Blood mercury in workers exposed to the preparation of mercury cadmium telluride layers on cadmium telluride base

Study was conducted in a group of 32 persons engaged in liquid phase epitaxial growth of mercury cadmium telluride (MCT) layers for nearly 11 years. Airborne mercury concentrations in work environment have been exceeding the threshold limit value of 0.05 mg/m3 recommended by ACGIHD. Hg concentration in workplace during peak working hours remained between 0.04-0.08 mg/m3. Findings were compared with 32 unexposed referents. Mercury value was estimated 1.60 +/- 0.20 (mean +/- SD) in control, and in Phase I and II, 10.72 +/- 1.34 ng Hg/ml and 8.08 +/- 1.15 ng Hg/ml of blood respectively. Results indicate a fall in blood mercury level during the second phase of study. But the values did not return to normal even after a gap of 3 months. An individual who met with a mercury accident showed 226 ng Hg/ml of blood which decreased to 25 ng/ml after 3 months. It is inferred from the present study that Hg level has increased significantly in MCT workers during working period, and also in non-working period, the values were higher than controls.     

Energy efficiency analysis of air cycle heat pump dryers

In this paper, the feasibility of an air heat pump (reversed Brayton) cycle for tumbler clothes dryers is investigated. The goal is to increase the energy efficiency as compared to conventional electrically heated driers. Relatively simple models were used to compare the energy efficiency of the heat pump drier with that of a conventional air vented drier. The components were modeled using overall performance indices and thermodynamic relations. An air cycle heat pump dryer with practical components was found to be capable of significant efficiency improvements as compared with conventional dryers.     

Evaluation of triple quantum-filtered 23Na NMR spectroscopy in the in situ rat liver

Expression of intermediate filaments (IFs) has been suggested to be a reliable marker for differentiating epithelial and non-epithelial tumors. Moreover, the c-erbB-2 and p53 genes are considered to be involved relatively early in the process of human carcinogenesis. In order to elucidate the origin of uterine carcinosarcomas, we analyzed IF, c-erbB-2 and p53 expression in and the ultrastructural characteristics of clones derived from a human uterine-carcinosarcoma cell line, EMTOKA. The expression of IFs and other proteins in the EMTOKA clones was identical to that in the EMTOKA cell line. It and its 7 clones all expressed cytokeratins 8, 17, 18 and 19, vimentin, epithelial membrane antigen, S-100, myoglobin, type-II collagen, alpha-smooth-muscle actin, placental alkaline phosphatase and epidermal-growth-factor receptor. The c-erbB-2 and p53 expression levels of all the cell types of the EMTOKA cell line and its clones were the same. Interestingly, an ultrastructural study showed that the EMTOKA cell line and its clones at early and late passages possessed the characteristics of epithelial cell types without either transitional forms between the epithelial and stromal components or differentiation into sarcomatous components. The results of this study lend particular support to the combination tumor hypothesis that a precursor (stem) cell gives rise both to epithelial and to mesenchymal components during the histogenesis of uterine carcinosarcoma, the epithelial component of which appears to be dominant, suggesting that the established cell lines derived from a common stem cell.     

Analysis of Test Application Time for Test Data Compression Methods Based on Compression Codes

We present an analysis of test application time for test data compression techniques that are used for reducing test data volume and testing time in system-on-a-chip (SOC) designs. These techniques are based on data compression codes and on-chip decompression. The compression/decompression scheme decreases test data volume and the amount of data that has to be transported from the tester to the SOC. We show via analysis as well as through experiments that the proposed scheme reduces testing time and allows the use of a slower tester. Results on test application time for the ISCAS'89 circuits are obtained using an ATE testbench developed in VHDL to emulate ATE functionality.     

COMAR [IEEE Committee on Man Radiation]

The author reports the activities of the IEEE Committee on Man and Radiation (COMAR). COMAR critically examines and interprets the literature on biological effects. Its findings are usually reported in the form of Technical Information Statements (TISs). While the Committee holds several regular meetings every year, most of the technical work is done offline, and discussed via e-mail. It should be pointed out that COMAR does not establish safety standards, but it has an interest in the standards activity within its scope     

Creating gold nanoprisms directly on quartz crystal microbalance electrodes for mercury vapor sensing

A novel electrochemical route is used to form highly {111}-oriented and size-controlled Au nanoprisms directly onto the electrodes of quartz crystal microbalances (QCMs) which are subsequently used as mercury vapor sensors. The Au nanoprism loaded QCM sensors exhibited excellent response-concentration linearity with a response enhancement of up to ～ 800% over a non-modified sensor at an operating temperature of 28?°C. The increased surface area and atomic-scale features (step/defect sites) introduced during the growth of nanoprisms are thought to play a significant role in enhancing the sensing properties of the Au nanoprisms toward Hg vapor. The sensors are shown to have excellent Hg sensing capabilities in the concentration range of 0.123-1.27 ppm(v) (1.02-10.55 mg m(-3)), with a detection limit of 2.4 ppb(v) (0.02 mg m(-3)) toward Hg vapor when operating at 28?°C, and 17 ppb(v) (0.15 mg m(-3)) at 89?°C, making them potentially useful for air monitoring applications or for monitoring the efficiency of Hg emission control systems in industries such as mining and waste incineration. The developed sensors exhibited excellent reversible behavior (sensor recovery) within 1 h periods, and crucially were also observed to have high selectivity toward Hg vapor in the presence of ethanol, ammonia and humidity, and excellent long-term stability over a 33 day operating period.     

On the boundary conditions applicable in the analysis of a matrix air heater

A dimensionless analysis of matrix air heaters has been developed to study the effect of different boundary conditions on its performance. The theoretical results have been compared with measurements of an experiment performed with one type of matrix solar air heater. For the fourth set of boundary conditions, the theoretical results agree fairly well with experimental data, thus providing confidence in particular boundary conditions. For this particular set of boundary conditions, the thermal performance of the system has been studied for different mass flow rates of air and as a function of other physical parameters.     

Experimental investigations on solar chimney for room ventilation

Experimental investigations on a small size solar chimney show that the rate of ventilation increases with increase of the ratio between height of absorber and gap between glass and absorber. This finding is in agreement with results of the steady-state mathematical model developed for analysis of such systems. Nine different combination of absorber height and air gap have been investigated on the experimental set-up. Highest rate of ventilation induced with the help of solar energy was found to be 5.6 air change per hour in a room of 27 m³, at solar radiation 700 W/m² on vertical surface with the stack height-air gap ratio of 2.83 for a 1 m high chimney.