Effect of waterjet cleaning parameters during paint removal operation on automotive steel components

The automotive industry is expanding quickly, and each year, many vehicles are produced with beautiful paints. Increases in the number of end-of-life or old vehicles will occur as a result of uncontrolled growth in the number of manufactured vehicles. Recycling car parts is therefore necessary in the automotive industry specially to beautify the appearance of old vehicles with new paint. Waterjet cleaning is one of the most contemporary techniques frequently employed to guarantee uniform paint removal with no secondary pollutions. Study on waterjet cleaning parameters mostly focuses on pressure, traverse rate, and standoff distance. However, there are other new parameters associated with waterjet cleaning process namely number of cleaning passes and overlap rate which shows improvement in paint removal but lack in literature reviews. In the present study, paint is removed using the abrasive waterjet (AWJ) and plain waterjet (PWJ) paint removal techniques from parts made for automobiles in order to examine cleaning characteristics such as effectiveness and surface roughness. The findings indicated that AWJ cleaning process was more effective at cleaning than PWJ, which had a smaller cleaning capacity. However, AWJ cleaning process resulted in a rougher surface due to complete removal of paints as well as erosion of the substrate material. A better control of AWJ cleaning process may result in more efficient of paint removal without damaging the substrate material

Combinación de ozono y nanopartículas magnéticas verdes para la degradación de azul de metileno en agua residual sintética textil

Trabajo de investigaciónSe usaron nanopartículas de magnetita verdes en un proceso de ozonización para remoción del colorante azul de metileno proveniente agua residual sintética textil. La concentración inicial del contaminante fue de 2mg/L. Se obtuvo una capacidad máxima de adsorción sobre el material de 0.0086mg/g debida a la modelación cinética e isotermas. Finalmente se encontró un porcentaje de remoción de 87.02 usando ozonización catalítica.RESUMEN 1. INTRODUCCIÓN 2. PLANTEAMIENTO Y FORMULACIÓN DEL PROBLEMA 3. JUSTIFICACIÓN 4. OBJETIVOS 5. ESTADO DEL ARTE 6. ANTECEDENTES 7. MARCO DE REFERENCIA 8. ALCANCE Y LIMITACIONES 9. METODOLOGÍA 10. RESULTADOS CONCLUSIONES RECOMENDACIONES REFERENCIAS ANEXOSPregradoIngeniero Civi

Development of biomimetic flow sensor based on artificial lateral line flow sensor for underwater applications

527-532Present study consists the development of superficial neuromast and concentrates on the fabrication method and measurement system. Biomimetic flow sensor of this study consisted of single hair cell that attached perpendicular to subtract and strain gage was used as a sensing element. Simulation and experiment were done for various flow rates 0.1 to 0.5 m/s. Sensitivity of the sensor was obtained as 0.26 mV/ms-1 based on the applied flow rate and output voltage. The experiment of moving object detection have been demonstrated where it enables to detect the moving object at close range 2 cm

Ultra low-pressure filtration system for energy efficient microalgae filtration

Microalgae-based products have gained growing interest leading to an increase in large-scale cultivation. However, the high energy associated with microalgae harvesting becomes one of the bottlenecks. This study evaluated an energy-efficient microalga harvesting via ultra-low-pressure membrane (ULPM) filtration (<20 kPa) in combination with aeration. ULPM offered various benefits especially in terms of reducing the energy consumption due to it operated under low transmembrane pressure (TMP). High TMP often associated with high pumping energy hence would increase the amount of energy consumed. In addition, membrane with high TMP would severely affect by membrane compaction. Results showed that membrane compaction leads to up to 66 % clean water permeability loss when increasing the TMP from 2.5 to 19 kPa. The Chlorella vulgaris broth permeabilities decreased from 1660 and 1250 to 296 and 251 L/m2hrbar for corresponding TMPs for system with and without aeration, respectively. However, it was found that membrane fouling was more vulnerable at low TMP due to poor foulant scouring from a low crossflow velocity in which up to 56 % of permeability losses were observed. Membrane fouling is the biggest drawback of membrane system as it would reduce the membrane performance. In this study, aeration was introduced as membrane fouling control to scour-off the foulant from membrane surface and pores. In terms of energy consumption, it was observed that the specific energy consumption for the ULPM were very low of up to 4.4 × 10−3 kWh/m3. Overall, combination of low TMP with aeration offers lowest energy input

Tailored Ge-doped fibres for passive electron radiotherapy dosimetry.

Study has been made of the thermoluminescence yield of various novel tailor-made silica fibres, 6 and 8 mol % Ge-doped, with four differing outer dimensions, comprised of flat and cylindrical shapes, subjected to electron irradiation. Main thermoluminescence dosimetric characteristics have been investigated, including the glow curve, dose response, energy dependence, minimum detectable dose, effective atomic number, linearity of index and sensitivity of the fibres. The studies have also established the uncertainties involved as well as the stability of response in terms of fading effect, reproducibility and annealing. In addition, dose-rate dependence was accounted for as this has the potential to be a significant factor in radiotherapy applications. The 6 and 8 mol % fibres have been found to provide highly linear dose response within the range 1 to 4 Gy, the smallest size flat fibre, 6 mol% Ge-doped, showing the greatest response by a factor of 1.1 with respect to the highly popular LiF phosphor-based medium TLD100. All of the fibres also showed excellent reproducibility with a standard deviation of < 2% and < 4% for 6 and 8 mol % Ge-doped fibres respectively. For fading evaluation, the smallest 6 mol% Ge-doped dimension flat fibre, i.e., 85 × 270 μm displayed the lowest signal loss within 120 days post-irradiation, at around 26.9% also showing a response superior to that of all of the other fibres. Moreover, all the fibres and TLD-100 chips showed independence with respect to electron irradiation energy and dose-rate. Compared with the 8 mol% Ge-doped optical fibres, the 6 mol% Ge-doped flat optical fibres have been demonstrated to possess more desirable performance features for passive dosimetry, serving as a suitable alternative to TLD-100 for medical irradiation treatment applications

Thermoluminescence response of Ge-doped optical fiber dosimeters with different core sizes

Thermoluminescence (TL) properties of five different core diameter of 6 mol% germanium (Ge) doped optical fibers have been investigated for the purpose of TL dosimetry. The optical fiber dosimeter TL properties is compared with commercially available TLD-100 chips (LiF:Mg,Ti). Samples were irradiated using Cobalt-60 standard radiation source ranging from 1Gy to 10 Gy. These fibers show good linear dose response up to 10 Gy. Highest core diameter of Ge doped optical fiber (core 100 μm) provides the best response among all fibers. We observe the larger core fiber show better response than smaller core fiber. The relative sensitivity of 100 μm core optical fiber is 0.26 ± 0.04 with respect to TLD-100 chip. © 2013 IEEE

Thermoluminescence response of ge-doped optical fiber dosimeters with different core sizes

Thermoluminescence (TL) properties of five different core diameter of 6 mol% germanium (Ge) doped optical fibers have been investigated for the purpose of TL dosimetry. The optical fiber dosimeter TL properties is compared with commercially available TLD-100 chips (LiF:Mg,Ti). Samples were irradiated using Cobalt-60 standard radiation source ranging from 1Gy to 10 Gy. These fibers show good linear dose response up to 10 Gy. Highest core diameter of Ge doped optical fiber (core 100 μm) provides the best response among all fibers. We observe the larger core fiber show better response than smaller core fiber. The relative sensitivity of 100 μm core optical fiber is 0.26 ± 0.04 with respect to TLD-100 chip

Graphite as a Skin and Epithelium Dosimeter at mammographic energies

Use is made of 50 μm high purity graphite foils, investigating the potential of these in evaluation of dose in dermal and epithelial layers, measuring the thermoluminescence yield obtained as a result of irradiation at mammographic energies. In particular the effort supports the ICRU recommendation that skin dose be assessed at a skin depth 0.07 mm, equating to the uniquely mitotically active dermal layer responsible for the replenishment of skin cells. Support for the results of empirical investigation have been sought from Monte Carlo simulations using the TOPAS code. In study of x-rays generated in the 25- to 30 kVp range, the energetic electrons produced in interaction with the graphite have an approximate range of ∼7 μm, so that with a stacked graphite layer arrangement dose assessment is provided at 7 μm, 57 μm, 107 μm etc. TL yield results for the first three layers of graphite, covering nominal depths from the surface through to 150 μm, obtained on a 50 μm spatial resolution scale, show deposited dose values to be approximately flat to within throughout this depth. The indication is that for irradiations made using x-ray energies of a few tens of keV use of the present graphite layer arrangement can provide estimation of dermal and epithelial dose