Experiments on the Life of Self-Quenching Geiger Mueller Counters

Because of the several superior properties of counters containing organic vapor as a quenching agent, it is desirable to extend the life of such counters. It is, therefore, of interest to determine the relative importance of factors which limit their useful life. It is also worthwhile to further the investigation of counters containing an inorganic gas as a quenching agent

Determination of Chlorinated Solvent Contamination in an Upward Flow Constructed Wetland

The purpose of this study is to determine chlorinated solvent contamination levels in an upward flow constructed wetland at Wright-Patterson Air Force Base (WPAFB), Ohio. A stratified grid sampling methodology will be used in sampling the contaminated groundwater. Analysis will be accomplished by means of purge-and-trap gas chromatography. The contaminant concentration levels will be used to enhance the design and construction of man-made wetlands used to remove chlorinated solvents from aquifers. PCE levels declined from an average of 33.97 ppb in the inflow stream to an average of 3.65 ppb in the upper layer, a 91% reduction. High concentrations occurred in areas where high hydraulic pressure gradients and hydraulic conductivities combined to allow contaminated water to migrate to the upper layers of the wetland with minimal contact time for reduction. Removing these areas from the data set increased the PCE reduction efficiency to nearly 98% with an upper level concentration average of 0.84 ppb. Trichloroethene (TCE) inflow rates averaged 0.63 ppb while TCE concentrations in the upper layer averaged 0.175 ppb. TCE concentrations peaked in the middle layer of the wetland suggesting that reduction of PCE was occurring there and in the bottom layer

Re-evaluating blood culture incubation times during SARS-CoV-2: Can we shorten incubation times without compromising results?

No abstract

The Effect Of Training Frequency On Selected Physical And Biochemical Health Parameters In The Conditioning And Reconditioning Of Sedentary Employees

Non-communicable disease evolved as a major health risk in South Africa and accounts for about 37% of all deaths. This burden also challenges human resources in the corporate environment where poor health status (high health risks) may lead to increased health care costs, lowered productivity and eventually to premature death. Some of the South African companies have tackled this challenge by providing various employee health promotion initiatives. One of the popular contributions in this endeavour is to encourage employees to become more physically active in order to prevent detrimental health risk factors or to remedy the existing factors. A major challenge in this initiative is to keep up the compliance of the employees with their physical conditioning programmes, especially when business responsibilities take them away from their health facilities which, in turn, may lead to physical deconditioning. This endorses the motivation of this research as little information is available in South Africa on the aspect of conditioning, deconditioning and reconditioning in the corporate environment. In this study, 60 healthy but sedentary employees, ages 28-49 years, from an academic institution were recruited to participate. They were randomly assigned to three groups, where Groups A and B form the experimental groups with Group C the control group. During the initial training phase (first 12 weeks) Group A and B followed a training frequency of three times per week, while retraining took place at a frequency of two and four times per week for Groups A and B, respectively. Group C was not involved in any intervention and continued with their normal daily activities and lifestyle. Results of this study indicated that after training at a program frequency of three times per week, a salutogenic response occurred in the selected physical and biochemical health parameters. With deconditioning, about 50% of the physical benefits were lost, which occurred faster than the decline in the biochemical (lipids) benefits. With reconditioning, a program frequency of two times per week seems to maintain the physiological status, while with a program frequency of four times per week, an improvement reoccurred, exceeding the benefits of the program frequency of three times per week. In conclusion, it is clear that a physical intervention regime, to the apparently healthy employees, can decrease some health risks; but with an interruption of the program, salutogenic benefits will be partially lost. With retraining, a program frequency of two times per week will not produce significant improvement, but will only maintain the physical status