Development of a Cyclogyro-Based Flying Robot With Variable Attack Angle Mechanisms

This paper presents an experimental study on the development of a cyclogyro-based flying robot with a new variable angle of attack mechanism. A cyclogyro is a flying machine supported in the air by power-driven rotors that rotate about a horizontal axis, like the paddle-wheels of a steamboat. Machines of this type have been designed by some companies but there has been no record of any successful flights. Our design starts with a new variable angle of attack mechanism with an eccentric (rotational) point in addition to a rotational point connecting to a motor. The main feature of the mechanism with the eccentric rotational point is the ability to change attack of angles in accordance with the wing positions (as determined by the rotational angles of the cyclogyro) without actuators. The design parameters (wing span, the number of wings, and eccentric distance) of the flying robot are determined through a series of experiments. Experimental results show that the cyclogyro-based flying robot with the new variable angle of attack mechanism is capable of generating sufficient lift force for flying.     

Development of quasi-end-fired waveguide plastic dye laser

A quasi-end-fire (QEF) pumping scheme was proposed and studied as a novel laser-pumping-scheme for a laser-dye-doped plastic waveguide laser with distributed feedback. This pumping scheme resembled longitudinal pumping, but also has the advantage of controllable absorption length of the injected pump beam. A first demonstration of the QEF was performed and the pumping beam controlling was also investigated.     

Block-coded modulation and multiple block-coded modulation withViterbi decoding for fading channels

This paper describes how block-coded modulation (BCM) and multiple BCM (MBCM) with Viterbi decoding can be designed for use in Rayleigh fading and severe Rician fading channels. New codes are developed by modifying known codes to increase the minimum symbol distance, which is one of the distances that has a strong effect on the bit error rate (BER) performance under fading channels. Combined with anti-fading techniques such as fading compensation, interleaving, and branch weighting, the new codes significantly improve BER performance. Computer simulations were used to confirm the code performance     

Multichannel fiber ferrule for a stable laser-diode array module

We developed a multichannel fiber ferrule for a stable laser-diode array module. To apply YAG laser welding to parallel butt couple between the laser-diode and the single-mode fiber arrays, hermetically sealed and precisely aligned equi-interval fibers are required. We describe a V-grooved ceramic ferrule for embedding fibers. Fibers are fixed by soldering, using a flat ceramic lid and aligned with a 250 μm pitch. Our ferrule allowed a metallic, stem mounting laser-diode, to be fixed by YAG laser welding. All 30 samples tested have a leak rate of less than 1×10^-10 atm·cc/s. Optical coupling of fabricated modules was 9.7±0.2 dB and coupling loss change from 25°C to 115°C was within 0.5 dB     

Ultrahigh Electrical Resistance of Poly(cyclohexyl methacrylate)/Carbon Nanotube Composites Prepared Using Surface‐Initiated Polymerization

Multiwalled carbon nanotubes on which poly(cyclohexyl methacrylate)s are densely grafted (PCHMA‐CNTs), are synthesized using a modified surface‐initiated atom transfer radical polymerization technique. The electrical resistance of PCHMA‐CNT is systematically characterized under direct current (DC) and alternating current and compared to that of conventional nanocomposites prepared by blending PCHMA with the CNT (PCHMA/CNT). At a comparable volume fraction of CNT, DC volume resistivity of PCHMA‐CNT is 14 orders of magnitude higher than that of PCHMA/CNT. This is because the grafted polymer with a combination of the high molecular weight and the high grafting density isolates individual CNTs at a long distance in the PCHMA‐CNT system. In addition, impedance analysis reveals that the highly insulated PCHMA‐CNT has the same electrical nature as neat PCHMA, i.e., it is a dielectric. Furthermore, dynamic mechanical analysis shows PCHMA‐CNT has a good mechanical properties as well as ultrahigh electrical resistance.     

Optimization of L-lactic acid feeding for the production of poly-D-3-hydroxybutyric acid by Alcaligenes eutrophus in fed-batch culture

We investigated optimization of the feeding of L-lactic acid for the production of poly-D-3-hydroxybutyric acid [P(3HB)] by Alcaligenes eutrophus in a fed-batch culture system. An acidic substrate solution was fed automatically so as to maintain the pH of the culture liquid at 7.0. Feeding of a substrate solution containing 45% (w/v) L-lactic acid, 6.2% (w/v) sodium L-lactate, 5.8% (w/v) ammonia water and 1.8% (w/v) potassium phosphate [at a molar ratio of carbon to nitrogen (C/N molar ratio) of 10], allowed the L-lactate concentration in the culture liquid to be maintained at approximately 2 g/l and the cell concentration reached 27.4 g/l after 15 h of cultivation. To promote P(3HB) production, a two-stage fed-batch culture consisting of a culture for cell growth and one for P(3HB) accumulation was carried out. When the substrate solution, whose C N molar ratio was 23, was fed during the P(3HB) accumulation phase, the cell concentration and the P(3HB) content in the cells reached 103 g/l and 57.6% (w/w), respectively, in 51.5 h.     

Isolation and characterization of the ATF2 gene encoding alcohol acetyltransferase II in the bottom fermenting yeast Saccharomyces pastorianus

The ATF2 gene encodes alcohol acetyltransferase II, which catalyses the synthesis of isoamyl acetate from acetyl coenzyme A and isoamyl alcohol. To characterize the ATF2 gene from the bottom fermenting yeast Saccharomyces pastorianus, the S. pastorianus ATF2 gene was cloned by colony hybridization using the S. cerevisiae ATF2 gene as a probe. When an atf1 null mutant strain was transformed with a multi-copy plasmid carrying the S. pastorianus ATF2 gene, the AATase activity of this strain was increased by 2.5-fold compared to the control. The S. pastorianus ATF2 gene has 99% nucleic acid homology in the coding region and 100% amino acid homology with the S. cerevisiae ATF2 gene. Southern blot analysis of chromosomes separated by pulse-field gel electrophoresis indicated that the ATF2 gene probe hybridized to chromosome VII in S. cerevisiae and to the 1100 kb chromosome in S. pastorianus. As S. pastorianus is thought to be a hybrid of S. cerevisiae and S. bayanus, the S. bayanus-type gene, which has a relatively low level of homology with the S. cerevisiae-type gene, is also usually detected. Interestingly, an S. bayanus-type ATF2 gene could not be detected. These results suggested that the cloned ATF2 gene was derived from S. cerevisiae. Analysis using an ATF2-lacZ fusion gene in S. pastorianus showed that expression of the ATF2 gene was relatively lower than that of the ATF1 gene and that it is repressed by aeration but activated by the addition of unsaturated fatty acids. The S. pastorianus ATF1, Lg-ATF1 and ATF2 Accession Numbers in the DDBJ Nucleotide Sequence Database are D63449, D63450 and D86480, respectively.     

An 8.1-ns Column-Access 1.6-Gb/s/pin DDR3 SDRAM With an 8:4 Multiplexed Data-Transfer Scheme

Three circuit techniques for an 8.1-ns column-access 1.6-Gb/s/pin 512-Mb DDR3 SDRAM using 90-nm dual-gate CMOS technology were developed. First, an 8:4 multiplexed data-transfer scheme, which operates in a quasi-4-bit prefetch mode, achieves a 3.17-ns reduction in column-access time, i.e., from 11.3 to 8.13 ns. Second, a dual-clock latency counter reduces standby power by 22% and cycle time from 1.7 to 1.2 ns. Third, a multiple-ODT-merged output buffer enables selection of five effective-resistance values Rtt (20, 30, 40, 60, and 120 Omega) without increasing I/O capacitance. Based on these techniques, 1.6-Gb/s/pin operation with a 1.36-V power supply and a column latency of 7 was accomplished     

Thiamine pyrophosphatase activity in the Golgi apparatus of calcitonin-treated osteoclasts.

The thiamine pyrophosphatase (TPPase) activity described by Novikoff and Goldfisher was examined in osteoclasts affected by calcitonin in order to elucidate whether the morphological and functional changes of the osteoclasts have an influence over the secretion function of their Golgi apparatus. The Golgi apparatus of osteoclasts of which the ruffled border had disappeared and bone resorption discontinued as the result of treatment with calcitonin showed a slight TPPase activity. The reaction products of the enzyme in these inactive osteoclasts were distinctly fewer than that of control osteoclasts, which were not affected by calcitonin. From these results, it is suggested that there may be a connection between the morphological and functional changes of osteoclasts and the secretion function of the Golgi apparatus.     

Practical model for gas temperature effects on CO2lasers

An analytical and experimental investigation on the effect of gas temperature on convection flow CO₂ lasers is presented. A simple and practical model neglecting the population of lower laser levels is proposed and examined by experiments. The model indicates simply that the gas temperature affects the `inherent threshold discharge power'. Appropriateness of the model has been proven regardless of the schemes of cross flow or axial flow