A low-voltage low-power CMOS voltage reference based on subthreshold MOSFETs

This paper describes a CMOS voltage reference using only resistors and transistors working in weak inversion,without the need for any bipolar transistors.The voltage reference is designed and fabricated by a 0.18μm CMOS process.The experimental results show that the proposed voltage reference has a temperature coefficient of 370 ppm/℃at a 0.8 V supply voltage over the temperature range of-35 to 85℃and a 0.1%variation in supply voltage from 0.8 to 3 V.Furthermore,the supply current is only 1.5μA at 0.8 V supply voltage.     

Efficient Synthesis of the Very-Long-Chain n-3 Fatty Acids,Tetracosahexaenoic Acid (C<Subscript>24</Subscript>:6n-3) and Tricosahexaenoic Acid (C<Subscript>23</Subscript>:6n-3)

Tetracosahexaenoic acid (C₂₄:6n-3, THA, 3) is an essential biosynthetic precursor in mammals of docosahexaenoic acid (C₂₂:6n-3, DHA, 1), the end-product of the metabolism of n-3 fatty acids. THA 3 is present in commercially valuable fishes, such as flathead flounder. Tricosahexaenoic acid (C₂₃:6n-3, TrHA, 2), an odd-numbered-chain fatty acid, has been identified from marine organisms such as the dinoflagellate, Amphidinium carterae. To date, few studies have examined THA 3 and TrHA 2 due to difficulties in detecting and identifying these compounds, so their chemical and biological properties remain poorly characterized. Only one methodology for the chemical synthesis of THA 3 has been presented, and no method for the synthesis of TrHA 2 has been reported. We report here the efficient synthesis of THA 3 in four steps in 56% overall yield, and the synthesis of TrHA 2 in six steps in 48% overall yield. We also present the synthesis of Δ²-THA 4, an intermediate of β-oxidation of THA 3 to DHA 1, in three steps in 73% overall yield.     

Effect of Dietary Partial Hydrolysate of Phospholipids,Rich in Docosahexaenoic Acid‐Bound Lysophospholipids,on Lipid and Fatty Acid Composition in Rat Serum and Liver

Lysophospholipids have been recognized as potent biologically active lipid mediators. However, attention has not been paid to the health benefits of dietary partial hydrolysate of phospholipids (PH‐PL), which is rich in docosahexaenoic acid (DHA)‐bound lysophospholipids. In this study, the effects of PH‐PL on serum and liver lipid profiles of rats upon administration of PH‐PL are demonstrated in comparison to those of fish oil (FO), which comprises eicosapentaenoic acid (EPA) and DHA‐bound triglyceride (TG). PH‐PL containing EPA and DHA was prepared via enzymatic modification of squid (Todarodes pacificus) meal that is rich in phospholipids. Male Wistar rats were fed a basal diet containing soybean oil alone (7%), FO, and PH‐PL. The FO and PH‐PL diets had similar EPA and DHA contents. After the rats had been fed their respective diets for 28 d, their serum and liver lipid contents, fecal lipid excretion, and hepatic gene expression level were measured. The results demonstrated that compared with the soybean oil diet alone, the PH‐PL diet decreased serum and liver TG contents partially because of the enhancement of liver acyl‐CoA oxidase activity and suppression of liver fatty acid synthase activity. In addition, compared with the soybean oil diet, the PH‐PL group exhibited lower serum cholesterol content at least in part because of the reduction of hepatic 3‐hydroxy‐3‐methylglutaryl‐CoA reductase mRNA expression level. We found that dietary administration of EPA and DHA containing PH‐PL has a hypolipidemic effect that may help prevent the development lifestyle‐related diseases.     

Servo techniques for optical disk drives —high-speed and precise optical beam-positioning control—

We introduce advanced servo techniques for optical disk drives. High speed and precise optcal beam-positioning and following controls are required archival memories such as high density and high data transfer rate optical disk drives for recording many data and high quality moving pictures toward next generation systems. The zero phase error tracking-feed-forward (ZPET-FF) control method is effective for the next generation systems, which have high disk rotation speed beyond the limit of 10,000 rpm of optical disk drives such as current CDs, DVDs or Blu-ray discs. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

On the Interpretation of some Visual Illusions by a Geometrical Model of Riemannian Spaces

Behaviormetrika - The visual spaces with some visual illusions are discussed from the point of Riemannian geometry. On the assumption that each local visual space is furnished with parallel lines...     

Transfer Processes for Thermally Stable Large-Size TFT Flexible Substrates

We report on glass etching transfer processes to obtain thermally stable large-size TFT flexible substrates on plastic film bases. The transfer processes include high-pressure jet etching that allows us to achieve good etch-rate uniformity over the large area and the utilization of an adhesive having a low elastic modulus. From the experiments and simulations, we find that using an adhesive having a low elastic modulus is effective in reducing bend of the flexible substrate under thermal stresses. The simulations also predict that the reduction in the bend corresponds to the reduction in the principal stress of the adhesive, leading to the suppression of the film peeling off from the thinned glass. Using the transfer processes, we have successfully fabricated thermally stable TFT flexible substrates (300 mmtimes350 mm times200 mum) that have satisfactory electrical characteristics     

Diffusion properties of point defects in barium strontium titanate thin films

The relationship between the diffusion behavior of hydrogen and the electrical properties of (Ba, Sr)TiO3 (BST) thin-film capacitors was investigated using thermal desorption spectroscopy and secondary ion mass spectroscopy analyses. It has been clearly shown that the frequency dependence of the complex impedance profile of the BST thin-film capacitors could be successfully represented by two parallel resistor-capacitor (RC) electrical equivalent networks in series correlated with the distribution of the hydrogen, namely, the Pt/BST interface region with the influence of hydrogen and the BST bulk region without the influence of hydrogen. However, the I-V properties of the BST thin-film capacitors could be determined almost from the hydrogen atoms existing at the Pt/BST interface.     

Particle motion at the wall of a circulating fluidized bed

The motion of alumina particles of mean size 74.9 μm in the region near to the wall of the 305 mm diameter riser of a cold model circulating fluidized bed has been studied using a high-speed video camera employing normal and magnifying lenses. Particles in this region were found to move predominantly downwards, against the main gas flow. High density groups or swarms of particles typically arch-shaped were observed to descend in contact with the wall at velocities in the range 0.3–0.4 m s⁻¹. Tfie distribution of swarm descent velocities was shown to be little affected by changes in superficial gas velocity over the range 3–5 m s⁻¹ and imposed mean solids mass flux over the range 2 to 80 kg m⁻² s⁻¹. A region of steady bulk downflow of solids with a velocity of approximately 1.0 m s⁻¹ was observed to appear a few millimetres from the wall at mean suspension densities greater than 5.6 kg m⁻³. Motion of particles in contact with the riser was analysed by identification of three flow forms; dilute, dense and swarm flow. Results of the analysis are linked with the observations of other workers concerning the onset of the so-called ‘similar profiles’ regime. The relationship between the measured effective particle swarm length and the cross-sectional mean suspension density was established and the implications for modelling suspension-to-wall heat transfer discussed.