On Relativistic Wave Equation for Particles of Integer Spins

The representation given by Mathews to describe particles of integer spins is modified in such a way that the Hamiltonian does not contain the matrix Co which is a null matrix. An extreme relativistic limit of the modified Hamiltonian is also obtained

Hot Isostatic Pressing Technology for Defence and Space Applications

Hot isostatic pressing (HIP) technology has been established for the development of AISI-304 stainless steel and nickel base superalloy Inconel 718 integral turbine rotors, for liquid propulsion engine of Prithvi missile, and cryoengine of geostationary satellite launch vehicle (GSLV), respectively. Before making the full size rotors, the structure – property relationships in hot isostatic pressed (HIPed) 304 stainless steel and superalloy 718 were established. The HIPed steel and superalloy have shown near 100 per cent theoretical density, homogeneous, and fine grained microstructure. Their mechanical properties were found to be in agreement with those specified for the integral turbine rotors and hence, development of full size near net shaped integral turbine rotors was undertaken. The HIPed steel rotors subjected to the static engine tests have shown a satisfactory performance, and therefore a large number of rotors could be produced to fulfill the requirement of target labs. The HIP technology for the integral turbine rotors was found to be cost effective (about 50 per cent) over the conventional fabrication method which involves forging, machining, and welding of blades to the disk. The processing, structure, and properties of the HIPed 304 stainless steel and superalloy 718 in relation to the performance of integral turbine rotors for missile and space vehicle applications are discussed in this paper.Defence Science Journal, 2012, 62(1), pp.73-80, DOI:http://dx.doi.org/10.14429/dsj.62.37

Quantum Corrections to the ‘Atomistic’ MOSFET Simulations

Published versio

Component and System Sensitivity Considerations for Design of a Lunar ISRU Oxygen Production Plant

Component and system sensitivities of some design parameters of ISRU system components are analyzed. The differences between terrestrial and lunar excavation are discussed, and a qualitative comparison of large and small excavators is started. The effect of excavator size on the size of the ISRU plant's regolith hoppers is presented. Optimum operating conditions of both hydrogen and carbothermal reduction reactors are explored using recently developed analytical models. Design parameters such as batch size, conversion fraction, and maximum particle size are considered for a hydrogen reduction reactor while batch size, conversion fraction, number of melt zones, and methane flow rate are considered for a carbothermal reduction reactor. For both reactor types the effect of reactor operation on system energy and regolith delivery requirements is presented

Consensus of the 'Malasars' traditional aboriginal knowledge of medicinal plants in the Velliangiri holy hills, India

There are many vanishing cultures that possess a wealth of knowledge on the medicinal utility of plants. The Malasars of Dravidian Tamils are an indigenous society occupying the forests of the Western Ghats, South India. They are known to be exceptional healers and keepers of traditional aboriginal knowledge (TAK) of the flora in the Velliangiri holy hills. In fact, their expertise is well known throughout India as evidenced by the thousands of pilgrims that go to the Velliangiri holy hills for healing every year. Our research is the first detailed study of medicinal plants in India that considers variation in TAK among informants using a quantitative consensus analysis. A total of 95 species belonging to 50 families were identified for medicinal and general health purposes. For each species the botanical name, family, local name, parts used, summary of mode of preparation, administration and curing are provided. The consensus analysis revealed a high level of agreement among the informants usage of a particular plant at a local scale. The average consensus index value of an informant was FIC > 0.71, and over 0.80 for some ailments such as respiratory and jaundice. Some of the more common problems faced by the Malasars were gastrointestinal disorders, respiratory illness, dermatological problems and simple illness such as fever, cough, cold, wounds and bites from poisonous animals. We also discovered several new ethnotaxa that have considerable medicinal utility. This study supports claims that the Malasars possess a rich TAK of medicinal plants and that many aboriginals and mainstream people (pilgrims) utilize medicinal plants of the Velliangiri holy hills. Unfortunately, the younger generation of Malasars are not embracing TAK as they tend to migrate towards lucrative jobs in more developed urban areas. Our research sheds some light on a traditional culture that believes that a healthy lifestyle is founded on a healthy environment and we suggest that TAK such as that of the Malasars may serve toward a global lifestyle of health and environmental sustainability

Microstructural Study of Galvanized coatings formed in Pure as well as Commercial Grade Zn Baths

The hot dip galvanizing is a complex metallurgical process wherein a steel strip is immersed in a zinc alloy bath normally between 450 and 480°C. The protective coating that is formed consists of a series of intermetallic Fe—Zn compound layers, which have been identified as gamma (r), delta (6), zeta (4) and an outer eta (T) layer, highly rich in Zn. There is no apparent delay in the formation of 4 or 6 phases (less than 5 s reaction time) in pure Zn bath as well as the commercial grade Zn bath. The gamma (I') phase is formed after an incubation time of 30 s at a bath temperature of 470°C in the pure Zn bath. The forma-tion and growth of F phase, however, is delayed in the commercial grade Zn bath. The last morphological feature is the formation of a second 4 layer at the 4/6 interface in reaction time above 30 s. Presence of Pb in the comme-rcial grade Zn bath seems to increase the overall coating thickness. Commercial grade Zn, however, enhances the dross formation in the bath and detoriates the quality of the coating. Presence of transverse cracks as well as entrapment of dross particles in these coatings is attr-ibuted to the less compact coatings that are formed in the commercial grade Zn baths. The present investigation is an effort to have a better understanding of the kinetics of growth and morphology of the coatings during the galva-nizing process in the pure as well as commercial grade Zn baths

Signatures of the disk-jet coupling in the Broad-line Radio Quasar 4C+74.26

Here we explore the disk-jet connection in the broad-line radio quasar 4C+74.26, utilizing the results of the multiwavelength monitoring of the source. The target is unique in that its radiative output at radio wavelengths is dominated by a moderately-beamed nuclear jet, at optical frequencies by the accretion disk, and in the hard X-ray range by the disk corona. Our analysis reveals a correlation (local and global significance of 96\% and 98\%, respectively) between the optical and radio bands, with the disk lagging behind the jet by $250 \pm 42$ days. We discuss the possible explanation for this, speculating that the observed disk and the jet flux changes are generated by magnetic fluctuations originating within the innermost parts of a truncated disk, and that the lag is related to a delayed radiative response of the disk when compared with the propagation timescale of magnetic perturbations along relativistic outflow. This scenario is supported by the re-analysis of the NuSTAR data, modelled in terms of a relativistic reflection from the disk illuminated by the coronal emission, which returns the inner disk radius $R_{\rm in}/R_{\rm ISCO} =35^{+40}_{-16}$. We discuss the global energetics in the system, arguing that while the accretion proceeds at the Eddington rate, with the accretion-related bolometric luminosity $L_{\rm bol} \sim 9 \times 10^{46}$ erg s$^{-1}$ $\sim 0.2 L_{\rm Edd}$, the jet total kinetic energy $L_\textrm{j} \sim 4 \times 10^{44}$ erg s$^{-1}$, inferred from the dynamical modelling of the giant radio lobes in the source, constitutes only a small fraction of the available accretion power.Comment: 9 pages and 6 figures, ApJ accepte

The impact of successful cataract surgery on quality of life, household income and social status in South India.

BACKGROUND: To explore the hypothesis that sight restoring cataract surgery provided to impoverished rural communities will improve not only visual acuity and vision-related quality of life (VRQoL) but also poverty and social status. METHODS: Participants were recruited at outreach camps in Tamil Nadu, South India, and underwent free routine manual small incision cataract surgery (SICS) with intra-ocular lens (IOL) implantation, and were followed up one year later. Poverty was measured as monthly household income, being engaged in income generating activities and number of working household members. Social status was measured as rates of re-marriage amongst widowed participants. VRQoL was measured using the IND-VFQ-33. Associations were explored using logistic regression (SPSS 19). RESULTS: Of the 294 participants, mean age ± standard deviation (SD) 60 ± 8 years, 54% men, only 11% remained vision impaired at follow up (67% at baseline; p<0.001). At one year, more participants were engaged in income generating activities (44.7% to 77.7%; p<0.001) and the proportion of households with a monthly income <1000 Rps. decreased from 50.5% to 20.5% (p<0.05). Overall VRQoL improved (p<0.001). Participants who had successful cataract surgery were less likely to remain in the lower categories of monthly household income (OR 0.05-0.22; p<0.02) and more likely to be engaged in income earning activities one year after surgery (OR 3.28; p = 0.006). Participants widowed at baseline who had successful cataract surgery were less likely to remain widowed at one year (OR 0.02; p = 0.008). CONCLUSION: These findings indicate the broad positive impact of sight restoring cataract surgery on the recipients' as well as their families' lives. Providing free high quality cataract surgery to marginalized rural communities will not only alleviate avoidable blindness but also - to some extent - poverty in the long run

Dynamical cluster-decay model for hot and rotating light-mass nuclear systems, applied to low-energy 32^{32}S + 24^{24}Mg →56\to ^{56}Ni reaction

The dynamical cluster-decay model (DCM) is developed further for the decay of hot and rotating compound nuclei (CN) formed in light heavy-ion reactions. The model is worked out in terms of only one parameter, namely the neck-length parameter, which is related to the total kinetic energy TKE(T) or effective Q-value $Q_{eff}(T)$ at temperature T of the hot CN, defined in terms of the both the light-particles (LP), with $A \leq$ 4, Z $\leq$ 2, as well as the complex intermediate mass fragments (IMF), with $4 2$, is considered as the dynamical collective mass motion of preformed clusters through the barrier. Within the same dynamical model treatment, the LPs are shown to have different characteristics as compared to the IMFs. The systematic variation of the LP emission cross section $\sigma_{LP}$, and IMF emission cross section $\sigma_{IMF}$, calculated on the present DCM match exactly the statistical fission model predictions. It is for the first time that a non-statistical dynamical description is developed for the emission of light-particles from the hot and rotating CN. The model is applied to the decay of $^{56}$Ni formed in the $^{32}$S + $^{24}$Mg reaction at two incident energies E$_{c.m.}$ = 51.6 and 60.5 MeV. Both the IMFs and average $\bar{TKE}$ spectra are found to compare reasonably nicely with the experimental data, favoring asymmetric mass distributions. The LPs emission cross section is shown to depend strongly on the type of emitted particles and their multiplicities