Behavior of Ga,In, Sn,and Te in Copper Matte Smelting

Metallurgical and Materials Transactions B - The distributions of Ga, In, Sn, and Te between copper-iron mattes and silica-saturated iron silicate slags over a wide range of matte grades 55 to 75...     

Exposure to Pesticides by Medium and Route: The 90th Percentile and Related Uncertainties

Multiple route, multiple media distributions of exposure to chlorpyrifos and diazinon and associated uncertainties are investigated using the database generated by the National Human Exposure Assessment Survey in Arizona (NHEXAS-AZ). Exposure to pesticides and associated uncertainties may be estimated using either deterministic or probabilistic methods. This paper employs probabilistic models to estimate the 90th percentile of inhalation, dietary ingestion, dermal, and nondietary ingestion exposures to chlorpyrifos and diazinon. Questions associated with the uncertainty of exposure estimates for the two pesticides are also investigated. Probabilistic models are used to formulate distributions of exposures to each of the two pesticides for several subpopulation groups. Parameter uncertainties associated with the 90th and other percentiles of population and subpopulation groups are addressed in this paper. Highly exposed subpopulations have been defined as those with route-specific 90th percentile exposure that is higher than the population 90th percentile. All subjects exposed to levels above the 90th percentile of inhalation exposure live in dwellings with carpeting covering over 50% of their floor areas. The relative uncertainty of the 90th percentile of dermal exposure is larger than corresponding uncertainties for inhalation, dietary ingestion, and nondietary exposure.     

Hypernatriuria and kaliuresis in enuretic children and the diurnal variation

PURPOSE: We investigate the underlying pathophysiological cause of primary nocturnal enuresis by comparing electrolyte alterations in urine samples of enuretics during the daytime and nighttime compared with those of nonenuretic subjects. MATERIALS AND METHODS: Urine output, urine specific gravity and urinary electrolytes in 15 enuretic and 12 nonenuretic children were measured. We collected daytime serum and urine samples of children fed a similar diet between 7 a.m. and 7 p.m., and nighttime between samples 7 p.m. and 7 a.m. Urinary calcium/creatinine ratio, tubular reabsorption of phosphorus and excretions of fractional sodium and potassium were calculated. RESULTS: There was no significant difference between the calcium/creatinine ratio ratios. There was a significant increase in fractional sodium and fractional potassium values in enuretics compared to nonenuretics during the day and at night. Daytime and nighttime fractional sodium and fractional potassium values in enuretics were similar. In contrast to nonenuretics, enuretic patients had no diurnal variation of fractional sodium. There was significant positive correlation between bedwetting status, and fractional sodium and fractional potassium. CONCLUSIONS: Since sodium and potassium excretions were higher in enuretic patients than nonenuretic children, and no significant diurnal variation in urinary excretion of these ions there might be a difference in the mechanism of reabsorption of sodium and potassium between enuretic and nonenuretic children.     

Regulation of salt tolerance in fission yeast by a protein-phosphatase-Z-like Ser/Thr protein phosphatase

In the yeast Saccharomyces cerevisiae, Na+ efflux is mediated by the Ena1 ATPase, and the expression of the ENA1 gene is regulated by the Ppz1 and Ppz2 Ser/Thr protein phosphatases. On the contrary, in the fission yeast Schizosaccharomyces pombe, effective output of Na+ is attributed to the H+/Na+ antiporter encoded by the sod2 gene. We have isolated a S. pombe gene (pzh1) that encodes a 515-amino-acid protein that is 78% identical, from residue 193 to the COOH terminus, to the PPZ1 and PPZ2 gene products. Bacterially expressed Pzh1p shows enzymatic characteristics virtually identical to those of recombinant Ppz1p. When expressed in high-copy number from the PPZ1 promoter, the pzh1 ORF rescues the caffeine-induced lytic defect and slightly decreases the high salt tolerance of S. cerevisiae ppz1delta mutants. Disruption of pzh1 yields viable S. pombe cells and has virtually no effect on tolerance to caffeine or osmotic stress, but it renders the cells highly tolerant to Na+ and Li+, and hypersensitive to K+. Although lack of pzh1 results in a 2-3-fold increase in sod2 mRNA, the pzh1 mutation significantly increases salt tolerance in the absence of the sod2 gene, suggesting that the phosphatase also regulates a Sod2-independent mechanism. Therefore, the finding of a PPZ-like protein phosphatase involved in the regulation of salt tolerance in fission yeast reveals unexpected aspects of cation homeostasis in this organism.     

Spatial coherence effects in light scattering from metallic nanocylinders

We study the scattering of a partially coherent electromagnetic beam from metallic nanocylinders and analyze the effects of plasmon resonances on the coherence and polarization properties of the optical near field. We employ the coherent-mode representation for the incident field and solve the scattering problem independently for each mode by using a boundary-integral method. Our results show that the plasmon resonances may significantly affect the coherence and polarization characteristics of the near field and that partial coherence influences the energy flow in nanocylinder arrays.     

Scalability of a Metropolitan Bidirectional Multifiber WDM-Ring Network

We analyze the scalability of a metropolitan bidirectional multifiber wavelength-division-multiplexed (WDM) ring network. The analysis is carried out by using a bidirectional transmission model for optical networks and by building an experimental network. The model includes major limiting factors in WDM-ring networks such as relative intensity noise (RIN) due to multiple Rayleigh backscattering, amplified spontaneous emission (ASE) accumulation in a cascade of bidirectional erbium-doped fiber amplifiers (EDFA), tilting of the EDFA gain spectrum and input saturation power of the EDFA. We found that in metropolitan areas the scalability of a WDM-ring network using bidirectional transmission is not mainly limited by the RIN arising from the Rayleigh backscattering. The result was verified experimentally. The maximum size of the demonstrated network is 33–43 nodes with a spacing of 5–10 km between nodes. With this spacing, which is typical in metropolitan areas, the scalability of the network is mainly limited by the gain tilt and the input saturation power of the EDFA.     

Carbon dioxide emission from the Turkish electricity sector and its mitigation options

In this study, electricity generation associated CO₂ emissions and fuel-specific CO₂ emission factors are calculated based on the IPCC methodology using the data of fossil-fueled power plants that ran between 2001 and 2008 in Turkey. The estimated CO₂ emissions from fossil-fueled power plants between 2009 and 2019 are also calculated using the fuel-specific CO₂ emission factors and data on the projected generation capacity of the power plants that are planned to be built during this period. Given that the total electricity supply (planned+existing) will not be sufficient to provide the estimated demand between 2011 and 2019, four scenarios based on using different fuel mixtures are developed to overcome this deficiency. The results from these scenarios show that a significant decrease in the amount of CO₂ emissions from electricity generation can be achieved if the share of the fossil-fueled power plants is lowered. The Renewable Energy Scenario is found to result in the lowest CO₂ emissions between 2009 and 2019. The associated CO₂ emissions calculated based on this scenario are approximately 192 million tons lower than that of the Business As Usual Scenario for the estimation period.     

Evaluating SoC Network Performance in MPEG-4 Encoder

This paper shows how a bus topology performs as a System-on-Chip (SoC) interconnection. We measure and analyze Heterogeneous IP Block Interconnection (HIBI) bus for a multiple clock domain, Multiprocessor System-on-Chip (MPSoC) with an MPEG-4 video encoding application on FPGA. The studied MPSoC contains up to 22 IP blocks: 11 soft processors, 8 hardware accelerators and three other components. A novel approach of frequency scaling is used to isolate the impact of various architecture components. The system is benchmarked in various configurations. For example, HIBI is run at 100× speed with respect to processors to resemble ideal interconnection. Based on the measurements with up to 16.9frames/s CIF (352 × 288) encoding speed, estimation for HDTV resolution video encoder is presented. The required optimizations are discussed. Finally, it is shown that 25frames/s 1280 × 720 video encoder needs 55 MHz HIBI but 670 MHz general-purpose soft RISC processors. In practice, the processing performance has to be boosted by implementing hardware acceleration and improving memory hierarchy. Clearly, HIBI is not the limiting factor.