Dissertations / Theses on the topic 'Gavin Holt'

Turbulent and cavitation induced pipe vibration is a large problem in industry often resulting in pipe failures. This thesis provides an experimental investigation on turbulent flow and cavitation induced pipe vibration caused by sharp edged baffle plates. Due to large pressure losses across a baffle plate, cavitation can result. Cavitation can be destructive to pipe flow in the form of induced pipe wall vibration and cavitation inception. Incipient and critical cavitation numbers are design points that are often used in designing baffle plate type geometries. This investigation presents how these design limits vary with the influencing parameters by exploring a range of different baffle plate geometries. The baffle plates explored contained varying hole sizes that ranged from 0.159 cm to 2.54 cm, with the total through area, or openness, of each baffle plate ranging between 11% and 60%. Plate thickness varied from 0.32–0.635 cm. Reynolds numbers ranged from 5 x 10^4 -85 x 104. The results show that the cavitation design limits are function of size scale effects and the loss coefficient only. The results also show that the loss coefficient for a baffle plate varies not only with total through area ratio, but also due with the plate thickness to baffle hole diameter ratio. Pipe wall vibrations were shown to decrease with increased through area ratio and increased thickness to diameter ratios. An investigation was also performed to characterize the attenuation of vibration in the streamwise direction of a baffle plate. It was show that the attenuation was largely effected by the presence of cavitation. Attenuation was shown to be a function of the geometry of the baffle plate. This work resulted in empirical models that can be used for predicting pipe vibration levels, the point of cavitation inception, and the streamwise distance where the attenuation of vibration levels caused by a baffle plate occurs.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.
Includes bibliographical references (p. 71-72).
by John Kenneth Fiorenza.
S.M.

This research is concerned with the flight dynamic, pitch flight control and flying qualities assessment for the reference BWB aircraft. It aims to develop the longitudinal control laws which could satisfy the flying and handing qualities over the whole flight envelope with added consideration of centre of gravity (CG) variation. In order to achieve this goal, both the longitudinal stability augmentation system (SAS) and autopilot control laws are studied in this thesis. Using the pole placement method, two sets of local Linear-Time-Invariant (LTI) SAS controllers are designed from the viewpoints of flying and handing qualities assessment and wind disturbance checking. The global gain schedule is developed with the scheduling variable of dynamic pressure to transfer gains smoothly between these two trim points. In addition, the poles movement of short period mode with the varying CG position are analysed, and some approaches of control system design to address the problem of reduced stability induced by CG variation are discussed as well. To achieve the command control for the aircraft, outer loop autopilot both pitch attitude hold and altitude hold are implemented by using the root locus method. By the existing criteria in MIL-F-8785C specifications being employed to assess the augmented aircraft response, the SAS linear controller with automatic changing gains effectively improve the stability characteristic for the reference BWB aircraft over the whole envelope. Hence, the augmented aircraft equals to a good characteristic controlled object for the outer loop or command path design, which guarantee the satisfactory performance of command control for the BWB aircraft. The flight control law for the longitudinal was completed with the SAS controller and autopilot design. In particular, the SAS was achieved with Level 1 flying and handing qualities, meanwhile the autopilot system was applied to obtain a satisfactory pitch attitude and altitude tracking performance.

This thesis considers the problem of designing gain scheduled flight control system (FCS) for large transport aircraft that satisfy handling qualities criteria. The goal is to design a set of local Linear Time Invariant (LTI) controllers to cover the wide non- linear aircraft operation flight envelope from the viewpoint of the handling qualities assessment. The global gain scheduler is then designed that interpolates between the gains of the local controllers in order to transfer smoothly between different equilibrium points, and more importantly to satisfy the handling qualities over the entire flight envelope. The mathematical model of the Boeing 747-100/200 aircraft is selected for the purpose of the flight controller design and handling qualities as- sessment. In order to achieve an attitude hold characteristic, and also improve the dynamic tracking behavior of the aircraft, longitudinal pitch Rate Command-Attitude Hold (RCAH) controllers are designed as the local flight controllers at the specific equilib- rium points in the flight envelope by means of a state space pole placement design procedure. The handling qualities assessment of the aircraft is presented, based on which the scheduler is designed. A number of existing criteria are employed to assess the han- dling qualities of the aircraft, including the Control Anticipation Parameter (CAP), Neal and Smith, and C∗ criteria. The gain scheduled flight controller is found to have satisfactory handling qualities. The global gain scheduler is designed by interpolating the gains of the local flight controllers in order to transfer smoothly between different equilibrium points, and more importantly to satisfy the handling qualities over the flight envelope. The main contribution of this research is the combination of the gain scheduling technique based on the local controller design approach and handling qualities as- sessment. The controllers are designed based at a number of operating points and the interpolation between them (scheduling) takes place through the scheduling scheme functions. The aircraft augmented with gain-scheduled controller performs satisfactorily and meets the requirement of handling qualities. Moreover, the per- formance using the gain-scheduled controller is considerably improved compared to the performance using the fixed one.

The roles of net positive oxide trapped charge and surface recombination velocity in producing excess base current in bipolar junction transistors (BJTs) are identified. Although the interaction of these two quantities is physically complex, simple approaches for estimating their magnitude from measured BJT characteristics are presented. The oxide charge is estimated using a transition voltage in the plot of excess base current versus emitter bias. Two approaches for quantifying the effects of surface recombination velocity are described. The first measures surface recombination directly using a gated diode, while the second estimates its effects using an intercept current that is easily obtained from the BJT itself. The results are compared to two-dimensional simulations and measurements made on test structures. The techniques are simple to implement and provide insight into the mechanisms and magnitudes of the radiation-induced damage in BJTs. A physically-based comparison between hot-carrier and ionizing radiation stress in BJTs is presented as well. Although both types of stress lead to qualitatively similar changes in the current gain of the device, the physical mechanisms responsible for the degradation are quite different. Implications for correlating and comparing hot-carrier-induced and ionizing-radiation-induced damage are discussed. Finally, the worst-case increase in base current is shown to be dose-rate independent. This fact allows the worst-case response of bipolar devices to be determined using convenient laboratory dose rates.

A large number of recently-built residential buildings in Libya provide a poor quality indoor environment or require a huge amount of energy to run the air conditioning, therefore influencing the thermal comfort, energy consumption and carbon emissions. As the use of energy in buildings is the major contributor to air pollution and global climate change, improving energy efficiency through the application of bioclimatic design principles in residential buildings in Libya is a critical factor in reducing energy consumption, securing thermal comfort, and hence is an effective policy for reducing the environmental impacts such as global warming and ozone layer depletion. This research assumes that the use of appropriate orientation, materials and building configuration would offer suitable solutions for energy and environmental problems in hot, arid countries. This hypothesis is examined through an example located in Libya. A domestic building in Libya was studied with a view to reducing its energy consumption. The study included detailed monitoring for 45 days continuously, followed by computer simulation of a range of intervention strategies. A field study including temperature, humidity and electricity consumption measurements was carried out and results from the study were gathered and analysed. Moreover a computer simulation model was built using IES software, a fully dynamic simulation model to investigate the potential influence of changes to the building. The thermal comfort of users in a residential building in Tripoli, Libya was investigated. Field measurements and subjective environmental perception survey were used. It was established that building design in hot arid regions must consider thermal requirements.

The atypical antipsychotic risperidone is associated with weight gain and cardio-metabolic side effects. In light of growing evidence implicating the gut microbiome in the host’s energy regulation and in xenobiotic metabolism, it is hypothesized that risperidone-induced weight gain is mediated through alterations in the gut microbiome. The impact of chronic and short-term risperidone treatment on the gut microbiome of pediatric, psychiatric patients was examined in a cross-sectional and prospective design. Chronic treatment with risperidone was associated with a significant increase in body mass index (BMI) and a significant reduction in the ratio of Bacteroidetes to Firmicutes, as compared to naïve psychiatric controls. Predictive metagenomic analyses, indicate that gut microbiota dominating the risperidone-treated patients are enriched for pathways, such as short-chain fatty acid production, which have been implicated in weight gain. Alterations in the microbiome due to risperidone treatment were further demonstrated in wild-type female mice and shown to be a result of a reduction in host energy expenditure. Risperidone-treated mice exhibit significant weight gain and an altered gut microbiome relative to controls while maintaining normal food intake behavior and digestive efficiency, indicating that increased weight gain is due to reduced energy expenditure. Moreover, fecal transfer from risperidone-treated mice to a second cohort of naïve mice was performed via daily gastric gavage and aerobic and non-aerobic resting metabolic rates (RMR) were monitored using combined calorimetry. This transfer has no effect on aerobic RMR in recipients, but induces a significant suppression of non-aerobic RMR in mice receiving stool from risperidone-treated donors establishing a causal effect of the altered gut microbiome upon energy expenditure. Finally, daily transfer of phage, a subset of the gut microbiome, isolated from the gut of risperidone treated donors was also sufficient to cause excess weight gain in naïve recipients animals through suppression of energy expenditure. Together, these data highlight a major role for the gut microbiome for weight gain following chronic use of risperidone, and demonstrate that the mechanism depends upon suppression of energy expenditure.

Le schéma d'allumage par choc représente une alternative aux schémas d'allumage classiques en Fusion par Confinement Inertiel. Sa singularité repose sur la relaxation des contraintes sur la phase de compression et l'atteinte des conditions d'allumage par l'envoi d'une impulsion laser brève (~500 ps) et très puissante (~300 TW) sur le combustible en fin d'implosion.Au cours de ce travail de thèse, il a été établi que ce procédé induit une configuration non-isobare du combustible au moment de l'allumage, modifiant ainsi les critères d'inflammation du Deutérium-Tritium (DT) par rapport aux schémas conventionnels d'allumage. Un modèle de gain pour la combustion est ensuite développé et des courbes de gain pour l'allumage par choc sont alors obtenues puis validées numériquement. La modélisation hydrodynamique présentée a démontré qu'il est ainsi possible d'obtenir de hauts gains à plus faibles énergies laser que l'allumage conventionnel du fait de la haute pression du point chaud au moment de l'allumage résultante de la propagation du choc d'allumage.Le code d'hydrodynamique radiative CHIC du CELIA a été utilisé afin de développer des dépendances paramétriques définissant les conditions optimales en termes de paramètres de dimensionnement de cibles pour l'atteinte des conditions d'ignition. Ces études numériques ont mis en lumière le potentiel du procédé d'allumage par choc en termes d'économie d'énergie laser, de hauts gains mais aussi de marges de sécurité et de robustesse pour l'allumage. Enfin, les résultats des premières campagnes expérimentales d'allumage par choc en symétrie sphérique effectuées sur l'installation laser OMEGA (NY, USA) sont présentés. Une interprétation des résultats est proposée à partir de simulations hydrodynamiques mono et bidimensionnelles. Différentes pistes sont alors explorées afin d'expliquer les différences observées et des solutions potentielles pour l'amélioration des performances à l'échelle de l'installation OMEGA sont proposées
The Shock Ignition (SI) scheme is an alternative to classical ignition schemes in Inertial Confinement Fusion. Its singularity relies on the relaxation of constraints during the compression phase and fulfilment of ignition conditions by launching a short and intense laser pulse (~500 ps, ~300 TW) on the preassembled fuel at the end of the implosion.In this thesis, it has been established that the SI process leads to a non-isobaric fuel configuration at the ignition time thus modifying the ignition criteria of Deuterium-Tritium (DT) against the conventional schemes. A gain model has been developed and gain curves have been infered and numerically validated. This hydrodynamical modeling has demonstrated that the SI process allows higher gain and lower ignition energy threshold than conventional ignition due to the high hot spot pressure at ignition time resulting from the ignitor shock propagation.The radiative hydrodynamic CHIC code developed at the CELIA laboratory has been used to determine parametric dependences describing the optimal conditions for target design leading to ignition. These numerical studies have enlightened the potential of SI with regards to saving up laser energy, obtain high gains but also to safety margins and ignition robustness.Finally, the results of the first SI experiments performed in spherical geometry on the OMEGA laser facility (NY, USA) are presented. An interpretation of the experimental data is proposed from mono and bidimensional hydrodynamic simulations. Then, different trails are explored to account for the differences observed between experimental and numerical data and alternative solutions to improve performances are suggested

L’hépatite B est causée par le virus de l’hépatite B (VHB) qui est une cause majeure du carcinome hépatocellulaire, deuxième cancer le plus meurtrier au monde. Le VHB infecte des hépatocytes humains, et, dû à la petite taille de son génome, dépend de nombreux facteurs de l’hôte, qui contribuent au tropisme d’espèce et à sa spécificité tissulaire. Cependant, au niveau moléculaire les interactions virus-hôtes nécessaires au cycle viral restent mal connues, à cause de l’absence de modèles cellulaires robustes pour l’étude de l’infection par le VHB. Un criblage innovant de génomique fonctionnel a révélé le rôle de CDKN2C comme facteur d’hôte proviral promouvant la réplication du VHB lors d’une étape du cycle viral postérieure à la formation de l’ADN super-enroulé, ceci, par sa fonction de régulateur du cycle cellulaire. Les travaux réalisés offrent une meilleure compréhension des interactions virus-hôte et des limites des systèmes de culture cellulaire actuellement disponibles, et contribuera au développement de systèmes modèles infectieux plus performantes et à l’élaboration de stratégies thérapeutiques novatrices pour lutter contre l’hépatite B chronique
Hepatitis B is caused by the hepatitis B virus (HBV) and is a major cause of progressive liver disease including cirrhosis and hepatocellular carcinoma (HCC), the second leading cause of cancer death worldwide. HBV infects human hepatocytes, and, because of the tiny size of its genome, depends on multiple host functions, contributing to species and tissue tropism. However, fundamental virus-host interactions remain obscure, owing to the lack of robust infectious models for HBV research. An innovative functional genomics screen revealed the role of CDKN2C as proviral host factor promoting HBV replication in a step of the life cycle after the formation of covalently closed circular (ccc) DNA via its function as cell cycle regulator. This provides a better understanding of virus-host interactions and limitations of currently available cell culture systems, and will contribute to the development of physiological infectious model systems and novel therapeutic strategies for viral cure

Ce travail de thèse concerne les circuits ultra-rapides pour la conversion analogique numérique performante en technologie bipolaire à hétérojonctions sur substrat Indium Phosphore (TBDH/InP). L'étude s'intéresse à la fonction principale qui est l'échantillonnage blocage. Elle a été menée par simulation de l'ensemble des blocs composant cette fonction. En particulier une étude extensive des cœurs des circuits Echantillonneurs/Bloqueurs a été effectuée pour différents paramètres électriques pour aboutir à des valeurs optimales réalisant un compromis entre la bande passante la résolution et la linéarité.Des architectures de circuits Echantillonneurs/Bloqueurs (E/B) avec ou sans l'étage d'amplification à gain variable ont été conçues, optimisées, réalisées et caractérisées et des performances à l'état de l'art ont été obtenues : des circuits E/B de bande passante supérieure à 50 GHz et cadencées à 70 Gs/s ont été réalisés pour les applications de communications optiques et des circuits de bande passante supérieure à 16 GHz cadencés à (2-8) Gs/s ont été réalisés pour la transposition de fréquence
This thesis concerns the design of high speed circuits in Indium phosphide heterojunction Bipolar technology for High performance analog to digital conversion (ADC).The study focuses on the Track and Hold block (THA) which is the main function of the ADC. The study was conducted by simulating all blocks of the THA circuit. In particular, an extensive study of the THA main block was performed for various electrical parameters to achieve optimal conditions in order to obtain a good tradeoff between resolution bandwidth and linearity. THA architectures circuits with or without Voltage Gain Amplifier stage were designed, optimized and characterized. High THA performances were achieved: THA circuit with a bandwidth greater than 50 GHz at 70 Gs/s were achieved for optical communications and circuits of bandwidth more than16 GHz at (2-8 GS /s) have been realized for down conversion operation

This master thesis describes the design of a track-and-hold (T&H) circuit with 10bit resolution, 80MS/s and 30MHz bandwidth. It is designed in a 0.18µm CMOS process with a supply voltage of 1.8 Volt. The circuit is supposed to work together with a 10bit pipelined analog to digital converter.

A switched capacitor topology is used for the T&H circuit and the amplifier is a folded cascode OTA with regulated cascode. The switches used are of transmission gate type.

The thesis presents the design decisions, design phase and the theory needed to understand the design decisions and the considerations in the design phase.

The results are based on circuit level SPICE simulations in Cadence with foundry provided BSIM3 transistor models. They show that the circuit has 10bit resolution and 7.6mW power consumption, for the worst-case frequency of 30MHz. The requirements on the dynamic performance are all fulfilled, most of them with large margins.

This research is focused on single-collision energy transfer events between highly vibrationally excited benzene-like donor molecules and small bath molecules, CO2 and N2O in the vibrational ground level. Measuring how much energy is transferred from donors to bath molecules was accomplished by probing bath molecules scattered into specific-rotational states using a tunable Δv=0.0003 cm-1 solid state diode laser. The normalized energy transfer probability distribution function, P(E,E'), determined from energy gain information, is very useful in comparing collisional energy transfer efficiency between various collision systems. P(E,E') is also used to investigate the effects of donor and bath physical properties on collisional energy transfer. The first chapter details the C6H5F–CO2 system, which is the basis of a study on the effect of donor fluorination on strong collision energy transfer. The second chapter is about all fluorobenzene–CO2 systems, which investigates the effect of excess vibrational excitation energy of donors on supercollision energy transfer efficiency as well as donor fluorination effect. The third chapter focuses on how the physical properties of bath molecules affect supercollision energy transfer by measuring state-specific energy gain of N2O scattered into 0000, J=59−75. Instead of CO2, N2O was used as a bath molecule with a pyrazine donor to compare energy gain results of bath molecules with somewhat different physical properties. N2O and CO2 are isoelectronic and have similar mass, but N2O has a small dipole moment. Comparison of P(E,E') obtained from pyrazine–CO2, –N2O, –DCl, and –H2O systems helps to elucidate the effect of the bath physical properties on supercollision energy transfer efficiency. The last chapter is dedicated to the extension of the measurement range of N2O energy gain to the mid J states (J=37–75). In this chapter I discuss reliability of P(E,E') obtained from only high J tail as well as the correction of overall energy transfer rate constant.

Thesis deals with the possibility of reducing the energy costs of a typical family house located in Brno. In the first part is a detailed calculation of heat loss of the building, considering heat gain and subsequent quantification of costs for heating, hot water and total annual costs. In other sections provide specific calculation of the economics for the partial implementations of planned procedures leading to a reduction in heating costs (replacing windows, doors, facades and floor ceiling). A calculation for changing the heating method and compared to the existing boiler. A possible reduction in the energy required when using energy from the Sun. In the penultimate section briefly review the options for what you get a subsidy from the grant program "New Green Savings Programme" and reduce the initial investment. Finally the comprehensive proposals of different options exchanges boiler insulation, replacing windows and doors, and the subsequent evaluation of the best solution when investing 350 000 CZK.

Etude des caracteristiques du plasma electron-trou. Interpretation des courbes de gain optique obtenues par deux modeles theoriques. Etude des proprietes des biexcitons par melange degenere a quatre ondes et determination de leur energie de liaison (2 mev)

碩士
國立交通大學
工學院半導體材料與製程設備學程
101
This research fabricated high-gain avalanche rushing amorphous photoconductors (HARP) for medical x-ray detector applications, using amorphous selenium (a-Se) as the photoconductive material because of its high photoconversion efficiency. Under a strong electric field, photogenerated holes travel in the photoconductive layer with a high velocity and collide with atoms on the drift path, resulting in more photogenerated carriers. The successive impact ionization process induces the so-called “avalanche multiplication” of the electrical signal. For medical x-ray imagers of low irradiation exposure, HARP devices should have a high photoconversion gain with a very low noise so that a high image contrast can be obtained. The injection of holes and electrons into the a-Se layer via the top and bottom contact electrodes is the primary noise source. We used thermal evaporation to deposit a-Se thin films at temperatures below 40 °C. The CeO2 &; ZnO hole blocking layers, which sandwiched between the ITO substrate and the a-Se layer, were prepared by sputter deposition. In order to observe the correlation between the dark current and traps inside the CeO2 &; ZnO thin film, we controlled the flow rate of oxygen when sputtering CeO2 &; ZnO. In addition, we also deposited distributed resistive layer on the a-Se layer to improve the electrical breakdown voltage for the HARP structure.

碩士
國立交通大學
材料科學與工程學系奈米科技碩博士班
101
This research fabricated high-gain avalanche rushing amorphous photoconductors (HARP) for medical low dose X-ray detector applications, using amorphous selenium (a-Se) as the photoconductive layer. The greatest advantage of a-Se is its high photoconversion efficiency result from avalanche multiplication under high electric field. For application of low dose X-ray exposure, HARP devices should have a high photoconversion gain with a very low dark current so that a high image contrast can be obtained. In order to reduce dark current, a hole blocking layer is used between the photoconductive layer and the anode of HARP device. Here are two goals of this research about ZnO hole blocking layer prepared by rf magnetron reactive sputter deposition. First, we optimized the ZnO hole blocking layer. Second, by changing the oxygen flow rate and substrate temperature during deposition, we investigate how these parameter affect the ZnO hole blocking layer and discover the relationship between the microstructure and traps of ZnO hole blocking layer and the dark current of HARP. We concluded that because the deep hole traps related to oxygen vacancy in ZnO hole blocking layer can prevent hole from injecting into the photoconductive layer, the dark current of HARP can be reduce if ZnO hole blocking layer is introduced in HARP.

Η χρήση διαφορισμού σε συστήματα κινητών επικοινωνιών είναι μία ευρέως χρησιμοποιούμενη τεχνική για την καταπολέμηση των διαλείψεων που παρατηρούνται στις ραδιοζεύξεις. Στην παρούσα διατριβή παρουσιάζονται διάφοροι τρόποι και τεχνικές για την μελέτη της απόδοσης συστημάτων που κάνουν χρήση διαφορισμού στον δέκτη. Οι τεχνικές διαφορισμού που μελετώνται είναι ο διαφορισμός ίσου κέρδους (equal-gain combining) και ο διαφορισμός επιλογής (selection combining). Επιπλέον, στα πλαίσια της διατριβής αυτής, υποθέτουμε ότι ο δέκτης λειτουργεί σε κανάλια μη-επιλεκτικών συχνοτήτων με βραδείες διαλείψεις (flat and slow fading channels), ενώ το εκπεμπόμενο σήμα υφίσταται διαλείψεις κατά Rayleigh, Nakagami-m, Rice ή Hoyt. Αποδεικνύεται ότι η απόδοση του συστήματος στο οποίο ο δέκτης κάνει χρήση διαφορισμού εξαρτάται σε μεγάλο βαθμό από: • τη συσχέτιση μεταξύ των καναλιών διαφορισμού και • τη διαφορά της ισχύος μεταξύ των καναλιών διαφορισμού. Για να μελετηθεί η απόδοση ενός ΔΕ που λειτουργεί σε συσχετισμένα Nakagami-m κανάλια παρουσιάζεται παρουσιάζονται για πρώτη φορά σε κλειστή μορφή η συνάρτηση πυκνότητας πιθανότητας (ΣΠΠ) Nakagami-m μεταβλητών με εκθετική συσχέτιση, ενώ η αντίστοιχη συνάρτηση αθροιστικής κατανομής (ΣΑΚ) που προκύπτει έχει τη μορφή πολλαπλών άπειρων αθροισμάτων.
Diversity reception has been successfully used in wireless communications systems to mitigate the negative effect of channel fading. This thesis deals with the performance analysis of wireless systems employing receiver diversity. The diversity schemes studied are selection combining (SC) and equal-gain combining (EGC). We assume that the receiver operates in flat and slow fading channels and that the signal undergoes Rayleigh, Nakagami-m, Rice or Hoyt fading. As it will be shown, the performance of the diversity system depends greatly on: • the correlation among the diversity branches, • the average power imbalance of the received signals In order to study the performance of a SC receiver operating in correlated Nakagami-m fading channels, we first present a statistical analysis of correlated Nakagami-m random variables (rvs). The probability density function (pdf) of exponentially correlated Nakagami-m rvs is presented in closed-form, while the corresponding cumulative distribution function (cdf) has the form of multiple converging infinite series. Furthermore, bounds for the truncation of the infinite series.

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.