The Effect of Peer-Editing on the Quality of 11th Grade Composition

The relationship between peer-editing and composition quality was investigated. The thirty subjects involved were 11th-grade English students randomly assigned to control and experimental groups. During a nine week period, both groups received the same assignments and teacher evaluation. The control group, which did not revise unless upon individual initiative, participated in a dramatics workshop while the experimental group used a worksheet developed by Leila Christenbury (1982) to edit and proofread each other\u27s writing before evaluation by the teacher. Pre and post writing assignments were blind rated at the end of the experiment using the Diederich Rating Scale. Individual item scores and total scores were compared. The t-ratios proved insignificant at the .05 level. Positive student feedback, however, indicated that the procedure deserves further investigation

OH+ in Diffuse Molecular Clouds

Near ultraviolet observations of OH+ and OH in diffuse molecular clouds reveal a preference for different environments. The dominant absorption feature in OH+ arises from a main component seen in CH+ (that with the highest CH+/CH column density ratio), while OH follows CN absorption. This distinction provides new constraints on OH chemistry in these clouds. Since CH+ detections favor low-density gas with small fractions of molecular hydrogen, this must be true for OH+ as well, confirming OH+ and H2O+ observations with the Herschel Space Telescope. Our observed correspondence indicates that the cosmic ray ionization rate derived from these measurements pertains to mainly atomic gas. The association of OH absorption with gas rich in CN is attributed to the need for high enough density and molecular fraction before detectable amounts are seen. Thus, while OH+ leads to OH production, chemical arguments suggest that their abundances are controlled by different sets of conditions and that they coexist with different sets of observed species. Of particular note is that non-thermal chemistry appears to play a limited role in the synthesis of OH in diffuse molecular clouds.Comment: 15 pages, 4 figures, to appear in ApJ Letter

A Needs Assessment of the Homeless of Birmingham and Jefferson County

The information contained in this report, and summarized here, derives from two data collection activities. One, a point-in-time count of homeless persons in a 24-hour period on January 26-27, 2005 that included a two-page survey of basic demographic information and a needs assessment. Two, an hour-long survey of 161 homeless adults conducted between April 4 and May 25, 2005 providing information on residential and housing histories, duration and causes of homelessness, stressful life events and circumstances, resources, social supports and social capital, mental and physical health, and access to health services

XY checkerboard antiferromagnet in external field

Ordering by thermal fluctuations is studied for the classical XY antiferromagnet on a checkerboard lattice in zero and finite magnetic fields by means of analytical and Monte Carlo methods. The model exhibits a variety of novel broken symmetries including states with nematic ordering in zero field and with triatic order parameter at high fields.Comment: 6 page

Health Disparities and COVID-19 Pandemic: Increasing Clinical Research Participation among African Americans

Health disparities in African Americans is a persistent issue. Higher rates and severity of the novel coronavirus-19 [COVID-19] among African Americans only widens health disparities. Effective COVID-19 treatment options are imperative, requiring representation of African Americans in clinical research. However, low participation and under-representation of African Americans is complex in nature. This article describes health disparities, the impact of COVID-19, and participation in clinical research among African Americans. We offer strategies for researchers to enhance the inclusion of African Americans. We also offer strategies in conducting clinical research during COVID-19

Satisfaction with Medical Encounters Among Caregivers of Geriatric Outpatients

Caregivers\u27 experiences and satisfaction with physicians and medical services provided to geriatric patients are reported. An outstanding predictor of satisfaction with physician communication and overall patient care was the extent to which caregivers were experiencing role strain. Other significant predictors included caregiver knowledge of clinic and social support services provided to patients. The data suggest that, irrespective of the quality of clinic services and physician communication style, some caregivers will be dissatisfied because their encounter is mediated by the stress of activities separate from the medical encounter. We assert the importance of specialized geriatric services and argue that if these services are not in place, caregiver satisfaction with the overall medical encounter will likely be much lower

Drake University Through Seventy-Five Years, 1881-1956

288 page

Effects of Non-Uniform Heating on the Location and Magnitude of Critical Heat Flux in a Microchannel Heat Sink

Decreasing form factors and diminishing numbers of thermal interfaces and spreading layers in modern, compact electronic packages result in non-uniform heat generation profiles at the chip level being transmitted directly to the heat sinks. An improved understanding of the effects of non-uniform heating on the heat dissipation limits in microchannel heat sinks has become essential. An experimental investigation is conducted to measure the location and magnitude of critical heat flux (CHF) in a microchannel heat sink exposed to a range of non-uniform heating profiles. A 12.7 mm × 12.7 mm silicon microchannel heat sink with an embedded 5 × 5 array of individually controllable heaters is used in the experiments. The microchannels in the heat sink are 240 mm wide and 370 micrometers deep, and are separated by 110 mm wide fins. The dielectric fluid HFE-7100 is used as the coolant, with an average mass flux in the heat sink of approximately 800 kg/m2s. High-speed visualizations of the flow are recorded to capture the CHF phenomena observed. A central ‘hotspot’ spanning the entire length of the heat sink in the flow direction (formed by heating only the central 20 percent of the base area) produced both the largest wall excess temperature and the lowest CHF of all the heat flux distributions investigated, due to the flow maldistribution induced. A single transverse hotspot spanning the heat sink perpendicular to the flow direction resulted in different CHF values based on its streamwise location; CHF was largest when the hotspot was placed nearest the inlet and smallest when placed nearest the outlet. The visualizations revealed that CHF occurs when there is a sudden and unalleviated upstream expansion of vapor in one or more channels above the hotspot, causing the local wall temperature to rapidly increase. The proximity of the hotspot to the inlet manifold, which communicates between all channels and can relieve downstream vapor expansion, appears to determine the resiliency of the heat sink to conditions leading to CHF

Local Measurement of Flow Boiling Heat Transfer in an Array of Non-Uniformly Heated Microchannels

As electronics packages become increasingly thinner and more compact due to size, weight, and performance demands, the use of large intermediate heat spreaders to mitigate heat generation non-uniformities are no longer a viable option. Instead, non-uniform heat flux profiles produced from chip-scale variations or from multiple discrete devices are experienced directly by the ultimate heat sink. In order to address these thermal packaging trends, a better understanding of the impacts of non-uniform heating on two-phase flow characteristics and thermal performance limits for microchannel heat sinks is needed. An experimental investigation is performed to explore flow boiling phenomena in a microchannel heat sink with hotspots, as well as non-uniform streamwise and transverse peak-heating conditions spanning across the entire heat sink area. The investigation is conducted using a silicon microchannel heat sink with a 5 x 5 array of individually controllable heaters attached to a 12.7 mm x 12.7 mm square base. The channels are 240 lm wide, 370 lm deep, and separated by 110 lm wide fins. The working fluid is the dielectric fluorinert liquid FC-77, flowing at a mass flux of approximately 890 kg/m2 s. High-speed visualizations of the flow are recorded to observe the local flow regimes. Despite the substrate beneath the microchannels being very thin (200 lm), significant lateral conduction occurs and must be accounted for in the calculation of the local heat flux imposed. For non-uniform heat input profiles, with peak heat fluxes along the streamwise and transverse directions, it is found that the local flow regimes, heat transfer coefficients, and wall temperatures deviate significantly from a uniformly heated case. These trends are assessed as a function of an increase in the relative magnitude of the nonuniformity between the peak and background heat fluxes