Assessment of Ration Scales of the Armed Forces Personnel in Meeting theNutritional Needs at Plains and High Altitudes–I

Adequate nutrition is very essential, especially for the Armed Forces, to buildup their nutritional reserveswhile deriving maximum benefits of training/peak performances in operational situations by keeping theirmorale high. The present study reviews/examines the adequacy of the existing ration scales of the ArmedForces personnel stationed under different terrain conditions of the country/recruits at various training centres.Food samples were collected from different strategic locations during different seasons of the year and analysedfor their nutrient composition like proximal constituents, vitamins A, E, B1, B2, C, and dietary fibre. Basedon the data generated, the daily nutrients/energy consumption by the soldiers/recruits, were calculated separatelyboth for personnel in plains and at high altitudes. Soldiers in plains, on an average consumed protein 124.2+ 13.0 g, fat 98.8 + 29.6 g and energy 3632+317 kcal/person/day, while their counterparts at high altitudesconsumed protein 120.4 + 11.2 g, fat 120.1 + 31.1 g, and energy 3906 + 423 kcal/person/day. The study clearlyindicate that the present ration scales for the Service personnel, both in plains and at high altitudes (9000 ftto 15000 ft) is adequate wrt their nutrient density. It is however suggested to ensure adequate supply of goodquality fresh vegetables, fruits, and meat, which inturn would not only help to keep the morale of the soldiers,high and cheerful, especially at high altitudes, but will also enable adequate micronutrient availability. Thefibre levels in the diets of these soldiers have also been found to be well within the limits (20 -35 g/ person/day) recommended for optimal health.Defence Science Journal, 2008, 58(6), pp.734-744, DOI:http://dx.doi.org/10.14429/dsj.58.170

Evaluation of Tensile Properties and their Correlation with Microstructural Characteristics of a Closed Die Forging of Iso-symmetrical Aerospace Grade Ti-6Al-4V Alloy

In the present technical paper an iso-symmetrical forging in titanium alloy, i.e., Ti-6Al-4V is chosen for cut-up evaluation and study of mechanical properties and their correlation with microstructural characteristics. Tensile test specimens were extracted from rim, web and bore regions of the forgings aligned in radial and tangential directions. Test specimens varying from various locations were extracted to conduct the tests (ASTM E8) at various temperatures from room temperature to 300 °C. Statistical analyses of the tested data were carried out to quantify the variation in tensile properties along rim, web, and bore regions at room temperature. Effects of radial and tangential alignments of specimens at room temperature was also studied. Among the different test specimens, the specimen that exhibited mechanical properties close to average values were further subjected to microstructural and fractographic investigations using optical and scanning electron microscopes. These studies revealed that there is a marginal inhomogenity in the microstructure of the forgings and this variation controls the mechanical properties and fracture characteristics of the material. Microstructure marginally varies from rim to bore region. Similarly, along the thickness of the forging, there is a small variation in the microstructure. The aforementioned correlations have established the fact that the microstructure variations from different locations and among different specimen orientations have resulted in mild variation in the tensile properties.Defence Science Journal, Vol. 65, No. 2, March 2015, pp.171-178, DOI:http://dx.doi.org/10.14429/dsj.65.723

Formulation and Evaluation of Tacrolimus Transdermal Gel

The present investigation is concerned with formulation and evaluation of Transdermal gels of Tacrolimus, anti-psoriasis drug, to circumvent the first pass effect and to improve its bioavailability with reduction in dosing frequency and dose related side effects. Twelve formulations were developed with varying concentrations of polymers like Carbopol 934P, HPMCK4M and Sodium CMC. The gels were tested for clarity, Homogeneity, Spreadability, Extrudability, Viscosity, surface pH, drug Content uniformity, in-vitro drug diffusion study and ex-vivo permeation study using rat abdominal skin. FTIR studies showed no evidence on interactions between drug, polymers and excipients. The best in-vitro drug release profile was achieved with the formulation F4 containing 0.5 mg of exhibited 6 hr drug release i.e. 98.68 % with desired therapeutic concentration which contains the drug and Carbopol 934p in the ratio of 1:2. The surface pH, drug content and viscosity of the formulation F4 was found to be 6.27, 101.3% and 3, 10,000cps respectively. The drug permeation from formulation F4 was slow and steady and 0.89gm of tacrolimus could permeate through the rat abdominal skin membrane with a flux of 0.071 gm hr-1 cm-2. The in-vitro release kinetics studies reveal that all formulations fit well with zero order kinetics followed by non-Fickian diffusion mechanism. Keywords: Transdermal gel, Viscosity, In-vitro drug release, In-vitro drug release kinetics study, Ex-vivo permeation stud

Hydrodynamic analysis of a low head prototype Francis turbine for establishing an optimum operating regime using CFD

Hydraulic turbines need to operate at regimes other than designed ones. Off-design functioning of these turbines yields an inefficient and uneconomical operation of hydro projects. Performance and energy losses at different possible operating conditions need to be evaluated before finalizing the design of water turbines for satisfactory operations. Moreover, hydraulic turbines are unique machines designed for unique set of operating conditions and cost a huge percentage of the overall cost of the project. This work is compiled with twofold objectives; derivation of complete performance characteristics of a 48m head prototype Francis turbine in order to establish an optimum operating regime and, determination and analyses of head loss at different components of the turbine. Steady state flow simulations for four different load operations (60%, 80%, 100% and 120%) have been carried out using computational fluid dynamics. It is found that the optimum regime of operation lies within the speed factor range of 0.412-0.48 along with discharge factor range of 0.27-0.329 and maximum efficiency is obtained as 90.64% at full load operation. Maximum head loss in critical components of the turbine such as runner and draft tube is found as 12.7% at speed factor of 0.568 and 26.31% at 0.202 speed factor respectively. Also, the maximum total head loss in all the components is found as 47.8% at 60% load and 0.609 speed factor. It is concluded that the functioning of the turbine at higher speed factors is more detrimental than that at lower speed factors. Requirement of performance improvement at off-design conditions (especially at 60% load operation) is also suggested in order to widen the range of optimum operating regime. Obtained computational results are validated with experimental results and a strong agreement is found between the two

Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms

Experimental and numerical investigation of single-beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to the appearance of a single peak of the probe beam amplification at the transition frequency. The greater probe intensity results in an asymmetrical transmission spectrum with amplification at the blue wing of the absorption line and attenuation at the red one. Under high medium density, a broad band of amplification appears. Theoretical model is based on the solution of the Maxwell-Bloch equations for a two-level system. Different types of probe transmission spectra obtained are attributed to complex dynamics of a coherent medium response to broadband polychromatic radiation of a multimode dye laser.Comment: 9 pages, 13 figures, corrected, Fig.8 was changed, to be published in Phys. Rev.

Diffusion of particles moving with constant speed

The propagation of light in a scattering medium is described as the motion of a special kind of a Brownian particle on which the fluctuating forces act only perpendicular to its velocity. This enforces strictly and dynamically the constraint of constant speed of the photon in the medium. A Fokker-Planck equation is derived for the probability distribution in the phase space assuming the transverse fluctuating force to be a white noise. Analytic expressions for the moments of the displacement $$ along with an approximate expression for the marginal probability distribution function $P(x,t)$ are obtained. Exact numerical solutions for the phase space probability distribution for various geometries are presented. The results show that the velocity distribution randomizes in a time of about eight times the mean free time ($8t^*$) only after which the diffusion approximation becomes valid. This factor of eight is a well known experimental fact. A persistence exponent of $0.435 \pm 0.005$ is calculated for this process in two dimensions by studying the survival probability of the particle in a semi-infinite medium. The case of a stochastic amplifying medium is also discussed.Comment: 9 pages, 9 figures(Submitted to Phys. Rev. E