The present article investigates the heat transfer due to a boundary condition in an annular cylinder such that the outer surface is heated with constant temperature and inner surface cooled to isothermal temperature....
The present article investigates the heat transfer due to a boundary condition in an annular cylinder such that the outer surface is heated with constant temperature and inner surface cooled to isothermal temperature. The impact of thermal non-equilibrium between the two phases i.e. fluid and solid phase of porous medium is analyzed. This article deliberates the effect of various physical parameters such as inter-phase heat transfer coefficient, thermal conductivity ratio and Rayleigh number of the heat transfer characteristics of the porous medium. The upper and lower surfaces of cylinder are maintained adiabatically. Results are repressed in terms of isotherms of fluid and solid phase along with streamline.
Agriculture is the primary concern in India and it requires more technological developments to be incorporated when compared to other industrial developments. Information and Communication Technologies (ICT) provides ...
Agriculture is the primary concern in India and it requires more technological developments to be incorporated when compared to other industrial developments. Information and Communication Technologies (ICT) provides a simple and cost effective technique to the farmers for enabling the precision agriculture. An information sharing system is developed through this study to support the small scale farmers. The technological developments in smart phone application and web application are used as a path to reach the small scale farmers. The application developed through this study shares an information about sugar cane crop like fertilizer requirement, pesticide requirement etc. This system will provide important and timely information to the small scale farmers like a handy agriculture guide.
Photoresist removal method using hydrogen radicals produced by decomposing hydrogen on a hot-wire catalyst is one of an environmentally friendly methods. We examined the relationship between photoresist removal rate a...
Photoresist removal method using hydrogen radicals produced by decomposing hydrogen on a hot-wire catalyst is one of an environmentally friendly methods. We examined the relationship between photoresist removal rate and its surface temperature and the surface element analysis for a tantalum catalyst. In this study, we considered an adaptability of the catalyst to the removal.
In this paper, a subdomain Galerkin method is set up to find solutions of singularly perturbed boundary value problems which are used widely in many areas such as chemical reactor theory, aerodynamics, quantum mechani...
In this paper, a subdomain Galerkin method is set up to find solutions of singularly perturbed boundary value problems which are used widely in many areas such as chemical reactor theory, aerodynamics, quantum mechanics, reaction-diffusion process, optimal control, etc. A combination of the cubic B-spline base functions as an approximation function is used to build up the presented method over the geometrically graded mesh. Thus finer mesh can be established through the end parts of the problem domain where steep solutions exist.
A new acoustic impact-echo testing device has been developed for detecting and mapping delaminations in concrete bridge decks at highway speeds. The apparatus produces nearly continuous acoustic excitation of concrete...
A new acoustic impact-echo testing device has been developed for detecting and mapping delaminations in concrete bridge decks at highway speeds. The apparatus produces nearly continuous acoustic excitation of concrete bridge decks through rolling mats of chains that are placed around six wheels mounted to a hinged trailer. The wheels approximately span the width of a traffic lane, and the ability to remotely lower and raise the apparatus using a winch system allows continuous data collection without stationary traffic control or exposure of personnel to traffic. Microphones near the wheels are used to record the acoustic response of the bridge deck during testing. In conjunction with the development of this new apparatus, advances in the algorithms required for data analysis were needed. This paper describes the general framework of the algorithms developed for converting differential global positioning system data and multi-channel audio data into maps that can be used in support of engineering decisions about bridge deck maintenance, rehabilitation, and replacement (MR&R). Acquisition of position and audio data is coordinated on a laptop computer through a custom graphical user interface. All of the streams of data are synchronized with the universal computer time so that audio data can be associated with interpolated position information through data post-processing. The audio segments are individually processed according to particular detection algorithms that can adapt to variations in microphone sensitivity or particular chain excitations. Features that are greater than a predetermined threshold, which is held constant throughout the analysis, are then subjected to further analysis and included in a map that shows the results of the testing. Maps of data collected on a bridge deck using the new acoustic impact-echo testing device at different speeds ranging from approximately 10 km/h to 55 km/h indicate that the collected data are reasonably repeatable. Use of
An automated acoustic impact-echo testing device with seven channels has been developed for faster surveying of bridge decks. Due to potential variations in bridge deck overlay thickness, varying conditions between te...
An automated acoustic impact-echo testing device with seven channels has been developed for faster surveying of bridge decks. Due to potential variations in bridge deck overlay thickness, varying conditions between testing passes, and occasional imprecise equipment calibrations, a method that can account for variations in deck properties and testing conditions was necessary to correctly interpret the acoustic data. A new methodology involving statistical analyses was therefore developed. After acoustic impact-echo data are collected and analyzed, the results are normalized by the median for each channel, a Gaussian distribution is fit to the histogram of the data, and the Kullback-Leibler divergence test or Otsu’s method is then used to determine the optimum threshold for differentiating between intact and delaminated concrete. The new methodology was successfully applied to individual channels of previously unusable acoustic impact-echo data obtained from a three-lane interstate bridge deck surfaced with a polymer overlay, and the resulting delamination map compared very favorably with the results of a manual deck sounding survey.
An equipment for calibrating three earth pressure cells simultaneously is proposed in this article, which including the first level drum, the second level drum, the third level drum, loading platform and weighting blo...
An equipment for calibrating three earth pressure cells simultaneously is proposed in this article, which including the first level drum, the second level drum, the third level drum, loading platform and weighting blocks. The earth pressure cell is placed in the circular placing groove of drum, and the signal transmission line of earth pressure cell is embedded in the wire slot of drum and extended to outside of drum. The second level drum is embedded in the upper of the first level drum, the third level drum is embedded in the upper of the second level drum, and the loading platform is embedded in the upper of the third level drum. Three earth pressure cells could be calibrated simultaneously by adding weighting blocks gradually on the loading platform.
Superconducting Magnetic Energy Storage (SMES) technology is attracting scientists as an alternative in energy storage technologies since superconducting materials incorporated in SMES have a potential to overcome cha...
Superconducting Magnetic Energy Storage (SMES) technology is attracting scientists as an alternative in energy storage technologies since superconducting materials incorporated in SMES have a potential to overcome challenges related to increase in electric load demand, power security, transmission control and stabilization. Due to fast response and high energy densities characteristics, SMES can work efficiently while stabilizing the power grid. Solenoidal configuration has been widely employed in the development of SMES prototypes as it is simpler to manufacture and allows an easier handling of the mechanical stresses imposed on the structure due to Lorentz forces. Moreover, it has been found that this configuration allows minimum wire consumption and represents the most cost effective solution for isotropic superconductors. In the present work, solenoidal configuration has been employed in the development of 1MJ SMES Magnet using 2G (SuperPower, YBCO having Tc=90K @0T) High Temperature Superconducting (HTS) tape. The superconducting tape has been cooled at 14K using conduction cooling. A reference field of 3.5T has been considered in the development of electromagnetic design of superconducting magnet and its effect on the total number of turns around the solenoidal magnet for various aspect ratios have been studied. An electromagnetic analysis has been done on 1MJ SMES having aspect ratio 5. The effect of maximum operating current (650A, 1300A and 1950A) on the length of superconductor has also been evaluated for a constant deliverable energy of 1MJ. Maximum Lorentz forces (N/m3) have been evaluated in the superconducting domain as these can result into structural instabilities. The extent of average force (N) imposed on the SC tape has also been evaluated. It has been concluded that it would be beneficial to operate at higher currents as it can reduce the total length of the superconductor.
This study is undertaken to investigate the effect of segmental heating on the porous annulus having embedded with two solid walls at two radii. The heat transfer from hot surface to cold surface is analyzed with resp...
This study is undertaken to investigate the effect of segmental heating on the porous annulus having embedded with two solid walls at two radii. The heat transfer from hot surface to cold surface is analyzed with respect to half of the annulus being heated at inner radius and outer radius subjected to cooling temperature. The appropriate governing equations are solved numerically using finite element method. It is found that the thermal conductivity ratio of two solids being implanted on annulus plays a vital role in determining the heat transfer behavior of whole domain.
Vertical electrical impedance scanning of concrete bridge decks is a non-destructive method for quantifying the degree of protection provided to steel reinforcement against the ingress of corrosive agents. Four concre...
Vertical electrical impedance scanning of concrete bridge decks is a non-destructive method for quantifying the degree of protection provided to steel reinforcement against the ingress of corrosive agents. Four concrete bridge decks with asphalt overlays in northern Utah were evaluated using scanning vertical electrical impedance measurements in this study. At the time of testing, the bridges ranged in age from 21 to 34 years, and asphalt overlays had been in place for 7 to 22 years, depending on the bridge. Electrical impedance measurements were collected using a previously constructed apparatus that consisted of six probes spanning a transverse distance of 12 ft. The impedance measurements were compared to surface cracking observations and cores obtained from the same four bridge decks. The results presented in this paper demonstrate the utility of scanning vertical electrical impedance measurements for detecting cracks in asphalt overlays and quantifying their severity. In addition, the results demonstrate the sensitivity of impedance measurements to the presence of an intact membrane beneath the asphalt overlay.
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