 to 6.6%/h) and bottom internodes (4.2 to 6.7%/h) but did not vary in blades (3.8%/h). Significant interactions existed between irrigation treatment and corn hybrid for the effective ruminal degradation (ERD) of upper and bottom internodes. This interaction did not exist for blades. The ERD of fibre varied substantially among corn hybrids in blades (32.5 to 39.1%). The conclusions of this study are that drought-stressed corn had a marginal increase in fibre digestibility of blades but not in internodes, that drought stress had no effects on ERD of fibre within hybrids, and that the effect of drought stress on fibre digestibility of corn for silage is still inconclusive

Detection of a Cool, Accretion-Shock-Generated X-Ray Plasma in EX Lupi During the 2008 Optical Eruption

EX Lupi is the prototype for a class of young, pre-main-sequence stars which are observed to undergo irregular, presumably accretion-generated, optical outbursts that result in a several magnitude rise of the optical flux. EX Lupi was observed to optically erupt in 2008 January, triggering Chandra ACIS Target of Opportunity observations shortly thereafter. We find very strong evidence that most of the X-ray emission in the first few months after the optical outburst is generated by accretion of circumstellar material onto the stellar photosphere. Specifically, we find a strong correlation between the decreasing optical and X-ray fluxes following the peak of the outburst in the optical, which suggests that these observed declines in both the optical and X-ray fluxes are the result of declining accretion rate. In addition, in our models of the X-ray spectrum, we find strong evidence for an approx 0.4 keV plasma component, as expected for accretion shocks on low-mass, pre-main-sequence stars. From 2008 March through October, this cool plasma component appeared to fade as EX Lupi returned to its quiescent level in the optical, consistent with a decrease in the overall emission measure of accretion-shock-generated plasma. The overall small increase of the X-ray flux during the optical outburst of EX Lupi is similar to what was observed in previous X-ray observations of the 2005 optical outburst of the EX Lupi-type star V1118 Ori but contrasts with the large increase of the X-ray flux from the erupting young star V1647 Ori during its 2003 and 2008 optical outbursts

Limits on I-band microvariability of the Galactic Bulge Miras

We search for microvariability in a sample of 485 Mira variables with high quality I-band light curves from the second generation Optical Gravitational Lensing Experiment (OGLE-II). Rapid variations with amplitudes in the ~0.2-1.1 mag range lasting hours to days were discovered in Hipparcos data by de Laverny et al. (1998). Our search is primarily sensitive to events with time-scales of about 1 day, but retains a few percent efficiency (per object) for detecting unresolved microvariability events as short as 2 hours. We do not detect any candidate events. Assuming that the distribution of the event time profiles is identical to that from the Hipparcos light curves we derive the 95% confidence level upper limit of 0.038 per year per star for the rate of such events (1 per 26 years per average object of the ensemble). The high event rates of the order of 1 per year per star implied by the Hipparcos study in the H_P band are excluded with high confidence by the OGLE-II data in the I band. Our non-detection could still be explained by much redder spectral response of the I filter compared to the H_P band or by population differences between the bulge and the solar neighborhood. In any case, the OGLE-II I-band data provide the first limit on the rate of the postulated microvariability events in Mira stars and offer new quantitative constraints on their properties. Similar limits are obtained for other pulse shapes and a range of the assumed time-scales and size-frequency distributions.Comment: Accepted for publication in Ap