VOLUME 29, NO6, DEC 2007
Hydro-geochemistry of the Indus Basin in Rahim Yar Khan District, Central Pakistan


 Hydro-geochemistry of 135 water samples, collected at depths of 75 to 250 feet from tube wells in 1300 km2 area, indicates that I) the water is highly mineralized, with electric conductivity values > 22500 micromohs! cm in over 75 % of the area, and 2) the mineralization increases from northeast to southwest. The amounts of total dissolved solids (TDS) and sodium adsorption ratio (SAR) range from 515 to 26650 and 3 to 54 mg/ I, respectively, but in > 85 % of the area the TDS values are >11000 and SAR values >30. In most of the samples, pH varies between 7.5 and 8.3 (overall range 6.9 to 9.2) and organic content between 50 and 100 mg/ I (overall range 20 to 185). The dissolved constituents (Na, Mg, Ca, K, CI, SO., HCOJ, P and Cr) are dominated by Na (mostly 200-300 m eq/ I), Mg (variably high; 40-100 in 76 % analyses), CI (mostly 123-316) and SO. (55-216 m eq/ 1). Nearly 83 % of the analyses classify as sodium chloride type, and 17 % sodium sulfate type, with some Mg component in many. The data suggest that the groundwater belongs to a single, large aquifer. The concentration of dissolved solids and the salinity reflect the influence of geologic and hydrologic factors on the groundwater in the area. Much of the water is saline and seemingly associated with the highly soluble evaporite deposits occurring nearby. Only 10 % of the groundwater in the northeastern part of the area, occurring at shallow depth below 75 feet and probably diluted by seepage from canals and the Indus River, can be used for irrigation. Ninety percent of the groundwater shows hard type of incrustation.  
A New Approach of Split Dosage for Application of Aluminium Phosphide against the PH3 Resistant Psocids in Stored Grain


While inspection of wheat stores situated in districts Jehlum and Faisalabad, it was revealed that phosphine gas released from solid formulation of aluminium phosphide failed to control infestation of Liposcelis bostrychophila (Badonnel). Failure of fumigation as well as interception of this pest created a lot of fretfulness as the pest was not reported earlier from food godowns in Pakistan. Live presence of the pests was a proof that they survived the toxicant. Results of the godowns with fumigation failure were analyzed minutely. Survival of the pest in the treated godowns opened a window of new questions about the fate of phosphine, intensity and degree of resistance of the pest as well as status of this insect as grain pest. However, control of the pest became a top priority. This time one of the godowns was refumigated with the Split Dosage Techmque which involved application of aluminum phosphide tablets @ 720 ppm (1 tablet/cubic meter) as first dose supplemented by 360 ppm (0.5 tablet/cubic meter) after 24, 48 hours and 240 ppm (0.33 tablet/cubic meter) each after 96, 120, and 240 hours, respectively. The other godown having the same storage capacity was fumigated with the routine practice of the Food Department, i.e., 1080 ppm (1.5 tablet/cubic meter) as first dose, supplemented by 1080 ppm (1.5 tablet/cubic meter) after 48 hours. The sealed godowns were kept closed and the results of refumigation were checked after 25 and 15 days of the initial dose administration, respectively. The technique proved successful and the infestation of psocids was completely controlled. The key to psocid survival of phosphine has been attributed to the high tolerance of their eggs. Split Dosage Technique, however, addressed this problem resulting in 100% control of all stages of the pest. The technique is fea~ible not only for Asian but also for African and other countries of the world where storage facilities are leaky and the insect pests have developed resistance against phosphine fumigant ultimately posing a threat to the food secunty and safety. 
Study of the Physicochemical Properties of Silybum marianum Seed Oil


Proximate composition of Si/ybum marianurTt seeds showed Ihat the seeds have oil content (26.05 %), moisture content (4.48 %), ash content. (1.l}3 %), crude fibre (5.48 %), carbohydrates content (87.2 'Yo), total protein (23 'Yo), acid value (1.2 %), and saponification value (190.74). In physicochemical properties the iodine value is (108.8 gli 00 g), pero"ide value (16.17 meql kg), free fatty acid value (17.92 'Yo), anisidine value (1.8979), color I optical density (0.3413). Fatty acid composition of the oil reveals that linoleic acid·(64.4 'Yo) and oleic acid (26.38 'Yo) are the predominant unsaturated fatty acids-. The saturated fatty acids found in Si/ybum mananllln seed oil are palmitic acid (7.22 'Yo) and stear~ acid-(2.0 'Yo). 
Electrical Resistivity and Thermoelectric Power Measurements of Pyrite (FeS2) in the Temperature Range, 78-300 K


We studied the electrical resistivity and thermoelectric power of pyrite in the temperature range, 78-300 K. Electrical resistivity measurements show diverse transitions at different temperatures especially a semiconducting pumping transition, where semiconducti-vity sets in at 115 K. The insulator to metal transition in pyrite is referred to as shallowing of deep quantum wells. The shallowing of quantum well sets in at 158 K. At 195 K, the pyrite behaves as a pure metal. Further a comparative study of experimental thermoelectric power with theoretically estimated result is made.  
Synthesis of Acid Doped Conducting Polyaniline


Conducting polymers have received considerable attention in the fields of nanoscience and nanotechnology. These materials exhibit enhanced properties in a variety of applications, such as chemical sensors, microreactors/ containers and fuel cells. Micro/ nano­materials of conducting polymers also include micro-containers, nanowires, nanotubes, nanobelts, core corona, hollow spheres, and nanntibers. Polyaniline (PAN I) is an air-stable conducting polymer and has attracted increased attention for several reasons; monomer is inexpensive, polymerization reaction is simple, and processing is easy. In this study polyaniline was synthesized by the chemical method in acidic medium using H,O" K,S,03 and K,Cr,07 as oxidizing agents. The reaction was studied at three different temperatures and it was found that maximum yield of aniline was obtained at lower reaction temperature. The polymer was characterized by FTIR, UV-Visible absorption spectroscopy, and conductivity (four probe method). The conductivity measurements revealed that PANI prepared in the presence of K,Cr,07 is a better conducting material among other samples.  
Adsorption of Acid Orange 7 by Activated Carbon Produced from Agriculture Waste: 1. Kinetics


Carbon was produced from corncobs waste by physical and chemical activation and evaluated for their physical (bulk density), chemical (ash, pH), surface (surface area, pore size distribution), and adsorption properties for acid orange 7. Activation at 800 ·C increased the surface area with increase in pore size distribution. First order and parabolic intraparticle diffusion models were found to apply to the data, indicating the adsorption to be diffusion controlled. Rate constant increased with the increase in both the adsorption temperature and the activation temperature of the carbon. Thermodynamic parameters of adsorption ( h.E~, h.W and h.S~ ) were calculated from the kinetic data. The endothermic nature of the adsorption was indicated by the positive values of h.W . Negative values of !!>s' for adsorption, reflect decrease in the disorder of the system at the solid­solution interface during adsorption. 
Quality Improvement of Used Fried Silybum marianum Oil by Treatment with Activated Charcoal and Magnesium Oxide


The crude Silybum marianum oil was used for frying of potato fillets (French fries) for 4 consecutive days at a rate of 20 minutes per day. The quality constants such as peroxide value (POY), anisidme value (AY), iodine value (IY), free fatty acid (FFA) and color index as optical density (O.D at 420 nm) have been determined before and after frying. The results showed an increasmg pattern in the values of the above quality parameters. The peroxide value mcreased from 5.03 to 19.41 meql kg, AV from 1.34 to 16.4, FFA from 0.09 to 2.41 %, and color from 0.02 to 1.9. Fried Silybum marianum oil was mixed separately wlth 3 levels of MgO (4,6, g % wI w) and acttvated charcoal (2, 6, 10 % wI w). For all the treatments, the average percent improvement of quality mdices was statistically analyzed. Increasing levels of both activated carbon and MgO significantly affected (P < 0.05) the different quality parameters tested so far 
Chemical Evaluation of Major Salt Deposits of Pakistan


Seven salt samples from major salt deposits were analyzed for sodium chloride, moisture content, water insoluble matter, calcium, magnesium, sulphate, potassium and trace elements respectively. Except Kohat rock salt and Khaller salt where insoluble matter and other impurities were high, other salt samples contained permissible limits of insoluble matter and other impurities as per Codex Alimentarius Specifications. Trace elements like zinc, iron, copper, mantanese, chromium and lead were analyzed by atomic absorption spectrophotometer. Metal load in salt samples of all SOUrces are within limits as per RDA specifications for respective metals. The geological settings including nature, origin of the salt deposits and impacts of impurities present in salt samples on human health and other chemical industries have also been discussed in this study. 
Development of a Spectroscopic Method for Quantitative Determination of Pharmaceutical Preparations of Vitamin C


Vitamin C in aqueous solution shows concentration v s absorbance a linear relationship for dilute solutions (0.004 % to 0.005 % w/v). The pH also affects the linearity of the curve such as pH 3 is found to give a linear relationship between concentration and absorbance up to a wide range (0.001 % to 0.009 % w/v). The E (1 %, 1 cm) values at pH 3 may be exploited to determine the % age purity of the vitamin C in separate vitamin C tablets or syrups. This method for the quantitative determination of Vitamin C is more accurate, precise and applicable as compared to simple methods of UV spectrophotometry. 
Role of Distribution System in Safe Water Supplies A Study Case of Rawalpindi


Water distribution network is the most significant part in terms of cost and the vulnerability of a potable water system. MIcro organism can enter the pipe system by a variety of routes ranging from insufficient treatment to leakage! faults in the pipes. Pollution occurring during storage and distribution was the main cause of 8 outbreaks out of 21 occurring between 1911 and 1937. Water crisis of Hyderabad is live in minds of the people of Pakistan. Water and Sanitation Agency (W ASA) is responsible for water distribution system in Rawalpindi. Water from Rawal Dam and Khanpur Dam is treated in treatment plants at Chak Shahzad and Sangjani and released in distribution system comprising of ground reservoirs, overhead reservoirs and distribution pipes. Water samples collected from 27 different points of the distribution systems were analyzed for the assessment of bacteriological contamination. Water samples collected from three ground/ overhead reservoirs and seven distribution points were found free from bacterial contamination. Remaining samples have high level of bacterial contamination, which is a matter of great concern. WASA should make immediate remedial measures to decontaminate these water supplies. 


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