3,732 research outputs found
Water distribution rules and water distribution performance: a case study in the Tambraparani Irrigation System
Irrigation management / Irrigation systems / Performance / Irrigation operation / Irrigation scheduling / Water distribution / Water allocation / Water delivery / Water users' associations / Legislation / Large-scale systems / Bananas / Case studies / India / Tamil Nadu / Tambraparani Irrigation System
A study of methods of prediction and measurement of the transmission of sound through the walls of light aircraft
The acoustic intensity technique was applied to the sound transmission loss of panel structures (single, composite, and stiffened). A theoretical model of sound transmission through a cylindrical shell is presented
Varying Vector Pulse Width Modulation for Three Phase Inverter
This paper mainly deals with designing a control scheme to eliminate the OFF STATE (T0 state) present in a Space Vector Pulse-Width Modulation; this has been achieved by redesigning the equations for calculating the reference vector of modulating signal (Vref). In widely used Space Vector Pulse Width Modulation Vmax of carrier signal is greater than Vref of modulating signal (except when Vref = Vmax). Thus during this state the drive goes into the OFF STATE (T0 state). T0 States are similar mirror image states; hence they have no good or bad effect on the system. But there is an amount of switching loss occurring when the switch executes the T0 state. The new equations for reference vector resulted in reducing the switching losses to half the actual value. Also it has various other advantages like. Increase in DC-Link utilization from 15.47 to 21.14 at 2 KHz carrier frequency and Reduction in THD of the system compared to widely used SVPWM
A re-evaluation of finite-element models and stress-intensity factors for surface cracks emanating from stress concentrations
A re-evaluation of the 3-D finite-element models and methods used to analyze surface crack at stress concentrations is presented. Previous finite-element models used by Raju and Newman for surface and corner cracks at holes were shown to have ill-shaped elements at the intersection of the hole and crack boundaries. These ill-shaped elements tended to make the model too stiff and, hence, gave lower stress-intensity factors near the hole-crack intersection than models without these elements. Improved models, without these ill-shaped elements, were developed for a surface crack at a circular hole and at a semi-circular edge notch. Stress-intensity factors were calculated by both the nodal-force and virtual-crack-closure methods. Both methods and different models gave essentially the same results. Comparisons made between the previously developed stress-intensity factor equations and the results from the improved models agreed well except for configurations with large notch-radii-to-plate-thickness ratios. Stress-intensity factors for a semi-elliptical surface crack located at the center of a semi-circular edge notch in a plate subjected to remote tensile loadings were calculated using the improved models. The ratio of crack depth to crack length ranged form 0.4 to 2; the ratio of crack depth to plate thickness ranged from 0.2 to 0.8; and the ratio of notch radius to the plate thickness ranged from 1 to 3. The models had about 15,000 degrees-of-freedom. Stress-intensity factors were calculated by using the nodal-force method
Studies of new media radiation induced laser
Various lasants were investigated especially, 2-iodohepafluoropropane (i-C3F7I) for the direct solar pumped lasers. Optical pumping of iodine laser was achieved using a small flashlamp. Using i-C3F7I as a laser gain medium, threshold inversion density, small signal gain, and laser performance at the elevated temperature were measured. The experimental results and analysis are presented. The iodine laser kinetics of the C3F7I and IBr system were numerically simulated. The concept of a direct solar-pumped laser amplifier using (i-C3F7I) as the laser material was evaluated and several kinetic coefficients for i-C3F7I laser system were reexamined. The results are discussed
Recruitment of the Fouling Bivalve, Mytilopsis sallei (Recluz), on Metallic and Nonmetallic Surfaces at Visakhapatnam Harbor, India
In 1967, the dreissinid bivalve, Mytilopsis saUei (Recluz), was first noticed in Indian waters at the Southern Lighter Channel of Visakhapatnam
harbor, Andhra Pradesh, India. It is believed that his species was introduced into the Indo-Pacific region from Central America via the Panama
Canal and Fiji through ship foulin
Estimation of serum glutamic oxaloacetic transaminase, serum glutamic-pyruvic transaminase, gamma-glutamyl transferase and cholesterol levels in prolonged (30 years) daily consumption coffee in people
Background: Although prolonged (30years) coffee consumption has been associated with reduced or increased frequency of liver (SGOT, SGPT, GGT) enzymes and cholesterol levels, it is unclear whether the effect is from coffee or caffeine.Methods: A self-administered questionnaire ascertained lifestyle characteristics, including alcohol consumption, cigarette smoking, Diabetes mellitus and Dietary habits. As for drinking habit, examinees were first asked about their current drinking frequency (none, 1-2 times/ week, or almost daily) past or current smokers about the number of cigarettes smoked per day and the duration of smoking in years. As regards coffee, examinees were asked their usual daily intake in cups.Results: A total No of 200 cases were studied by dividing them into two group’s controls and cases. The results so obtain were compared with 50 healthy controls (not to consumed caffeine contained things that include nor coffee, tea, any type of cola’s). Statistical evaluation was carried out to confirm any deviation from the normal values. In men the mean serum SGOT, SGPT, GGT and cholesterol of cases is having higher level as compared to the mean value of controls. This increase is statistically highly significant (SGOT<0.0001, SGPT=0.045, GGT=0.0043, cholesterol<0.0001). In women’s the mean serum SGOT, SGPT, GGT and cholesterol of Cases is having higher level as compared to the mean value of Controls. This increase is statistically significant (SGOT< 0.05, SGPT=0.0319, GGT <0.0001, cholesterol: <0.0001).Conclusion: It has been shown from this study that prolonged daily consumption of coffee in many people it results increasing of levels of serum concentrations of the SGOT, SGPT, GGT and Cholesterol. It is observed that liver enzymes and cholesterol could be a target for caffeine or other components of coffee.
Influence of light on serum cholesterol levels in complete (by birth) blind people
Background: With blindness normal stimulation of the hypothalamic pituitary axis is reduced. The serum cholesterol is frequently increased the upper limit of normal it is unclear whether the effect is due to complete absence of light, HPA axis function reduction or diurnal variation of melatonin levels.Methods: A self-administered questionnaire ascertained lifestyle characteristics, including alcohol consumption, cigarette smoking, diabetes mellitus and dietary habits. Inclusion criteria: 50 complete blindness persons (by birth), healthy adults, Age group between 30-50 years. Exclusion area: age 50, alcoholic, liver diseases, kidney diseases, diabetes mellitus, thyroid diseases.Results: A total No of 100 cases were studied by dividing them into two groups controls 50 and cases 50. The results so obtain were compared with 50 healthy controls (excluded consumed alcoholic, liver diseases, kidney diseases, diabetes mellitus, thyroid diseases.). Statistical evaluation was carried out to confirm any deviation from the normal values. The mean serum cholesterol of Cases (298.28±26.82) is having higher level as compared to the mean value of controls (153.38±11.79). This increase is statistically highly significant (<0.0001).Conclusions: It has been shown from this study with blindness normal stimulation of the HPA is reduced consequently the serum cholesterol is frequently increased the concentration may exceed the upper limit of normal. On this basis we observed increases the upper limit of the cholesterol levels in blind healthy people than subjects with normal healthy light perception
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