http://www.nccor.org/annualreport2013/downloads/Obesity-3.pdf

Quantification of the effect of energy imbalance on bodyweight

The prevalence of obesity, measured by body mass index, has risen to unacceptable levels in both men and women in the United States and worldwide with resultant hazardous health implications. Genetic, environmental, and behavioral factors influence the development of obesity, and both the general public and health professionals stigmatize those who suffer from the disease. Obesity is associated with and contributes to a shortened life span, type 2 diabetes mellitus, cardiovascular disease, some cancers, kidney disease, obstructive sleep apnea, gout, osteoarthritis, and hepatobiliary disease, among others. Weight loss reduces all of these diseases in a dose-related manner-the more weight lost, the better the outcome. The phenotype of "medically healthy obesity" appears to be a transient state that progresses over time to an unhealthy phenotype, especially in children and adolescents. Weight loss is best achieved by reducing energy intake and increasing energy expenditure. Programs that are effective for weight loss include peer-reviewed and approved lifestyle modification programs, diets, commercial weight-loss programs, exercise programs, medications, and surgery. Over-the-counter herbal preparations that some patients use to treat obesity have limited, if any, data documenting their efficacy or safety, and there are few regulatory requirements. Weight regain is expected in all patients, especially when treatment is discontinued. When making treatment decisions, clinicians should consider body fat distribution and individual health risks in addition to body mass index.

/pdf/the-science-of-obesity-management-an-endocrine-society-4door6qgsk.pdf

The Science of Obesity Management: An Endocrine Society Scientific Statement.

Publisher Summary Thermal control of electronic components has one principal objective, to maintain relatively constant component temperature equal to or below the manufacturer's maximum specified service temperature, typically between 85 and 100°C. It is noted that even a single component operating 10°C beyond this temperature can reduce the reliability of certain systems by as much as 50%. Therefore, it is important for the new thermal control schemes to be capable of eliminating hot spots within the electronic devices, removing heat from these devices and dissipating this heat to the surrounding environment. Several strategies have developed over the years for controlling and removing the heat generated in multichip modules, which include advanced air-cooling schemes, direct cooling, and miniature thermosyphons or free-falling liquid films. The chapter summarizes analytical, numerical, and experimental work in literature, in order to facilitate the improvement of existing schemes and provide a basis for the development of new ones. The chapter focuses on investigations performed over the past decade and includes information on the thermal control of semiconductor devices, modules, and total systems.

Thermal Control of Electronic Equipment and Devices

The Keynote Paper reviews and highlights over 40 years of research on solutions for steady-state and transient thermal constriction and spreading resistances, and thermomechanical models for contact, gap and joint resistances of joints formed by conforming rough surfaces, nonconforming smooth surfaces, and nonconforming rough surfaces. Microgap and macrogap thermal resistance and conductance models are reviewed, and important relations and correlation equations are presented. Contact microhardness, determined by Vickers indenters, are correlated and incorporated into the contact model for conforming rough surfaces. Microhardness parameters are correlated with Brinell hardness values. Elastoplastic contact models for joints formed by smooth sphere-smooth flat and conforming rough surfaces are presented. A simple thermomechanical model for microgaps occupied by oil, grease, grease filled with solid particles, and phase change materials such as paraffins is reviewed, and good agreement with recently published data is noted.

/pdf/four-decades-of-research-on-thermal-contact-gap-and-joint-1ekgb6e7o2.pdf

Four decades of research on thermal contact, gap, and joint resistance in microelectronics

Review of Heat Transfer Technologies in Electronic Equipment

Enhancement of Thermal Contact Conductance by Metallic Coatings: Theory and Experiment

The equations governing weight change in human beings

Recently a new thermomechanical model for coated contacts has been developed and shown to be quite accurate. After a brief overview of the theory, this paper concentrates on illustrating the utility of the new model by applying it to a common electronics packaging problem: heat transfer across an aluminum joint. Several soft metallic coatings are considered, and the thermomechanical model is used to predict the improvement in the contact conductance over that for a bare aluminum-to-aluminum joint. For each coating material, heat transfer performance is presented as a function of the coating thickness, the surface roughness, and the applied pressure. Finally, a parameter is proposed that allows candidate coating materials to be ranked.

Using Metallic Coatings to Enhance Thermal Contact Conductance of Electronic Packages

A highly reliable fluid cooling system is provided having a first and second cooling loop, each of which is adapted to provide cooling for separate sections of the system to be cooled. Each of the cooling loops is connected to an expansion tank at opposite sides of a partition therein. Crossover piping is provided at the discharge side of the first and second pumps connecting the first loop to the second loop and containing a normally open valve therein. In normal operation, the first pump is adapted for pumping fluid through both the first and second cooling loops via the crossover piping and the common expansion tank. A sensor is provided in each half of the partitioned expansion tank for sensing the drop in fluid level below the partition. Either sensor causes the normally open valve in the crossover piping to close and energizes the second pump so that fluid is circulated in the second loop simultaneously with the circulation of the fluid in the first loop by the first pump, thereby providing a highly reliable dual loop cooling system which acts like one loop during normal operation and automatically separates into two separate loops when a leak is detected.

Vincent W. Antonetti

Papers

Enhancement of Thermal Contact Conductance by Metallic Coatings: Theory and Experiment

The equations governing weight change in human beings

Using Metallic Coatings to Enhance Thermal Contact Conductance of Electronic Packages

Inter-active dual loop cooling system

Small scale thermal contact resistance of aluminum against silicon