Search for physiologically active compounds. Part XXV. Synthesis of 7, 8-furano- and pyrono-3-methyl-2-(2-furyl)-chromones

α-Methyldihydrofurano, γ and α-pyrono ring systems have been built on 7, 8-position of 2-(2-furyl)-3-methyl chromone. The structure-activity relationship among 2-(2-furyl)-chromones is discussed

Search for physiologically active compounds. Part XVIII. Synthesis of 6- and 7-halo-2-alkylchromones

This article does not have an abstract

Computational analysis of viscous dissipation and joule-heating effects on non-Darcy MHD natural convection flow from a horizontal cylinder in porous media with internal heat generation

In the present paper we examine the effects of viscous dissipation, Joule heating and heat source/sink on non-Darcy MHD natural convection heat transfer flow over permeable horizontal circular cylinder in a porous medium. The boundary layer equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller-box finite difference scheme. A parametric study illustrating the influence of Darcy parameter (Da), Forchheimer parameter (Λ), Grashof number(Gr), heat source/sink parameter (Ω) and viscous dissipation parameter (Ec) on the fluid velocity, temperature as well as local skin-friction and Nusselt numbers is conducted Increasing Forchheimer inertial drag parameter (Λ) retards the flow considerably but enhances temperatures. Increasing viscous dissipation parameter(Ec) is found to elevate velocities i.e. accelerate the flow and increase temperatures. Increasing heat source/sink parameter (Ω) is found to elevate velocities and increase temperatures. Increasing the Grashof number (Gr) is found to elevate the velocity and decrease the temperatures. Local skin friction number is found to be increases with increasing heat source/sink parameter (Ω) where as Local Nusselt number is found to decrease with increasing heat source/sink parameter (Ω)

Proliferating trichilemmal tumour: a case report with review of literature

Proliferating trichilemmal tumour is a solid-cystic neoplasm that shows trichilemmal differentiation similar to that of the isthmus of the hair follicle histologically characteristed by the presence of trichilemmal keratinization.  Proliferating Trichilemmal Tumour (PTT) appears mainly in elderly women and is in general a solitary lesion on the scalp. Proliferating trichilemmal tumours generally have a benign clinical course, and a clinical differentiation from squamous cell carcinoma is often difficult. We report a case of PTT in a 30 year old man presenting as a solitary 10x8 cm ulcerated nodule on the scalp since 3 months clinically resembled a malignant tumour. The therapeutic approach is surgical removal with a wide clear margin

Photoelectrochemical studies on the mixed oxides, A<SUB>6</SUB>Nb<SUB>8</SUB>Ti<SUB>2</SUB>O<SUB>30</SUB>(A=Ba,Sr)

The photoelectrochemical behaviour of oxide bronzes of the type A6Nb8Ti2O30 (A=Ba, Sr) has been studied. They show good photoactivity with photopotentials of the order of 700-800 mV. The flat band potential has been estimated to be -0&#183;9 V vs SCE. The band gap estimated from the spectral response is 3&#183;1 eV

Studies on atmospheric gravity wave activity in the troposphere and lower stratosphere over a tropical station at Gadanki

MST radars are powerful tools to study the mesosphere, stratosphere and troposphere and have made considerable contributions to the studies of the dynamics of the upper, middle and lower atmosphere. Atmospheric gravity waves play a significant role in controlling middle and upper atmospheric dynamics. To date, frontal systems, convection, wind shear and topography have been thought to be the sources of gravity waves in the troposphere. All these studies pointed out that it is very essential to understand the generation, propagation and climatology of gravity waves. In this regard, several campaigns using Indian MST Radar observations have been carried out to explore the gravity wave activity over Gadanki in the troposphere and the lower stratosphere. The signatures of the gravity waves in the wind fields have been studied in four seasons viz., summer, monsoon, post-monsoon and winter. The large wind fluctuations were more prominent above 10 km during the summer and monsoon seasons. The wave periods are ranging from 10 min-175 min. The power spectral densities of gravity waves are found to be maximum in the stratospheric region. The vertical wavelength and the propagation direction of gravity waves were determined using hodograph analysis. The results show both down ward and upward propagating waves with a maximum vertical wave length of 3.3 km. The gravity wave associated momentum fluxes show that long period gravity waves carry more momentum flux than the short period waves and this is presented

Synthesis of substituted isoxazoles and 1,3,4-oxadiazoles

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Draft proposal for establishment of CNC centre at NAL

This is a proposal for setting up Computer Numerically Controlled machining facilities at N.A.L. to cater to the increasing requirements for fabrication of complex shaped and intricate/precision components for the aerospace R & D projects of the laboratory for the next 10 - year period. This fairly comprehensive document has been prepared by an internal technical committee constituted by the Director, after detailed study and discussions and covers the technical and financial aspects for setting up such facilities

Superconductivity behaviour of screen-printed LnBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7</SUB> (Ln=Eu,Y)films

Thick films of the high Tc superconducting oxides, LnBa2Cu3O7, Ln=Eu, Y, have been fabricated by screen printing on alumina and SrTiO3 substrates. Conditions for optimum superconductivity behaviour of the films have been established. Tconset varies from 90-94 K for all the films but zero resistance was observed only in a few cases

First record of Veneridae clam Protapes ziczac (Linnaeus, 1758) from east coast of India, Andhra Pradesh

250-252A venerid bivalve Protapes ziczac (Linnaeus, 1758) from benthic collections is reported for the first time from the coastal waters of Andhra Pradesh, east coast of India. The findings of this study indicate the extended distributional range of the species, until now documented from the west coast of India