Full simulation for the Qweak experiment at 1.16 and 0.877 GeV and their impact on extracting the PV asymmetry in the N→Δ a transition

The Qweak project is seeking to find new physics beyond the Standard Model. It is aimed to measure the weak charge of the proton, which has never been measured, at 4% precision at low momentum transfer. The experiment is performed by scattering electrons from protons and exploiting parity violation in the weak interaction at low four-momentum transfer. In this experiment, two measurements were considered: which are elastic and inelastic. The elastic is to measure the proton\u27s weak charge. In addition, the inelastic asymmetry measurement, which will extract the low energy constant dΔ. That measurement works in the neutral current sector of the weak interaction. Qweak measures the asymmetry in the N→ Δ transition. Because the elastic radiative tail gives a dominant contribution to the uncertainty to the N→ Δ asymmetries, this thesis will discuss the radiative correction. In addition, this thesis will describe in details the extensive simulations preformed to determine the impact of all simulated background processes on extracting the PV N→ Δ asymmetries. In the process of verifying the validity of these background fractions, we determined the best value of a quantity measured during the Qweak experiment: the beam normal single spin asymmetry, Bn, in the N→ Δ transition

Enclosure enhancement of flight performance

We use a potential flow solver to investigate the aerodynamic aspects of flapping flights in enclosed spaces. The enclosure effects are simulated by the method of images. Our study complements previous aerodynamic analyses which considered only the near-ground flight. The present results show that flying in the proximity of an enclosure affects the aerodynamic performance of flapping wings in terms of lift and thrust generation and power consumption. It leads to higher flight efficiency and more than 5% increase of the generation of lift and thrust. © 2014 The Chinese Society of Theoretical and Applied Mechanics

Experimental study for air cooling using membrane covered tray

An experimental study is conducted to cool the outdoor air using a humidification technique. A wind tunnel was built with a membrane covered tray serves as a test section. An outdoor air passes over a tray full of water and covered with a specific membrane. Air temperatures and relative humidity are measured before and after the tray for several air and water speeds. Air speed is measured at different locations along the centerline of the cross section. Results show that as the angle of the tray increases the air temperature drop increases which improve the efficiency of the humidification technique. This enhancement is reflected by a maximum and minimum temperature drop of 7.52 and 2.41oC respectively. Results also show that as the tray angle increases the air relative humidity increases as expected

An artificial neural network approach to modelling absorbent asphalts acoustic properties

Sound-absorbing asphalts are particularly useful for reducing noise emissions from vehicular traffic. This solution is perfectly suited for urban areas, in fact the use of sound-absorbing asphalt represents a noise control measure with a negligible environmental impact. In the present work, the results of an experimental investigation on sound-absorbing asphalts were reported. First, the characteristics of the sound-absorbing asphalts used were experimentally found. Then, the measurements of the sound absorption coefficient of the asphalt specimens were investigated. In the final part, numerical simulation model with artificial neural networks of the acoustic coefficient were compared with the data obtained from the measurements. The neural network model showed good Pearson correlation coefficient values (0.894) which can be used with good accuracy to predict the sound absorption coefficient

Numerical simulation of GE 7001 EA gas turbine using experimental data for compressor inlet air cooling

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.In this paper computer Simulation of GE 7001 EA gas turbine that widely used in the kingdom of Saudi Arabia is reported. Simulation is done using cooled air data obtained previously from different experiments. These data are used as input to the compressor to see its effect on the output power and efficiency of the gas turbine. GE 7001EA gas turbine, (GE7121EA models) is simulated using THERMOFLEX software. The specifications of this type of turbines are built in this software. This type of gas turbine model is used in Riyadh and Taif power stations. ISO conditions and actual weather conditions are used for simulations. The results show that the maximum increase in the net power output is about 12, 6 and 5.8% depend on the used cooling data. On the other hand, the maximum percentage increase in efficiency is turned to about 2.5, 1.3 and 0.9 respectively.cf201

Q

The Qweak experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q2 = 0.025 (GeV/c)2. The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well as the method of extracting the weak charge of the proton. The results from a small subset of the data, that has been published, will also be presented. Furthermore an update will be given of the current status of the data analysis

Experimental study of forced convection heat transfer around triangular cylinder in cross flow

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.Experimental investigations have been reported on steady state forced convection from the outer surface of horizontal triangular surface ducts in cross flow of air. The triangular cylinder was set such that its vertex faces the flow. Four equilateral triangular ducts have been used with cross section side length of 0.03, 0.05, 0.08 and 0.12 m, corresponding to blockage ratios 0.066, 0.110, 0.175 and 0.263 respectively. The ducts are heated using internal constant heat flux heating elements. The temperatures along the surface and peripheral directions of the duct wall are measured. Local Nusselt numbers at the middle of the duct are obtained around the perimeter for the larger ducts 0.12 and 0.08 m for various Reynolds numbers. Total overall averaged Nusselt numbers are obtained for transition to turbulent regime and critical points are tabulated for turbulent distinction. Empirical correlations are obtained for the overall averaged Nusselt numbers and Reynolds number using the equilateral side length as a characteristic length. Furthermore, other general correlations are obtained for the overall averaged Nusselt number using the duct length as a characteristic length and the blockage ratio as a parameter.ej201