Static and fatigue failure properties of thoracic and lumbar vertebral bodies and their relation to regional density

This study investigated (1) whether a characterization of the macroscopic architecture within the vertebral centrum would improve predictions of vertebral strength, (2) if regions in the centrum where least bone loss with age occurs are more predictive of vertebral strength, and (3) whether different patterns of the macroscopic architecture are predictive of static as compared to fatigue strength. To characterize the vertebral macroscopic architecture, a regional bone mineral density (rBMD) technique was used that estimated the cancellous density distribution (in 18 specific regions of the vertebral centrum) for vertebrae T7-L4, from spines of 20 female cadavers. Static and fatigue failure properties of whole vertebrae were obtained, and predictive models of static and fatigue failure properties of whole vertebrae were examined. We found that (1) vertebral failure properties were better predicted by combinations of vertebral regional cancellous density (multiple linear regressions) rather than by any individual region of cancellous density alone (simple linear regressions); (2) models using regions of density that demonstrated minimum decline with age [from the data of Flynn and Cody (Calcif. Tissue Int. 53, S170-S175 (1993))] resulted in better correlations with ex vivo vertebral static failure properties than models using density regions that showed maximum decline with age, and (3) static and fatigue characteristics required different density regions to reach significance. (A comparison of models predictive of static and fatigue failure properties revealed that anterior density regions were most often included in predictive models of the static properties while posterior regions were more predictive of the fatigue properties).(ABSTRACT TRUNCATED AT 250 WORDS)     

Re-Engineering the Undergraduate Building Construction Program for the 21st Century

This paper presents an integrative model developed this past year by the Building Construction (BC) Department at Virginia Tech (VT), designed to help each student master the competencies necessary to succeed in the 21st Century as a building constructor in a changing global market-place. The curriculum described in this paper presents a dynamic, practical, applied academic model; balances the construction education concepts of practical experience based knowledge with academic inquiry; integrates people and communication skills with the pragmatic building construction skills; and provides a construction program that maintains a strong identity positioned between architecture and engineering. Strategically this task was accomplished by weaving vertical and horizontal integration into the BC curriculum at Virginia Tech. Results of this first year are presented, including lessons learned, external evaluations, and recommendations for adaptation.     

Viscosity Model for CO-Noble Gas Mixtures at Atmospheric Conditions

We have presented an empirical model for predicting the viscosity of binary mixtures of gases, based on our previous correlation for natural gas mixtures (Miadonye and Clyburn, 2003). New parameters were derived for binary mixtures of carbon monoxide-noble gases and for carbon monoxide-nitrogen gases, for temperatures from 0-1000°C. The model was validated with the Chapman-Enskog equation for gas mixtures, with and without length scaling factor. For five equimolar and eight non-equimolar mixtures of gases at temperatures from 0-1000°C, the model gave an excellent viscosity prediction with an overall average absolute deviation of 0.45%. The model is simple to incorporate in design and simulation packages, and more accurate than any correlation currently used for estimating the viscosities of gas mixtures.     

It's Different to Give Than to Receive: Predictors of Givers' and Receivers' Reactions to Favor Exchange.

The present research examines episodes of favor exchange among peer employees. We posit that favor receivers' and favor givers' commitment to their exchange relationships with one another will be accounted for by different factors. As predicted, in 2 different organizational contexts, receivers' commitment to their relationships with givers was found to be more related to their judgments of the givers' interactional justice when performing the favor, whereas givers' commitment to their relationships with receivers was shown to be more associated with their judgments of the favorability of the outcomes associated with the favor that they performed. The implications of these findings for how givers and receivers can better manage favor exchange, and hence their relationships with each other, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dehydration anorexia in decerebrate rats.

Hypertonic saline (HS) administered intraperitoneal/ly (ip) reduced the intake of sucrose solution infused intraorally in tube-fed decerebrate rats, as it did in control animals. Similarly, either ip or intravenous HS markedly decreased the intake of laboratory chow by neurologically intact control rats. These observations complement recent findings that lesions of putative osmoreceptors in the ventral diencephalon, which eliminate thirst and blunt pituitary secretion of vasopressin and oxytocin in response to HS in rats, have no apparent effect on the HS-induced inhibition of food intake. Taken together they support previous studies indicating an important role for the caudal brainstem in the central control of food intake and suggest that such brainstem control may also include the inhibition of food intake induced by acute hyperosmolality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental measure of dynamic spatial-hole burning in DFB lasers

Spatially resolved measurements of carrier density in two 1.3-μm distributed feedback laser diodes are reported. By measuring the response of the spontaneous emission intensity to a 50-MHz drive current, small relative changes in the carrier density can be observed. When biased below threshold, the carrier density fluctuates uniformly in the laser cavity with a phase delay corresponding to the carrier lifetime. When biased above threshold, the carrier density response shows clear evidence of spatial hole burning. The location of the minimum and the net change in carrier density, however, depend on the particular laser     

Adaptive Filter Processing in Microwave Remote Heart Monitors

This commmunication describes some current applications tions of adaptive filtering to the processing of microwave Doppler signals for heart rate monitoring. The problem has been approached in the past using signal processing techniques such as peak detection or autocorrelation. These methods either require large amounts of data or tend to be unreliable. This communication utilizes some recent techniques used in speech processing and applies them to heartbeat detection, thus allowing on-line processing of sampled microwave heart signals. The presentation includes a model for the signal, brief discussions of the algorithms evaluated, and qualitative analysis of performance compared to EKG measurements.     

A decision support system for telecommunications

We have built a Decision Support System (DSS) which can to aid strategic management within the industry in making vital decisions in relation to Customer and Network profiles. This enables managers in the respective areas within the industry to fully utilise the vast amounts of data available to make projections and decisions in relation to utilisation of valuable resources. Copyright © 2002 John Wiley & Sons, Ltd.     

A techno-economic evaluation of biomass briquetting in India

A financial analysis of biomass briquetting technology in India has been undertaken. Simple cost functions for briquetting machines have been developed. Unit cost of briquette production for various types of raw materials and different capacities of briquetting units have been calculated. Role of different factors affecting the cost of production of briquettes have also been analysed.