Transistor-and Circuit-Design Optimization for Low-Power CMOS

CMOS-technology scaling has moved to a power-constrained condition regardless of the application segments. Power management in advanced CMOS technology drives the need to conciliate scaling-driven fundamental material limitations with product and application evolution requirements. Flexible CMOS technologies and tighter interaction between process development and circuit/system design are needed to efficiently realize systems on a chip. This paper reviews issues associated with transistor scaling and co-optimization for power-management circuit-design schemes for active-and leakage-power control. This paper also addresses the derived trends and implications on I/O and analog-transistor scaling.     

Isolation of a recombinant desulfurizing 4,6-diproply dibenzothiophene in n-tetradecane

Rhodococcus erythropolis strain KA2-5-1 is unable to desulfurize 4,6-dipropyl dibenzothiophene (DBT) in the oil phase. The dsz desulfurization gene cluster from R. erythropolis strain KA2-5-1 was transferred into 22 rhodococcal and mycobacterial strains using a transposon-transposase complex. The recombinant strain MR65, from Mycobacterium sp. NCIMB10403, was able to grow on a minimal medium supplemented with 1.0 mM 4,6-dipropyl DBT in n-tetradecane (50%, v v ) as the sole sulfur source. Resting cells of recombinant strain MR65 could desulfurize 68 mg l- of sulfur in light gas oil (LGO) containing 126 mg sulfur l-. Strain MR65 had about 1.5-times the LGO desulfurization activity of R. erythropolis strain KA2-5-1. The application of a recombinant, which is able to utilize 4,6-dipropyl DBT in the oil phase, was effective in enhancing LGO biodesulfurization.     

Multi-residue method for determination of veterinary drugs and feed additives in meats by HPLC

A simple and rapid multi-residue method was developed for the determination of 28 kinds of veterinary drugs and feed additives (drugs) in muscle of cattle, pig and chicken. The drugs were extracted with acetonitrile-water (95:5) in a homogenizer and ultrasonic generator. The extracted solution was poured into an alumina column and the drugs were eluted with acetonitrile-water (90:10). The eluate was washed with n-hexane saturated with acetonitrile and then evaporated. The drugs were separated on a Inertsil ODS-3V column (4.6 mm i.d. x 250 mm) with a gradient system of 0.1% phosphoric acid-acetonitrile as the mobile phase, with monitoring at 280 and 340 nm. The recoveries of the 26 kinds of drugs were over 60% from the meats fortified at 0.1 microg/g, and the quantification limits of most drugs were 0.01 microg/g. This proposed method was found to be effective and suitable for the screening of the above drugs in meats.     

Uniaxial Ratchetting Behavior of Solder Alloys and Its Simulation by an Elasto-Plastic-Creep Constitutive Model

Ratchetting deformation occurring at solder joints in electronic packaging is a concern for electronic devices. Therefore, ratchetting deformation due to thermal cycling at solder joints should be simulated by structural analysis employing tools such as the finite-element method (FEM). However, simulation of ratchetting deformation is difficult, and little modeling to simulate ratchetting deformation accurately has been reported. This work experimentally examines uniaxial ratchetting deformation of Pb-free and Pb-containing solder alloys to elucidate the effect of rate on uniaxial ratchetting. An elasto-plastic-creep constitutive model is developed to simulate uniaxial ratchetting deformation. The constitutive model incorporates a method to determine the material constants simply from a small number of pure tensile tests and subsequent stress relaxation tests. Uniaxial ratchetting deformation of solder alloys was successfully simulated using this constitutive model and simple method for material constant determination.     

Isolation of the Pseudomonas aeruginosa gene affecting uptake of dibenzothiophene in n-tetradecane

The dsz desulfurization gene cluster from Rhodococcus erythropolis KA2-5-1 was transferred into the chromosomes of Pseudomonas aeruginosa strain NCIMB9571 using a transposon vector. All of the recombinant strains completely desulfurized 1 mM dibenzothiophene (DBT) in n-tetradecane (n-TD) except one, named strain PARMI. Strain PARMI was unable to desulfurize DBT in n-TD, but was able to desulfurize it in water. The n-alkane utilization ability, the biosurfactant production and the fatty acid composition of cells in strain PARMI were the same level as those of the other recombinants. The transposon insertion area of strain PARMI was analyzed by transposon tagging. We cloned three possible open reading frames (ORFs), designated hcuA, hcuB and hcuC, from the genomic DNA of P. aeruginosa NCIMB9571 using the transposon insertion area of strain PARMI as a DNA probe. Examination of the sequence revealed the transposon was inserted into hcuA. The full length of the hcuABC genes transformed into strain PARMI achieved 87% recovery of the desulfurization activity of DBT in n-TD, but partial hcuABC genes achieved only 0-12%. These results indicate that DBT desulfurization in the oil phase by recombinant P. aeruginosa strain NCIMB9571 requires the full length of the hcuABC gene cluster. The hcuABC gene cluster relates to DBT uptake from the oil phase to inside of the cell, and the uptake ability is independent of the n-alkane utilization ability, the biosurfactant production and the fatty acid composition of cells.     

Linearizing optical frequency-sweep of a laser diode for FMCWreflectometry

We propose and demonstrate a novel linearizing method of optical frequency-sweep of a laser diode for frequency-modulated continuous-wave (FMCW) reflectometry. In order to linearly sweep the optical frequency, we adopt a reference interferometer and an electric phase comparator. The interference beat signal of the reference interferometer is phase-compared with an external reference rectangular signal having a fixed frequency near the interference beat signal frequency by a lock-in amplifier. The error signal from the lock-in amplifier is fed back to the modulating signal of the injection current of the laser. Thus, a phase-locked loop composed of optical and electric circuits can be established, and the beat signal frequency is locked to the frequency of the reference signal. The optical frequency of the laser diode is, therefore, excellently linearly swept in time. In order to experimentally confirm the linearity of the proposed method, we apply this frequency-swept laser diode to the FMCW reflectometry. Resultingly, the improvement of the linearity is estimated to be about 10 dB. And the theoretically limited spatial resolution of the FMCW reflectometry is achieved. The backscattered light in optical waveguide devices is measured by the FMCW reflectometry using the proposed light source, and the propagation loss of a single-mode glass waveguide is successfully evaluated     

Extravesical tumor implantation caused by perforation during transurethral resection of a bladder tumor: a case report

We report a case of invasive bladder cancer in which cancer dissemination occurred through a perforation of the vesical wall during transurethral resection of the tumor. A radical cystectomy was performed 1 month later and several clusters of viable cancer cells were histologically identified in a fibrous foreign body granuloma in the paravesicular adipose tissue of the lymphadenectomy specimen. The patient received adjuvant chemotherapy, but developed right inguinal lymph node metastasis 21 months after cystectomy.     

Involvement of prostaglandin E2 and interleukin-1 alpha in the differentiation and survival of osteoclasts induced by lipopolysaccharide from Actinobacillus actinomycetemcomitans Y4

Lipopolysaccharide (LPS) is a bacterial cell component that plays multifunctional roles in inflammatory reactions. LPS from various periodontal pathogens is supposed to be a major virulence factor of periodontal diseases. In the present study, we demonstrated that LPS from periodontopathic bacterium Actinobacillus actinomycetemcomitans Y4 (Y4 LPS) stimulated osteoclast formation in mouse bone marrow culture systems. Addition of anti-interleukin-1 alpha (IL-1 alpha) antibody or indomethacin in the marrow cultures resulted in the suppression of osteoclast differentiation. Quantitative analyses revealed that Y4 LPS stimulated the production of IL-1 alpha and prostaglandin E2 (PGE2) by bone marrow cells. Furthermore, an immunoblot analysis showed that Y4 LPS stimulated bone marrow cells to upregulate the expression of cyclooxygenase-2, a rate-limiting enzyme for the conversion of arachidonic acid to prostanoids. These findings suggest that both IL-1 alpha and PGE2 are involved in the LPS-mediated osteoclast differentiation. In addition, we found that Y4 LPS supported the survival of osteoclasts. Addition of anti-IL-1 alpha antibody in the osteoclast culture resulted in a reduction of osteoclast survival. Indomethacin, however, showed no effect on osteoclast survival. These findings suggest that the increased PGE2 and IL-1 alpha synthesis by bone marrow cells may play an important role in the differentiation and survival of osteoclasts induced by A. actinomycetemcomitans LPS.     

Microparticle acceleration for hypervelocity experiments by A 3.75MV van de Graaff accelerator and a 100KV electrostatic accelerator in Japan

In-situ dust detectors have been calibrated by dust electrostatic accelerators that can accelerate projectiles to expected mass and velocity ranges of space debris and micrometeoroids. Unfortunately, In Japan, there was no such a facility dedicated to space science research until our research group was established a few years ago. Therefore, we have developed two high voltage accelerators. One is a modified 3.75MV Van de Graaff accelerator operated by High Fluence Irradiation Facility, Research Center for Nuclear Science and Technology, the University of Tokyo (HIT), and the other is a 100kV accelerator dedicated to dust experiment at the Institute of Space and Astronautical Science (ISAS). The particle velocity using the HIT Van de Graaff accelerator is higher than those reported in other accelerator facilities under the same particle mass conditions and encompasses the desired velocity range of micro-meteoroid. Time-Of-Flight dust mass spectrometer and Hybrid dust detector which are under development in Japan have been investigated using HIT dust accelerators. We have also constructed a 100kV electrostatic accelerator designed for easier handling and lower cost operation which is dedicated to dust acceleration, because the HIT Van de Graaff accelerator is being used for ion beam experiments mainly.     

A high-frequency electronic ballast for HID lamps based on aλ/4-long distributed constant line

A novel type of solid-state ballast, which operates in the megahertz-range frequency, is presented in this paper. A circuit composed of a voltage-source half-bridge inverter, a distributed constant line and a parallel LC resonant circuit has been developed for this purpose. The high-intensity discharge (HID) lamp is connected to the output terminal of the inverter through the distributed constant line. Here, since the length of the line is adjusted to 1/4 of the propagation wavelength λ (λ/4 condition), the output voltage of the voltage-source inverter can be converted to a current source on the load side. Therefore, the ballast can supply not only high voltage to the HID lamp for initiating discharge, but also stable current to it during discharge condition. The modification of the proposed circuit is also proposed in order to expand the operating frequency without increasing the undesirable harmonic current. The experimental results from a prototype system verify the theoretical procedure