A 1.8-V 128-Mb mobile DRAM with double boosting pump, hybrid current sense amplifier, and dual-referenced adjustment scheme for temperature sensor

To verify three important circuit schemes suitable for DRAMs in mobile applications, a 1.8-V 128-Mb SDRAM was implemented with a 0.15-/spl mu/m technology. To achieve an ideal 33% efficiency, the double boosting pump uses two capacitor's series connection at pumping phase, while they are precharged in parallel. The hybrid folded current sense amplifier together with a novel replica inverter connection improved power and speed performances. Also, a dual-referenced adjustment scheme for a temperature sensor was proposed to allow a very high accuracy in tuning. Without loss in productivity, the implemented dual-referenced searching technique achieved tuning error of less than /spl plusmn/2.5/spl deg/C.     

The optimization of conditions for the production of acid-hydrolysed winged bean and soybean proteins with reduction of 3-monochloropropane-1,2-diol (3-MCPD)

Response Surface Methodology (RSM) was used to establish the optimum time and temperature for production of acid‐hydrolysed winged bean protein (aHWBP) and acid‐hydrolysed soybean protein (aHSBP). Seven hours of hydrolysis at 125 °C was the optimum condition for producing aHWBP, whereas it was 5 h of hydrolysis at 125 °C for production of aHSBP. Although aHWBP and aHSBP produced using these conditions had favourable sensory qualities, they were found to have up to 25 mg kg^?1 of 3‐monochloropropane‐1,2‐diol (3‐MCPD). This exceeds the maximum level permissible in Commission Regulation (EC) No 466/2001. However, additional alkaline thermal treatment at pH 8.5 for 2 h at 100 °C effectively reduced the 3‐MCPD contents of aHWBP and aHSBP to undetectable levels. aHWBP has a distinctive flavour, which is different from that of aHSBP. The former has higher mean scores for meaty and vegetable attributes but lower mean scores for soy, umami and beany attributes than the latter.     

Ring sensor and heart rate monitoring system for sensor network applications

A ring-type pulse oximeter sensor attached to the finger and its 24-hour ambulatory heart rate monitoring system are presented. The PCB has been designed with a light-to-frequency converter and the CPU with a built-in Zigbee stack for simple and low power consumption. Also designed is the algorithm using a least square estimator to calibrate various signal distortions caused by motion artefacts for a proper accuracy.     

Selective Sharing of Load Current Components Among Parallel Power Electronic Interfaces in Three-phase Four-wire Stand-alone Microgrid

This paper investigates selective sharing of load current components among the parallel operation of distributed generators (DGs) in three-phase four-wire stand-alone microgrids. The proposed control method is based on master-slave operation of DGs, and the goal of selective sharing of load current components is to have DGs located in close proximity of the load operating in slave mode, in order to inject their available energy and also compensate the non-active load current components, while the distant DGs might operate in master mode to share the remaining load autonomously. Droop control is employed due to impracticality of communication at remote nodes, and resistive line impedance compensation is adopted to decouple active and reactive power controllers and ensure proper active power sharing among master DGs, irrespective of the mitigation of non-active current components by the slave inverters. The sharing factors for each current component are determined by a higher level control. The Conservative Power Theory (CPT) decompositions provide decoupled power and current references for the inverters, resulting in a selective sharing strategy. The principles supporting the developed control strategy are discussed, and the effectiveness of the control is demonstrated through computational simulations using PSIM software.     

Preparation of dandelion-type silica spheres and their application as catalyst supports

Dandelion-type silica spheres with a dendrimer-like porous structure were prepared by adding pore modifiers into aqueous synthetic mixtures of tetraethylorthosilicate (TEOS), hexadecyltrimethylammonium bromide (CTAB), ammonium hydroxide, and acetone. The formation of silica spheres and their porous characteristics were investigated using various techniques, including electron microscopy, nitrogen adsorption, and thermogravimetric analysis. Benzyl acetate (BENA) was very effective in the formation of a dendrimer-like porous structure. However, the composition of TEOS, CTAB, acetone, and BENA strongly influenced the size and shape of the silica spheres and their porous structure. The synthetic mixture of 1 TEOS: 0.22 CTAB: 1.9 BENA: 0.32 NH₄OH: 36 acetone: 236 H₂O produced dandelion-type silica spheres with diameters of ~300 nm. The phosphazenium hydroxide (PzOH) catalyst supported on the dandelion-type silica spheres prepared by adding BENA showed high catalytic performance in the transesterification of soybean oil with methanol due to its high feasibility for rapid access of large triglyceride molecules into the basic PzOH moieties incorporated in the pores.     

Microfluidic Design of Magnetoresponsive Photonic Microcylinders with Multicompartments

Colloidal photonic structures have been designed to have granular format to use them for paint pigments, encoded carriers, and display pixels. However, conventional approaches only provide spherical or discoid shapes, restricting their applications. Cylindrical granules with fan‐shaped compartments in the cross section are appealing for microcarriers with abundant optical codes and active display pigments for color switching. In this work, a stratified laminar flow of concentrated silica particles is employed, formed in a cylindrical microchannel, to produce cylindrical photonic microparticles with multiple compartments. To accomplish this, a microfluidic device is designed to have one cylindrical main channel connected with four branch channels. Four different photocurable suspensions are independently injected through the branches to form quarter‐cylindrically compartmentalized streams in the main channel. Local ultraviolet irradiation on the main channel polymerizes the suspension, thereby forming cylindrical microparticles with four compartments. In each compartment, silica particles form ordered array which develops particle size–dependent structural color. Therefore, different colors can be incorporated into single microcylinder by employing different sizes of silica particles. Moreover, one of the compartments can be rendered to be magnetoresponsive by embedding aligned magnetic particles, which enables the remote control of microcylinder orientation and therefore the switching of structural colors.     

Influence of modified atmosphere packaging and storage temperature on the sensory and microbiological quality of fresh peeled white asparagus

The sensory and microbiological quality of fresh peeled white asparagus packaged in two different types of P-Plus films and stored at two different temperatures (5 °C and 10 °C) for up to 14 days, was studied. The shelf life limiting alterations at each temperature were evaluated. The best modified atmosphere was determined.At 10 °C, the shelf life was 6 days, the loss of freshness was the main cause of quality loss, as indicated by colour darkening and presence of blotches. Moreover the sensorial acceptance of cooked asparagus was affected, being on the limit.Fresh appearance was maintained better at 5 °C than at 10 °C, being microbial spoilage the main limiting factor. The atmosphere generated with film A (around 7% CO₂ and 15% O₂) inhibited spoilage and maintained the acidity of asparagus better than the atmosphere generated by film B (around 2% CO₂ and 20% O₂). The shelf life of asparagus packaged in film A and stored at 5 °C was 14 days.Mesophiles and enterobacteriaceae counts in asparagus stored at 5 °C were acceptable during 14 days being around 7 log cfu/g. Mesophiles counts were slightly higher in asparagus stored at 10 °C than at 5 °C, while the increase in enterobacteriaceae was clearly higher in asparagus stored at 10 °C.     

High cell density culture of Anabaena variabilis using repeated injections of carbon dioxide for the production of hydrogen

Cyanobacteria have the unique characteristic of using CO₂ in the air as a carbon source and solar energy as an energy source. Reducing equivalents from the fermentation of carbohydrates are used as the primary electron donors in cyanobacteria for the hydrogen producing enzymes. The cells take up CO₂ first to produce cellular substances, which are subsequently used for H₂ production. Since the optimal operating conditions for the CO₂ uptake and H₂ production are different, a two-stage system can be effectively employed to separate these two phases. In this study, for the efficient production of H₂ in the second stage, the conditions for the effective CO₂ uptake and cell growth in the first stage were characterized, and high cell density culture was carried out using repeated injections of CO₂. The specific growth rate and growth yield based on CO₂ decreased with an increase in light intensity or CO₂ concentration. However, the effect of CO₂ concentration on the growth yield was much smaller than that of a light intensity. A CO₂ uptake rate per unit cell decreased linearly with the initial CO₂ concentration in the gas phase. With repeated injections of CO₂, the CO₂ was continuously consumed and the cell concentration reached 3.7 g dry cell/l in 20 days, which is 6.7 times higher than that in a batch culture without further supply of CO₂. The CO₂ injection in the cell growth phase increased not only the cell concentration but also the hydrogen production per gram cell.