Guidelines for the Application of Vacuum Contactors

The overvoltage phenomena associated with switching currents in vacuum and their effects on motor insulation are described in some detail, and a practical guideline for the application of overvoltage protective devices is presented.     

A polychrome stain for conventionally fixed paraffin-embedded woody plant tissues

A method for the differential staining of conventionally fixed paraffin-embedded woody plant tissue is described. A five-component stain combination is used with Bismarck Brown, included to avoid the stain variability, precipitation, and overstaining problems often encountered when using safranin.     

Electronic Synthesis of the Avian Retina

An electronic model, based upon reported physiological and anatomical findings and capable of replicating the optical-to-electrical transformations performed by the avian retina has been constructed.     

Electrochemical detection of ascorbic acid (vitamin C) using a glassy carbon electrode

A method for the detection of ascorbic acid (AA) was developed using square wave anodic stripping voltammetric (SWASV) analysis with a glassy carbon electrode (GCE). The results indicated a sensitive oxidation peak current of AA on the GCE. A linear curve was obtained within a concentration range of 1-130.0 microg/L with a preconcentration time of 270 s. The relative standard deviation of 30.0 microg/L observed was 0.1016% (n = 12) under optimum conditions. The low detection limit (S/N) was pegged at 0.30 microg/L. Results showed that the method developed can be used to assay biological and pharmaceutical samples, and food samples, as well as other materials requiring AA analyses.     

Initial perspectives on process threat management

Terrorist and criminal acts are now considered credible risks in the process industries. Deliberate attacks on the nation's petroleum refineries and chemical plants would pose a significant threat to public welfare, national security, and the US economy. To-date, the primary response of government and industry has been on improved security to prevent attacks and the associated consequences. While prevention is clearly preferred, the potential for successful attacks must be addressed. If plant security is breached, the extent of the inflicted damage is determined by the available plant safety systems and procedures. We refer to this "inside the gate" response as process threat management. The authors have initiated a joint industry/academia study to address: the level of safety provided by existing plant equipment and safety systems in response to a terrorist act, and identification of process (rather than security) needs or opportunities to address this new safety concern. This paper describes the initial perspectives and issues identified by the team at the beginning of the study.     

Classroom posture and self-reported back and neck pain in schoolchildren

The study reported here aims to identify the extent of back pain experienced by 11-14 year old schoolchildren, and establish the intensity, duration and frequency of exposure to physical risk factors present in schools. This paper considers the sitting postures of schoolchildren in the classroom. The sitting postures of 66 children were recorded in normal lessons using the Portable Ergonomic Observation Method (PEO). The study found significant associations between flexed postures and low back pain. Static postures and neck and upper back pain were also associated. This study has implications for schools, designers and people in the field of work related musculoskeletal disorders. Further research is required to examine the association between sitting posture and pain reported at different spinal locations.     

Psychological aspects of severe burn injuries in children.

Discusses 4 phases of the traumatic process associated with severe burn injuries in children. Predisposing factors (i.e., emotional disturbances) in the preinjury phase are discussed. The acute phase centers on treatment directed toward physiological stabilization. The intermediate phase, in which skin grafts and other painful medical procedures are performed, is characterized by dependency on adults and regression, behavior problems, and such emotional reactions as blaming the parents. Strategies for preparing children for and helping them cope with pain are discussed. The rehabilitative phase often involves difficulties in social readjustment. Strategies for dealing with each phase are presented, most of which focus on prevention efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of aerosol formation, flammability, and explosion information for heat-transfer fluid selection

The devastating consequences of aerosol/mist explosions have been widely documented, and there are currently efforts to understand the mechanisms of formation and explosion of aerosols. Heat-transfer fluids (HTFs) are particularly susceptible to these hazards, because they are utilized under high pressures and below their flash points, making them more prone to leaking as aerosols. In fact, there is a critical need during design stages for a perception of explosion risks associated with the selection of HTFs. This paper discusses a novel scheme to integrate the knowledge of HTF aerosol formation from leaks in process equipment into the selection of HTFs during the design process. Hazards of aerosols formed from leaks are classified qualitatively using process pressure and droplet sizes.     

Dialysis Disequilibrium Syndrome Revisited

An aggressive dialysis in a grossly azotemic patient, especially one with severe metabolic acidosis, can lead to dialysis disequilibrium syndrome (DDS). Mild forms present as nausea, vomiting, restlessness, and headache. Severe manifestations include seizures, obtundation, coma, and even death. This clinical picture is caused by cerebral edema induced by one or more of the following mechanisms:

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Hybrid Model to Detect Zero Quantized DCT Coefficients in H.264

In H.264 coding, there are a large number of discrete cosine transform (DCT) coefficients of the prediction residue which are quantized to zeros. Therefore, it is desired to design a method which can early detect zero quantized DCT coefficients (ZQDCT) before implementing DCT and quantization (Q) and thus reduce redundant computations for H.264 coding. To achieve this, a hybrid model is proposed in this paper in order to predict ZQDCT coefficients. First, the Gaussian distribution is applied to study the integer DCT coefficients in H.264 and hence an adaptive scheme with multiple thresholds is derived to realize different types of DCT and Q implementations. Then the adaptive scheme is further optimized by considering a more efficient condition to sufficiently detect all-zero DCT blocks. As a result, a hybrid model is developed. Compared with other methods in the literature, the proposed hybrid model is able to detect more ZQDCT coefficients and hence reduce more computations for H.264 encoding. It is shown by experimental results that the proposed hybrid model can achieve the best performance in reducing computations and obtain almost the same rate-distortion (R-D) performance as the original encoder in the H.264 reference software JM9.5