2,091 research outputs found
Quality of Root Canal Obturation Performed by Senior Undergraduate Dental Students
The aim of the present study was to assess the quality of canal obturation performed by undergraduate denal students at Saveetha Dental College and Hospitals, Chennai. Records of 200 endodontically treated teeth from patients who were visited by undergraduate students between month of November 2014 to May 2015. Periapical radiographs of all treated teeth were assessed in terms of canal obturation quality (adequate density and length). Forty-five percent of teeth fulfilled the criteria of an acceptable root canal obturation. Adequate length and density of root filling was found in 89% and 34% of teeth, respectively. There was a significant difference between maxillary and mandibular teeth regarding the length of root canal obturation. A significant difference was observed between molars and other tooth types. The frequency of root canals with an acceptable filling was significantly greater in the anterior teeth compared to premolars or molars. The technical quality of root canal treatment performed by undergraduate dental students was found to be less than ideal
Flutter parametric studies of cantilevered twin-engine transport type wing with and without winglet. Volume 2: Transonic and density effect investigations
Flutter characteristics of a cantilevered high aspect ratio wing with winglet were investigated. The configuration represented a current technology, twin engine airplane. Compressibility effects through transonic Mach numbers and a wide range of mass-density ratios were evaluated on a low speed and high speed model. Four flutter mechanisms were obtained from test, and analysis from various combinations of configuration parameters. It is shown that the coupling between wing tip vertical and chordwise motions have significant effect under some conditions. It is concluded that for the flutter model configurations studied, the winglet related flutter is amenable to the conventional flutter analysis techniques. The low speed model flutter and the high-speed model flutter results are described
Bhoi Khasi Compared to Standard Khasi
The paper briefly documents the Bhoi variety of Khasi, in comparison with the standard variety
eta-Einstein (k, mu)-Space Forms
In this paper we obtain the scalar curvatures of a (k, mu)-space form under h-projective, phi-projective semi symmetric and h-Weyl and phi-Weyl semisymmetry conditions
Effects of winglet on transonic flutter characteristics of a cantilevered twin-engine-transport wing model
A transonic model and a low-speed model were flutter tested in the Langley Transonic Dynamics Tunnel at Mach numbers up to 0.90. Transonic flutter boundaries were measured for 10 different model configurations, which included variations in wing fuel, nacelle pylon stiffness, and wingtip configuration. The winglet effects were evaluated by testing the transonic model, having a specific wing fuel and nacelle pylon stiffness, with each of three wingtips, a nonimal tip, a winglet, and a nominal tip ballasted to simulate the winglet mass. The addition of the winglet substantially reduced the flutter speed of the wing at transonic Mach numbers. The winglet effect was configuration-dependent and was primarily due to winglet aerodynamics rather than mass. Flutter analyses using modified strip-theory aerodynamics (experimentally weighted) correlated reasonably well with test results. The four transonic flutter mechanisms predicted by analysis were obtained experimentally. The analysis satisfactorily predicted the mass-density-ratio effects on subsonic flutter obtained using the low-speed model. Additional analyses were made to determine the flutter sensitivity to several parameters at transonic speeds
Quality Assessment of concrete utilizing treated waste water
concrete is the most extensively used construction material. Every year about 1.5 to 3 tonne/capita of concrete being produced using fresh water in developing countries. Approximately about 150 litres of portable water is required for producing 1m3 of concrete [1]. The present use of portable water for the preparation of concrete imposes a heavy burden on the cost of production, especially at places where there is high demand and shortage of supply of portable water for domestic consumption. Hence measures to be taken to conserve portable water as much as possible to prevent the shortage in the future. A practical solution would be the use of treated effluent from the wastewater treatment plant for concrete production, which will economically benefit the construction industries and conserve portable water.
The suitability of using wastewater for mixing in concrete was experimentally studied by moulding the concrete cubes using tap water (TW), treated wastewater (TWW). From the results it was observed that standard consistency, setting time and strength of concrete are found to be satisfactory in compression strength.
The average compressive strength was also being posh by the type of mixing water. It was found that the compressive strength of cubes obtained from TWW is almost same as that of TW. Hence, from this study it is concluded that treated wastewater (TWW) can be used in place of tap water for production of concrete. The environmental degradation can be reduced by using the treated effluent for concrete production and cost of the concrete can be reduced considerably. Hence, portable water can be conserve
A Critique of Drexler Dark Matter
Drexler dark matter is an alternate approach to dark matter that assumes that
highly relativistic protons trapped in the halo of the galaxies could account
for the missing mass. We look at various energetics involved in such a scenario
such as the energy required to produce such particles and the corresponding
lifetimes. Also we look at the energy losses from synchrotron and inverse
Compton scattering and their signatures. The Coulomb repulsive instability due
to the excess charge around the galaxies is also calculated. The above results
lead us to conclude that such a model for DM is unfeasible.Comment: 4 pages, 10 equation
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