Total dose radiation response of modified commercial silicon-on-insulator materials with nitrogen implanted buried oxide

Nitrogen ions of various doses are implanted into the buried oxide （BOX） of commercial silicon-on-insulator （SOI） materials, and subsequent annealings are carried out at various temperatures. The total dose radiation responses of the nitrogen-implanted SOI wafers are characterized by the high frequency capacitance-voltage （C-V） technique after irradi- ation using a Co-60 source. It is found that there exist relatively complex relationships between the radiation hardness of the nitrogen implanted BOX and the nitrogen implantation dose at different irradiation doses. The experimental results also suggest that a lower dose nitrogen implantation and a higher post-implantation annealing temperature are suitable for improving the radiation hardness of SOI wafer. Based on the measured C V data, secondary ion mass spectrometry （SIMS）, and Fourier transform infrared （FTIR） spectroscopy, the total dose responses of the nitrogen-implanted SOI wafers are discussed.

Experimental Study of Effluent Salty Wastewater Treatment from a Solar Desalination Pond

In this research, the quality of the wastewater discharged into the environment has been investigated. The effluent from solar desalination pond contains large amounts of TDS (3.68 grams per liter) and TH (6.50 grams per liter). Since the use of filter is not economical in this case, three types of commercial coagulants such as aluminum sulfate, ferric chloride and ferric sulfide have been used in this study. The main parameters such as effectiveness of three inorganic coagulants, ammonium sulfate, ferric sulfate, and ferric chloride, which separately help to remove hardness, have been studied. According to the results, using laboratory test, 25/g of ferric sulfate as coagulant is best coagulant mass and the ratio of 4 to 3 for auxiliary coagulant (sodium carbonate and sodium hydroxide) to coagulant will be best ratio. Also, the mixing rate of 120 rpm in the first reactor will give the best mixing speed. These conditions will lead to 0.348 grams per liter of TDS, 0.345 grams per liter of TH and 0.195 grams per liter of calcium hardness and 300 micro Siemens electrical conductivity of the purified sample.

Automatic Determination of Water Hardness by Vector Colorimetry with Acid Chrome Blue K

Based on the Mg^(2+)complexation with acid chrome blue K(ACBK)at pH 10.2,an automatic system was designed to determine total hardness of water.The system consists of a vector colorimeter,a multi-channel sampling pump and both reagents A and B.Two kinds of reagent solutions were prepared and used in this system,i.e.,ammoniacal buffer and ACBK—disodium magnesium EDTA solutions.The experimental results of the standard solutions containing 2 and 3 mg/L of total hardness showed that the relative standard deviations(RSDs)were 1.9%and 2.2%,respectively,and the limit of detection(LOD)was only 0.035 mg/L.The detection of four natural water samples showed that the recoveries were between 85.0%and 108.6%,consistent with those obtained by ICP-AES method.

Evaluation of groundwater quality in the Xinjiang Plain Area

Groundwater is the main source of drinking water for the urban and rural residents in the plain area of the Xinjiang Uygur Autonomous Region,China.The quality of groundwater has a direct relationship with human health.Thus,386 groundwater samples collected from April to August in 2003 were analyzed.The samples were collected in basic evaluation units which are determined on the basis of watersheds.Total dissolved solids,total hardness,pH value,NH3–N,C6H5OH,Chemiluminescence detection of permanganate index(CODMn)and intestinal germ group were evaluated according to the guidelines of Groundwater Quality Standard(GB/T14848-93).The quality of the groundwater in each evaluation unit was classified by using the One Veto Method(a unified approach stipulated by the Ministry of Water Resources).The results indicate that the groundwater in the mainstream area of the Tarim Basin and the Yerqiang River Sub-basin belongs to Category V;the groundwater in the Wulungu River Sub-basin,the KaiduKongque River Sub-basin,the Kashgar River Sub-basin,the Cherchen River Sub-basin and the Hotan River Subbasin belongs to Category IV;the groundwater in the Aibi Lake System belongs to Category II,and the groundwater of other evaluation units belongs to Category III.The causes of water quality formation were concisely analyzed.The results can be useful for the evaluation and management of water resources in the Xinjiang Plain Area.