Dissertations / Theses on the topic 'Plastics Treaty'

This thesis investigates the ability of transparent surface coatings to reduce xenon diffusion into plastic scintillators. The motivation for the work is improved radioxenon monitoring equipment, used with in the framework of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty. A large part of the equipment used in this context incorporates plastic scintillators which are in direct contact with the radioactive gas to be detected. One problem with such setup is that radioxenon diffuses into the plastic scintillator material during the measurement, resulting in an unwanted memory effect consisting of residual activity left in the detector. In this work coatings of Al2O3 and SiO2, with thicknesses between 20 and 400 nm have been deposited onto flat plastic scintillator samples, and tested with respect to their Xe diffusion barrier capabilities. All tested coatings were found to reduce the memory effect, and 425 nm of Al2O3 showed the most promise. This coating was deposited onto a complete detector. Compared to uncoated detectors, the coated one presented a memory effect reduction of a factor of 1000. Simulations and measurements of the expected light collection efficiency of a coated detector were also performed, since it is important that this property is not degraded by the coating. It was shown that a smooth coating, with a similar refractive index as the one of the plastic, should not significantly affect the light collection and resolution. The resolution of the complete coated detector was also measured, showing a resolution comparable to uncoated detectors. The work conducted in this thesis proved that this coating approach is a viable solution to the memory effect problem, given that the results are reproducible, and that the quality of the coating is maintained over time.

For the time different challenges are facing the world to stop the environment impacts  and availability of vital resources. Electrical and electronical Equipment (EEE) are contained harmful compounds which considered to be a major threat for living organisms and might cause long term impacts on environment (Md. Abdur Rakib, 2014). Furthermore, evolution of technology leads to production of a huge amount of electronic waste globally, which need to be treated by innovative technologies in order to minimize their environmental impact and simultaneously maximize their recovery rates. Pyrolysis is a promising method for treating these fractions of waste because it can potentially convert these waste into energy and metals.  Waste of Electrical and electronical Equipment (WEEE) contains both valuable and harmful materials, industrial waste are various physically and chemically from household waste. To avoid the opposite influence on environment and human health, presuppose particular recycling and treatment technique depending on the waste type (Gkaidatzis, Aggelakoglou, & Aktsoglou, 2009). Two types of WEEE have been processed using typical pyrolysis (Nitrogen) and pyrolysis (steam) at 600 °C, Fixed bed reactor was used in addition to a separate boiler for producing steam. Two samples were investigated Printed circuit board- main body and -sockets. The main focus of this work was to investigate the influence of steam presence on pyrolysis for recovering energy and metals from recycling WEEE. The comparison between pyrolysis at inert atmosphere and steam pyrolysis results of two various fractions of E-Waste were prepared, in addition to literature investigation related to recycling of E- waste and traditional routes which are followed in recovering materials nowadays was done. The results of this study  provides the incentive to continue experiments around pyrolysis process by using other methods.

This study examines the nanoindentation (energy inclusive) properties of 0.2 mg/kg alendronate treated ribs at one and three years against a vehicle treated control in a fresh-frozen, non-cold-mounted, condition. This was to verify if the tissue-level properties for 0.2 ALN treated beagles would increase because of an increased level of mineralization despite a microdamage increase. A total of twelve (12) skeletally mature (1–2 years old) female beagle dogs were treated daily for three years and one year with oral doses of vehicle (VEH, 1 mL/kg saline) or alendronate (ALN, 0.2 Merck, Rahway, NJ). The 0.2 mg dose corresponds, on a milligram per kilogram basis, to those used for treatment of postmenopausal osteoporosis. Transversely cut samples were ground and polished to 0.3μm, and were then mounted while nanoindentation was performed. The data obtained were analyzed using two modes of diamond area functions: ideal function and general function. The statistical analysis for the data were carried out using a repeated measured ANOVA (SAS V 9.1, Cary NC.) with the measured and calculated mechanical property (elastic modulus or hardness) or energy property (elastic work or plastic work) as the dependent variable and treatment (control, 1 year or 3 years) modeled as the subject. Either Turkey-Kramer or Bonferroni method was used to compute the pair-wise difference. The results indicate that when compared to one year, the three years of alendronate medication for postmenopausal osteoporosis did not have any effect on the strength of the canine cortical bone, whereas this had effect on the hardness of the subjects. This increase in the medication time resulted in an increase in the elastic work but a decrease in the plastic work. The two methods (modes) of diamond area function analysed showed different mechanical properties (elastic modulus and hardness).

This thesis investigates surface coatings as xenon diffusion barriers on plastic scintillators. The motivation for the work is improved radioxenon detection systems, used within the verification regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). One type of radioxenon detection systems used in this context is the Swedish SAUNA system. This system uses a cylindrical plastic scintillator cell to measure the beta decay from radioxenon isotopes. The detector cell also acts as a container for the xenon sample during the measurement. One problem with this setup is that part of the xenon sample diffuses into the plastic scintillator material during the measurement, resulting in residual activity left in the detector during subsequent measurements. This residual activity is here referred to as the memory effect. It is here proposed, and demonstrated, that it is possible to coat the plastic scintillator material with a transparent oxide coating, working as a xenon diffusion barrier. It is found that a 425 nm Al2O3 coating, deposited with Atomic Layer Deposition, reduces the memory effect by a factor of 1000, compared an uncoated detector. Furthermore, simulations show that the coating might also improve the light collection in the detector. Finally, the energy resolution of a coated detector is studied, and no degradation is observed. The focus of the thesis is measurements of the diffusion barrier properties of Al2O3 films of different thicknesses deposited on plastic scintillators, as well as an evaluation of the expected effect of a coating on the energy resolution of the detector. The latter is studied through light transport simulations. As a final step, a complete coated plastic scintillator cell is evaluated in terms of memory effect, efficiency and energy resolution. In addition, the xenon diffusion process in the plastic material is studied, and molecular dynamics simulations of the Xe-Al2O3 system are performed in order to investigate the reason for the need for a rather thick coating to significantly reduce the memory effect.

A spin-cast silicone membrane has been successfully bonded between two injection-molded microstructured plastic discs. This sandwich structure creates a useful platform for mass production of microfluidic systems, provided that the bonds are leakproof. The bonds were achieved by a silicon dioxide coating deposited on the plastic discs by evaporation. This investigation is concerned with the process and the result only, no theory is discussed.

Cette étude vise à bien comprendre puis à modéliser le comportement mécanique dans une large plage de vitesse de déformation des tôles d’acier austénitique AISI304 ayant subis un traitement d'attrition mécanique de la surface (SMAT). Ces tôles ainsi traités sont des matériaux multicouches avec un gradient de propriétés. Les principaux résultats obtenus sont résumés comme suit：(1) La sensibilité globale à la vitesse déformation des tôles d’acier austénitique AISI304 traités avec SMAT est caractérisée par des essais de double cisaillement sous chargements quasi-statiques et dynamiques, qui permet d’atteindre une grande déformation sans instabilité géométrique. Des essais de double cisaillement sous impact sont réalisés à l’aide des barres de Hopkinson de grande diamètre et un système d’attache qui a une même impédance acoustique que la barre. Une sensibilité significative a été révélée et on observe ce renforcement n’a pas induit une réduction importante de la ductilité.(2) Dans le but d’un meilleur dépouillement de ces essais de double cisaillement, leur conditions d’essai est analysé dans le détaillé. Le modèle numérique avec le système d’attache a été construit pour étudier l’influence du système d’attache au début de chargement. On trouve un effet limité pour les diverses conditions imparfaites des essais comme la souplesse de système d’attache, des champs mécaniques non-homogènes, l’état de non-équilibre, etc. Par contre, les études numérique et analytique ont démontré que l’hypothèse simple de petites perturbations habituellement utilisé pour le dépouillement de ces essais n’est pas suffisamment précise. La déformation Eulérien cumulée doit être utilisée pour obtenir un résultat numérique correct. A partir de ce résultat, la sensibilité à la vitesse déformation des tôles d’acier austénitique AISI304 traités avec SMAT obtenue expérimentalement a été retouchée.(3) Un modèle multicouche elasto-plastique en dommageable a été proposé pour décrire le comportement des tôles d’acier austénitique AISI304 traités avec SMAT. Les paramètres sont identifiées à partir des essai de traction. La partie elasto-plastique est calée par une loi d’écrouissage de type Ludwig. Par contre, les paramètres d’endommagement sont obtenus avec une méthode d’identification inverse sur la base de simulation numérique de ces essais de traction. Pour valider ce modèle multi-couche elasto-plastique dommageable, un essai d’indentation/perforation est réalisé sur des tôles d’acier austénitique AISI304 traités avec SMAT. Des simulations numériques correspondantes montres que ce modèle multi-couche elasto-plastique en dommageable une prédiction plutôt précise de ces essais de d’indentation/perforation.(4) Pour évaluer la performance anti-perforation des tôles d’acier austénitique AISI304 traités avec SMAT, des essais de perforation sous impact a été réalisés avec des barres de Hopkinson. Des simulations numériques de ces essais de perforation sous impact sont réalisées avec un modèle numérique comparable avec le cas quasi-statique. ́tant donne que la sensibilité globale à la vitesse déformation des tôles d’acier austénitique AISI304 traités avec SMAT est caractérisée par des essais de double cisaillement, la sensibilité à la vitesse a été introduite dans le modèle multi-couche elasto-plastique en dommageable. Le résultat numérique correspond bien à la mesure expérimentale, ce qui indique non seulement l’efficacité du modèle numérique mais aussi celle du modèle multicouche elasto-plastique en dommageable
This Ph.D dissertation aimed at the comprehensive understanding and the constitutive modeling of the mechanical behaviours of the surface mechanical attrition treatment (SMAT) treated AISI304 stainless steel sheet under a large range of loading rates. SMAT treated AISI304 stainless steel sheets are multi-layered functionally graded materials (FGM). The main research results and conclusions are summarized as followed:(1) The overall rate sensitivity SMAT treated AISI304 stainless steel sheet is characterized by the double shearing test under quasi-static and dynamic loading where a large strain can be achieved without geometry instability. Impact double shear test are performed with a large diameter Hopkinson bar system and an adapted equal-impedance clamping device. Significant rate sensitivity is found. It is also observed that such a rate enhancement does not induce an important reduction of the ductility.(2) In order to extract accurate material information from the double shear tests, their testing conditions are thoroughly analyzed using numerical simulation. Numerical models including clamping devices have been built to investigate the influence of this clamping device at the early stage of loading. A limited effect was found for various imperfect testing conditions such as the clamping device stiffness, non-homogeneous stress and strain fields, non-equilibrium state, etc. On the contrary, numerical and analytical study shows that the simple small strain assumption usually used in double shear tests are not accurate enough. Eulerian cumulated strain definition should be used to get consistent numerical results. From this finding, the experimental rate sensitivity obtained for the SMAT treated AISI304 stainless steel sheet are recalculated.(3) A multi-layers elastic plastic damageable constitutive model is proposed to model SMAT treated AISI304 stainless steel sheet. The parameters are identified using tensile testing results. The elastic plastic behavior is curve fitted with a simple Ludwig hardening model. However, the damage parameters should be identified using an inverse method on the basis of numerical simulation of these tensile tests. In order to validate this multi-layer elastic plastic damageable constitutive model, indentation/piercing tests on SMAT treated AISI304 stainless steel sheet are performed. Numerical simulation of this indentation/piercing tests is also realized. It is found that the identified multi-layer elastic plastic damageable constitutive model allows for a quite accurate prediction of the experimental piercing tests.(4) In order to evaluate the impact anti-piercing capacity of the SMAT treated AISI304 stainless steel sheet, the impact perforation tests using Hopkinson bar are carried out. Numerical simulation of these impact perforation tests are realized with a similar FEM model as the quasi-static case. As the rate sensitivity of SMAT treated AISI304 stainless steel sheet is experimentally characterized with double shear test, a rate sensitive multi-layer elastic plastic damageable constitutive model is introduced. The numerical results agree well with the experimental ones, which indicates the effectiveness of the numerical model as well as the rate sensitive multi-layer elastic plastic damageable constitutive model

Rubber tread compounds worn by grinding wheels on a Lambourn abrader exhibited fatigue and cutting wear mechanisms. Fatigue wear occurred on blunt alumina grinding wheels and cutting wear on sharp, faceted silicon carbide grinding wheels. The rubber wear rate in cutting was directly proportional to the normal load and increased with grit sharpness and rubber modulus. Fatigue wear was characterized by the formation of a pattern of ridges, and wear took place by fatigue crack growth at the base of the ridge, eventually rupturing a portion of the ridge. A fatigue wear model reduced the wear rate to the crack growth rate for a calculated tearing energy, which depended on the friction force and the morphology of the rubber-alumina grinding wheel contact. The derived crack growth rate as a function of the calculated tearing energy showed superposition of the wear data from the different alumina grinding wheels. And, the tearing energy exponent for the derived crack growth rate in wear were 14 and 19 for EXXPRO and SBR which are close to 1.6 and 2.6 obtained in tensile FCG for the two compounds, respectively. However, the derived crack growth rate in wear is an order of magnitude smaller than the tensile FCG at the same tearing energy. Analysis of the ridge pattern movement showed that the movement rate was similar to the derived crack growth rate supporting the fatigue wear model but revealed that only 18% of the calculated tearing energy was being used in crack growth, the remainder being dissipated in viscous deformation. The role of viscous deformation as a rate controlling process of wear was flaggested from an activation energy analysis of the Eyring type temperature and stress dependence of wear. The activation energies for fatigue wear were between 25-50 kJ/mol which are in general close to the activation energy for viscous deformation.

碩士
國立臺北科技大學
資源工程研究所
100
A study of fixing plastics to an aluminum-magnesium alloy 5052. First, the aluminum-magnesium alloy 5052 was surface-treated via electropolishing reaction. While the surface roughness of the aluminum-magnesium alloy 5052 was 16.3 mm before electropolishing, the roughness of the electropolished surface was 3.1 nm. We find that the surface morphology was uniform. The aluminum-magnesium alloy 5052 was further surface-treated via anodic treatment. After that, we observed self-organized formation of nanopores arrays in aluminum-magnesium alloy 5052, and the diameters of nanopores were measured 31.8 ± 3.6 nm. The connection between surface-treated aluminum-magnesium alloy 5052 and polyphenylene sulfide (PPS) was via injection molding. The mechanical properties of bonding plastic on aluminum-magnesium alloy 5052 were studied through both normal tension test and horizontal strength test. The testing result of normal tension test and horizontal strength test are respectively 95.7 ± 3.2 nm and 389.8 ± 7.4 nm. And in order to ensure the practical application in environmental temperature and humidity, the environment test of bonding plastic on aluminum-magnesium alloy 5052 was operated in the temperature between -10 ℃ ~ 70 ℃ and relative humidity remained at 75%. The result shows a slightly reduction mechanical properties after the environmental test.

碩士
國立中央大學
光電科學研究所
93
The application of plastic substrates in optical components increased recently. The limitation in using plastic substrates for optical components was the poor adherence between thin films and substrates. This research focused on plasma surface treatment to enhance the adhesion. The change of surface roughness, chemical bonding, substrate transmittance with different gas and pre-treatment power was investigated. In addition, we coated Ta2O5 single layer on substrates after pre-treatment to find out the phenomenon of the inhomogeneity as well as the adhesion degree between Ta2O5 and plastic substrate. The results revealed that the improvement of adhesion related to plasma power and pre-treatment time. It took shorter time to reach good adhesion under high plasma power, while longer time under low plasma power. But, high power plasma treatment caused substrate overheated due to the volatile interaction between plasma and substrates. So we chose low power treatment with longer time as well as cathode cooling. Finally, it is found that by refining the design of anti-reflection coating with an interface layer, an anti-reflection coating on plastic substrates with good adhesion can be made.

碩士
國立中興大學
森林學系
82
The main results are summarized as follows： 1.It is di fferent between monomer loading and polymer loadi ng at bamboo speies， and the polymer loading decreasing with the increasing specific gravity at oven dry. 2.Among the three species，Green bamboo showed the highest m onomer loading. The effect of the polymerization of Green bamboo appeared the better. 3.Dyes would inhibite the reaction of polymerization of monom er .Swelling action of organic solvents could assist the formatio n of grafting in the cell walls，also shorten the distance betwee n monomer and cell wall. 4.Ma bamboo the improved effect of water-excluding efficiency and the improved effect of antishrink efficiency was the highest among the three species. 5.The hardness and cleavability are the highest， whereas sta tic bending strength was the opposite. 6.Ma bamboo appeared to have the highest improved effect in the abrassive resistance. 7.The order of light resistance for untreated bamboo was Thor ny bamboo，Greenen bamboo then Mabamboo，while the dyed BPC was G reen bamboo，Thorny bamboo then Ma bamboo. 8.The BPC showing higher strength reservation，and the better weathering resistance.The weight reservation of BPC was higher th an that of untreated bamboo.

碩士
國立中興大學
森林學系
83
This mixture of styrene monomer, methyl methacrylate monomer and dye chemical was applied for the impregnation of MA bamboo, Thorny bamboo, Gigantic bamboo and Green bamboo to be made as dyed bamboo and plastic composites by means of heat catalyst. The modified gross appearance, physical and mechanical proper- ties as well as the factors influence on the effects of impreg- nation were investigated. The main results obtained by study may be summarized as follows: 1. MA bamboo appeared to have the highest improved effect in water excluding efficiency(WEE). The values of antishrink efficiency(ASE) of radial durection was higher than that of tangential direction, and Green bamboo appeared to have the highest improved effect. 2. The inner portions of culm appeared to have higher improved effect in static bending strength, among the four species Thorny bamboo showed the highest improved effect. The outer portions of culm also had the same tendency. 3. The inner portions of culm appeared to have higher improved effect in hardness, and Thorny bamboo was the most evident among the four species. The outer portions of culm showing the same tendency too. 4. MA bamboo appeared to have the highest improved effect in cleavability, and all of the four bamboo species appeared to have improved effect evidently. 5. Gigantic bamboo appeared to have the highest improved effect in the abrasive resistance, and the tested bamboos which had not been treated by artificial weathering treatment, they showing higher abrasive resistance. 6. Thorny bamboo appeared to have the highest static bending strength reservation after artificial weathering test, and MA bamboo showed the highest hardness reservation. The BPC appeared to have higher weathering resistance, therefor, it holding the higher strength reservation.

碩士
國立中興大學
森林學研究所
84
Bamboos growing widely in subtropical and tropical zones and there are many species in Taiwan.Ever since antiquity ,bamboo has important role in the livelihood.Recent years,because of the sever shock to the bamboomarketing,it is necessary to modify the natural disadvantages of bambooto be made as bamboo and plastic combinations to enhance the value and extending the new utilization of bamboo.In order to improve bamboo''s disadvantages,We used melamine formaldehydesolution,and mixture monomer of Acrylonitrile and Methy Methacrylate anddye chemical was applied for the impregnation of bamboos to be made as dyed bamboo and plastic combinations.The modified gross appearance ,physical and echanical properties were investigated.