IMPROVEMENTS IN SOLID DESICCANT COOLING

The DINC (Direct-Indirect Evaporative Cooling) cycle was proposed in 1986 by Texas A6H researchers. The idea wae to combine the benefits of direct and indirect evaporative cooling with desiccant dehumidifying using a rotating aolid silica-gel dehumidifier. Recent parametric studies completed for the Texas Energy Ramarch In Applications Program have-devoloped a computer desrgn for s nomlnal 3-con system that would minimize the energy conuvmption (both thermal and electric) while mslntainina a sensible heat ratio of 75% or less. That “optimum design” for the original 1986 DINC cycle wae modified to improve ite energy efficiecy. The modifications deecribed in this paper were: (1) staging the desiccant regeneration air and (2) recirculation of the primary air to the secondary aide of the indirect evaporative cooler. Computer simulations were run to study the effect of the modifications on the performance of the system. American Refrigeration Institute (ARI) standard conditions (Ambient sir at 35°C. 40% R.H. and Room air at 26.7°C. 50% R.H.) were used for all the modifications. Results were sleo compared to the familiar Pennington (ventilation) cycle.

The atudy indicated that recirculating the indirect evaporative cooler air only degenerated the performance. However, staging a portion of the regeneration air could improve the thermal Coefficient of Performance by 25% over the non-staged DINC cycle. Compared to a aimilar staged-regeneration Pennington Cycle it is a 16% improvement in thermal COP and the sensible heat ratio was 70%.     

Rapid Hybrid Acquisition of Ultra-Wideband Signals

Impulsive ultra-wideband (UWB) radio provides many promising features for wireless communications in a dense multipath environment. However, these features are largely the result of the enormous effective processing gain, which can make acquisition difficult at the receiver. In this paper, a recently developed theory of minimum complexity sequential detection is applied to the hybrid acquisition problem. As in previous hybrid schemes, a number of potential timing phases are checked as a group; however, a phase is disregarded as soon as it appears unlikely rather than waiting for a “winner” to be chosen from the group. Another phase then replaces the disregarded one. Analysis and simulation results indicate that the proposed scheme can improve average acquisition times for highly spread systems operating over either additive white Gaussian noise (AWGN) or multipath fading channels. This paper is based in part upon work supported by the Army Research Office under Contract DAAD10-01-1-0477 and employed equipment obtained under National Science Foundation Grant EIA-0080119.     

Design of a hinge kit system in a Kimchi refrigerator receiving repetitive stresses

Based on field data and a tailored set of accelerated life tests, the hinge kit system of a closing door in a Kimchi refrigerator was redesigned. Using a force and moment balance analysis, the simple mechanical loads from the closing of the door were evaluated. The failure modes and mechanisms found experimentally were similar to those of the failed sample in the field. Failure analysis, accelerated life tests and corrective action plans were used to identify the key control parameters and level for the mechanical hinge kit system. The missing controllable design parameters of the hinge kit system in the design phase included the corner rounding and rib of the housing hinge kit, the oil sealing method of the oil damper, and the material of the cover housing. After a tailored series of accelerated life tests with corrective action plans, the B₁ life of the new hinge kit design is now guaranteed to be over 10 years with a yearly failure rate of 0.1%.     

Detecting a Security Disturbance in Multi Commodity Stochastic Networks

Here is a multi-criteria approach to identify and evaluate network-flow monitoring strategies in a stochastic environment. We propose an analytical approach for assessing flow disturbance, based on limited sampling of arc-flow information in multi commodity, or multiple origin-destination (O–D), networks. A disturbance is defined here as abnormal network traffic beyond routine fluctuations. The network is characterized by arcs that are available with certain probabilities, suggesting a busy packet-switching/circuit-switching network, or simply network with failing components. Given the huge state space of such stochastic networks, our first objective is to bound the expected flow for computational efficiency. This is accomplished by extending available single-commodity-network results to the multi commodity case. The second objective is to determine the best placement of flow monitors to obtain the most accurate estimates of traffic flow, as represented by O–D pair traffic volumes in order to detect a disturbance. We followed a multi-criteria approach in defining and evaluating all possible monitor-placement strategies satisfying monitor availability. To assess a traffic pattern, O–D volumes are estimated using the l_p-metric for p = 1, 2 and ∞, representing a decision-maker's risk-preference structure. The final objective is to define a disturbance metric providing confident assessments on the occurrence of a flow disturbance. In this regard, we use linear-regression to generate confidence intervals around the expected flow for each O–D pair. This is supplemented by the Fisher Method of Randomization, a non-parametric test, for small networks. Unlike the Fisher-test results, it appears the linear-regression “disturbance metric” is very sensitive to detecting “disturbance.” Preliminary results suggest that among the three l_p metrics in O–D estimation, it appears that the best is the l₂-metric, which provides the appropriate sensitivity and accuracy. Counter to intuition, it is also observed that the “disturbance” estimation error generally decreases as the number of sampled arcs decreases.     

A comparison of posttraumatic stress disorder in veterans with and without spinal cord injury.

The authors assessed effects of paraplegic and quadriplegic spinal cord injuries (SCls) on posttraumatic stress disorder (PTSD) by comparing severity and prevalence of PTSD in these groups to a sample of controls who experienced traumatic injuries other than SCI. The authors found that veterans with quadriplegia reported significantly less severe current PTSD symptoms than controls who were not significantly different from veterans with paraplegia. These results suggest that sustaining a quadriplegic SCI decreases risk of current PTSD, whereas sustaining a paraplegic SCI is associated with greater risk of PTSD, although the risk is no greater than that incurred from experiencing the trauma itself. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychosocial adjustment following ostomy.

Examined a range of postsurgical adjustment difficulties in 131 adult ostomy patients. Ss reported experiencing a significant number of technical, emotional, social, marital/family, and sexual difficulties postsurgically. Technical and emotional difficulties were associated with problematic social and marital/family adjustment and impaired sexual functioning. Technical problems, emotional difficulties, and social problems were all associated with the S's perception of having received inadequate preparatory information. Marital/family and sexual maladjustment, on the other hand, were associated with low levels of perceived social support. Results support the biopsychosocial model of chronic illness proposed by G. L. Engel (see record 1978-01423-001). Clinical implications are discussed, as well as their relation to previous research on adjustment to stressful medical procedures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Therapists' emotional reactions to substance abusers: A new questionnaire and initial findings.

Developed and tested the Ratings of Emotional Attitudes to Clients by Treaters (REACT) scale. The REACT was administered to 52 therapists and 140 cocaine-dependent outpatients, at sessions 2, 5, and 24 of psychotherapy. It was found to have high internal consistency at each time point, moderately high convergent validity with therapists' (but not patients') therapeutic alliance ratings, and a factor structure that appeared to meaningfully derive 4 factors: "therapist in conflict with self," "therapist focused on own needs," "positive connection," and "therapist in conflict with the patient." Therapists' emotional responses were found to become more negative over the course of treatment, and, when compared by theoretical orientation, were found more positive for 12-step drug counselors than for cognitive or supportive-expressive therapists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of oil properties on spark-ignition gasoline engine friction

The effects of base oil, friction modifier (FM) and viscosity grade on firing engine friction are investigated in an automotive gasoline engine. Unique aspects of the study are (1) viscosity grade is maintained when synthetic and conventional base oils are compared, (2) the influence of engine operating condition on the effectiveness of base oil, FM and viscosity grade in reducing engine friction is considered, and (3) friction-relevant design details of the test engine are discussed. Results show that replacing conventional oil with synthetic oil of the same viscosity grade reduces friction, especially at high boundary friction conditions. Molybdenum dithiocarbamate (MoDTC), and to a lesser extent organic FM, also reduce friction, especially at high boundary friction conditions. Furthermore, using 5W-20 oil causes less friction than 5W-30 and 10W-40 oil at both high and low boundary friction conditions. Results are expected to hold true for engines with similar friction-relevant designs.