830 research outputs found
MK Morphological Study of Am Stars at 66 Å/mm
The pseudo-luminosity effect in the metallic line A-type stars found by Abt & Morgan (1976) is confirmed in a random sample of 27 Am stars. From a morphological study of their spectra in the wavelength interval 3850-4400 Å at a reciprocal dispersion of 66 Å/mm, revised spectral types are given on the MK system for their K-line and metallic-line spectra. This shows that: (a) our segregation of weak Am from the Am stars largely agrees with that by Cowleyet al. (1969); (b) all the stars in the sample are dwarfs according to their K-line classification; (c) more than 80 per cent exhibit the pseudo-luminosity effect significantly, with their metallic-line spectra resembling a giant or even a supergiant in the violet (3850-4100 Å), and a giant rather than a dwarf in the blue region (4260-4400 Å); (d) in two-thirds of the stars under (c), the Sr n 4077 Å line is found to have a markedly brighter luminosity class compared to any region, and in more than one-third of the sample it is comparable to that in Ap stars; (e) at least five stars exhibit characteristics which might suggest a spectrum variability: among these, the most striking example is 41 Sex A which was found to show a phase-modulated spectrum variation hitherto unknown in Am stars; (f) the metallic-line spectra of another five stars appear to be similar to A-shell type in differing degrees; (g) less than 20 per cent of the sample comprises stars which do not show any significant differential luminosity effect; these stars might have been misclassified or perhaps they are in a quiescent state. We also confirm the conclusion arrived at by Bohm-Vitense & Johnson (1978) that all Am stars may vary and our observations suggest that groups may exist among them
Process control & instrumentation for titanium sponge plant
A large scale facility for establishing the technology of production of titanium sponge in 4000 kg batches by high temperature reduction of titanium tetrachloride has been set up at the Defence Metallurgical Research Laboratory, Hyderabad. The steps involved in the process are (i) two stage distillation for the purification of titanium tetrachloride (ii) high temperature reduction of titanium tetrachloride by molten magnesium followed by pyro-vacuum distillation of sponge in a combined reductionvacuum disti-llation furnace and (iii) processing of the sponge produ-ced which include sponge ejection, cutting, crushing and blending. To produce high purity sponge in a reproducible manner batch after batch, very close monitoring & control of process parameters is essential. In view of the highly
reactive nature of the metal, any post reduction purifica-tion is totally ruled out. This paper discusses in detail the process control scheme adopted for the titanium tetra-chloride purification and reduction operations, highlight-ing the type of instrumentation adopted considering the corrosive nature of titanium tetrachloride. A microproce-ssor based Distributed Control System has been installed for controlling the process operation. Salient features of this system are also described in this paper
Laser Induced Breakdown Spectroscopy for Classification of High Energy Materials using Elemental Intensity Ratios
A simple, yet efficient, methodology is proposed to classify three high energy materials (HEMs) with diverse composition using nanosecond laser induced breakdown spectroscopic data. We have calculated O/N, N/H, and O/H elemental peaks ratios using a ratiometric method. The present work describes a novel way to construct 1D, 2D, and 3D classification model using the above mentioned ratios. Multivariate statistical methods are followed for construction of the classification models. A detailed procedure for classification of three different HEMs is presented here.Defence Science Journal, Vol. 64, No. 4, July 2014, pp.332-338, DOI:http://dx.doi.org/10.14429/dsj.64.474
ECONOMIC IMPACT EVALUATION OF GLOBAL MARKETING SUPPORT SERVICES - AN EXPORTS ASSISTANCE PROGRAM ON THE ECONOMY OF ARKANSAS
This study determines the impact of Global Marketing Support Services (GMSS) - an exports assistance program in assisting 13 small and medium sized businesses to export. The total impact of exports (direct, indirect and induced effects) on added value, employment, labor income and tax impacts in Arkansas are estimated using Impact Analysis for Planning (IMPLAN).International Relations/Trade,
Clinical, ultrasonographical and hormonal correlation in women with polycystic ovarian syndrome
Background: Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder in women of fertile age. The prevalence, time of onset and severity of clinical presentation vary among different ethnic and racial groups. Though there is significant reproductive, endocrine and metabolic morbidity of PCOS, very little is known about its different modes of presentation in Indian population. It is a cross sectional observational study. The objective To study the correlation between the clinical, ultrasonographical and hormonal features in women diagnosed as PCOS based on the revised diagnostic criteria, 2003.Methods: A cross-sectional study of 74 PCOS women who had oligo ovulatory cycles and polycystic ovarian morphology on ultrasound was done. Data about menstrual history and anthropometric measurements were collected. Clinical observations of acne and hirsutism were made. Transvaginal ultrasonography and biochemical analysis for free testosterone was done.Results: In all, 74 PCOS women were studied and analyzed. The mean age was 24.88±4.03, mean BMI was 25.48 ±3.75 and mean free testosterone was 3.81±4.05. Among the PCOS women 39.8% were hirsute, 10.1% were obese, 2.3% had acne and 38% were hyperandrogenemic. Of the hyperandrogenemic women 61.2% were hirsute, 53.22% were obese and 36.54% had acne. The association between BMI and free testosterone level was statistically significant (p=0.0023). BMI was moderately correlated with hyperandrogenemia (r=0.446). The mean left ovarian volume was higher in obese than in non-obese women, which was statistically significant (p=0.003). The mean left ovarian volume was high in hyperandrogenemic women which was statistically significant (p=0.00034).Conclusions: In the present study it was found that there is association between obesity and free testosterone level which was significant. There was statistically significant association between ovarian volume and obesity. Similarly, there was association between ovarian volume and hyperandrogenemia which was significant. Hirsutism and acne had no association with hyperandrogenemia
X-ray photoelectron spectroscopic investigation of phenosafranine adsorbed onto micro and mesoporous materials
The phenosafranine adsorbed onto the micro and mesoporous materials prepared by ion exchange method and interaction of the dye with host materials were studied by X-ray photoelectron spectroscopy to elucidate the influence of the host matrix on the binding energy of N 1s orbital. Core level N 1s X-ray photoelectron spectroscopy reveals the interaction between the dye and the solid surface through the hydrogen bonding between the hydrogen atoms of primary amino groups in dye molecule and the oxygen atom of surface hydroxyl groups. The strength of the hydrogen bonding depends on the nature of the solid surface. In the dye adsorbed onto the micro and mesoporous materials the interaction between adsorbed phenosafranine and the surfaces of the porous materials are found to modify the optical spectra and the excited state dynamics of the confined phenosafranine molecules. The change in photophysical properties of phenosafranine adsorbed on to the host materials on dehydration at elevated temperatures is attributed to the modification of host surface during dehydration process
A Clinical Study on the efficacy of Laksha Choorna Pratisarana and Tila Taila Kavala in the control of Danta Sharkara
Introduction: Danta Sharkara (Dental Calculus) is one among the Danta Rogas (Diseases of Tooth) characterized by, hardened accumulation of Mala (dirt) on tooth surface which destroys the teeth and its surrounding structures. It can be compared to Dental calculus, which is a calcified mass that forms on and adheres to the surface of teeth causing periodontal diseases. Modern approach of treatment is Scaling and Root planing. Ultrasonic scalers are used widely by the dentists, which is more efficient method, but it has certain drawbacks. Long term use of mouth washes and dentifrices also have shown adverse effects. Considering these drawbacks in modern dentistry present study was taken up to evaluate the efficacy of local therapeutic procedure mentioned in our classics for calculus removal and its control. Materials and Methods: 40 patients were selected and randomly divided into Group A and B consisting of 20 patients each. Group A was treated by Lakshachoorna Pratisarana (rubbing lac) with Madhu (honey) after Scaling followed by Tilataila Kavala (gargle with gingelly oil) for a period of 3 months. Group B was treated by Ultrasonic Scaling followed by Chlorhexidine mouth wash for a period of 3 months. Result: In the present study, It was found that Group A showed better improvement in calculus index and lesser recurrence rate
The Appropriateness of Different Modes of Strategy from a Product-Market Perspective
Strategy-making is an important yet complex task. The present research examines the issue of strategy mode, that is, the manner or style in which strategy is determined in an organization. Prior researchers have proposed various typologies for strategy modes. However, research into which strategy modes are appropriate to what kinds of firm situations and contexts has been limited. Specifically, there has been no research that explores strategy modes from a marketing environment perspective. Given that research at the intersection of marketing and management disciplines has often produced mutually beneficial, rich insights, we approach strategy modes from a product-market perspective and examine the normative appropriateness of different strategy modes with reference to firms\u27 external and internal environments. The research also explores the relevance and value of combining various strategy modes in regard to different stages of the product-market life cycle. In exploring strategy modes and their combinatory influences from a product-market perspective, we develop specific propositions. The paper concludes with a discussion of implications for academics and practitioners
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