Development of Metallurgical Refractories with Indian Raw Materials - Pilot Plant Studies

Refractories play a vital role in the development of metallurgical industries. With rapid industrialisation in the country, demand for refractories is ever increasing and has been estimated at about one million tons per annum by the end of the 2nd Five Year Plan. The present produc-tion is of the order of 4,60,000 tons of refractories per annum. The gap between the present capacity and demand is largely being met by imports from other countries, thereby draining lot of valuable foreign exchange. Though there is no dearth of raw materials for refractory manufacture in our country, success of our refractory production prog-ramme depends on detailed and systematic investigation of various raw materials and their processing methods, effecting improvements in the quality of the products manufactured at present and development of compositions and processes for new products hereto not manufactured in the country. With this end in view, indigenous refractory raw materials have been scientifically and systematically investigated in this Laboratory. In all cases, before translating such laboratory efforts into commercial scale production, it is necessary that pilot plant studies should be carried out in order to obtain operating; data which can be extrapolated with confidence in industrial practice. To meet this and a refractories pilot plant is being set up in this Laboratory. The projects which have reached a pilot plant stage of investigation are enume-rated below: (i) Dense mullite and hot face insulation refractories from bladed kyanite. (ii) Zircon and sillimanite refractories from Travancore beach sands. (iii) Magnesite refractories from Almorah magnesite. (iv) Forsterite refractories from magnesium silicate rocks. (v) Chemically bonded and metal clad mixed basic refractories

Pandanus odoratissimus

Pandanus odoratissimus Linn. (family: Pandanaceae) is traditionally recommended by the Indian Ayurvedic medicines for treatment of headache, rheumatism, spasm, cold/flu, epilepsy, wounds, boils, scabies, leucoderma, ulcers, colic, hepatitis, smallpox, leprosy, syphilis, and cancer and as a cardiotonic, antioxidant, dysuric, and aphrodisiac. It contains phytochemicals, namely, lignans and isoflavones, coumestrol, alkaloids, steroids, carbohydrates, phenolic compounds, glycosides, proteins, amino acids as well as vitamins and nutrients, and so forth. It is having immense importance in nutrition. A 100 g edible Pandanus pericarp is mainly comprised of water and carbohydrates (80 and 17 g, resp.) and protein (1.3 mg), fat (0.7 mg), and fiber (3.5 g). Pandanus fruits paste provides 321 kilocalories, protein (2.2 g), calcium (134 mg), phosphorus (108 mg), iron (5.7 mg), thiamin (0.04 mg), vitamin C (5 mg), and beta-carotene (19 to 19,000 μg) (a carotenoid that is a precursor to vitamin A). Pandanus fruit is an important source of vitamins C, B1, B2, B3, and so forth, usually prepared as a Pandanus floured drink. Traditional claims were scientifically evaluated by the various authors and the phytochemical profile of plant parts was well established. The methods for analytical estimations were developed. However, there is paucity of systematic compilation of scientifically important information about this plant. In the present review we have systematically reviewed and compiled information of pharmacognostic, ethnopharmacology, phytochemistry, pharmacology, nutritional aspects, and analytical methods. This review will enrich knowledge leading the way into the discovery of new therapeutic agents with improved and intriguing pharmacological properties

Evaluation of quartzites for the manufacture of silica bricks

Chemical, physical and inversion characteristics of quartzites from different sources have been studied to evaluate their suitability for the conventional as well as superduty type of silica refractories. Results of small scale trials carried out on quartzite samples with addition of lime and iron oxide and physical properties of the specimens after firing to 1450°C have also been furnished and in the light thereof, the suitability of indigenous quartzites have been assessed. (Mr. Gurbux Singh Minhas, Senior Scientific Assistant and Mr. H.V. Bhaskar Rao, Senior Scientific Officer, National Metallurgical Laboratory, Jamshedpur.

SYNTHESIS AND ANTIOXIDANT ACTIVITY OF NOVEL 2-ARYL SUBSTITUTED BENZOTHIAZOLE DERIVATIVES

Objective: A series of 2-aryl substituted benzothiazole was designed and synthesized with various substituted benzoic acid. 2-mercaptobenzothiazole and thionyl chloride also used to get carbothiaote. The present study was carried to assess the pharmacological potential towards antioxidant activity of 2-aryl substituted benzothiazole derivatives. Methods: The antioxidant activity of the synthesized compounds was evaluated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide radical scavenging assay methods. Results: Compounds showed significant radical scavenging potential due to the presence of electron donating substituent. Conclusion: These indicate that benzothiazole derivatives showed the defence mechanism to prevent formation of excess free radicals

Temperature Profiles of Accretion Disks around Rapidly Rotating Neutron Stars in General Relativity and Implications for Cygnus X-2

We calculate the temperature profiles of (thin) accretion disks around rapidly rotating neutron stars (with low surface magnetic fields), taking into account the full effects of general relativity. We then consider a model for the spectrum of the X-ray emission from the disk, parameterized by the mass accretion rate, the color temperature and the rotation rate of the neutron star. We derive constraints on these parameters for the X-ray source Cygnus X-2 using the estimates of the maximum temperature in the disk along with the disk and boundary layer luminosities, using the spectrum inferred from the EXOSAT data. Our calculations suggest that the neutron star in Cygnus X-2 rotates close to the centrifugal mass-shed limit. Possible constraints on the neutron star equation of state are also discussed.Comment: 18 pages, 9 figs., 2 tables, uses psbox.tex and emulateapj5.sty. Submitted to Ap

Real-Gas Effects and Phase Separation in Underexpanded Jets at Engine-Relevant Conditions

A numerical framework implemented in the open-source tool OpenFOAM is presented in this work combining a hybrid, pressure-based solver with a vapor-liquid equilibrium model based on the cubic equation of state. This framework is used in the present work to investigate underexpanded jets at engine-relevant conditions where real-gas effects and mixture induced phase separation are probable to occur. A thorough validation and discussion of the applied vapor-liquid equilibrium model is conducted by means of general thermodynamic relations and measurement data available in the literature. Engine-relevant simulation cases for two different fuels were defined. Analyses of the flow field show that the used fuel has a first order effect on the occurrence of phase separation. In the case of phase separation two different effects could be revealed causing the single-phase instability, namely the strong expansion and the mixing of the fuel with the chamber gas. A comparison of single-phase and two-phase jets disclosed that the phase separation leads to a completely different penetration depth in contrast to single-phase injection and therefore commonly used analytical approaches fail to predict the penetration depth.Comment: Preprint submitted to AIAA Scitech 2018, Kissimmee, Florid

Stochastic Budget Optimization in Internet Advertising

Internet advertising is a sophisticated game in which the many advertisers "play" to optimize their return on investment. There are many "targets" for the advertisements, and each "target" has a collection of games with a potentially different set of players involved. In this paper, we study the problem of how advertisers allocate their budget across these "targets". In particular, we focus on formulating their best response strategy as an optimization problem. Advertisers have a set of keywords ("targets") and some stochastic information about the future, namely a probability distribution over scenarios of cost vs click combinations. This summarizes the potential states of the world assuming that the strategies of other players are fixed. Then, the best response can be abstracted as stochastic budget optimization problems to figure out how to spread a given budget across these keywords to maximize the expected number of clicks. We present the first known non-trivial poly-logarithmic approximation for these problems as well as the first known hardness results of getting better than logarithmic approximation ratios in the various parameters involved. We also identify several special cases of these problems of practical interest, such as with fixed number of scenarios or with polynomial-sized parameters related to cost, which are solvable either in polynomial time or with improved approximation ratios. Stochastic budget optimization with scenarios has sophisticated technical structure. Our approximation and hardness results come from relating these problems to a special type of (0/1, bipartite) quadratic programs inherent in them. Our research answers some open problems raised by the authors in (Stochastic Models for Budget Optimization in Search-Based Advertising, Algorithmica, 58 (4), 1022-1044, 2010).Comment: FINAL versio