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Tillage is the mechanical manipulation of the earth surface for providing favorable conditions for crop production. Mechanization of farm operations has become very necessary and the methods for reducing the power consumption have to be found out. This paper deals with factors affecting the tillage operation and the effects of the tillage operation on soil. Tillage implements usually produce large amount of vibration but providing a vibration to the implement reduces the draft force. Considering the performance of tillage tools, the main factors to be considered are its draft torque and power requirements. These tillage tools affect the properties of the soil in which it is working. This may be even cause degradation of the properties of soil. Another important factor is wear, which is the major cause of failure in tillage tools. Thus, studying the various factors, the best tillage tool may be selected or methods of reduction of power consumption may be identified.

Studies of the potential role of bisphosphonates in dentistry date back to physical chemical research in the 1960s, and the genesis of the discovery of bisphosphonate pharmacology in part can be linked to some of this work. Since that time, parallel research on the effects of bisphosphonates on bone metabolism continued, while efforts in the dental field included studies of bisphosphonate effects on dental calculus, caries, and alveolar bone loss. While some utility of this drug class in the dental field was identified, leading to their experimental use in various dentrifice formulations and in some dental applications clinically, adverse effects of bisphosphonates in the jaws have also received attention. Most recently, certain bisphosphonates, particularly those with strong bone targeting properties, but limited biochemical effects (low potency bisphosphonates), are being studied as a local remedy for the concerns of adverse effects associated with other more potent members of this drug class. Additionally, low potency bisphosphonate analogs are under study as vectors to target active drugs to the mineral surfaces of the jawbones. These latter efforts have been devised for the prevention and treatment of oral problems, such as infections associated with oral surgery and implants. Advances in the utility and mechanistic understanding of the bisphosphonate class may enable additional oral therapeutic options for the management of multiple aspects of dental health.

A family of PT -symmetric complex potentials is obtained, which is isospectral to free particle in an infinite complex box in one dimension (1-D). These are generalizations to the cosec2 (x) potential, isospectral to particle in a real infinite box. In the complex plane, the infinite box is extended parallel to the real axis having a real width, which is found to be an integral multiple of a constant quantum factor, arising due to boundary conditions necessary for maintaining the PT -symmetry of the superpartner. As the spectra of the particle in a box is still real, it necessarily picks out the unbroken PT -sector of its superpartner, thereby invoking a close relation between PT -symmetry and SUSY for this case. As expected, the broken PT -sector has no isospectrality with any real system., 8 pages, 2 figures, figures have been updated and PACS numbers have been added, text have been updated with enhanced contents and references

ABSTRACT 203 km long, 30?? dia sub sea pipeline transports Mumbai High crude oil to Uran onshore terminus (BUT oil line). In order to ensure that there is no congealing of crude and restartability is easy after prolonged shutdown, Pour Point Depressant (PPD) was being dosed. The average cost of treatment for flow assurance was very high (to the tune of 10 million USD per annum). Expanding database, infrastructure development has led to the present studies to explore the possibility of flow assurance without PPD usage. Extensive rheological studies have been carried out at BHS platform on live Mumbai High crude to analyze the effect of temperature, pressure, shear history, water cut, ageing etc. Results of field and laboratory studies were integrated with the observations made during rupture/ repair of BUT oil line in since1992. Case studies of BUT pipeline rupture in recent past have given authentic information about heat losses and gel strength of the aged crude. Concept of estimation of pour point of live crude (with pressure and lighter cuts) was used for the first time on PPD treated and untreated crude to understand the crude behavior under pipeline conditions. Field experiments in 18 km long BHN-SA sub sea well fluid line were also carried out to understand heat losses and restartability behavior. Bathymetry data from IPSHEM, Goa and software modeling has also been used. It was observed that cooling of crude oil in the sub sea pipeline is less pronounced than estimated earlier. Restartability of crude oil after prolong shutdown (˜30 days) would not pose any problems. Rheological behavior of crude under pipeline conditions is much better than observed in laboratory. Flow assurance with out PPD usage can be attained. PPD usage has been completely stopped and pipeline is functioning smoothly without any increase of pressure drop / wax deposition. INTRODUCTION: Mumbai High- Uran sub sea trunk crude oil pipeline (BUT oil line) is 30?? dia, 203 km long pipeline carrying Mumbai High crude oil to Uran onshore terminus. The pipeline is buried and insulated. The pipeline was commissioned in 1979 and adequate data and information is now available to have relook into the salient aspects of its operation.