Дисертації з теми "Modified engine"

The engine of JAS 39 Gripen, RM12, has recently been equipped with a new flameholder and a new engine inlet. This change has caused an increased noise level from the engine when the afterburner is in use. The noise level reaches its peak when the afterburner is partially used. The problem is thought to be unstable combustion in the regions around the flameholder. A solution to the problem has been proposed by Volvo Aero. The idea is to modify the software in the engine control unit (FADEC) that changes the airflows in the engine. This master thesis implements the proposed changes and analyzes the effects of this implementation. The analysis is done by simulations of a model of the engine that Volvo Aero has created and implemented in MatrixX/SystemBuild. Simulations showed that it is possible to achieve the desired result by the software changes. Further the simulations showed some problems with stability for the engine when controlled by the modified control unit. This was solved by implementing a filter in the FADEC software.

The automotive internal combustion engine industry operates in a sector that relies on high production volumes for economies of scale, and dedicated production equipment for efficiency of operations and control of quality, yet is subject to the vagaries of a dynamic marketplace, with the need for constant change. These circumstances place pressure on engine designs to be optimised at launch to be competitive and meet market needs, yet be adaptable to uncertain requirements for change over their production life. Engine designers therefore need concept configuration evaluation tools that can assess architectures for resilience to geometric change over the production life of the product. The problem of being resource efficient whilst having the capacity to adapt tochanging environments is one that has been addressed in nature. Natural systems have evolved strategies of satisficing conflicting requirements whilst being resource efficient. The theory of adaptive landscapes helps us to visualise the adaptive capacity of potential morphological forms. A concept attribute analysis methodology based on satisficing and adaptive landscapes has been developed and tested for application to engine concept design. The Plateau, Flooded Adaptive Landscape technique (PFAL),has been evaluated against exemplar engine life histories and shows merit in aiding the decision-making process for concept designers working with sparse data. The process lets the designer visualise the attribute map, enabling them to make better trade-off decisions and share these with non-expert stakeholders to gain their input in final concept choices.

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This thesis provides a comparison of the accuracies of two methods for fitting a Weibull distribution to a set of aircraft engines time between failure data. One method used is the Maximum Likelihood Method and assumes that these engine failure times are independent. The other method is a Modified Method of Moments procedure and uses the fact that if time to failure T has a Weibull distribution with scale parameter lambda and shape parameter beta, then T(beta) has an exponential distribution with scale parameter lambda(beta). The latter method makes no assumption about independent failure times. A comparison is made from times that are randomly generated with a program. The program generates times in a manner that resembles the way in which engine failures occur in the real world for an engine with three subsystems. These generated operating times between failures for the same engine are not statistically independent. This comparison was extended to real data. Although the two methods gave good fits, the Maximum Likelihood Method produced a better fit than the Modified Method of Moments. Explanations for this fact are analyzed and presented in the conclusions

The master thesis deals with the design of a single-cylinder diesel piston internal combustion test engine by modifying the initial mass-produced three-cylinder engine. The first part of the thesis is devoted to the introduction to the problems of diesel and experimental single cylinder engines. Subsequent chapters focus on the adaptation of the baseline engine itself, including balancing of inertial forces. Furthermore, the crankshaft operability is checked, including the determination of safety against high-cycle fatigue. The last chapter deals with the design of the connection of the adapted unit to the dynamometer.

The corrosion resistance of chemically modified β-eucryptite (Li_0.41Mg_0.035AlP_0.52Si_0.480₄) having low expansion anisotropy and a near zero coefficient of thennal expansion was evaluated. Samples were exposed to aqueous hydrochloride acid at temperatures up to 100°C and environments containing sodium sulfate up to l000°C. The corrosion resistance was characterized by dilatometry, scanning electron microscopy, X-ray diffraction, energy dispersive x-ray analysis, weight variations, and mechanical properties variations. The results show that modified β-eucryptite is more severely corroded than commercial lithium-alumina-silicate glass-ceramics when exposed to these environments. Aqueous HCI removes AIP04 from modified β-eucryptite leaving a very porous structure. Molten salt corrodes modified β-eucryptite by penetration of sodium and sulfur which form an alkali melt under the surface. The modulus of rupture and the Young's modulus are reduced by both types of corrosion.
Master of Science

>Magister Scientiae - MSc
The use of diesel engines in vehicles and heavy machinery throughout the world has been slowly increasing in the past few decades. This has led to high demand for diesel and gasoline with high octane number. Diesel and gasoline are in high demand due to its qualities as fuels containing low or no sulfur and nitrogen compounds, making them environmentally friendly and the anti- knocking properties respectively. With these reasons and more, researchers have been studying processes like the catalytic oligomerization of olefins to produce synthetic fuels with augmented qualities and properties. The effectiveness of the process will depend on the quality of the catalyst.

Les technologies actuellement utilisées pour les moteurs diesel conduisent à la dégradation accélérée des constituants chimiques des lubrifiants, notamment des additifs non polymériques de type antioxydants, anti-usures, modificateurs de friction et de détergence.Nos travaux visent à identifier la nature des modifications chimiques de ces additifs au cours du fonctionnement moteur. Ainsi, un protocole analytique a été établi afin d’étudier qualitativement et quantitativement ces familles dans les lubrifiants.Ce protocole a ensuite été utilisé pour l’analyse d’huiles vieillies lors de tests sur banc moteur et d’essais réalisés en laboratoire. L'évolution de la composition chimique des lubrifiants, la nature des produits de dégradation formés, et les processus d'altération impliqués ont ainsi été étudiés, et des modèles cinétiques de la dégradation de chaque famille d’additifs ont été établis.Il ressort de notre étude que les processus mis en jeu dans l’altération des additifs en laboratoire ne reproduisent pas ceux existant lors du fonctionnement moteur, ce qui laisse envisager le développement d'expériences de laboratoire mieux adaptées
Current technologies used for diesel engines lead to an accelerated degradation of the non-polymeric additives from lubricants, such as antioxidants, antiwear, friction modifiers and detergency additives.Our work intends to identify the nature of the chemical modifications undergone by such additives during engine functioning. In this respect, an analytical protocol has been developed in order to investigate qualitatively and quantitatively these compound families in engine oils. Following this, the analytical methodology has then been used to study oils altered during engine bench tests and laboratory experiments. Thus, the evolution of the chemical composition, the nature of the degradation products and the alteration processes have been considered. Furthermore, kinetic models have been established for each family of additives.It appears from this study that the processes implied in the alteration of the additives during laboratory tests do not reproduce those existing while engine running. Further laboratory experiments are needed in order to develop tests mimicking more closely the conditions occurring during engine functioning

This thesis deals with the optimization of the structural design of large technology compounds. The main emphasis is placed on the participation of available optimization instruments in the design of supporting structures of these constructions. The introductory part is primarily focused on the optimization itself. In this part are further specified also used optimization methods, computational finite element method, implemented code checks and calculation of cost of construction. The main part is dedicated to application of optimization procedure for the design of steel supporting structure of the auxiliary technological object of thermal power plant. The objective criterium shall then constitute the total cost of construction works along with operating costs. For the solution is used Scia Engineer software together with optimization module Scia Engineer Optimization Toolbox. The whole analysis is presented comprehensively from the description of computational model to results evaluation. The attention is paid to the optimization task settings, technical solution of optimization, optimization methods deployment and during the calculation process (especially to the development of objective function values and desing constraints during the optimization solution).

碩士
國立雲林科技大學
機械工程系
102
This study applied a 500C.C. modified GDI engine with common rail injection pressure at 100 bars. The 1st: and @ns injection ratio (F1:F2=6：4、7：3、8：2) is varied at different engine speed (3000、4000、5000rpm) and load (TPS20%、30%、40%). Then the combustion equivalence rati is slightly decreased to from Φ=1 to Φ=0.9 to exam the engine performance and emissions. The first stage result indicates when the pilot injection is increased, the homogeneous charge inside the combustion chamber cause better combustion so that the engine toque and emission are improved. However, if F1:F2=8：2, the combustion is not stable under high engine speed and load condition. Thus, a F1:F2=7：3 case has best results. The 2nd stage result indicates when from Φ=1 is reduced to Φ=0.9, the volumetric efficiency is increased so that the engine torque is improved. The Co and HC are also reduced. NOX is also reduced. The BSFC is also improved under load engine speed and load conditions. This research reveals the engine output and emissions are improved when the overall equivalence ratio is reduced. However, this Air-Guided engine geometry has flat piston surface which may cause non GDI engine operation.

Thesis (M.S.)--University of Wisconsin--Madison, 1990.
Typescript. Title from title screen (viewed July 27, 2007). Includes bibliographical references (leaves 175-186). Online version of the print original.

碩士
國立雲林科技大學
機械工程系碩士班
99
This research attempts to add the common-rail injection system onto the traditional diesel engine to study the engine performance and exhaust emissions. The CY190 1000c.c. single cylinder is chosen as the test bench, the fuel injection pressure and injection angle are varied to study their effects on the engine combustion characteristics. The first part of the study has the injection pressure set at 600, 450, and 300 bars while the engine load is set at different equivalence ratio (Φd = 0.2, 0.3, 0.4, and 0.5). The injection timing is 19°BTDC and the engine speed is set at 1500, 1800, 2100, and 2400 rpm. The second part of this research studies the effects of injection timing modification (14°, 19°, and 24° BTDC) on the engine ignition quality and the exhaust emissions. The results show the high pressure common-rail fuel injection system has substantial improvements on the engine performance. The engine torque and the emissions are improved when the injection pressure is raised to 600 bars. The torque is increased by 30.6%, the smoke is reduced by 49%, and the NOx is increased by 25.6%. When the injection timing is advanced by 5 degrees, the engine torque is increased by 17.5%, the smoke is reduced by 32.8%, the NOx is increased by 70.6%, and the HC and HC are reduced by 53.8% and 41.5%. This implies the fuel injection atomization and mixing wit air have significant on the engine performance. This research strongly suggest the usage of common-rail injection system o the diesel engine system.

Serpentine ducts used by both military and commercial aircraft can generate significant flow angularity (inlet swirl) and total pressure distortion at the engine face. The impact of inlet swirl on the engine performance and operability must be quantified to ensure safe operation of the aircraft and propulsion system and to define installed deficiencies. Testing is performed over a wide range of flight conditions in the propulsion system flight envelope in order to quantify these effects. Turbine engine compressor models are based on experimental data which can be collected at a limited number of discrete operating points. These models can be used as an analysis tool to optimize the engine test plan and help during validation of the design. The Dynamic Turbine Engine Compressor Code (DYNTECC) utilizes parallel compressor theory and quasi-one-dimensional Euler equations to determine compressor performance. In its standard form, DYNTECC uses user-supplied characteristic stage maps in order to calculate stage forces and shaft work for use in the momentum and energy equations. These maps are typically developed using experimental data. These maps can also be created using characteristic codes such as the 1-D Mean Line Code or the 2-D Streamline Curvature Code. The 1-D Mean Line Code was originally created to predict the performance of individual compressor stages and requires greatly reduced computational time when compared to 2-D and 3-D models. This thesis documents work done to incorporate the 1-D Mean Line code into DYNTECC as a subroutine. The combine DYNTECC/1-D Mean Line Code was then used to analyze the effects of inlet swirl on the fan performance and operability of the Honeywell F109 turbofan engine. The code was calibrated and validated using the F109 cycle deck. Additional code validation was performed using experimental data gathered at the United States Air Force Academy. F109 fan maps were developed for various cases of inlet swirl and results were presented showing shifts in corrected mass flow, fan pressure ratio and fan stability limit.

碩士
國立雲林科技大學
機械工程系碩士班
101
This research applied a 500c.c. modified GDI engine. A common rail injection system with 100 bar injection pressure system is assembled. The equivalence ratio is fixed atΦ=1 condition, the engine speed is varied (3000、4000、5000rpm), and the throttle position is controlled at 35%、45%、and 55%. The first and second stage injection ratio is varied (F1:F2=4：6、5：5、6：4). The engine performance is studied. The previous research had bad injection nozzle and spark plug placement. In this research, the engine has side injection and right-top spark plug ignition. The air-guided spray pattern is adapted in this study. The spray injection timing is adjusted to the intake stroke stage. Under two stages injection, the first injection allows a homogeneous charge existed in the cylinder, the second injection creates a stratified charge inside the cylinder. The engine combustion is more completely, the torque is increased, and the emission is reduced. Especially under the conditions. 1st=70°CA、2nd=170°CA, the result is best among the test condition. The two stage injection results are compared to the single-stage injection results (which simulates the 10°CA BTDC port injection mode). The two stage injection volumetric coefficient is slightly increase by 1%~4%; the CO emission is reduced by 35%~75% under the 4000 rpm condition. However, the NOx is reduced by 10~30% under two stage injection. The torque is increased by 4%~30%. The BSFC is reduced by 17%~35.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1993.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 156-162).

博士
國立臺北科技大學
電子工程系
107
Search engine optimization (SEO) has been considered one of the most important techniques in internet marketing. This study establishes a decision model of search engine ranking for administrators to improve the performances of websites that satisfy users’ needs. To probe into the interrelationship and influential weights among criteria of SEO and evaluate the gaps of performance to achieve the aspiration level in real world, this research utilizes hybrid modified multiple criteria decision-making (MCDM) models, including decision-making trial and evaluation laboratory (DEMATEL), DEMATEL-based analytic network process (called DANP), and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR). The empirical findings discover that the criteria of SEO possessed a self-effect relationship based on DEMATEL technique. External website optimization is the top priority dimension that needs to be improved when implementing SEO. Among the six criteria for evaluation, meta tags is the most significant criterion influencing search engine ranking, followed by keywords and website design.

碩士
國立彰化師範大學
車輛科技研究所
106
In this study, a single-cylinder spark ignition engine was used as an experimental machine to change the ignition timing. Mixed 95 unleaded gasoline and pure water into emulsion fuel (5%, 10%, and 15%), also added hydrogen generator (HHO). The experiment is divided into three parts, the first part is the low load, using programmable ECU to adjust AFR under idle speed, fixed rotation (rpm), and the temperature was first examined to see the improvement of engine performance and pollutant emission by modifying ignition timing. In addition to the first part of the test, the second part of experiment imported another 10 L/min hydrogen fuel (HHO) to discuss the engine performance and exhaust emission. The third part is the load test; we used DYNO-mite dynamometer to adjusting ignition timing to 30 N-m and 60 N-m. We tested it under throttle valve opening at below 100 % to discuss engine performance and exhaust emissions. According to the first and second part of the experimental results, in the aspect of pollutant emission shows that before the introduction of HHO, the use of emulsion fuel can effectively reduce the emission of CO, CO2, and NOx, but the emission of HC increased. After introducing HHO, the HC emission concentration improved, but the NOx emissions will slightly increase. In addition to ignition timing, delayed the timing of the ignition will reduce the emission of HC and NOx. In the third part when we increase the load and the HHO introduction was absence, we found that in terms of pollutant emission, the use of emulsion fuel can effectively reduce the CO emissions, but CO2 and NOx emissions will increase, while the HC emissions are approximately at zero. For ignition timing, retarding the ignition will cause the power to decrease, and the HC and NOx emissions will decrease as the delay angle increases.

碩士
國立成功大學
高階管理碩士在職專班(EMBA)
103
This study intended to focus on the decisive factors of endusers chose modified fuel electric controller of EFi engine. Therefore, the main purpose of this study was to examine the behavior analysis when they chose modified fuel electric controller of EFi engine and discussed the influences from attitude, subjective norm, behavioral intention, perceived behavioral control and demographic variables. A total of 400 questionnaires were handed out and returned. The overall response rate for surveys was 100.00%. Establishment of assumptions based on LMP, we using SPSS 18.0 and EViews 8.0 statistical analysis software. Finally, the results of this study showed that: (1) Attitude had a significant positive influence on endusers’ choice behavior; (2) Perceived behavioral control (PCB) had a significant positive influence on endusers’ choice behavior; (3) There was a significant influence of demographic variables (include age, personality traits, occupation and parents occupation) on choice behavior.

A residential micro-cogeneration system based on a Stirling engine unit was modified to operate with wood derived fast pyrolysis liquid (bio-oil)-ethanol blend. A pilot stabilized swirl combustion chamber was designed to replace the original evaporative burner due to bio-oil’s nondistillable nature. This also required modifications of the engine’s control systems. Efficiencies for the bio-oil/ethanol blend were found be higher than those of diesel due to the higher heat loss incurred with diesel. Based on a modified efficiency, which disregarded the heat loss through the combustion chamber, power efficiencies were found to be comparable. The maximum time of operation with the bio-oil/ethanol blend was approximately 97 minutes due to the clogging of the narrow passages. Carbon monoxide emissions were higher for the bio-oil/ethanol blend due to the operation conditions of the combustion chamber. Oxides of nitrogen emissions were also higher for the bio-oil/ethanol blend due to its inherent nitrogen content.

Four problems in non-equilibrium statistical physics are investigated: 1. The thermodynamics of single-photon gas; 2. Energy of the ground state in Multi-electron atoms; 3. Energy state of the H2 molecule; and 4. The Condensation behavior in N weakly interacting Boson gas. In the single-photon heat engine, we have derived the equation of state similar to that in classical ideal gas and applied it to construct the Carnot cycle with a single photon, and showed the Carnot efficiency in this single-photon heat engine. The energies of the ground state of multi-electron atoms are calculated using the modi ed Bohr model with a shell structure of the bound electrons. The di erential Schrodinger equation is simpli ed into the minimization problem of a simple energy functional, similar to the problem in dimensional scaling in the H-atom. For the C-atom, we got the ground state energy -37:82 eV with a relative error less than 6 %. The simplest molecular ion, H+ 2 , has been investigated by the quasi-classical method and two-center molecular orbit. Using the two-center molecular orbit derived from the exact treatment of the H+ 2 molecular ion problem, we can reduce the number of terms in wavefunction to get the binding energy of the H2 molecule, without using the conventional wavefunction with over-thousand terms. We get the binding energy for the H2 with Hylleraas correlation factor 1 + kr12 as 4:7eV, which is comparable to the experimental value of 4:74 eV. Condensation in the ground state of a weakly interacting Bose gas in equilibrium is investigated using a partial partition function in canonical ensemble. The recursive relation for the partition function developed for an ideal gas has been modi ed to be applicable in the interacting case, and the statistics of the occupation number in condensate states was examined. The well-known behavior of the Bose-Einstein Condensate for a weakly interacting Bose Gas are shown: Depletion of the condensate state, even at zero temperature, and a maximum uctuation near transition temperature. Furthermore, the use of the partition function in canonical ensemble leads to the smooth cross-over between low temperatures and higher temperatures, which has enlarged the applicable range of the Bogoliubov transformation. During the calculation, we also developed the formula to calculate the correlations among the excited states.

Tese de Doutoramento em Engenharia Civil
As novas metas ambientais no que concerne à conservação dos recursos naturais e à valorização de resíduos têm servido de motivação para vários estudos científicos de diferentes áreas de investigação. Nesse sentido, no domínio da indústria da pavimentação rodoviária, que consome imensos recursos naturais, tem sido investigada a incorporação de diferentes resíduos em misturas betuminosas de modo a desenvolver soluções mais sustentáveis. Sendo o betume um dos materiais mais valiosos utilizados na pavimentação é fundamental o estudo de novos ligantes que permitam reduzir a quantidade de betume novo utilizado, quer pela reutilização de betume envelhecido (reciclagem), quer pela adição de alguns resíduos, pelas vantagens económicas e ambientais associadas. Deste modo, o principal objetivo deste trabalho consiste em desenvolver betumes inovadores que maximizem a utilização de resíduos, particularmente óleo de motor usado e fundo de coluna de destilação (substitutos parciais do betume), para a produção de misturas betuminosas convencionais e recicladas mais sustentáveis. Este trabalho pretende assim desenvolver novas soluções para pavimentação, que aliem o desempenho técnico e a viabilidade económica aos benefícios ambientais que resultam da utilização de resíduos industriais e material fresado em misturas betuminosas. Adicionalmente, pretende garantir-se que estas soluções com elevada incorporação de resíduos não apresentem riscos associados à sua utilização, quer ao nível dos seus lixiviados, quer das suas emissões de dióxido de carbono. Para a concretização deste trabalho, foi realizada a caracterização térmica, química e física dos diferentes materiais a utilizar nos betumes modificados com resíduos e nas misturas betuminosas. Além disso, de modo a verificar a dispersão do polímero no betume com óleo de motor usado, foram avaliados através de microscopia de fluorescência diferentes procedimentos de produção dos betumes modificados. Desta forma, foi possível minimizar o tempo e/ou a temperatura de digestão e obter uma dispersão mais eficaz do polímero no betume com óleo de motor usado. Em seguida, os betumes modificados com várias percentagens dos diferentes resíduos (óleo/fundo de coluna e polímeros) foram avaliados através de ensaios de caracterização básica e reológica, tendo sido selecionados aqueles cujas características foram mais promissoras. Os betumes selecionados foram ainda avaliados a nível térmico, químico e quanto à resistência ao envelhecimento. Em seguida, foram produzidas misturas convencionais e recicladas do tipo Stone Mastic Asphalt (SMA) com estes betumes inovadores modificados com resíduos, que foram avaliadas quanto ao seu desempenho mecânico e superficial. Finalmente, a sustentabilidade destas soluções foi analisada no que respeita à produção de lixiviados, emissões de dióxido de carbono, e quanto à sua viabilidade económica. Os resultados deste estudo confirmam que os betumes inovadores modificados com resíduos desenvolvidos neste trabalho permitem produzir misturas convencionais e recicladas mais sustentáveis, que aliam um bom desempenho mecânico com benefícios económicos e ambientais. Estes betumes modificados com resíduos exibem menor suscetibilidade térmica, sendo mais resistentes à deformação permanente a elevadas temperaturas e mais flexíveis a temperaturas mais baixas. Quando utilizados nas misturas betuminosas, a maioria dos betumes modificados com resíduos aumenta a resistência à ação da água, à deformação permanente e ao fendilhamento por fadiga, sem comprometer as características superficiais das misturas. Apesar de se ter desenvolvido neste trabalho vários ligantes inovadores mais sustentáveis do que o betume convencional, aqueles que apresentam os resultados mais promissores a nível mecânico, económico e ambiental são os betumes modificados com resíduos de polietileno de alta densidade e óleo de motor usado ou fundo de coluna. De facto, ao comparar estruturas de pavimentos com um desempenho equivalente, as misturas com estes ligantes apresentam em geral os custos e as emissões de dióxido de carbono mais baixos de todas as soluções analisadas.
The new environmental targets related to conserving the natural resources and recovering the waste materials have been the basis for several scientific studies in different research areas. Therefore, in the road paving industry field, which consumes massive amounts of natural resources, the incorporation of different waste materials in asphalt mixtures has been investigated in order to develop more sustainable solutions. As bitumen is one of the most valuable materials used in pavements, the study of new binders that incorporate a lower amount of new bitumen is essential, both by reusing aged bitumen (recycling) and by adding some waste materials, due to the associated economic and environmental advantages. Thus, the main aim of this study is the development of innovative modified bitumens that maximize the use of waste materials, especially waste engine oil and recycled engine oil bottoms (partial replacements for bitumen), to produce more sustainable conventional and recycled asphalt mixtures. With this work, new solutions for road paving materials, combining adequate performance and economic viability with environmental advantages that result from the use of industrial waste and reclaimed asphalt materials in asphalt mixtures, shall be developed. Ultimately, this work should assure that these solutions with high incorporation of waste materials do not present risks related to their use, either from their leachates or from their carbon dioxide emissions. For the accomplishment of this work, thermal, chemical and physical characterisation of the materials used in the modified bitumens with waste materials and in the asphalt mixtures was carried out. Additionally, different bitumen modification procedures were evaluated through fluorescence microscopy tests to verify the polymer dispersion in the blend of bitumen and waste engine oil. Thus, it was possible to minimize the digestion time and/or temperature and to obtain a more effective polymer dispersion in the blend of bitumen and waste engine oil. Afterwards, several modified bitumens with different amounts of waste materials (waste engine oil/recycled engine oil bottoms and polymers) were evaluated through basic and rheological characterization, and those with the most promising properties were selected. The selected bitumens were further characterised regarding their thermal, chemical and aging resistance behaviour. Then, conventional and recycled Stone Mastic Asphalt (SMA) mixtures produced with those innovative bitumens modified with waste materials were evaluated regarding their mechanical and surface performance. Finally, the sustainability of these solutions was analysed in relation to their leachates production, carbon dioxide emissions and economic viability. The results from this study confirm that the innovative bitumens modified with waste materials developed in this work are able to produce more sustainable conventional and recycled asphalt mixtures, which combine a good mechanical performance with economic and environmental benefits. These binders present lower thermal susceptibility, being more resistant to permanent deformation at high temperatures and more flexible at lower temperatures. When used in asphalt mixtures, the majority of the bitumens modified with waste materials increases the water sensitivity, permanent deformation and fatigue cracking resistances, without compromising their surface characteristics. Although several innovative binders that are more sustainable than the conventional bitumen have been developed in this study, those modified with waste high density polyethylene and waste engine oil or recycled engine oil bottoms have presented the most promising results at the mechanical, economic and environmental levels. Indeed, when comparing pavement structures with equivalent performance, the asphalt mixtures with these modified bitumens have generally shown the lowest costs and carbon dioxide emissions amongst all analysed solutions.
Este trabalho foi financiado pelo Governo de Portugal e pelo Fundo Social Europeu da União Europeia (EU/FSE), através da Fundação para a Ciência e Tecnologia (FCT), através de uma Bolsa de Doutoramento SFRH/BD/98379/2013, e no âmbito do Programa Operacional Potencial Humano inscrito no Quadro de Referência Estratégico Nacional (POPH/QREN).

碩士
世新大學
傳播管理學研究所(含碩專班)
106
Computing technologies have been changed and improved rapidly since the first personal computer launched by IBM in 1981. Computer was a high-end technologies for few people in the past, and it became personal tool for everyone in present. There are not much people aware of the importance of BIOS although most of people own the computers. Desktop computer, notebook, server, workstation and popular current product “pad, all of them require BIOS for booting up the initialization of the operation system. More and more computer products be launched and been replaced in a short period of time. For the better market opportunities, launch product earlier than other companies is very important which means speed up the time spend of new product development and shorten the development schedule are essentially. Except the initialization of booting operating system, BIOS also responsible for stability and normalization of the operation system; BIOS is one of major components of the computer. There are a lots of new functions and new techniques, and the computing becomes more complex afterwards. BIOS engineer is the productivity of the BIOS company in this industry, the BIOS senior engineer is the key point for product development who effects the productivity and quality. BIOS engineer requires most of the knowledges and skills in both software and hardware, therefore a senior BIOS engineer requires three to five years BIOS experiences at least. This job requires high-end technique, not much people focus on BIOS field and hard to recruit a qualified BIOS senior engineer accordingly. This study aims to develop a model for selecting the BIOS senior engineer, the goal is recruiting qualified program developer who brings actual performance. There are two parts of this study, first, get the criteria of the best BIOS engineer by refer the relevant literatures and apply the Modified Delphi Method. Second, determine the weights of above criteria by applying Analytic Hierarchy Process (AHP), and establish a selection model. Finally, work with a BIOS company, actually operate this selection model, and list the alternative selections, then select for the best choice "qualified BIOS senior engineer". This thesis provides an objective and credible way for BIOS company to choose an qualified BIOS senior engineer, this certain achieve the research goal and brings the efforts practically.