Rozprawy doktorskie na temat „EFFECTIVE MODE AREA”

The purpose of this research is to develop a new approach to estimate the effective leakage area using the inverse modeling process as an alternative to the blower door test. An actual office building, which is the head quarter of Energy Efficiency Hub, was used as an example case in this study. The main principle of the inverse modeling process is comparing the real monitor boiler gas consumption with the result calculated from the EnergyPlus model with a dynamic infiltration rate input to find the best estimation of the parameter of effective leakage area (ELA). This thesis considers only the feasibility of replacing the blower door test with the calibration approach, so rather than attempting an automated calibration process based on inverse modeling we deal with generating a first estimate and consider the role of model uncertainties that would make the proposed method less feasible. There are five steps of the whole process. First, we need to customize our own actual weather data (AMY) needed by the energy model (EnergyPlus model), which can help increase our quality of the result. Second, create the building energy model in EnergyPlus. Third, create a multi-zone model using CONTAM with different ELA estimation of each facade to calculate the dynamic infiltration rate of each ELA estimate. Fourth, input the dynamic infiltration rate got from the CONTAM model to EnergyPlus model and output the boiler energy consumption. Fifth, compare the boiler gas consumption from the model and the real monitor data and find the best match between the two and the corresponding ELA, which gives the best estimate from the whole inverse modeling process. From the simulation result comparison, the best estimation of the total building ELA from the inverse modeling process is the 23437cm2 at 4pa, while the result from the blower door test is 10483cm2 at 4pa. Because of the insufficient information of the building and also the uncertainty of the input parameters, the study has not led to a definite statement whether the proposed calibration of the ELA with consumption data can replace a blower door test to get an equally valid or even better ELA estimate, but it looks feasible. As this this case study is done in a deterministic context, the full feasibility test should be conducted under uncertainty. A first step towards this will talk be discussed in chapter 4.

For students with learning disabilities, positive academic achievement outcomes are a chief area of concern for educators across the country. This achievement emphasis has become particularly important over the last several years because of the No Child Left Behind legislation. The content area of mathematics, especially in the higher order thinking arena of algebra, has been of particular concern for student progress. While most educational research in algebra has been targeted towards remedial efforts at the high school level, early intervention in the foundational skills of algebraic thinking at the elementary level needs consideration for students who would benefit from early exposure to algebraic ideas. A key aspect of students' instruction with algebraic concepts at any level is the degree and type of preparation their teachers have received with this content. Using a mixed methods design, the current researcher investigated the usage of the Developing Algebraic Literacy (DAL) framework with preservice special education teacher candidates in an integrated practicum and coursework experience. Multiple survey measures were given at pre-, mid-, and post- junctures to assess teacher candidates' attitudes about mathematics, feelings of efficacy when teaching mathematics, and content knowledge surrounding mathematics. An instructional knowledge exam and fidelity checks were completed to evaluate teacher candidates' acquisition and application of algebraic instructional skills. Focus groups, case studies, and final project analyses were used to discern descriptive information about teacher candidates' experience while engaging in work with the DAL framework. Results indicated an increase in preservice teachers' attitudes towards mathematics instruction, feelings of efficacy in teaching mathematics, and in the content knowledge surrounding mathematics instruction. Instructional knowledge also increased across preservice teacher candidates, but abilities to apply this knowledge varied across teacher candidates', based on their number of sessions working with students within their practicum site. Further findings indicate the desire of preservice teachers to increase the length and number of student sessions within the DAL experience, as well as the need for increased levels of instructional support to enhance their own experience. This study provides preliminary support for utilizing the DAL instructional framework within preservice teacher preparation experiences for future special educators.

The cold-formed steel utilization in buildings has increased globally due to its higher strength to weight ratio, ease of transportation and rapid erection and dismantlement. However, cold-formed steel buildings must be designed with adequate Fire Resistance Ratings (FRR). Hence cold-formed Light gauge Steel Frames (LSF) are assembled using channel sections and lined with fire resistive plasterboards to provide load-bearing wall and floor systems. There is an industry need to develop LSF floor systems with improved FRR. Adding multiple layers of plasterboard to increase the FRR of LSF floor systems is not an efficient method. Past research has focused on investigating the behaviour of LSF floor systems made of Lipped Channel Section (LCS) joists. No attempt has been made to use an improved joist section in LSF floor systems. The Hollow Flange Sections (HFS) with torsionally rigid hollow flanges and no free edges have higher local and lateral distortional buckling capacities than the conventional LCSs. This research focuses on investigating the structural and fire performance of LSF floor systems made of HFS joists with a goal to improve their FRRs. Four full scale standard fire tests were undertaken on non-insulated dual and single plasterboard lined LSF floor panels and cavity insulated dual plasterboard lined floor panel made of welded HFS joists known as LiteSteel beams (LSB). Fire tests of these panels undertaken for varying load ratios provided valuable results, which included failure times, joist temperatures and modes, and deflection versus time curves. The floor panels failed due to the section failures of joists. Both non-insulated and cavity insulated LSF floors made of LSB joists showed a significant improvement in the FRRs in comparison to Baleshan's (2012) results for LSF floors made of LCS joists. Another experimental study was undertaken to determine the elevated temperature mechanical properties of the steel used in LSB web and flange elements. The mechanical property reduction variation of LSB steel elements was found to be quite different to that of normal cold-formed steels and was even dissimilar amongst them. The yield strength reduction factors of Eurocode 3 Part 1.2 (ECS, 2005) were proposed for the web elements since they closely followed them whereas a new yield strength reduction factor model was proposed for the flange elements. An identical variation was proposed for the elastic modulus reduction factors of both web and flange elements. Suitable modifications were made to Dolamune Kankanamge and Mahendran's (2011) stress-strain model for improved predictions of LSB web and flange elements' stress-strain curves. A Finite Element (FE) model of an individual simply supported LSB joist was developed and validated using the cold-formed steel design standards and Anapayan et al.'s (2011b) section moment capacity test results. By using the accurate mechanical property reduction factors of LSB steel elements, the FE model was then extended to simulate the full scale fire tests. Finite element analyses (FEA) showed reasonably good agreements in terms of failure times, temperatures and modes, and the mid-span deflection versus time curves. Such good agreements verified the accuracy of the developed FE model to simulate the LSF floor panels made of HFS joists under fire conditions. Thermal FE models of LSF floor systems made of HFS joists were then developed and the time-temperature profiles were compared with the fire test results. They showed better agreements for Tests 1 and 4 whereas there were some discrepancies for Tests 2 and 3. Thermal FEA results obtained using appropriate thermal properties of plywood showed a reasonably good agreement with Baleshan's (2012) fire test results. Parametric studies using the validated model showed that joist section depth and profile had no significant impact on the thermal performance of LSF floor systems whereas steel joist thickness had a significant influence. An extensive FEA based parametric study was then undertaken to investigate the effects of joist thickness, depth, section profile, steel grade and mechanical property reduction factors, and web openings on the structural and fire performances (FRR) of LSF floor systems. Steel joist thickness significantly influenced the FRR of LSF floor systems due to different temperature developments in the steels for varying thicknesses. Joist section depth, section profile and web openings had no significant impact on the FRRs of LSF floor systems. Steel type affected the FRRs of LSF floor systems significantly due to different mechanical property reduction factors, especially different yield strength reduction factors. It was shown that Baleshan's (2012) critical average joist temperature method can be used to determine the FRR of non-insulated dual and single plasterboard lined floor panels made of HFS joists. However, it can be used for cavity insulated floor panels when the load ratio is less than 0.3. Fire test and FEA results showed that LSF floor panels made of LSB joists gave higher FRRs due to improved elevated temperature mechanical properties of LSB plate elements and lower temperature development due to thicker joists. Fire design rules were developed to predict the FRRs of LSF floor systems made of HFS joists based on Eurocode 3 Part 1.3 (ECS, 2006), AS/NZS 4600 (SA, 2005) and Direct Strength Method (DSM). For this purpose, Baleshan's (2012) three fire design rules of LCS joists were used and suitable modifications were made in order to use them for HFS joists. A good agreement was observed between the FRR predictions using two design methods and FEA, and thus they were recommended. In addition, the FRR predictions of HFS joists using the fire design method developed based on DSM were modestly conservative and therefore they were also recommended. Finally, the spread sheet based design tool was developed to undertake the complex calculations in predicting the FRR of LSF floors made of HFS joists with varying sizes and steel types, and subjected to varying load ratios. In summary, this research has significantly improved the knowledge and understanding of the fire performance of LSF floor systems made of hollow flange section joists and developed accurate fire design rules. Structural and fire design engineers can use the developed spread sheet based design tool to predict the fire performance of LSF floor systems made of HFS joists with varying sizes and steel types for a range of applications in commercial and residential buildings.

La mesure des caractéristiques des feuilles et du couvert végétal par télédétection est un moyen efficace et non destructif d’effectuer un suivi des cultures, que ce soit pour la prise de décision dans la gestion d’itinéraires techniques an agriculture de précision ou pour le phénotypage au champ pour améliorer l'efficacité de la sélection variétale. Grâce à l’augmentation de la puissance de calcul des machines et à la disponibilité croissante d'images à haute résolution spatiale, les méthodes d’estimation peuvent maintenant bénéficier de simulations plus précises des modèles de transfert radiatif (RT) dans la végétation. L'objectif de ce travail est de proposer et d'évaluer des moyens efficaces pour estimer les caractéristiques des feuilles et du couvert végétal à partir d'observations rapprochées ou de télédétection en utilisant des modèles RT basés sur une description réaliste de la structure des feuilles et du couvert. Au niveau des feuilles, nous avons d'abord évalué la capacité des différentes versions du modèle PROSPECT à estimer des variables biochimiques comme la chlorophylle (Cab), la teneur en eau et en matière sèche. Nous avons ensuite proposé le modèle FASPECT pour décrire les différences de propriétés optiques entre les faces supérieure et inférieure des feuilles en considérant un système à quatre couches. Après avoir étalonné les coefficients d'absorption spécifiques des principaux constituants de la feuille, nous avons validé FASPECT sur 8 jeux de données. Nous avons montré que les spectres de réflectance et de transmittance des deux faces sont simulés avec une très bonne précision, et même meilleure que PROSPECT pour la face supérieure. De même, en mode inverse, les performances d'estimation de la teneur en matière sèche sont considérablement améliorées avec FASPECT par rapport à PROSPECT, et restent du même ordre de grandeur pour la chlorophylle et l’eau. Au niveau du couvert végétal, nous avons utilisé le simulateur de rendu physique réaliste LuxCoreRender pour calculer le transfert radiatif à partir d'une description 3D de l’architecture de la culture. Nous avons d’abord vérifié ses bonnes performances par comparaison aux modèles 3D les plus récents en utilisant ROMC (RAMI On Line Model Checker). Afin d’accélérer les simulations, nous avons développé une méthode qui repose sur l’utilisation d’un nombre limité de propriétés optiques du sol et des feuilles. Pour estimer les variables d'état du couvert végétal (indice de surface verte, GAI, contenu en chlorophylle du couvert (CCC) ou des feuilles (Cab), nous avons ensuite entrainé des algorithmes d’apprentissage automatique à partir de bases de données « culture spécifique » simulées avec LuxCoreRender pour le blé et le maïs et d’une base de données générique simulée avec le modèle 1D PROSAIL de transfert radiatif. Les résultats sur des simulations et sur des données in situ combinés aux images SENTINEL2 ont montré que les algorithmes spécifiques aux cultures surpassent les algorithmes génériques pour les trois variables, en particulier lorsque la structure du couvert s’éloigne de l'hypothèse 1D du milieu turbide, comme dans le cas du maïs où la structure en rang domine pendant toute une partie de la saison de croissance
Measuring leaf and canopy characteristics from remote sensing acquisitions is an effective and non destructive way to monitor crops both for decision making within the smart agriculture practices or for phenotyping under field conditions to improve the selection efficiency. With the advancement of computer computing power and the increasing availability of high spatial resolution images, retrieval methods can now benefit from more accurate simulations of the Radiative Transfer (RT) models within the vegetation. The objective of this work is to propose and evaluate efficient ways to retrieve leaf and canopy characteristics from close and remote sensing observations by using RT models based on a realistic description of the leaf and canopy structures. At the leaf level, we first evaluated the ability of the different versions of the PROSPECT model to estimate biochemical variables like chlorophyll (Cab), water and dry matter content. We then proposed the FASPECT model to describe the optical properties differences between the upper and lower leaf faces by considering a four-layer system. After calibrating the specific absorption coefficients of the main absorbing material, we validated FASPECT against eight measured ground datasets. We showed that FASPECT simulates accurately the reflectance and transmittance spectra of the two faces and overperforms PROSPECT for the upper face measurements. Moreover, in the inverse mode, the dry matter content estimation is significantly improved with FASPECT as compared to PROSPECT. At the canopy level, we used the physically based and unbiased rendering engine, LuxCoreRender to compute the radiative transfer from a realistic 3D description of the crop structure. We checked its good performances by comparison with the state of the art 3D RT models using the RAMI online model checker. Then, we designed a speed-up method to simulate canopy reflectance from a limited number of soil and leaf optical properties. Based on crop specific databases simulated from LuxCoreRender for wheat and maize and crop generic databases simulated from a 1D RT model, we trained some machine learning inversion algorithms to retrieve canopy state variables like Green Area Index GAI, Cab and Canopy Chlorophyll Content (CCC). Results on both simulations and in situ data combined with SENTINEL2 images showed that crop specific algorithms outperform the generic one for the three variables, especially when the canopy structure breaks the 1D turbid medium assumption such as in maize where rows are dominant during a significant part of the growing season

The purpose of this study is to develop an improved human radiation exchange model for use by planners and researchers. Although applicable for all environments, emphasis will be on urban areas. All processes of radiation exchange between the human body surface and surrounding environments were investigated through human body area factors (effective radiation area factor, feff, and projected area factor, fp), existing human thermal exchange models and three-dimensional (3D) computer simulation models with collected microclimatic data. For new body area factors, a sample of standing contemporary Canadian adults in normal-weight (male: 31 persons, female: 40) and over-weight (male: 48, female: 20) body mass index (BMI) categories were analyzed. A 3D mean body model was created for each category. Only very small differences in feff and fp were found between genders and BMI categories. Differences in feff and fp values between this study and previous studies were very large, up to 0.101 and 0.173, respectively. Another common body posture, walking, was also studied for the normal-weight male and female BMI categories. 3D computer walking body models at four stride positions were created. The directionless fp values for walking posture had minor differences between genders and positions in a stride. However, the differences of mean directional fp values between azimuth angles were great enough (up to 0.072) to create important differences in modeled radiation receipt. When both standing and walking postures are considered, the mean feff value of standing (0.826) and walking (0.846), 0.836, could be used. However, fp values should be selected carefully because differences between directional and directionless fp values were large enough that they could influence the estimated level of human thermal sensation. A new human radiation exchange model was developed using the new body area factors and compared with five existing models and one method (Burt, COMFA, MENEX, OUT_SET* and RayMan models and the six-directional method) using collected microclimatic data observed in Guelph, Ontario, Canada. Most differences between models came from absorbed solar radiation, especially absorbed direct beam solar radiation because of differences in fp* (=fp×feff) and feff or some missing components (feff or view factors). The lowest differences between the new model and the RayMan model alter the net all-wave radiation estimate up to 29 Wm-2, which can be significant in the human thermal exchange model. For 3D computer estimation, a new human-urban radiation exchange simulation model was developed combining the new human radiation exchange model and improved urban area factors (i.e., albedos and view factors of sunny and shaded building, ground and vegetation surfaces). The results of the new computer model were compared with microclimatic data collected in Nanaimo, B.C., Canada and Changwon, Republic of Korea as well as with two other 3D computer simulation programs, RayMan Pro and ENVI-met 3.1. The differences between the collected data and the new model were very small. Their correlation was very strong, over 0.99 for total radiation. RayMan Pro and ENVI-met 3.1 programs had larger differences, and their correlations with measured data were weaker than the new model’s. Accurate meteorological and urban setting data should be obtained for better results. The new model will give planners and researchers a simple tool to estimate accurate radiation effects in complex urban areas.
Graduate

碩士
立德大學
資源環境研究所
97
The problem of depositing silt in the Baihe Reservoir is so serious that the capability of storing water becomes decreasing. The average annual rainfall from October to next May in this region always becomes lower than other regions in Taiwan. Thus, the water supply for the crop irrigation lacks of imbalance, even cause fallow problem. How to make good use of the limited water is needed to overcome nowadays. In order to solve the problem of water scarcity at Baihe River reservoir irrigation area, the adjustment crops planter structure and uses the CROPWAT model to estimate crops water demand. Meanwhile, the analysis transfer water source supplemented the Baihe River reservoir water used is insufficient feasibility. Firstly, collecting rainfall, water reservation volume and others data by HusehChia Experiment Station of ChiaNan Irrigation Association from 1984 to 2006. According to the cultivation time, the model will simulate the current situation to offer the flexible suggestions to irrigate crops effectively during the drought to reach the optimal utilization for the Baihe Reservoir. Such a simulation model could be used as the reference to set up the irrigation in the future. The result showed that the simulation of Cane, which planted dates are on 1/15, 2/15 and 3/30 respectively, was utilized as the subject crop. The quantity of output for the crop were 98.8%, 97.1% and 93.2% respectively; effective rainfall were 1027.8mm, 1060.2mm and 919.8mm, which demonstrated that the volume of Cane in February were not decreasing dramatically in comparison to the dates on 1/15 and 3/30, the rainfall utilization ranging 30mm to 140mm. In spring season, the cultivation for sweet melon were set on 2/1, 3/1 and 3/21 respectively, was utilized as the subject crop. The quantity of output for the crop were all 100% respectively; effective rainfall were 341.2mm, 375.2mm and 394.7mm, which demonstrated that the volume of sweet melon in March were not decreasing dramatically in comparison to the dates on 2/1 and 3/1, the rainfall utilization ranging 43.5mm to 77.5mm. In addition, in the autumn season, the cultivation for sweet melon were set on 8/1, 8/11 and 9/1 respectively, was utilized as the subject crop. The quantity of output for the crop were all 93.2%、89.7% and 87.4% respectively; effective rainfall were 197mm、167.2mm and 119.2mm, which demonstrated that the volume of sweet melon in August reached maximum in comparison to the dates on 8/11 and 9/1, the rainfall utilization ranging 29.8mm to 77.8mm.

碩士
中原大學
土木工程學系
87
This research is to develop a method to predict the effective rainfall based on the operating procedure of the watergate. Also, by considering the height of paddy field boarder and in associate with the irrigation plan in Tao-Yuan Irrigation Association, a practical model is developed. To estimate the monthly planning effective rainfall, the best distribution of the monthly effective rainfall is first determined, than 75% of is occurring probability is used for analysis. The calculated monthly effective rainfall is about 90% of the value used by the current Tao-Yuan Irrigation Association. In order to keep the current calculation method of the Tao-Yuan Irrigation Association and the watergate operating style the same, this practical method can be applied. Besides, currently using one branch one station to represent the irrigating rainfall, effective rainfall and planning effective rainfall is also investigated. Results show that it is very close to the results based on Thiessen’s method. Therefore, for simple operation, the one branch one station method can be used.

碩士
國立清華大學
電子工程研究所
102
Charge pump is a kind of DC-DC converter circuit which uses capacitors as energy store elements to create a higher output steady voltage. It’s widely used in voltage converter, power management system and phase lock loop because of its simple circuit structure and high power efficiency. Building the circuit model to do analysis work is helpful for circuit design and optimization. Dickson charge pump circuit is the fundamental and most widely used charge pump circuit. The conventional analytical model based on the Dickson charge pump is studied in this thesis. An improved Dickson charge pump model with an effective Vth parameter is derived in response to the drawbacks of the conventional model (as can’t be used to analysis the effect of MOS width on the circuit performance). The improved model can predict the steady-state output voltage more accurate. As linear capacitor is used as the charging capacitor in the charge pump circuit, the circuit area problem can’t be ignored. Larger circuit area leads to larger costs, so circuit area optimization work should be done on the design of charge pump circuit. In this thesis, to decrease the circuit area, a new design using varactor as the charging capacitor to replace of linear capacitor is derived. An improved area minimization work based on the effective threshold voltage Dickson charge pump model and varator charging capacitor is done on the Dickson charge pump circuit. Circuit which has been done by this area optimized work will have great area advantage compared to the conventional Dickson charge pump circuit which hasn’t been area optimized. In this thesis, all simulations are based on TSMC 0.18um CMOS model. The clock has an amplitude of -1.5V to 1.5V, of which frequency is 100 (KHz) and the duty cycle is 50%. The objective steady-state output voltage is 1.5 (V) and output current is 1 0(uA).

ABI has a sophisticated and effective distribution fleet which delivers canned and bottled non alcoholic beverages to 12000 wholesale and retail outlets in the Durban Metropole and to 46000 outlets nationally. Delivery is normally executed once per week, 48 hours after a separate order is taken by an account manager. In the more rural or "emerging market" areas traditional retail outlets such as supermarkets and superettes are scarce and reliance is made on spaza and house shops. Cash flow and storage space is limited. The sales and distribution calls are expensive, relative to the size order that the spaza would place. Spaza shop owners rely on distributors or collect from wholesalers. These outlets often run out of stock. Sales revenue is thus not maximized. Outlet development is marginal. The writer embarked on a research project to develop a sustainable and cost effective Sales and Distribution model in order to address these constraints in the Emerging Market territories of ABI Durban. Traditional theory turns to channel distribution as a means to effectively reaching an entire retail market. Levels are thus added to the distribution channel. The research however showed that service levels are sometimes compromised. The model that was developed returns ABI to DSD (direct service delivery) via specially designed vehicles and combines the function of "preseller" and "delivery merchandiser" on a dedicated route. Although a marginal increase in cost per case has been experienced, deliveries are direct to store, at least twice per week. Sales growth in these routes have been in excess of 85% while the total Umlazi area grows at 13%. Customer service levels, as surveyed, are exceptional. Although the model was specifically designed by ABI Durban for use in Durban, the concept has been adopted as a best practice and is being "rolled out" across the business. By the end of 2005, 10% of ABl's fleet nationally will function as MOTD (Merchandiser Order Taker Driver) routes. Additional vehicles have been ordered for delivery during the period July 2005 to September 2005 in order for this to be achieved. This model has assisted ABI in achieving its goal of maximizing DSD and lifting service levels to its customers (retailers). Revenue has increased significantly along with volume in these areas. Invariably MOTD acts as a significant barrier to competitor entry in those geographic areas where it is utilized. The Merchandiser Order Taker Driver (MOTD) model is successful and has potential for wider use, even in more developed markets.
Thesis (MBA)-University of KwaZulu-Natal, 2005.

Dissertação de Mestrado Integrado em Engenharia Mecânica apresentada à Faculdade de Ciências e Tecnologia
A presente investigação tem como principal objetivo o desenvolvimento de metodologias adequadas à aquisição de dados relativos à evolução temporal de parâmetros considerados fundamentais no estudo das forças de resistência atuantes sobre o conjunto ciclista + bicicleta num contexto de alta competição. Através do pós processamento destes dados, pretende-se efetuar um estudo detalhado da influência que estes parâmetros em análise têm, nomeadamente, nas forças de resistência aerodinâmica atuantes sobre o conjunto ciclista + bicicleta, por forma a chegar a conclusões sobre o tipo de alterações que podem ser implementadas ao nível da posição de condução e do equipamento utilizado pelo ciclista, no sentido de otimizar a eficiência da potência mecânica produzida pelo mesmo no decorrer de uma prova.Foram desenvolvidas metodologias aplicáveis em ensaios de túnel de vento, nas quais foi utilizada a balança multiaxial de forças HBM MCS10 para medição das forças aerodinâmicas que atuam sobre o conjunto em análise. Foram também desenvolvidas metodologias para aquisição de dados de evolução temporal de parâmetros como a velocidade do conjunto ciclista + bicicleta relativamente ao solo e ao escoamento incidente, através da instalação de um conjunto de sondas de pressão de dois furos (mais concretamente, um tubo de Pitot e uma sonda direcional) e ainda de um SRM Powermeter, que permitiu também registar a evolução de temporal de parâmetros como a altitude do terreno e a potência mecânica produzida pelo ciclista.Concluindo, foram desenvolvidas várias metodologias aplicáveis em diferentes contextos de ensaio (em túnel de vento ou em estrada e em pista), sendo que os resultados obtidos serão úteis para a otimização da aquisição de dados em futuras investigações que recorram a sondas de pressão de dois furos.
The present investigation aims to develop adequate methodology for data acquisition over the temporal evolution of several major parameters in the analysis of drag resistance forces acting on a cyclist in a road bicycle. Through post-processing of the collected data, this study intends to carry out a detailed report in order to reach conclusions on which alterations should be made to the riding position of the cyclist and to the equipment that he uses, in order to achieve noticeable reductions in terms of aerodynamic drag acting upon the cyclist. This reduction in the aerodynamic drag is expected to improve the efficiency of the mechanical power output produced by the cyclist in the pedaling exercise.Wind tunnel testing methods were developed using a six component balance, the MCS10 model from the manufacturing brand HBM, which facilitates data acquisition of the aerodynamic drag forces acting on both the cyclist’s and the bicycle’s systems.Field methods such as the deceleration method were also developed for observing the evolution of parameters such as ground speed and incident flow over time, as well as altitude and mechanical power output over time. These parameters were obtained using resources such as two hole pressure probes and an SRM Powermeter.In summary, this investigation aims to reach a more accurate method of observing and registering data yielded by the system under study, as well as adequately proposing solutions for optimizing the sustained speed in relation to the power output that the cyclist needs to produce over time. Thus, conducting this study produced several methods suitable for various applications (in wind tunnel or field testing), and the results may positively inform future studies, which can provide more accurate conclusions regarding data acquired from the two-hole pressure probes.
Outro - A presente investigação foi financiada pela Federação Portuguesa de Ciclismo e pelo Comité Olímpico de Portugal.

Plasmonic properties and the related novel applications are studied on various types of metallic nano-structures in one, two, or three dimensions. For 1D nanostructure, the motion of free electrons in a metal-film with nanoscale thickness is confined in its normal dimension and free in the other two. Describing the free-electron motion at metal-dielectric surfaces, surface plasmon polariton (SPP) is an elementary excitation of such motions and is well known. When further perforated with periodic array of holes, periodicity will introduce degeneracy, incur energy-level splitting, and facilitate the coupling between free-space photon and SPP. We applied this concept to achieve a plasmonic perfect absorber. The experimentally observed reflection dip splitting is qualitatively explained by a perturbation theory based on the above concept. If confined in 2D, the nanostructures become nanowires that intrigue a broad range of research interests. We performed various studies on the resonance and propagation of metal nanowires with different materials, cross-sectional shapes and form factors, in passive or active medium, in support of corresponding experimental works. Finite- Difference Time-Domain (FDTD) simulations show that simulated results agrees well with experiments and makes fundamental mode analysis possible. Confined in 3D, the electron motions in a single metal nanoparticle (NP) leads to localized surface plasmon resonance (LSPR) that enables another novel and important application: plasmon-heating. By exciting the LSPR of a gold particle embedded in liquid, the excited plasmon will decay into heat in the particle and will heat up the surrounding liquid eventually. With sufficient exciting optical intensity, the heat transfer from NP to liquid will undergo an explosive process and make a vapor envelop: nanobubble. We characterized the size, pressure and temperature of the nanobubble by a simple model relying on Mie calculations and continuous medium assumption. A novel effective medium method is also developed to replace the role of Mie calculations. The characterized temperature is in excellent agreement with that by Raman scattering. If fabricated in an ordered cluster, NPs exhibit double-resonance features and the double Fano-resonant structure is demonstrated to most enhance the four-wave mixing efficiency.