4,941 research outputs found
Effects of the extrusion process parameter
No full textRetraction of: Effects of the Extrusion Process Parameter by Prashant Baredar, Jitendra Kumar, Anil Kumar, Shankar Kumar and Ajeet Kumar Giri as it was republished due to oversite.</jats:p
Book Review: Shankar Kumar Bhaumik, Principles of Econometrics: A Modern Approach Using EViews
No full text Shankar Kumar Bhaumik, Principles of Econometrics: A Modern Approach Using EViews, 2015, New Delhi: Oxford University Press, 496 pp., ₹795. ISBN: 978-0-19-809853-9 </jats:p
sj-docx-1-pie-10.1177_09544089221111258 - Supplemental material for Low elastic modulus and highly porous triply periodic minimal surfaces architectured implant for orthopedic applications
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089221111258 for Low elastic modulus and highly porous triply periodic minimal surfaces architectured implant for orthopedic applications by Rati Verma, Jitendra Kumar, Nishant Kumar Singh and
Sanjay Kumar Rai, Shekhar Kumta, Shankar Sehgal, Kuldeep Saxena in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
Silicon-photonic-assisted on-chip RF signal processing
No full textWe present a Silicon-photonic-assisted RF signal processing, in particular, frequency up conversion and RF pulse generation. For frequency up-conversion, we use compact silicon PN micro-ring modulator to frequency double the input RF signal. Experimentally we report an up-conversion of the baseband to a maximum of 12 GHz covering L, S, C and X band. We achieve a maximum suppression of 30 dB of the baseband at the output. The extinction could be improved by operating the ring modulator at the critical coupling. We present a detailed study on the effect of the optical carrier offset from the resonance wavelength and its effect on the suppression and the upconverted RF linewidth. Using the same platform, we also demonstrate RF-pulse generation using a PN Mach-Zehnder modulator. An RF modulated optical carrier, and an RF signal can be fed to the MZM to create pulsed RF of desired pulse width and rate. As a demonstrator, we show that RF-signal of frequency between L-X band could be fed and pulsed at various rates from 100-0.1 millisecond. The two examples demonstrate the feasibility of the Silicon Photonics Platform for building photonic assisted RF technology
Precise modelling of spacecraft relative motion for formation flying spacecraft
No full textRelative spacecraft motion has long been a problem for mission analysts who plan rendezvous maneuvers. These planners look to the solution devised by Clohessy and Wiltshire as their primary analysis tool. The Clohessy-Wiltshire (CW) equations are usually sufficient for the rendezvous problem that is of short duration and has frequent thruster firings. Consequently, the long-term accuracy of the equations of motion is not as important in the rendezvous problem as in the formation-flying problem. The errors resulting from the assumptions made in the CW equations such as circular reference orbit, very close target orbit are unacceptable for the long-term prediction of relative motion needed for formation flying satellites. A precise analytic solution for the relative motion of and formation flying
satellites is needed to minimize fuel consumption and maximize lifetime. In this paper, we derive the relative coordinates of a deputy satellite with respect to a master satellite by a series of transformations and translations from the Earth-centered inertial frame to the spacecraftcentered rotating frame. The equations of relative coordinates derived in this paper are very precise and
can be used to analyze orbits of any eccentricity and of any initial separation with or without the inclusion of orbit perturbations
A numerical study of some vortex ring phenomena using direct numerical simulation (DNS)
No full textDirect numerical simulation (DNS) is used to study some aspects of the dynamics of vortex rings in viscous, incompressible flow at Reynolds numbers (defined as the ratio of the initial circulation to the kinematic viscosity) in the range of 103 to 104. Firstly, the effect of the particular initial core azimuthal vorticity profile of a vortex ring on its subsequent evolution in unbounded flow is studied. Vortex rings with a wide range of initial core vorticity profiles are shown to relax to a common equilibrium state. Additionally the behaviour of the equilibrium vortex ring at large times is studied. When the slenderness ratio of the vortex rings increases beyond a particular limit, the vortex rings diverge from the common equilibrium state and follow paths determined by the viscosity of the fluid. Secondly, the interaction of a laminar vortex ring with a non-deformable, free-slip surface at an oblique angle of incidence leading to the phenomenon of vortex reconnection is investigated. Specifically the effect of Reynolds number on the dynamics of the reconnection process is studied. The scaling of the reconnection timescale with the Reynolds number is obtained. At high Reynolds numbers the reconnection process leads to a breakdown of the entire vortex ring structure to a turbulent-like flow. This phenomenon is shown to be related to the mechanics of the reconnection process. Finally, the dynamics of vortex rings with swirl in unbounded flow is studied. Two different types of vortex rings with swirl were considered: i) Vortex rings with Gaussian distributions of core azimuthal vorticity and core azimuthal velocity and ii) Steady state solutions of the Euler equations for vortex rings with swirl. Both types of vortex rings develop an elongated axial vortex after initialisation. The existence of a maximum limit for the swirl on a vortex ring is shown above which the vortex rings undergo a rapid de-swirling readjustment. A helical instability occurring in vortex rings due to swirl at high Reynolds numbers is presented. A relation is shown to exist between one of the modes of the helical instability and the geometric parameters of the vortex ring
System design issues of small formation-flying spacecraft
No full textThis paper deals with the analysis of the relative trajectory of small formation flying spacecraft and shows how the orbit control requirements of the formation impose particular constraints on the overall spacecraft design. The relative trajectory is simulated in the presence of perturbative forces like drag, solar radiation and J2. The fuel requirements for different formation flying patterns are studied and the feasibility of using either passive or active control methods is discussed. The effects of small differences in drag-area on cluster stability and spacecraft design are addressed. The assessment of the relative trajectory is imperative for selecting the actuators for station keeping, designing control laws and deciding the configuration of the spacecraft
Dynamics of spacecraft formation flight
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
ROLE OF KUMAR KALYAN RAS AND SITOPALADI CHURNA IN CHILDREN’S DEVELOPMENT
No full textChildhood is an important age of human being and growth and development mainly occurs in this age. Balanced diet and well nutritional foods are necessary for growth and development. In Ayurveda this stage is called Kapha dominant period of life. In this age a child should be healthy for proper development. So this study is focused on child’s growth and development and the role of Kumar Kalyan ras and Sitopaladi churn in the management of childhood.STUDY DESIGN: The study was single grouped, which contains 12 children selected from the O.P.D. and I.P.D of Vd. Prem Shankar Ayurveda hospital, colleges, campus, M.M.M Government Ayurved College Udaipur. For the well development and growth of a child, Kumar Kalyan ras and Sitopaladi churn drug, dosage of 1-2 gram is given twice a day with honey (Madhu) before meal. The regimen followed for a period of three months with follow up after every 15 days interval. Base line assessment was done after selection of children as per inclusion and exclusion criteria.RESULTS: The study suggests that the oral consumption of Kumar Kalyan ras and Sitopaladi churna with honey improves digestion, immunity and general growth.
Modelling and Analysis of Spark Ignition Carburettor
No full textModern passenger vehicles with gasoline engines are provided with different compensating devices for fuel air mixture supply. Even there is a high fuel consumption because of many factors. One of the important factors that affects the fuel consumption is carburettor. The venturi of the carburettor is important that provides a necessary pressure drop in the carburettor device. For a better economy and uniform air fuel supply there is a need to design the carburettor with an effective analytical tool or software. In this work three parameters namely, pressure drop and fuel discharge nozzle angle and the throttle angle will be analysed using the computational fluid dynamics. For this analysis two soft wares are used namely CATIA and ANSYS. Whereas CATIA for designing of carburettor and ANSYS for analysis of the carburettor. The results obtained from the soft wares will be analysed for optimum design of a carburettor and also find out the exact pressure at various throttle angles and choke valve for a proper homogenous air fuel mixture. B. Phanindra Kumar | Ravi Shankar Sidar | Rohan Kumar | M. Kavya "Modelling and Analysis of Spark Ignition Carburettor" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23523.pd
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