Internal combustion engines have dealt with increasingly restricted emissions requirements. After-treatment devices are successful in bringing emissions into compliance, but in-cylinder combustion control can reduce their burden by reducing engine out emissions. For example, oxides of nitrogen (NOx) are diesel combustion exhaust species that are notoriously difficult to remove by after-treatment. In-cylinder conditions can be controlled for low levels of NOx, but this produces high levels of soot potentially leading to increased particulate matter (PM). The simultaneous reduction of NOx and PM can be realized through a combustion process known as low temperature combustion (LTC). In this study, the typical definition of LTC as the defeat of the inverse relationship between soot and NOx is not applicable as a return to the soot-NOx tradeoff is observed with increasing exhaust gas recirculation (EGR). It is postulated that this effect is the result of an increase in the hot ignition equivalence ratio, moving the combustion event into a slightly higher soot formation region. This is important because a simple emissions based definition of LTC is no longer helpful. In this study, the manifestation of LTC in the calculated heat release profile is investigated. The conditions classified as LTC undergo a two-stage ignition process. Two-stage ignition is characterized by an initial cool-flame reaction followed by typical hot ignition. In traditional combustion conditions, the ignition is fast enough that a cool-flame is not observed. By controlling initial conditions (pressure, temperature, and composition), the creation and duration of the cool-flame event is predictable. Further, the effect that injection timing and the exhaust gas recirculation level have on the controlling factors of the cool-flame reaction is well correlated to the duration of the cool-flame event. These two results allow the postulation that the presence of a sufficiently long cool-flame reaction indicates a combustion event that can be classified as low temperature combustion. A potential method for identifying low temperature combustion events using only the rate of heat release profile is theorized. This study employed high levels of EGR and late injection timing to realize the LTC mode of ordinary petroleum diesel fuel. Under these conditions, and based on a 90 percent reduction in nitric oxide and no increase in smoke output relative to the chosen baseline condition, a two part criteria is developed that identifies the LTC classified conditions. The criteria are as follow: the combustion event of conventional petroleum diesel fuel must show a two-stage ignition process; the first stage (cool-flame reaction) must consume at least 2 percent of the normalized fuel energy before the hot ignition commences.

In the first, we design and implement a Two -Point Voltage-Controlled Oscillator which applied in Open-Loop and Two-Point Close-Loop Modulation Bluetooth transmitter and include Hybrid and CMOS RFIC design. Second, we design six LTCC embedded components including inductors and capacitors. The extraction result via traditional equivalent £kmodel match the simulation and the frequency response of adopted model can accurate to device¡¦s Self-Resonant-Frequency nearby compare with measurement. In the end, we design and implement a LTCC Two-Point Voltage-Controlled Oscillator module and effective ly reduce the module size.

We have studied the electronic properties of AlxGa1-xN/GaN heterostructures by using Shubnikov¡Vde Haas(SdH) measurement. Two SdH oscillations were detected on the samples of x=0.35 and 0.31, due to the population of the first two subbands with the energy separations of 128 and 109 meV, respectively. For the sample of x=0.25, two SdH oscillations beat each other, probably due to a finite zero-field spin splitting. The spin-splitting energy is equal to 9.0 meV. The samples also showed a persistent photoconductivity effect after illuminating by blue light-emitting diode. For the part of experiment , we installed a "Regulator" on low temperature and high magnetic field system, in order to control the temperature of sample from 0.3K to 10K accurately. For the convenience of SdH measurements at different tempertures.

Since the traditional CRT(Cathode Ray Tube) replaced by FPD(Flat Panel Display), e.g. LCD¡BOLED¡BPDP, FPD industry is regarded as the important one of global industry following Semi-conductor industry. The main stream of Large-Area Displays is TFT-LCD(Thin Film Transistor-Liquid Crystal Display) and it¡¦s applied a-Si:H TFT (the hydrogenated Amorphous Silicon Thin Film Transistor) as pixel-switch device on LCD. In a-Si:H TFT Cell process, the active region material(a-Si:H) with higher Photoconductivity results into higher off-state current under light illumination and that causes color performance discrepancy as incomplete On/Off operation of pixel-switch devices. As long as the introduction of F into a-Si:H modify the density of states in the gap of a-Si:H(:F), that may result the shift of the Fermi level toward the valence band edge and The density-of-states increasing. It¡¦s effective to decrease the photo leakage current. Due to electro-optical properties of liquid crystal(LC), to drive Pixel-switch device in TFT-LCD shall force On/Off voltage to change Twist Angle of LC is corresponding to have Stress on TFT device. According to DC Stress experiment results, it¡¦s found TFT device with SiF4 dopant can reach better reliability. This issue is aimed to research the photo leakage current variation of a-Si:H TFT at low temperature and ON/Off state effect by stress on TFT device.

ABSTRACT Our Atlantic Ultra-Low-Temperature Tuna Fishing fleets were under attack from Japan during the 2004 ICCAT (International Commission for the Conservation of Atlantic Tunas) Annual Meeting. Japan openly called for tough penalty for our fleet such as significantly cutting our fishing quotas in the Atlantic and revoking our national membership in the ICCAT for over-fishing, violating International Conservation Regulations and washing fish right on the ocean. This resulted in catastrophic damage in our Ultra-Low-Temperature fishing operation in the pacific and undue pressure from our international competitors. Under the strict monitoring of international conservation groups, our government was forced reform its regulations of the fishing industry and focus on the long-neglected area of offshore fishing. To express its sincerity in active management of the industry, the government offered a series of matching measures. The first of these measures was the reduction of the number of ships to achieve cutback in fishing capacity. The three-year plan spanning from 2005 to 2007 involved a joint venture by the government and the offshore industry with joint contribution of 12.5 million US dollars to disassemble 183 large Tuna Long line Fishing Vessels in the three oceans. Fishing vessels in the Atlantic were reduced from 100 to 76. The next measures were to improve the monitoring of the fishing industry and to end any and all illegal, unreported and unregulated fishing. How will our offshore fishing industry recover after a series of attack? How will our industry thrive in the austere environment of conservatism? Do we still possess any competitive advantage after the vessel-reduction measure? This thesis will cover the analysis of the competitive advantage of the Offshore Ultra-Low-Temperature Fishing Industry after the vessel-reduction, the analysis of the supply-and-demand of the Ultra-Low-Temperature market and SWOT analysis. It will also discuss in depth the post-reform fishing industry management strategy for reference.

This thesis proposes a novel dual passband filter architecture and develops a design flow and synthesis method for this architecture. The technical contents include the fundamental passband filter design and the further methods for generating the higher second passband and the multiple transmission zeros. This thesis organizes a design flow based on analytical formulation for the proposed dual passband filter architecture. One can follow this design flow to substitute the filter specifications into the formulation and then can obtain the necessary element values for the filter architecture that match the specified specifications. The dual passband filter architecture is finally implemented on LTCC substrate for WLAN (IEEE 802.11 a/b/g) applications with verification of S parameters using EM-simulation and actual measurement.

Although copper (Cu) is the preferred interconnect material due to its lower resistivity than aluminum (Al), Cu subtractive etching processes have not been developed at temperatures less than 180 °C, primarily due to the inability to form volatile etch products at low temperature. The conventional damascene technology avoids the need for subtractive etching of Cu by electroplating Cu into previously etched dielectric trenches/vias, followed by a chemical/mechanical planarization (CMP) process. However, a critical "size effect" limitation has arisen for damascene technology as a result of the continuing efforts to adhere to "Moore's Law". The size effect relates to the fact that the resistivity of damascene-generated lines increases dramatically as the line width approaches the sub-100 nm regime, where feature size is similar to the mean free path of electrons in Cu (40 nm). As a result, an alternative Cu patterning process to that of damascene may offer advantages for device speed and thus operation. This thesis describes investigations into the development of novel, fully-plasma based etch processes for Cu at low temperatures (10 °C). Initially, the investigation of a two-step etch process has been studied. This etch approach was based on a previous thermodynamic analysis of the Cu-Cl-H system by investigators at the University of Florida. In the first step, Cu films are exposed to a Cl₂ plasma to preferentially form CuCl₂, which is believed to be volatilized as Cu₃Cl₃ by subsequent exposure to a hydrogen (H₂) plasma (second step). Patterning of Cu films masked with silicon dioxide (SiO₂) layers in an inductively coupled plasma (ICP) reactor indicates that the H₂ plasma step in the two-step process is the limiting step in the etch process. This discovery led to the investigation of a single step Cu etch process using a pure H₂ plasma. Etching of blanket Cu films and Cu film patterning at 10°C, display an etch rate ~ 13 nm/min; anisotropic etched features are also observed. Comparison of H₂ plasma etching to sputtering of Cu films in argon (Ar) plasmas, indicates that both a chemical component and a physical component are involved in the etching mechanism. Additional studies using helium plasmas and variation of power applied to the plasma and etching surface demonstrate that the etch rate is controlled by reactive hydrogen species, ion bombardment flux and likely photon flux. Optical Emission Spectroscopy (OES) of the H₂ plasma during the Cu etching process detects Cu emission lines, but is unable to identify specific Cu etch products that desorb from the etching surface. Variation of Cu etch rates as a function of temperature suggests a change in mechanism for the removal of Cu over the temperature of -150 °C to 150 °C. OES analyses also suggest that the Cl₂ plasma step in the two-step process can inhibit Cu etching, since the subsequent H₂ (second) plasma step shows a time delay in film removal. Preliminary results of the etching of the SiO₂ mask material in H₂ plasmas with various intentionally introduced contaminants demonstrate the robustness of the H₂ plasma Cu etch process.

<p>This thesis is a study of the heat transfer correlations between a wire and liquid helium cooled to either 1.9 or 4.3 K. The wire resembles a part of a superconducting magnet used in the Large Hadron Collider (LHC) particle accelerator currently being built at CERN. The magnets are cooled to 1.9 K and using helium as a coolant is very efficient, especially at extremely low temperatures since it then becomes a superfluid with an apparent infinite thermal conductivity. The cooling of the magnet is very important, since the superconducting wires need to be thermally stable.</p><p>Thermal stability means that a superconductive magnet can remain superconducting, even if a part of the magnet becomes normal conductive due to a temperature increase. This means that if heat is generated in a wire, it must be transferred to the helium by some sort of heat transfer mechanism, or along the wire or to the neighbouring wires by conduction. Since the magnets need to be superconductive for the operation of the particle accelerator, it is crucial to keep the wires cold. Therefore, it is necessary to understand the heat transfer mechanisms from the wires to the liquid helium.</p><p>The scope of this thesis was to describe the heat transfer mechanisms from a heater immersed in liquid and superfluid helium. By performing both experiments and simulations, it was possible to determine properties like heat transfer correlations, critical heat flux limits, and the differences between transient and steady-state heat flow. The measured values were in good agreement with values found in literature with a few exceptions. These differences could be due to measurement errors. A numerical program was written in Matlab and it was able to simulate the experimental temperature and heat flux response with good accuracy for a given heat generation.</p>

This work is a contribution to the evaluation of the power cycling reliability of different packaging and interconnection solutions at high temperature swings. It provides the designer of power circuits data for module lifetime prediction especially at high operational temperatures. Failure analysis with the different microscopic techniques provide cognitions about the failure mechanisms and eventual weak points of the power devices at high thermal stresses. / Diese Arbeit liefert einen Beitrag zur Qualifizierung der Lastwechselfestigkeit von modernen Aufbau- und Verbindungstechniken bei hohen Temperaturhüben. Dadurch wird den Designern von Leistungsschaltkreisen Daten zur Abschätzung der Lebensdauer ihrer Komponente besonders unter höheren Umgebungstemperaturen zur Verfügung gestellt. Eine Ausfallanalyse mit dem Rasterelektronenmikroskop (REM) und der Ultraschallmikroskopie liefert Erkenntnisse über die zu erwartende Ausfallmechanismen und die eventuellen Schwachpunkte der Bauelemente bei hohen Temperaturen

Lithium-ion batteries are being intensely pursued as energy storage devices because they provide higher energy and power densities compared to other battery systems such as lead-acid and nickel-metal hydride batteries. This dissertation (i) explores the use of a low-temperature microwave-assisted synthesis process to obtain aliovalently-doped lithium transition-metal phosphates and lower-valent vanadium oxide spinels, some of which are difficult to obtain by conventional high-temperature processes, and (ii) presents an investigation of the electrochemical properties of the aliovantly-doped phosphate cathodes and doped lithium manganese oxide and oxyfluoride spinel cathodes in lithium-ion batteries. Following the introduction and general experimental procedures, respectively, in Chapters 1 and 2, Chapter 3 first focuses on understanding of how the inductive effect and structural features in lithium transition-metal borate, silicate, and phosphate cathodes affect the M²⁺ʹ³⁺redox energies. It is found that the magnitude of the voltages delivered by the polyanion cathodes can be predicted based simply on the coordination of the transition-metal ion. Furthermore, the differences in the voltages delivered by the phosphates and pyrophosphates are explained by considering the resonance structures and their contribution to the covalency of the polyanion. Chapter 4 presents a low-temperature microwave-assisted solvothermal process to substitute 20 atom % V³⁺ for Mn²⁺ in LiMnPO₄. It is shown that the solubility of vanadium in LiMnPO₄ decreases upon heating the doped samples to ≥ 575 °C, demonstrating the importance of employing a low-temperature process to achieve aliovalent doping in LiMnPO₄. It is further demonstrated that by increasing the vanadium content in the material, the discharge capacity in the first cycle could be increased without any additional carbon coating. Subsequent X-ray absorption spectroscopy data reveal that the better performance is facilitated by enhanced Mn-O hybridization upon incorporating vanadium into the lattice. Chapter 5 explores the influence of various factors, such as the oxidation state of Mn, electronegativity of the dopant cation Mn+, and the dissociation energy of M-O bond, on the electrochemical properties of cation-doped oxide and oxyfluoride spinel cathodes. As an extension, Chapter 6 presents the effect of processing conditions on the surface concentration of the dopant cation Mn+. Chapter 7 presents an extension of the low-temperature microwave-assisted synthesis process to obtain AV₂O₄ (Mg, Fe, Mn, and Co) spinel oxides. The method is remarkably effective in reducing the synthesis time and energy use due to the efficiency of dielectric heating compared to conventional heating. The ability to access V³⁺ is facilitated by the relative positions of the energy levels of the cations in solution, which is lower than that in the solid, and the use of a strong reducing solvent like TEG. Finally, Chapter 8 provides a summary of the salient findings in this dissertation. / text