2,246 research outputs found

    Analysis of Regenerative System in Steam Power Plant

    Full text link
    The development of any country directly relates on capital energy consumption. The demand for power generation on the large scale is increasing day by day. Owing to their major contribution towards power production, thermal power plants have a vital role to play in the development of nation. Due to the scarcity of power, every power plant needs to be operated at maximum level of efficiency. In case of thermal power plants this applies equally to all its auxiliaries. The feed water heaters form a part of the regenerative system to increase the overall thermal efficiency of the plant. In the operation and maintenance of a power plant the feed water heaters are virtually neglected compared with other components. To realize the effect of feed water heating and an attempt is made in this project work to find the improvement in cycle efficiency due to FWH.nbs

    Comparisons of various configurations of the edge delamination test for interlaminar fracture toughness

    Get PDF
    Various configurations of Edge Delamination Tension (EDT) test specimens, of both brittle (T300/5208) and toughened-matrix (T300/BP907) graphite reinforced composite laminates, were manufactured and tested. The mixed-mode interlaminar fracture toughness, G sub C, was measured using (30/30 sub 2/30/90 sub N)sub s, n=1 or 2, (35/-35/0/90) sub s and (35/0/-35/90) sub s layups designed to delaminate at low tensile strains. Laminates were made without inserts so that delaminations would form naturally between the central 90 deg plies and the adjacent angle plies. Laminates were also made with Teflon inserts implanted between the 90 deg plies and the adjacent angle (theta) plies at the straight edge to obtain a planar fracture surface. In addition, interlaminar tension fracture toughness, GIc, was measured from laminates with the same layup but with inserts in the midplane, between the central 90 deg plies, at the straight edge. All of the EDT configurations were useful for ranking the delamination resistance of composites with different matrix resins. Furthermore, the variety of layups and configurations available yield interlaminar fracture toughness measurements needed to generate delamination failure criteria. The influence of insert thickness and location, and coupon size on G sub c values were evaluated

    Level of physical activity, determinants and barriers to motivate physical activities among south Indian diabetic patients: a prospective, questionnaire based study

    Get PDF
    Background: Several clinical trials have been reported that sedentary lifestyle modification including physical activity (PA) and weight loss significantly alters the sort-term as well as long-term incidence of diabetes. The present study explored the level of physical activity and its barriers among south Indian naïve patients who are attending the tertiary care teaching hospital.Methods: A prospective observational, questionnaire-based study. Patients with diabetes (both Type-1 and 2) who were attended diabetic clinic in the Department of General Medicine, Maharaja Institute of Medical Sciences (MIMS), Vijayanagaram, Andhra Pradesh, India was selected and recruited. Demographic data, clinical data were collected from the study participants. International Physical Activity questionnaire was used to determine each patient level of physical activity (PA). Physical activity is graded into low (3000 MET).Results: A total of 300 subjects were completed the entire study. Majority (62.7%) of the patients were suffering from Type-2 diabetes mellitus. Both male and female study subjects had low physical activity (70.5% and 74.1%) and moderate PA was seen in only one thirds of the patients. Patients with low physical activity had low glycaemic control compared to patients who were involved in moderate PA. Moderate PA patients had adequate glycaemic control (65.9 vs 34.1%, P <0.001). A total of 42.0% of subjects were suffering from one of the joint pains and friction joints, due to the following reason subjects were not involved in the PA.Conclusions: Low level of physical activity was observed in the study population, which is a risk factor for several micro-vascular complications over a period of time. It is very important to address the barriers of PA and vigorous counselling is needed which directs towards increasing PA

    Variability in stratification and flushing times of the Gautami–Godavari estuary, India

    Get PDF
    In order to examine the influence of forcing (river flow and tides) and anthropogenic activities (dredging and dam regulation) on stratification, a study was conducted over a period of 19 months (June 2008–December 2009) in the Gautami–Godavari estuary (G–GE) during spring and neap tide periods covering entire spectrum of discharge over a distance of 36 km from the mouth. The bathymetry of the estuary was recently changed due to dredging of &#8764;20 km of the estuary from the mouth for transportation of barges. This significantly changed the mean depth and salinity of the estuary from its earlier state. The variations in the distribution of salinity in the Godavari estuary are driven by river discharge during wet period (June–November) and tides during dry period (December–May). The weak stratification was observed during high discharge (July–August) and no discharge (January–June) periods associated with dominant fresh water and marine water respectively. The strong stratification was developed associated with decrease in discharge during moderate discharge period (October–December). Relatively stronger stratification was noticed during neap than spring tides. The 15 psu isohaline was observed to have migrated &#8764;2–3 km more towards upper estuary during spring than neap tide suggesting more salt enters during former than latter period. Total salt content was inversely correlated with river discharge and higher salt of about 400×106 m3 psu was observed during spring than neap tide. Flushing times varied between less than a day and more than a month during peak and no discharge periods respectively with lower times during spring than neap tide. The flushing times are controlled by river discharge during high discharge period, tides during dry period and both (river discharge and tides) under moderate discharge period. This study suggests that modification of discharge, either natural due to weak monsoon or artificial such as dam constructions and re-routing the river flow, may have significant impact on the stratification and biogeochemistry of the Godavari estuary

    Static Critical Behavior of the Spin-Freezing Transition in the Geometrically Frustrated Pyrochlore Antiferromagnet Y2Mo2O7

    Full text link
    Some frustrated pyrochlore antiferromagnets, such as Y2Mo2O7, show a spin-freezing transition and magnetic irreversibilities below a temperature Tf similar to what is observed nonlinear magnetization measurements on Y2Mo2O7 that provide strong evidence that there is an underlying thermodynamic phase transition at Tf, which is characterized by critical exponents \gamma \approx 2.8 and \beta \approx 0.8. These values are typical of those found in random spin glasses, despite the fact that the level of random disorder in Y2Mo2O7 is immeasurably small.Comment: Latex file, calls for 4 encapsulated postscript figures (included). Submitted to Phys. Rev. Letters

    The Spectrum of Yang Mills on a Sphere

    Full text link
    In this note, we determine the representation content of the free, large N, SU(N) Yang Mills theory on a sphere by decomposing its thermal partition function into characters of the irreducible representations of the conformal group SO(4,2). We also discuss the generalization of this procedure to finding the representation content of N=4 Super Yang Mills.Comment: 18 pages v2. references added. typos fixe

    Rational Terms in Theories with Matter

    Full text link
    We study rational remainders associated with gluon amplitudes in gauge theories coupled to matter in arbitrary representations. We find that these terms depend on only a small number of invariants of the matter-representation called indices. In particular, rational remainders can depend on the second and fourth order indices only. Using this, we find an infinite class of non-supersymmetric theories in which rational remainders vanish for gluon amplitudes. This class includes all the "next-to-simplest" quantum field theories of arXiv:0910.0930. This provides new examples of amplitudes in which rational remainders vanish even though naive power counting would suggest their presence.Comment: 10+4 pages. (v2) typos corrected, references adde
    • …
    corecore