Robust control with pole assignment in a specified region for systems under parameter perturbations; application to a nonlinear system

This paper deals with the problem of determination of feedback gains in order to achieve required performances under linear time invariant perturbations. Based upon the Lagrange multiplier method, the proposed method determines feedback gains that ensure both robust stability and robust performance for a linear uncertain system. It is applied to a nonlinear crane system control design. The nonlinear system is first partitioned into some uncertain linear systems. Then the proposed method is applied to each uncertain linear system. Application is easily demonstrated and, consequently, a nonlinear crane control system can be easily designed. Finally, it is shown in a numerical example that the proposed method is effective.     

Negative regulation of MAP kinase by diacylglycerol-dependent mechanisms via G protein-coupled receptors in rat basophilic RBL-2H3 (ml) cells

Carbachol and 5'-(N-ethylcarboxamido)-adenosine (NECA), stimulants of G protein-coupled receptors, induce MAP kinase activation in the muscarinic ml receptor-transfected mast cell line, RBL-2H3 (ml) cells. The phospholipase C inhibitor neomycin and the phosphatidate phosphohydrolase inhibitor propranolol augmented MAP kinase activation induced by carbachol and NECA without affecting the antigen-induced MAP kinase activation. Furthermore, the duration of MAP kinase activation induced by carbachol or NECA was also prolonged by neomycin and propranolol. The specific protein kinase C inhibitor Ro 31-8425 enhanced the carbachol- or NECA-induced MAP kinase activation. These findings suggest that the MAP kinase activation mediated by the G protein-coupled receptors is negatively regulated by diacylglycerol and activated protein kinase C(s).     

Case studies of large-scale PV systems distributed around desert area of the world

To show the huge potential of PV systems, the authors have been studying the feasibility of large-scale PV plants. If a PV module cost is assumed to be 100¥/W, it gives the electricity at a cost of 7.70−13.12 ¥/kWh for a 100 MW plant size located at 6 desert sites around the world, considering the site irradiation,local labor cost, etc. for each site. In spite of the fixed, flat plate, the cost can reach a fairly low level. The station will be composed of 20 sub-units × 10 units of 500 kW optimum size sub-units.     

Analysis of drying shrinkage and flow due to surface tension ofspin-coated films on topographic substrates

In semiconductor manufacturing processes, it is important that the SiO₂ isolation films around aluminum connection lines have flat surfaces in order to produce the multilayered connection lines used in high-density devices. In this paper, we analyzed transient changes, in the thickness distributions of a liquid-SOG (Spin-on-Glass) film on a two-dimensionally (2-D) grooved substrate during the evaporative shrinking process. The flow due to surface tension of the shrinking liquid film was calculated. Since the film is thin, a boundary layer approximation could be applied, and fourth-order differential equations of film thickness were solved using an iteration method. The viscosity and the shrinkage rate were assumed to be functions of the concentration of the solvent in the film. When the parameter of ratio [(surface tension)/{(viscosity)×(shrinking speed)}] is large and the width of the grooves is small, final surface undulations of the film are shallow. The effect of the centrifugal force was also analyzed     

Development of a process for the recovery of phosphorus resource from digested sludge by crystallization technology.

Removal and recovery of phosphorus from sewage in form of MAP (magnesium ammonium phosphate) have attracted attention from the viewpoint of eutrophication prevention and phosphorus resource recovery as well as scaling prevention inside digestion tanks. In this work, phosphorus recovery demonstration tests were conducted in a 50 m3/d facility having a complete mixing type reactor and a liquid cyclone. Digested sludge, having 690 mg/L T-P and 268 mg/L PO4-P, was used as test material. The T-P and PO4-P of treated sludge were 464 mg/L and 20 mg/L achieving a T-P recovery efficiency of 33% and a PO4-P crystallization ratio of 93%. The reacted phosphorus did not become fine crystals and the recovered MAP particles were found to be valuable as a fertilizer. A case study in applying this phosphorus recovery process for treatment of sludge from an anaerobic-aerobic process of a 21,000 m3/d sewage system, showed that 30% of phosphorus concentration can be reduced in the final effluent, recovering 315 kg/d as MAP.     

Serum levels of Clara cell 10-kDa protein are decreased in patients with asthma

The human immunodeficiency virus type-1 regulatory protein Rev is absolutely required for the production of viral structural proteins. Splice sites have been seen to function as cis-acting repressor sequendes (CRS) and inhibit expression of the Rev-dependent RNAs. In order to analyze the role of a splice donor in Rev dependence, the wild-type 5' splice donor of HIV-1 was mutated in the context of other gag sequences. Following transient transfection, RNA expression by RT-PCR was analyzed. The unspliced RNA produced by the mutant construct still required Rev for the cytoplasmic accumulation of the RNA. Despite deletion of the wild-type 5' splice donor and the tat splice acceptor was used. A cryptic splice donor was identified by PCR and subsequent cloning of the spliced RNA. The cryptic site is 5/9 to the consensus sequence and located immediately downstream of the initiation codon (ATG) for Gag. Analysis of the RNA product containing the cryptic splice donor revealed that the Rev was required for the cytoplasmic accumulation of unspliced RNA, while spliced RNA was Rev independent. Transfection of a wild-type construct also demonstrated usage of the cryptic splice donor. These results indicate that a cryptic splice donor can be activated when the wild-type splice donor is inactivated and that the cryptic splice donor may retain Rev regulation. The findings also suggest the potential for cryptic splice sites to serve as CRS in the determining the Rev dependence of viral RNAs.     

Deoxidation of molten copper with a rotating graphite cylinder

The kinetics of deoxidation of molten copper by the “vacuum-suction degassing” (VSD) method is investigated. The molten copper is deoxidized by a rotating porous graphite tube immersed in the copper bath. The inside space of the porous graphite tube is evacuated so that the CO gas formed at the graphite-metal interface is removed through the tube wall. The experimental results suggest that the mass transfer of oxygen in the metal phase controls the reaction rate. The kinetic data are arranged with a first-order rate equation. At (ppm O)≥10, the rate constant increases by decreasing the porosity of the graphite and increasing the thickness of the tube wall. This result suggests that the suction of CO gas weakens CO bubble stirring and, thereby, the mass transfer at the tube-melt interface. However, when the rate of CO suction becomes comparable to or larger than the CO gas evolution rate, the effect of CO stirring becomes negligible. This situation appears under the conditions of high porosity and large wall thickness at (ppm O) ≥ 10. At the low oxygen concentration range of (ppm O) ≤ 4, the effect of CO stirring becomes negligible, regardless of the CO suction condition, because of the considerably low CO formation rate. The achievement of deoxidation by the VSD method is evaluated in connection with the final oxygen concentration.     

Cold‐triggered/heat‐destroyed emulsions composed of phospholipids and triacylglycerols as thermal history indicators for cold‐chain distribution systems

BACKGROUND: Recently, cold‐chain distribution systems have come to play important roles in worldwide food processing/storage/transportation networks. To ensure the maintenance of the quality and safety of foods, it is necessary to develop thermal history indicators for products involved in cold‐chain distribution systems. To provide a record of the occurrence of a high‐temperature event during a cold‐chain system, a temperature‐related phase change in a material within the indicator is needed to indicate that the high‐temperature event occurred. Preferentially, for safety, the materials of the indicators should be edible and easy to handle. It should be possible to store the indicators at ambient temperature before use, and they should be triggered automatically just by cooling at the start of a cold‐chain system. Furthermore, if the indicator is heated even once during the cold‐chain distribution system, its appearance must be irreversibly altered to provide evidence of the high‐temperature experience. RESULTS: Based on the edible materials composed of lyso‐lecithin (15 g), lecithin (2 g), triacylglycerol (150 g), and water, we successfully constructed a stable emulsion that could be triggered just by cooling to 4 °C or lower for more than 12 h. After triggering, it was immediately destroyed by heating up to 20 °C or higher. Furthermore, the mechanism of cold‐triggering and heat‐destruction has been studied by nuclear magnetic resonance. CONCLUSION: The cold‐triggered/heat‐destroyed emulsion should be applied as a new thermal history indicator that can be automatically triggered just by cooling down and irreversibly change its appearance after a high‐temperature experience in cold‐chain distribution systems. Copyright © 2008 Society of Chemical Industry     

Signal bandwidth consideration of mutual coupling effects on adaptive array performance

The effect of mutual coupling on the performance of a least mean square (LMS) adaptive array using dipole elements is analyzed in consideration of the signal bandwidth. The purpose here is to illustrate quantitatively the significance of the effect of mutual coupling. The results show that the effect in the broad-band signal cases is much greater than that in the narrow-band cases, particularly when few antenna elements are used.