Qatar water challenges
Abstract Qatar has experienced rapid economic growth due to the discovery and production of fuel oil and natural gas (NG). The natural renewable water resources (rainfall and groundwater [GW]) are depleted; and are estimated as 71-m3/per year per capita in 2005. This is far below the water poverty line of 1,000-m3/yca. The GW withdrawal is excessive (compared to replenishment) and is used mainly for irrigation. A very small amount of GW is treated to become potable water and is distributed to consumers. The municipal potable water mainly contains (99%) desalted seawater (DW) and 1% GW. The consumption of DW and electric power (EP) is continuously rising due to the increase in both population and the standard of living. The population have been more than doubled from 2000 to 2010. The DW is produced in power plants generating both EP and DW, and is called Cogeneration Power Desalting Plants (CPDP). These CPDPs are using either: simple gas turbines (GT) cycle or GT combined with steam turbine (ST) to form a...
What do the trace metal contents of urine and toenail samples from Qatar׳s farm workers bioindicate?
Qatar׳s farm workers provide a unique population for exposure study: they are young, healthy males. This study combined trace element profiles in urine and toenail with survey information from 239 farm workers to assess the extent to which the biomarkers provide complementary exposure information. Urinary Mo levels (average=114 µg/L) were elevated; average urinary values (µg/L) for all other elements were: V (1.02), Cr (0.55), Mn (2.15), Fe (34.1), Co (0.47), Ni (2.95), Cu (15.0), As (47.8), Se (25.7), Cd (1.09), Ba (22.5), Pb (2.50) and U (0.15). Average toenail concentrations (mg/kg) were: Mn (2.48), Cu (4.43), As (0.26), Se (0.58), Mo (0.07), Cd (0.03), Ba (1.00), Pb (0.51) and U (0.02). No significant association was found between corresponding elements in urine and toenails. Elemental profiles suggest groundwater (with the exception of Mo) and soil-dust-crop exposure pathways cannot account for elemental variations. The main factors moderating trace element contents are related to depuration processes involving participants׳ trace element body burden prior to work in Qatar, and interactions of trace element metabolic cycles which over-ride the exposure footprint. Toenail and urine need to be carefully validated before reliable use as biomarkers of exposure in general populations for most elements in the study.
New approach to vision-based BGA package inspection
Ball grid array (BGA) techniques have developed very fast due to the advantages of more I/O ports, small size, and so on. In this paper, a vision-based algorithm for BGA package inspection is proposed to accurately estimate center and diameters of solder-balls of BGA packages, so that defects of BGA packages, such as missing or extra balls, oversize or undersize balls, over-height or under-height balls, and pitch can be detected for ensuring the quality of BGA packages.