Designing an Ultralow-Voltage Phase-Locked Loop Using a Bulk-Driven Technique

[[abstract]]This brief describes an ultralow-voltage phase-locked loop (PLL) using a bulk-driven technique. The architecture of the proposed PLL employs the bulk-input technique to produce a voltage-controlled oscillator (VCO) and the forward-body-bias scheme to produce a divider. This approach effectively reduces the threshold voltage of the MOSFETs, enabling the PLL to be operated at an ultralow voltage. The chip is fabricated in a 0.13-mum standard CMOS process with a 0.5-V power supply voltage. The measurement results demonstrate that this PLL can operate from 360 to 610 MHz with a 0.5-V power supply voltage. At 550 MHz, the measured root-mean-square jitter and peak-to-peak jitter are 8.01 and 56.36 ps, respectively. The total power consumption of the PLL is 1.25 mW, and the active die area of the PLL is 0.04 mm2.[[notice]]補正完畢[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙

The marching velocity of the capillary meniscus in a microchannel

In this paper we describe an experimental method and an analytical model for characterizing the surface energy inside a microchannel of micrometer size by measuring the marching velocity or position of a capillary meniscus. This method is based on the fact that the force summation of the meniscus surface tension and the filling reservoir gravitation might produce a pressure to pull liquid into the channel, and the marching velocity or the instantaneous position of the meniscus is related to the surface energy. Both parylene and silicon-nitride microchannels with different surface conditions were fabricated to perform the fill-in experiments subject to different liquids. It is shown that our model agrees well with the experimental data and is a valid method

Genetic and B Cell Functional Studies of X-Linked Immunodeficiencies

Eight types of X-linked immunodeficiency diseases have been described. In this thesis, I will focus on four, viz X-linked agammaglobulinaemia (XLA), X-linked severe combined immunodeficiency (X-linked SCID), Wiskott-Aldrich syndrome (WAS) and X-linked hyperimmuno-globulinaemia M (X-linked hyperlgM). Their clinical features, treatment and prognosis as well as cellular and genetic aspects are reviewed in Chapter 1; followed by objectives of the studies presented in this thesis, viz localization of the gene loci of XLA and X-linked SCID, clinical application of the linked DNA probes in families with XLA and identification of the B cell defects in patients with XLA and WAS. The practical issues of collecting patients and families for linkage analysis, as well as their immunological profiles and pedigrees are given in Chapter 2. Various laboratory techniques employed in these studies are detailed in Chapter 3. There are five sections in Chapter 4, which is on the genetic studies of XLA. Section one reviews the principle of linkage analysis, genetic heterogeneity and restriction fragment length polymorphism (RFLP) . Results of the genetic localization of XLA to Xq21.3-q22 are presented in section two. Evidence of non-allelic genetic heterogeneity in XLA is presented in section three, followed by the analysis of all the family data of XLA in the literature in order to estimate the proportion of families unlinked to Xq21.3-q22, which is probably 10-20%. The posterior probability of each family being linked to Xq21.3-q22 is also estimated. Section four describes the clinical application of the two linked probes, S21 and pXG12, in the genetic counselling of thirteen families with XLA; as well as developing a method of risk calculation allowing for non-allelic genetic heterogeneity. Seven obligate carriers under the age of 45 can all be offered prenatal diagnosis. Of the thirty-four females at risk of being carriers, seventeen have their risks increased, fifteen decreased and two unchanged by the RFLP results. Eleven of the seventeen women whose risks were increased are under 45 years of age and seven of them can be offered prenatal diagnosis. Successful predictions have been made in a newborn male infant and a male fetus at risk of being affected with XLA. Section five presents the evidence that X-linked hyperlgM is not an allelic genetic disease with XLA. Chapter 5 presents the results of the genetic localization of X-linked SCID to Xqll-ql3 and the clinical application of the linked probe, cpX73, in carrier detection. The results of the functional studies of Epstein-Barr virus (EBV) tranformed B cell lines from patients with XLA and WAS are presented in Chapter 6. B cell lines from patients with WAS did not differ from normal B cell lines in any of the functional assays I have used. However, differences were found in B cells from patients with XLA. EBV-transformed B cell lines from patients with XLA did not proliferate in response to KGl-a supernatant and they did not produce IgG in the presence or absence of various B cell growth and differentiation factors. Finally, Chapter 7 summarises the two approaches of investigations adopted in this thesis, which are applicable in investigating any diseases of single gene defect; future directions are also speculated

The effect of concentration on the viscosity of polyisobutylene solutions

In the past twenty years the viscosity of dilute polymer solutions (i.e., where the solute molecules are far apart) has been investigated in great detail, both theoretically and experimentally. The viscosity characteristics of such systems are well-understood. Only a few studies have been made of the effect of concentration on the viscosity of polymer solutions in the concentration range where the polymer molecules begin to overlap. This range of concentrations is important in practical applications such as dry spinning of fibers, cross-graded automotive motor oils and in many industrial formulations where polymers are used to thicken solvent vehicles. Development of correlations for predicting viscosities in this concentration range from dilute solution measurements (intrinsic viscosities) is needed. It was the purpose of this investigation to obtain accurate viscosity-concentration data in the dilute and in the moderately concentrated range in polyisobutylene solutions in order to correlate these measurements and the literature data on other polymer-solvent systems with concentration and intrinsic viscosity. The effects of the nature of the solvent and polymer molecular weight were studied along with the effect of concentration --Introduction, page 2

Optimisation Of Milling Parameter And Annealing Condition For Machining Polyetheretherketones (PEEK) Biomaterials Implant

Polyetheretherketones (PEEK) which has been widely used in many applications is now commercialized as implant components because of its biodegradability and non-allergic reactions compared to the metal implants. Generally, implants are fabricated by extrusion and injection molding for a larger scale. However, often for prototype designs or patient specific implant designs, it is not economically viable to manufacture by an injection molding. Under such circumstances, it is common to employ a machining process on the PEEK materials to form the components. However, milling parameters are the factors that have to be considered in the machining process to reduce the defects to the minimum and increase its durability. Apart from milling parameters, annealing also plays important roles in reducing residual stress and improving surface finishes. Thus, this research aims to develop exact milling parameters prior to the annealing process for machining PEEK material in order to enhance the machining performance and productivity. To achieve the objective, both statistical and experimental techniques were employed for the methodology. Response surface methods (RSM) were used to get the mathematical models and ANOVA analysis while milling parameters (feed rate, depth of cut and cutting speed) were used in order to get the machining performance on surface roughness, machining force, dimensional accuracy and material removal rate. Through experiments, the optimised parameters have improved the machining performance and qualities prior to the annaeling. The conclusions provide a theoretical basis for the annealing technique where the increased of the percentage crystalline, it helps improving the properties and the materials structure which leads to improve the machinability of the materials. Milling parameters (feed rate, depth of cut and cutting speed) are important factors in machining process and significantly affect the machining performances. To obtain 0.87μm surface finish, unannealed PEEK with 25.3 percentages crystalline will be using cutting speed 150.8 mm/min, feed rate of 0.035mm/tooth and 2mm depth of cut. PEEK annealed with 200°C increase crystalline to 30.3 percentages using high cutting speed (150.8 mm/min), low feed rate (0.033mm/tooth) and low depth of cut (2mm) can produce 0.4μm surface finish. PEEK annealed with 250°C has 30.9 percentages crystalline and 0.39μm surface finish can be obtained by using high cutting speed (150.8 mm/min), low feed rate (0.034mm/tooth) and low depth of cut (2mm). Therefore, milling machining is recommended to be further used in fabricating PEEK biomedical implants

A Low Phase Noise All-Digital Programmable DLL-Based Clock Generator

[[abstract]]This paper proposes a low phase noise all-digital programmable DLL-based clock generator. The proposed clock generator is fabricated in a 0.18 μm standard CMOS process with a 1.8 V supply voltage. The proposed digital programmable DLL-based clock generator is easy migration over different processes and low power dissipation. The measurement results show that the input and output frequency ranges can operate 100 MHz ~ 600 MHz and 100 MHz ~ 1.2 GHz, respectively. At 800 MHz, the phase noise is -112.36 dBc @ 1MHz offset frequency. The total power consumption of the clock generator is 23.87 mW, and the active die area of the clock generator is 0.14 mm2.[[conferencetype]]國際[[conferencedate]]20140426~20140428[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Sapporo, Japa

A GHz Full-Division-Range Programmable Divider with Output Duty-Cycle Improved

[[sponsorship]]Test Technology Technical Council (TTTC), IEEE Computer Society ; Faculty of Information Technology, Brno University of Technology[[conferencetype]]國際[[conferencedate]]20130408~20130410[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Karlovy Vary (Carlsbad), Czech Republi