CONSUMER ACCEPTANCE OF FORAGE FINISHED BEEF

Consumer/Household Economics,

Subcooled freon-11 flow boiling in top-heated finned coolant channels with and without a twisted tape

An experimental study was conducted in top-heated finned horizontal tubes to study the effect of enhancement devices on flow boiling heat transfer in coolant channels. The objectives are to examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for circular coolant channels with spiral finned walls and/or spiral fins with a twisted tape, and improve the data reduction technique of a previous investigator. The working fluid is freon-11 with an inlet temperature of 22.2 C (approximately 21 C subcooling). The coolant channel's exit pressure and mass velocity are 0.19 M Pa (absolute) and 0.21 Mg/sq. ms, respectively. Two tube configurations were examined; i.e., tubes had either 6.52 (small pitch) or 4.0 (large pitch) fins/cm of the circumferential length (26 and 16 fins, respectively). The large pitch fins were also examined with a twisted tape insert. The inside nominal diameter of the copper channels at the root of the fins was 1.0 cm. The results show that by adding enhancement devices, boiling occurs almost simultaneously at all axial locations. The case of spiral fins with large pitch resulted in larger mean (circumferentially averaged) heat transfer coefficients, h sub m, at all axial locations. Finally, when twisted tape is added to the tube with large-pitched fins, the power required for the onset of boiling is reduced at all axial and circumferential locations

Flow boiling with enhancement devices for cold plate coolant channel design

The use of flow boiling for thermal energy transport is intended to provide an alternative for accommodating higher heat fluxes in commercial space systems. The objectives are to: (1) examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls, spiral fins, or both spiral fins and a twisted tape; (2) examine the effects of channel diameter and subcooling; and (3) develop an improved reduction analysis and/or suggest possible heat transfer correlation of the present data. Freon-11 is the working fluid. Two-dimensional (circumferential and axial) wall temperature distributions were measured for coolant channels with the above noted internal geometries. The flow regimes which are being studied are: (1) single phase; (2) subcooled flow boiling; and (3) stratified flow boiling. The inside diameter of all test sections is near 1.0 cm. Cicumferentially averaged heat transfer coefficients at several axial locations were obtained for selected coolant channels for a mass velocity of 210 kg/sq m s, an exit pressure of 0.19 MPa (absolute), and an inlet subcooling of 20.8 C. Overall (averaged over the entire channel) heat transfer coefficients were compared for the above channel geometries. This comparison showed that the channel with large pitch spiral fins had higher heat transfer coefficients at all power levels

Improved methods for the preparation of alkyl sulfonic acids.

Typewritten sheets in cover. Thesis (M.A.)--Boston University This item was digitized by the Internet Archive. Bibliography: p. 36

Flow boiling with enhancement devices for cold plate coolant channel design

The effects of enhancement devices on flow boiling heat transfer in circular coolant channels, which are heated over a fraction of their perimeters, are studied. The variations were examined in both the mean and local (axial, and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls or with both a twisted tape and spiral finned walls. Improvements were initiated in the present data reduction analysis. These efforts should lead to the development of heat transfer correlations which include effects of single side heat flux and enhancement device configuration. It is hoped that a stage will be set for the study of heat transfer and pressure drop in single sided heated systems under zero gravity conditions

Exploring Screen Time Habits and the Life Empowerment Divide at an HBCU

College students at a historically black university used their social media accounts to recruit 1,232 of their peers to take an online survey that explored digital screen time and social media habits at this HBCU. The study revealed that 51% devoted daily screen time to academic empowerment, 31% devoted it to leisure, and 11% devoted it to life empowerment. Sixty-six percent said they spent too much screen time on leisure and not enough on life empowerment, i.e., using resources in the digital world to improve their lives. The paper explored the divide, its implications, and how to narrow it

Should we treat soft tissue injuries with Actovegin?

Actovegin is a biological drug produced from deproteinised hemodialysate of calf serum with over 50 years of history for its clinical use. There have been many in vitro studies to speculate its potential role and mechanism of action in cells; due to the nature of this drug and serum based culture techniques for most in vitro experiments, presumptuous conclusions and claims from these studies on performance enhancement should be cautiously interpreted. There have been well-designed human in vivo studies suggesting it does not enhance human performance, and has potentially good clinical applications to treat injuries, strokes and diabetes. Recently, evidence has emerged suggesting Actovegin has anti-inflammatory and anti-apoptotic effects on injured tissues; further clinical research is needed to define these effects. This article also provides a narrative review of Actovegin summarizing outcomes from recent publications

Operative versus nonoperative treatment of acute Achilles tendon ruptures: A pilot economic decision analysis

Background: The operative treatment of Achilles tendon ruptures has been associated with lower rerupture rates and better function but also a risk of surgery-related complications compared with nonoperative treatment, which may provide improved outcomes with accelerated rehabilitation protocols. However, economic decision analyses integrating the updated costs of both treatment options are limited in the literature. Purpose: To compare the cost-effectiveness of operative and nonoperative treatment of acute Achilles tendon tears. Study Design: Economic and decision analysis; Level of evidence, 2. Methods: An economic decision model was built to assess the cost-utility ratio (CUR) of open primary repair versus nonoperative treatment for acute Achilles tendon ruptures, based on direct costs from the practices of sports medicine and foot and ankle surgeons at a single tertiary academic center, with published outcome probabilities and patient utility data. Multiway sensitivity analyses were performed to reflect the range of data. Results: Nonoperative treatment was more cost-effective in the average scenario (nonoperative CUR, US$520; operative CUR, US$1995), but crossover occurred during the sensitivity analysis (nonoperative CUR range, US$224-US$2079; operative CUR range, US$789-US$8380). Operative treatment cost an extra average marginal CUR of US$1475 compared with nonoperative treatment, assuming uneventful healing in both treatment arms. The sensitivity analysis demonstrated a decreased marginal CUR of operative treatment when the outcome utility was maximized, and rerupture rates were minimized compared with nonoperative treatment. Conclusion: Nonoperative treatment was more cost-effective in average scenarios. Crossover indicated that open primary repair would be favorable for maximized outcome utility, such as that for young athletes or heavy laborers. The treatment decision for acute Achilles tendon ruptures should be individualized. These pilot results provide inferences for further longitudinal analyses incorporating future clinical evidence