A "fast growth" method of computing free energy differences

Let Delta F be the free energy difference between two equilibrium states of a system. An established method of numerically computing Delta F involves a single, long ``switching simulation'', during which the system is driven reversibly from one state to the other (slow growth, or adiabatic switching). Here we study a method of obtaining the same result from numerous independent, irreversible simulations of much shorter duration (fast growth). We illustrate the fast growth method, computing the excess chemical potential of a Lennard-Jones fluid as a test case, and we examine the performance of fast growth as a practical computational tool.Comment: 17 pages + 4 figures, accepted for publication in J.Chem.Phy

Directional solidification of flake and nodular cast iron during KC-135 low-g maneuvers

Alloys solidified in a low-gravity environment can, due to the elimination of sedimentation and convection, form unique and often desirable microstructures. One method of studying the effects of low-gravity (low-g) on alloy solidification was the use of the NASA KC-135 aircraft flying repetitive low-g maneuvers. Each maneuver gives from 20 to 30 seconds of low-g which is between about 0.1 and 0.001 gravity. A directional solidification furnace was used to study the behavior of off eutectic composition case irons in a low-g environment. The solidification interface of hypereutectic flake and spheroidal graphite case irons was slowly advanced through a rod sample, 5 mm in diameter. Controlled solidification was continued through a number of aircraft parabolas. The known solidification rate of the sample was then correlated with accelerometer data to determine the gravity level during solidification for any location of the sample. The thermal gradient and solidification rate were controlled independently. Samples run on the KC-135 aircraft exhibited bands of coarser graphite or of larger nodules usually corresponding to the regions solidified under low-g. Samples containing high phosphorous (used in order to determine the eutectic cell) exhibited larger eutectic cells in the low-g zone, followed by a band of coarser graphite

Preliminary science report on the directional solidification of hypereutectic cast iron during KC-135 low-G maneuvers

An ADSS-P directional solidification furnace was reconfigured for operation on the KC-135 low-g aircraft. The system offers many advantages over quench ingot methods for study of the effects of sedimentation and convection on alloy formation. The directional sodification furnace system was first flown during the September 1982 series of flights. The microstructure of the hypereutectic cast iron sample solidified on one of these flights suggests a low-g effect on graphite morphology. Further experiments are needed to ascertain that this effect is due to low-gravity and to deduce which of the possible mechanisms is responsible for it

A Survey of Medical Schools\u27 Disability Curricula

It is a well established problem that people with disabilities (PWD), as with many other groups disadvantaged by social inequities, often receive suboptimal care from health care providers. The root cause of this inequity in care can be traced to a lack of training in dealing with PWD for health care providers. Barriers result from issues of communication, knowledge of resources available, access to clinics/hospitals, difficulty using diagnostic equipment (exam tables, scales, mammography, etc) and attitudes towards PWD. Despite numerous reports outlining this issue and calls to action to address deficiencies in the care of PWD, few medical schools currently address the care of patients with disabilities in their curriculum. This poster provides a survey of disability curricula in medical schools and a summary of their content/approach and effectiveness.https://digitalrepository.unm.edu/hslic-posters-presentations/1058/thumbnail.jp

Experiment Checkout During Postmanufacturing Checkout of the Apollo Telescope Mount

The postmanufacturing checkout of the Apollo Telescope Mount (ATM) offers a real challenge for both the technology of today and the technology of tomorrow. The objective of this discussion is to explain the sequence of tests to be performed on t he ATM experiments to assure flight readiness, based on current preliminary planning information. Checkout means the verification of all operating systems. The challenge is to define tests today to check out experiments that will be built and flown tomorrow. The engineering state-ofthe art is identified today for a vehicle, including the experiments, that is scheduled to fly in 1972

Student Emotional Responses to Different Communication Situations

Communication and emotion are closely linked. Emotions experienced while communicating with others can affect one’s message both verbally and nonverbally. This study asked participants to identify the emotions they experienced when communicating with groups of different sizes. These emotions were drawn from, and displayed upon, the Circumplex Model of Affect, a figure developed by Posner, Russell, and Peterson (2005). This model divides 16 emotions into quadrants that lie along two axes: pleasantness and emotional arousal. Results show that as audience size increases, speakers’ emotions become more unpleasant, more highly aroused, and more variable overall. Prior research indicates that these negative emotions can have detrimental effects not just on the speaker’s message, but also on how the audience receives that message. Helping communicators understand the link between their emotions and their communication is a valuable step in improving communication ability and developing valuable emotional intelligence skills