Civil Engineering

In the title compound, 2C 24 H 21 N 3 SÁC 6 H 6 , the two independent Schiff base molecules (A and B) in the asymmetric unit differ in the orientation of the tetrahydrobenzothiophene ring system with respect to the carbazole ring system by 180 rotation about the CC bond in the CC N-C linkage. The two molecules also differ in the orientation of the ethyl groups [C-N-CC torsion angle of 90.7 (3) in molecule A, and À79.4 (3) in molecule B]. In molecule B, two methylene C atoms of the cyclohexene ring are disordered over two sites with occupancies of 0.58 (1) and 0.42 (1). The cyclohexene rings in both molecules adopt half-chair conformations. The dihedral angle between the thiophene ring and the carbazole ring system is 8.07 (9) in molecule A [3.10 (9) in molecule B]. In the crystal structure, the independent molecules are linked into dimers by intermolecular C-HÁ Á ÁN hydrogen bonds. In addition, C-HÁ Á Á interactions are observed. HKF and JHG thank Universiti Sains Malaysia (USM) for the Research University Golden Goose grant (No. 1001/ PFIZIK/811012). JHG also thanks USM for the award of a USM fellowship. The authors thank the Department of Chemistry, King Abdulaziz University, for providing research facilities. organic compounds o1200 Fun et al.

In the present experimental work, the efforts have been made to use the aluminum composite panel waste collected from a construction site in high strength concrete. This waste of aluminum composite panel contains aluminum coversheets and core of low-density polyethylene. In this investigation, concrete with aluminum waste with varying percentages of 2, 4, 7, and 12% by weight of cement, and LDPE as an additive mass of 3.5, 7, 12.5, and 21% by weight of cement were studied. The concrete was tested in the fresh and hardened state. In the fresh state, concrete was tested for workability and expansion. In the hardened state, the concrete was tested for various strength, Non-destructive tests, and durability tests. Based on the results showed for 28 days, it can be reported that the use of replaced aluminum waste and LDPE as additive waste by weight of cement had a significant decrease in workability as well as strength.

In the present experimental work, the efforts have been made to use the aluminum composite panel waste collected from a construction site in high strength concrete. This waste of aluminum composite panel contains aluminum coversheets and core of low-density polyethylene. In this investigation, concrete with aluminum waste with varying percentages of 2, 4, 7, and 12% by weight of cement, and LDPE as an additive mass of 3.5, 7, 12.5, and 21% by weight of cement were studied. The concrete was tested in the fresh and hardened state. In the fresh state, concrete was tested for workability and expansion. In the hardened state, the concrete was tested for various strength, Non-destructive tests, and durability tests. Based on the results showed for 28 days, it can be reported that the use of replaced aluminum waste and LDPE as additive waste by weight of cement had a significant decrease in workability as well as strength.

Concrete in the structures undergoes the environmental effect of changing weather during its life span and carries a certain minimum load. Some concrete structures suffer from damage due to weather effects of the environment at early age. Environmental effect with age on concrete specimens of different grades under loaded and unloaded conditions has been studied using; ultrasonic pulse velocity, rebound hammer, and crushing strength. A systematic planned experimental study (using ultrasonic pulse velocity and rebound hammer tests) has been conducted on unloaded and loaded concrete with 20% of expected crushing strength. The results of ultrasonic pulse velocity and rebound hammer obtained from concrete specimens of different strengths and ages have been correlated with their compressive strength. The experimental test results indicate that the pulse velocity response of concretes of different ages with regards to NDT and crushing strength show that lean mixes respond poorly under unloading and loading conditions. It can be also concluded that the average value of rebound hammer under loading and unloading conditions do not show a clear decreasing/increasing trend with increasing age. Based upon the experimental results it may be concluded that concretes of lower grades respond poorly with age due to environmental effect.

Plain concrete is poor in tensile strength but strong in compressive strength, and also possess a limited ductility property and low resistance to crack. In order to improve tensile strength, response to climate effect and as well as to be ductile member and play a significant role and show resistance to crack and punching shear. Hence, fibres are to be added in certain percentage in the mix of concrete to improve and impart the strain properties and as well as crack resistance, ductility property, flexural strength and toughness. Mainly the investigation studies and research have been done for the fibers which has been devoted to steel fibers. As the steel fibers are not showing resistance to corrosion especially when they exposed to environment. So, in the recent times, glass fibers have been introduced and is available, which are free from corrosion problem associated with steel fibers. Glass fiber reinforced concrete is more effective in resisting bending and punching shear. Fib...

Abstract -The natural resources of Eastern India are still comparatively less exploited. The availability of sustainable water resource in urban environment is a key to development and human health of the Region. 116 Eastern Indian cities with more than 0.1 million population are having adequate water resources. These cities are hotspots for progressive economic development of the country. Water requirement and availability of ground water resources up to present extractable depth of 250 meter has been assessed for 7 capital cities of Eastern India as a case study. The results so obtained clearly indicate availability of ground water is adequate to cope up with the pace of growing population and urbanisation in these cities. Aquifer based water security as sustainable solution of these cities of Eastern India has given the confidence for futuristic development. The result of these studies can be used to predict the aquifer based water security of other Eastern Indian Cities.

Karstic limestone aquifer of Mesoproterozoic Chandi Formation, Chhattisgarh is largely exploited to cater the domestic, irrigation and industrial needs around the major cities like Raipur, Durg, Bhilai, and Champa. The area of influence of recharge of the Chandi aquifer is largely governed by the conduit flow within the solution cavities or the fractures and joints. The behavior of these conduits depends upon the nature of openings-from open to tight. The impact of recharge, through rain water harvesting, in 15-20 m deep abandoned quarry pits as recharge structures, has been determined by monitoring ground water levels, electrical conductivity and studying ground water flow direction and pattern for the micro watershed. The analyses of results were used to propose the future need and site selection criterion for recharge structures.

The important parameters of climate change-increased carbon dioxide in atmosphere and global warming has direct implications on karstic terrain. Gypsum having solubility four times more than calcite and prone to karstification , is exposed to rapid impact of these parameters. The impact of climate change on geochemical or hydrogeological cycle can modify the magnitude of natural karstification process. The salinity and subsidence hazard produced in gypsum karst terrain got intensified due to increased quantity of carbonic acid and enhanced solubility caused by rise in temperature.

The newly formed developing states like Chhattisgarh, which is predominantly agriculture based has unique problems of ground water resource development and management, unlike other developed states of country due to the under developed ground water resource potential. Eighty seven percent geographical area of Chhattisgarh is covered by hard rock; still the availability of potential aquifer systems in the state is quite high in comparison to the surrounding hard rock terrain of other states. Ground water in the state is being developed by individuals thus need much more disciplined and scientifically acceptable abstraction pattern . Along with geomorphology and aquifer disposition, the socio-economic framework of this developing tribal dominated state also governs the ground water resource development. Proper understanding of hydrogeological and socio-economical structure of the state is key to the future sustainable development of ground water resource in the state. The role of credit agencies, governmental policies and availability of power etc play vital role in ground water resource development by individuals in the state. The political and social peace and conspicuously low industrial activity in the state along with the high per capita availability of over all water resources provides opportunity for steady growth of ground water resources. In the last two decades the change in ground water abstraction pattern from dug well zone to bore well zone has produced few complexities .The impact of geogenic contamination in drinking water sector has increased a lot though the threat of pathogenic contamination has reduced due to adoption of hand pump and borewells.

The impact of rainwater harvesting and artificial recharge on groundwater resource has been assessed. The results of rainwater harvesting and artificial recharge works in an urban area are discussed in this paper. The positive impact of scientific management of rainwater on groundwater regime of Raipur urban area is highlighted. The success of this plan now can be replicated in other urban centres of Peninsular India in general and karstic terrains in particular as a tool for supply side management.