International Journal of General Engineering and Technology

1-14

Authors: TZYY-JENG YONG, YAMUNA MUNUSAMY & SWEE-YONG CHEE

Sodium alginate (NaAlg) copolymers were prepared by free radical grafting of acrylic acid (AA) and acrylamide (AM) onto NaAlg with the presence of ammonium persulfate (APS) initiator. The copolymers were then cross linked with N, N-methylenebisacrylamide (NMBA) to produce an interpenetrating network. The superabsorbent polymer (SAP) hydrogel was then dropped into Ca2+ solution to produce spherical copolymer beads. The main objective of the work is to study the effect of different ratio of AA and AM (85:15, 70:30, 55:45, 40:60 and 25:75) on the characteristic and performance of the SAP. Infrared (IR) spectroscopy proves successful grafting of AA and AM onto NaAlg backbone and formation of Ca2+ layer onto SAPs. Biodegradability and water absorbency decreases as AM concentration increases. Moreover, SEM study shows that the surface of copolymer beads with higher concentration of AM is compact with less cracks and pin holes. In addition, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) also show that all the copolymer beads are thermally stable and the glass transition temperature (Tg) increases as AM concentration increases respectively.

23-34

Authors: GIRIJA SHANKAR YADAV

A simplified version of Gradient Profiling technique has been applied in the Rajiv Gandhi South Campus RGSC of Banaras Hindu University, Barkachha, Mirzapur district of Uttar Pradesh, India to identify the low resistive zone. The horizontal electric field was generated in the central region of widely separated two current electrodes fixed at the ground surface and the potential gradient was measured within onethird central region of the total spread using a moving dipole with considerably small electrode separation. The observations were taken along three transects. The lowest value of apparent resistivity was obtained almost in the middle portion of the fractured zone. Interested low along the profile was identified and geoelectrical sounding was also conducted at 12 such locations. One test borehole was drilled at GS8 location and groundwater discharge of about 8,000 liters per hour was obtained during the month of October 2006. Such low discharge of groundwater was obtained due to limited extent of fractures within the sandstone. The analysis presented here clearly shows the efficiency of the gradient profiling technique.