3,541 research outputs found

    Estimation of Demand Elasticity for Food Commodities in India

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    The food demand in India has been examined in the context of a structural shift in the dietary pattern of its population. The results have reinforced the hypothesis of a significant diversification in the dietary pattern of households in recent years and has found stark differences in the consumption pattern across different income quartiles. The food demand behaviour has been explained using a set of demand elasticities corresponding to major food commodities. The demand elasticities have been estimated using multi-stage budgeting with QUAIDS model and another alternative model, FCDS. The study has revealed that the estimated income elasticities vary across income classes and are lowest for cereals group and highest for horticultural and livestock products. The analysis of price and income effects based on the estimated demand system has suggested that with increase in food price inflation, the demand for staple food (rice, wheat and sugar) may not be affected adversely but, that of high-value food commodities is likely to be affected negatively. Therefore, the study has cautioned that if inflation in food prices remains unabated for an extended period, there is the possibility of reversal of the trend of diversification and that of consumers returning to cereal-dominated diet, thus accentuating under-nourishment.Food demand, Demand elasticity, QUAIDS model, FCDS model, Household food demand, Agricultural and Food Policy, Q11, Q18,

    A Transport Study of Sodium Phosphate Dodecahydrate Pipeline Plugging Mechanisms

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    The thesis investigates pipeline plugging mechanisms that have occurred during interim stabilization transfers at Hanford. A laboratory-scale saltwell pumping test loop was designed to evaluate a surrogate of Hanford Tank 241-SX-104 supernate. The effect of surrogate flow rate, cooling water flow rate and phosphate concentrations on plugging mechanisms was investigated. Critical parameters like particle and agglomerate size, velocity and bed growth rate were determined. Theoretical models were used to compare the experimental pressure rise and temperature drop of the surrogate in the channel. An operating region in which a plug would not form was developed, based on the experimental results. Experiments are also reported on plug remediation. Unplugging experiments at varying pump pressure heads and residence time of plug in the line were performed

    Role and efficacy of vaginal dinoprostone gel (PGE2) plus vaginal misoprostol (PGE1) in second trimester termination of pregnancy

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    Background: The addition of dinoprostone gel (PGE2) to standard regimen of second trimester abortion using vaginal misoprostol (PGE1) reduces failure rate and decrease induction abortion time interval. We evaluated the role and efficacy of vaginal dinoprostone gel with vaginal misoprostol in women undergoing second trimester abortion. Objective of present study was to assess the safety and effectiveness of vaginal dinoprostone gel plus vaginal misoprostol for second trimester termination of pregnancy.Methods: This study was a prospective cohort involving 100 women with 12-20 weeks gestation requesting termination of pregnancy. In study group 0.5mg dinoprostone gel applied vaginally followed by 400µg misoprostol every four hourly (max 3 doses) after six hours of dinoprostone gel application. The mean age of the women study was 27.2 years and mean gestational age was 18.9 weeks. The primary effectiveness of the study was the efficacy of the treatment to terminate pregnancy at 20 hrs. Secondary outcomes were induction abortion interval, failure rate, side effects. statistical analysis of study was carried out using chi square test.Results: At 20 hours, the complete abortion rate was 100%. Within 16 hours 98% women aborted without any significant side effects. Mean induction abortion interval was 14.56 hours.Conclusions: Combination of vaginal dinoprostone gel (PGE2) plus misoprostol (PGE1) is effective, safe and alternate method for second trimester pregnancy termination with. In this protocol induction to abortion interval time is less as compared to other methods of second trimester pregnancy termination

    Efficient Modeling and Simulation of Wavelength Division Multiplexing Dual Polarization QPSK Optical Fiber Transmission

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    Due to enormous growth in communications, wavelength division multiplexing (WDM) systems are popular because these systems allow us to expand the capacity of the networks without laying more optical fiber cables. In this thesis, we have systematically derived the coupled nonlinear Schrödinger (CNLS) equations, including a consistent definition of the complex envelope, Fourier transform, the state of polarization, and derivation under the engineering notation. After a discussion of coarse step based second order symmetrized split-step Fourier (SSSF) simulation method, which is applicable to the numerical solution of the CNLS equations, an analytical step-size selection based local error method is applied to the WDM optical fiber communication systems. With systematical simulation study of both standard single mode fiber (SSMF) fiber links and true-wave reduced slope (TWRS) fiber links. It is found that similar to the single channel systems, the global simulation accuracy for the vector propagation can be satisfied using the local error bound (LEB) obtained from a scalar propagation model for the same global error over a large range of simulation accuracy and differential group delay (DGD). Furthermore, carefully designed numerical simulations are used to show that the proposed local error method leads to higher computational efficiency compared to other prevalent step-size selection schemes in vector WDM simulations. The scaling of the global simulation error with respect to the number of optical fiber spans is demonstrated, and global error control for multi-span WDM simulations is proposed

    Efficient Modeling and Simulation of Wavelength Division Multiplexing Dual Polarization QPSK Optical Fiber Transmission

    Get PDF
    Due to enormous growth in communications, wavelength division multiplexing (WDM) systems are popular because these systems allow us to expand the capacity of the networks without laying more optical fiber cables. In this thesis, we have systematically derived the coupled nonlinear Schrödinger (CNLS) equations, including a consistent definition of the complex envelope, Fourier transform, the state of polarization, and derivation under the engineering notation. After a discussion of coarse step based second order symmetrized split-step Fourier (SSSF) simulation method, which is applicable to the numerical solution of the CNLS equations, an analytical step-size selection based local error method is applied to the WDM optical fiber communication systems. With systematical simulation study of both standard single mode fiber (SSMF) fiber links and true-wave reduced slope (TWRS) fiber links. It is found that similar to the single channel systems, the global simulation accuracy for the vector propagation can be satisfied using the local error bound (LEB) obtained from a scalar propagation model for the same global error over a large range of simulation accuracy and differential group delay (DGD). Furthermore, carefully designed numerical simulations are used to show that the proposed local error method leads to higher computational efficiency compared to other prevalent step-size selection schemes in vector WDM simulations. The scaling of the global simulation error with respect to the number of optical fiber spans is demonstrated, and global error control for multi-span WDM simulations is proposed

    Performance evaluations of latex-modified and silica fume modified concrete overlays for bridge decks

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    Most of the concrete bridge decks in the cold regions undergo severe reinforcement corrosion due to the transport of chloride ions within the concrete by application of deicing salts on bridge decks in the winter. As a result, protective concrete overlays of about 2-inch thickness are applied on bridge decks. Concrete overlays provide: (1) protection against heavy traffic and the further infiltration of the chloride ions; (2) skid resistance surface; and (3) uniform appearance to extend the service life of bridge decks. Despite these advantages, concrete overlays undergo premature delaminations, edge curling, and corner lifting due to expansion/shrinkage of concrete, temperature changes, and repetitive truck loading.;This research work is a part of Phase-II component of a large-scale project sponsored by WVDOH which is focused on the performance evaluation of Latex Modified Concrete (LMC) and Silica Fume Modified Concrete (SFMC) overlays on Type K substrate concrete deck prototypes. This work evaluated four prototype slabs in two stages with each slab of plan size 1829 mm. (6 ft.) by 2438 mm. (8 ft.). In Stage-I, two bi-layer deck slabs were constructed with the same LMC overlay but with two different bonding conditions. Considering the better bonding condition from Stage-I, Stage-II consisted of two bi-layer deck slabs that were constructed with LMC overlay on one slab and SFMC overlay on the other. Pull-Off testing was conducted at different ages for assessing the bond performance of the overlays. The differential length change and differential temperature developed at the interface were continuously monitored using concrete embedment gages and thermocouple loggers, respectively. Debonding due to corner lifting was monitored by installing displacement transducers (LVDT) connected to a data acquisition system. Ultrasonic Pulse Velocity (UPV) testing was conducted to compare the delamination profile at the interface between different types of slabs. Simultaneously with the UPV tester, an oscilloscope was connected to record the time-domain waveform, which was converted into a power spectrum for analysis.;The Stage-I study showed that at 5% level of significance, both the interface bond strength of the LMC slab with and without bonding slurry were similar. However, the other critical delamination parameters such as differential length changes at the interface and vertical displacement due to corner lifting were much less when bonding slurry was incorporated. Also, the time-domain waveform of LMC with bonding slurry showed less attenuation of wave through the interface compared to no-slurry LMC. Further, the frequency spectrum analysis displayed that LMC with bonding slurry had higher peak magnitude compared to LMC without bonding slurry. Based on the results, the use of bonding slurry was preferred for the Stage-II study. This study showed that in-situ pull-off/bond strength results and nature of failure varied widely due to presence of local voids, compaction, and consolidations.;In Stage-II study where the bonding slurries were used for each case, the results showed that the bond strength values of slab with LMC overlay were higher than those of the slab with SFMC overlay, at 5% level of significance as analyzed by three-way ANOVA. The vertical displacement due to corner lifting was found to be lower for the slab with LMC overlay. The time-domain signal indicated that the amplitudes of LMC overlay were higher compared to those of SFMC overlay. Further, the power spectrum analysis showed that LMC had higher magnitude of peaks both at center and edge compared to SFMC overlays indicating the strength of the signals were stronger for LMC compared to SFMC.;The overall conclusion of this study is that the bonding slurry has positive effect to reduce delamination and corner lifting; and when slurry is used, the LMC has advantages over SFMC, although both overlay types are viable options. A full-scale study is required in order to conclude the findings and finally develop a performance based specifications for the overlays for the state of West Virginia

    Regulating the Use of Commercial Drones: Quest for Finding A Space Within Airspace – An Asian Perspective

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    The advent of Unmanned Aerial Vehicle (UAV) has significantly affected the navigational route of the existing aviation system. Though there are sufficiently developed air routes for national and international flights, the drones have become a threat or at least an encroachment upon those peaceable use of the air navigational routes. At several reported instances, close collisions of aircraft and drones got averted that would have otherwise caused severe disturbances to the paths of the aircraft. On the request of its Member-States, the International Civil Aviation Organisation (ICAO) has developed a model for drone regulations. However, such regulations need uniformity and consanguinity among national regulations that  complement global initiatives. Thus, this paper seeks to analyze the prevalent Asian practices on drone regulations. Since the technology has got its imminence in Asian markets such as Hong Kong and Singapore with future scope for other Asian countries, the authors make a comparative analysis of “policies” of Asian countries, with the policies of the European Union and the United States. In conclusion, the paper prefers an argument for developing a dedicated Unmanned Aircraft Systems (UAS) for drones within the currently available flying zones so that any future misfortunes could be averted. Keywords: Drones, Asia, International, Policy, Navigation, Regulation. DOI: 10.7176/JAAS/71-05 Publication date: April 30th 202
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