Thermal Properties of Tissue Equivalent Phantom Materials

Thermal conductivity, specific heat, density, and thermal diffusivity were determined for standard RF and microwave phantom materials. Thermal conductivity data for seven phantom materials of varying aluminum content were analyzed using mixture theories. With the thermal diffusivity values obtained, worst case errors in SAR determination due to thermal conduction for adipose-muscle planar phantoms were estimated.     

Steady state segregation and heat flow in ESR

A combined theoretical and experimental study of steady-state heat flow and segregation in ESR is presented. The segregation model permits prediction of pressure gradients, hence, interdendritic flow velocities responsible for macrosegregation in the “mushy? zone of axisymmetric ESR ingots. The heat flow model considers the solidus isotherm as a moving boundary. The relationships between power and slag temperature as well as power and heat transfer coefficient are experimentally measured and included in the heat balance equation for the slag. Experiments on both a low-temperature simulated ESR apparatus and on a 200 mm diam ESR ingot mold verify both models.     

A method of estimating monthly average solar radiation on shaded receivers

The geometry of vertical solar radiation receivers shaded by overhangs is described. The instantaneous mean solar radiation on a shaded receiver is defined leading to a method of estimating , the monthly average daily radiation on a shaded receiver. Values of the monthly average beam irradiated fraction of the receiver area, , are presented in a series of figures. The effects of overhang extension and receiver azimuth on are considered. Example calculations are presented and the overall effect of an overhang as a shading device is discussed.     

"Changes in Leadership Appraisal as a Function of the Stress of a Simulated Panic Situation". Erratum to Klein.

Reports an error in the original article by Klein (Journal of Personality & Social Psychology, Vol 34(6) Dec 1976, 1143-1154). On page 1152, there is an error in the first two sentences of the first full paragraph in the right-hand column of the page. The corrected sentences are provided here. In addition, Table 3 on p. 1152 is corrected. (The following abstract of this article originally appeared in record 1978-31666-001.) Research by A. Mintz (see record 1951-08008-001) and by H. H. Kelley et al (see record 1965-06787-001) left unresolved the question of what level of personal threat leads to group incoordination of "panic behavior." The present study set out to resolve this issue and to explore the additional relationship between leadership and behavior in the panic situation. The dependent variables were Likert-type questionnaire items designed to investigate the level of responsibility attributed to a leader by members of a group as a function of 4 variables: (a) 2 levels of stress (threat of shock or of small monetary loss), (b) 2 levels of leadership authority (elected or appointed), (c) 2 conditions of leadership ("me-last" or "me-first"), and (d) group success or failure. 14 male college students were run in this 2-4 factorial design with a nonfactorial control group. The task setting, which required Ss to retrieve their wooden cones through the same hole, was analogous to the situation that would occur in a theater fire where only one narrow exit existed. Results support the contention of Kelley that group incoordination (panic) increases under personal threat. Additional results show that (a) leaders facilitated achieving the goal of safe exit; (b) elected leaders were given more responsibility and were seen as more competent than appointed leaders, but only when the stress was comparatively low; and (c) success or failure seemed to have had little effect on the leader's evaluation by the group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Thought Disorder Index: Short-form assessments.

Investigated whether short forms of the Rorschach Test are as effective as the standard 10-card administration in eliciting thought disorder as measured by the Thought Disorder Index. Results showed the short 4-card forms yield excellent composite indexes of total thought disorder, severity levels, and the more frequently occurring qualitative scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequential pulse defibrillation in man: comparison of thresholds in normal subjects and those with cardiac disease

We compared the parameters describing the defibrillation threshold in patients with normal hearts and in patients with ischemic heart disease, using a special electrode system and sequential pulses of current. Twenty-eight patients consented to the study (mean age: 36.6 +/- 10.1 years; mean mass: 80.7 +/- 13.8 kg). Twenty-one patients underwent surgery for Wolff-Parkinson-White syndrome (relatively normal hearts). Six patients had a history of previous myocardial infarction and aneurysm or coronary artery disease; and one patient had been resuscitated from an episode of sudden death, without evidence of consequent myocardial damage. For 26 patients, defibrillation thresholds were determined intraoperatively by passing sequential pulses through a catheter electrode and epicardial mesh electrode. For 2 patients defibrillation thresholds were determined during electrophysiologic study, after ventricular fibrillation was induced by programmed stimulation, by passing sequential pulses through a catheter and skin-patch electrode. Parameters for sequential pulse defibrillation thresholds between the two groups did not differ appreciably. Total energy for patients with normal hearts averaged 9.9 +/- 6.3 J compared to 8.9 +/- 4.6 J for patients with cardiac disease. No patient with cardiac disease had defibrillation parameters that exceeded the range of the normal patients. These results suggest that the presence of cardiac disease may not significantly alter the parameters necessary for successful defibrillation when using sequential pulses for delivery of energy.     

Repeated testing: A technique for assessing the roles of elaborative and organizational processing in the representation of social knowledge.

A new technique for evaluating the roles of elaborative and organizational processing in the representation of social information is described. Although these concepts have found increasing application in theories of social knowledge, most investigations of elaboration and organization have relied on measures that can lead to interpretive ambiguities. Two studies show how analysis of the item-gain and item-loss components of multitrial free recall provides a means for assessing the contributions of elaborative and organizational processing while avoiding many of the problems found with existing measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transformation reactions of special metals in organisms and in the environment. 2. Abiotic methylation reactions of mercury, especially by methyltin compounds and humic and fulvic acids

Following a literature survey concerning abiological methylation reactions including transmethylation of mercury we present the results of transmethylation experiments. Model experiments in aqueous solution show an instantaneous methylation of mercuric chloride by mono-, di-, and trimethyltin chloride, the dimethyl compound having the highest rate of formation. The same is valid for similar experiments with soils, in which influences of the kind of soil also play a certain role. The methylation experiments of HgCl2 with humic and fulvic acids isolated from soil yielded positive results only in some few of the extracts and only with humic acid fractions.