3,276 research outputs found

    System for plotting subsoil structure and method therefor

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    Data for use in producing a tomograph of subsoil structure between boreholes is derived by pacing spaced geophones in one borehole, on the Earth surface if desired, and by producing a sequence of shots at spaced apart locations in the other borehole. The signals, detected by each of the geophones from the various shots, are processed either on a time of arrival basis, or on the basis of signal amplitude, to provide information of the characteristics of a large number of incremental areas between the boreholes. Such information is useable to produce a tomograph of the subsoil structure between the boreholes. By processing signals of relatively high frequencies, e.g., up to 100 Hz, and by closely spacing the geophones, a high resolution tomograph can be produced

    On the naturality of the Mathai-Quillen formula

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    We give an alternative proof for the Mathai-Quillen formula for a Thom form using its natural behaviour with respect to fiberwise integration. We also study this phenomenon in general context.Comment: 6 page

    Plants used for topical application from Gingee hills, Tamil Nadu, India.

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    This study is a documentation of medicinal plants used for topical applications by villagers around Gingee hills of Villupuram District, Tamil Nadu, India. A total of 23 Dicot plants belong to 18 families are used as topical applications to treat various skin diseases such as sore, psoriasis, itching, scabies, eczema and other skin infections. Herbs (8 species) are the dominant life form category equal number of shrubs and trees (6 species) followed by 3 species of climbers. Generally fresh plant parts are used in the form of powder, extract and paste. Leaves are the mostly used part in the preparation of medicine. The present study concluded that the abundance of medicinally important plants is an excellent potential for discovery of novel drugs to cure various ailments

    Constitutive modeling of ice in the high strain rate regime

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    AbstractThe objective of the present work is to propose a constitutive model for ice by considering the influence of important parameters such as strain rate dependence and pressure sensitivity on the response of the material. In this regard, the constitutive model proposed by Carney et al. (2006) is considered as a starting basis and subsequently modified to incorporate the effect of brittle cracking within a continuum damage mechanics framework. The damage is taken to occur in the form of distributed cracking within the material during impact which is consistent with experimental observations. At the point of failure, the material is assumed to be fluid-like with deviatoric stress almost dropping down to zero. The constitutive model is implemented in a general purpose finite element code using an explicit formulation. Several single element tests under uniaxial tension and compression, as well as biaxial loading are conducted in order to understand the performance of the model. Few large size simulations are also performed to understand the capability of the model to predict brittle damage evolution in un-notched and notched three point bend specimens. The proposed model predicts lower strength under tensile loading as compared to compressive loading which is in tune with experimental observations. Further the model also asserts the strain rate dependency of the strength behavior under both compressive as well as tensile loading, which also corroborates well with experimental results
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