Dose Planning Evaluation of Intensity-Modulated Proton Therapy (IMPT) Technique Based on In-House Dynamic Thorax Phantom

One of the drawbacks of the Intensity Modulated Radiation Therapy (IMRT) technique is that the absorbed dose in healthy tissue is relatively high. Proton beam has characteristics that can compensate for these drawbacks. The Bragg peak characteristic of a proton beam allows the administration of high radiation doses to the target organ only. Non-Small Cell Lung Cancer (NSCLC) cases are located in the vicinity of many vital organs, so radiation doses that exceed a certain limit will have a significant impact on these organs. Proton is a heavy particle that exhibits interaction patterns with tissue heterogeneity that differ from that of photon. This study aims to determine the distribution of proton beam planning doses in the NSCLC cases with the Intensity Modulated Proton Therapy (IMPT) technique and compare its effectiveness with the IMRT technique. Treatment planning was done by using TPS Eclipse on the water phantom and on the in-house thorax dynamic phantom. The water phantom planning parameters used are one field at 0° and three fields at 45°, 135°, and 225°. In this study, a single, sum, and multiple field techniques on the in-house thorax dynamic phantom were used. The evaluation was performed by calculating Conformity Index (CI), Homogeneity Index (HI), and Gradient Index (GI) parameters for each treatment planning. As a result, a bit of difference in the CI the HI values are shown between IMPT and IMRT planning. The GI values of IMPT planning are in the range between 4.15-4.53, while the GI value of IMRT is 7.89. The histogram results of the planar dose distribution show that the IMPT treatment planning provides fewer off-target organ doses than the IMRT planning. Evaluation was also carried out on the    IMPT treatment planning of target organs in five areas of interest and four OAR positions. The evaluation results were then compared with the IMRT measurement data. As a result, the value of the point doses at the target organ      did not differ significantly. However, the absorbed dose with the IMPT technique at four OAR positions is nearly zero, which had a large difference compared to the IMRT technique

Comments on "Wall-plug (AC) power consumption of a very high energy e+/e- storage ring collider" by Marc Ross

The paper arXiv:1308.0735 questions some of the technical assumptions made by the TLEP Steering Group when estimating in arXiv:1305.6498 the power requirement for the very high energy e+e- storage ring collider TLEP. We show that our assumptions are based solidly on CERN experience with LEP and the LHC, as well accelerators elsewhere, and confirm our earlier baseline estimate of the TLEP power consumption.Comment: 6 page

Numerical investigation to examine two methods of passive control in urban street canyon using CFD: Comparison between crossing under building and solid barriers lbw

Different passive control methods are discussed in this paper with the purpose of improved the quality of the air and dispersed the pollution outside the urban canyon road. Numerical investigation model is used in this paper, to examine two methods of passive control within a crossing under building and Low Boundary Wall in center of road for reducing air pollution concentration using Reynolds-averaged Navier–Stokes  equations and the k-Epsilon turbulence model as close of the equation system. The results of this investigation show that a low boundary wall located at the central median of the street canyon creates a significant reduction in pedestrian exposure, relative to the same canyon with no wall. The magnitude of the exposure reduction was also found to vary according to the numbers of the crossing under building in the street canyon geometry. The values of the concentration normalized is  decreased in the critical region were located in the centerline of the street canyon.Keywords: Passive Methods, Barriers, Street Canyon, Pollutant  Dispersion, Numerical Simulation

Liquid film thickness behaviour within a large diameter vertical 180° return bend

Experimental results of liquid film thickness distribution of an air–water mixture flowing through a vertical 180° return bend are reported. Measurements of liquid film thickness were achieved using flush mounted pin and parallel wire probes. The bend has a diameter of 127 mm and a curvature ratio (R/D) of 3. The superficial velocities of air ranged from 3.5 to 16.1 m/s and those for water from 0.02 to 0.2 m/s. At these superficial velocity ranges, the flow pattern investigated in this work focused on churn and annular flows. It was found that at liquid and gas superficial velocities of 0.02 m/s and 6.2 m/s, respectively, the averaged liquid film thickness peak at 90°. At gas superficial velocity of 16.1 m/s, the relationship between them is linear due to the shear forces overcoming gravity. Additionally, it was found that deposition of entrained droplets keeps the liquid film on the outside of the bend. The results of polar plots of average liquid film thickness in the bend showed that the distribution of the liquid film is not symmetrical with thicker films on the inside of the bend due to the action of gravity. Experimental results on average liquid film thickness showed good agreement with the simulation data reported in the literature

Electrocoagulation/Electroflotation of real textile effluent: Improvement of the process in non-conventional pilot external loop airlift reactor

A pilot external-loop airlift reactor (ELAR) of 150 liters was designed and used as a non – conventional reactor to carry out Electrocoagulation/Electroflotation to treat real textile effluents containing disperse and reactive dyes. The designed reactor ensure the recovery of sludge by electroflotation (EF) in which complete flotation of the pollutants is achieved without additional mechanical power in the pilot external-loop airlift reactor (ELAR), using only the overall liquid recirculation induced by H2 microbubbles generated by water electrolysis without filtration process. Aluminum, iron electrodes and combined aluminum – iron electrodes were tested.The obtained results were interesting as they would help managing the Electrocoagulation/Electroflotation process in pilot external – loop airlift reactor to remove real textile effluent. The treatment of the mixtures of the real textile dyeing industry is better when using a combination of the electrodes of iron and aluminum providing a better treatment efficiency of 80% and a lower specific energy consumption (50 kWh/kg dye).In order to analyze the by-product of the electrocoagulation (EC) and the treated effluent, different techniques were used to elucidate the role of different kind of anodes especially when the combined iron – aluminum were used simultaneously as sacrificial anodes