A Method for Systematic Assessment of Intrinsically Disordered Protein Regions by NMR

Intrinsically disordered proteins (IDPs) that lack stable conformations and are highly flexible have attracted the attention of biologists. Therefore, the development of a systematic method to identify polypeptide regions that are unstructured in solution is important. We have designed an “indirect/reflected” detection system for evaluating the physicochemical properties of IDPs using nuclear magnetic resonance (NMR). This approach employs a “chimeric membrane protein”-based method using the thermostable membrane protein PH0471. This protein contains two domains, a transmembrane helical region and a C-terminal OB (oligonucleotide/oligosaccharide binding)-fold domain (named NfeDC domain), connected by a flexible linker. NMR signals of the OB-fold domain of detergent-solubilized PH0471 are observed because of the flexibility of the linker region. In this study, the linker region was substituted with target IDPs. Fifty-three candidates were selected using the prediction tool POODLE and 35 expression vectors were constructed. Subsequently, we obtained ¹⁵N-labeled chimeric PH0471 proteins with 25 IDPs as linkers. The NMR spectra allowed us to classify IDPs into three categories: flexible, moderately flexible, and inflexible. The inflexible IDPs contain membrane-associating or aggregation-prone sequences. This is the first attempt to use an indirect/reflected NMR method to evaluate IDPs and can verify the predictions derived from our computational tools.     

Effects of Smart Charging of Multiple Electric Vehicles in Reducing Power Generation Fuel Cost

The high penetration of variable sources of renewable power generation will lead to operational difficulties in supply/demand balancing in the entire power system. The mass deployment of electric vehicles (EVs) and plug‐in hybrid vehicles (PHEVs) will also cause significant changes in electricity demand. Therefore, controlling and managing the charging time of EVs/PHEVs are effective approaches that are imperative for improving balancing in power system operation. We assumed travel patterns for EVs in a model of the future Tokyo power system and analyzed the power system loads, including the charging load of the EVs, under several charging control scenarios. We verified that charging time controls are substantially effective for reducing the fuel costs in the power system. Further, we found that load leveling under a multicar charging management scenario gave the best results in terms of the fuel costs in all cases.     

Effect of ceria addition on NiRu/CeO2Al2O3 catalysts in steam reforming of acetic acid

NiRu bimetallic catalysts with different amount of CeO₂ loaded on the γ-Al₂O₃ support were prepared. The properties of catalysts were characterized by means of N₂ adsorption-desorption, XRD, H₂-TPR and XPS techniques. Catalytic activities for the steam reforming of acetic acid over these catalysts were investigated at the temperature range from 650 °C to 750 °C. The addition of CeO₂ dramatically improved the activity and stability of the catalyst. Among these catalysts, the NiRu/10CeAl catalyst showed the highest catalytic activity as well as a good stability owing to the abundant Ce³⁺ on the surface of catalyst. The existence of Ce³⁺ promoted the formation of CO₂ from CO because of the mobilizable oxygen, which was favorable for the formation of hydrogen. The coke amount and species deposited on the catalysts after the activity tests were analyzed by DTG. As expected, the NiRu/10CeAl catalyst showed the best resistance to carbon formation. The temperature stepwise steam decoking experiment of the spent catalysts was conducted to elucidate the relationship between the existence of Ce³⁺ and the decoking abilities of various catalysts. It was verified that the existence of Ce³⁺ significantly promoted the decoking abilities of the catalysts.     

Local boiling heat transfer characteristics of ammonia/water binary mixture in a vertical plate evaporator

The next-generation energy production systems are expected to be based on ocean thermal energy conversion (OTEC) and discharged thermal energy conversion (DTEC). These systems use a plate-type evaporator and ammonia or an ammonia/water mixture as a working fluid. It is important to clarify heat transfer characteristics for designing efficient power generation systems. Measurements of local boiling heat transfer coefficients and visualizations were performed for an ammonia/water mixture (z = 0.9) on a vertical flat plate heat exchanger at a range of mass fluxes (7.5-15 kg m⁻² s⁻¹), heat fluxes (15-23 kW m⁻²), and pressures (0.7-0.9 MPa). The results show that in the case of an ammonia/water mixture, the local heat transfer coefficients increase with an increase in the vapor quality and mass flux and decrease with an increase in the heat flux. The influence of the flow pattern on the local heat transfer coefficient is also observed.     

Construction of simulation model for spray flash desalination system

This paper describes a simulation model for a spray flash desalination system which makes fresh water from sea water by using the temperature difference between warm surface sea water and cool deep sea water. The spray flash desalination system can be modeled by using the energy conservation law and the mass conservation law. Simulation results of the model are compared with the experimental results and show the accuracy of the proposed simulation model. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(4): 9–17, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20975     

Uniformity of gallium doped zinc oxide thin film prepared by pulsed laser deposition

Recently, transparent conducting oxide thin films have attracted attention for the application to transparent conducting electrodes. In this work, we evaluated the uniformity of electrical, optical and structural properties for gallium doped zinc oxide thin films prepared on the 10 × 10 cm² silica glass substrate by pulsed laser deposition. The resistivity, carrier concentration, mobility, bonding state and atomic composition of the film were uniform along in-plane and depth direction over the 10 × 10 cm² area of the substrate. The film showed the average transmittance of 81-87%, resistivity of 1.4 × 10^− 3 Ω cm, carrier concentration of 9.7 × 10²⁰/cm³ and mobility of 5 cm²/Vs in spite of the amorphous X-ray diffraction pattern. The gradual thickness distribution was found, however, the potential for large-area and low temperature deposition of transparent conducting oxide thin film using pulsed laser deposition method was confirmed.     

Frequency-stabilized DFB laser module using 1.53159 μmabsorption line of C2H2

A frequency-stabilized distributed-feedback (DFB) laser module using the vibrational-rotational absorption of acetylene molecules is discussed. The size of this device is about 4.5 cm long, 2 cm wide, and 2 cm high. Frequency stability to within 0.5 MHz peak/peak fluctuation was achieved at the 1.53159 μm wavelength     

Processing of ethanol fermentation broths by Candida krusei to separate bioethanol by pervaporation using silicone rubber‐coated silicalite membranes

BACKGROUND: Pervaporation employing ethanol‐permselective silicalite membranes as an alternative to distillation is a promising approach for refining low‐concentration bioethanol solutions. However, to make the separation process practicable, it is extremely important to avoid the problems caused by the adsorption of succinate on the membrane during the separation process. In this work, the pervaporation of an ethanol fermentation broth without succinate was investigated, as well as the influence of several fermentation broth nutrient components. RESULTS: Candida krusei IA‐1 produces an extremely low level of succinate. The decrease in permeate ethanol concentration through a silicone rubber‐coated silicalite membrane during the separation of low‐succinate C. krusei IA‐1 fermentation broth was significantly improved when compared with that obtained using Saccharomyces cerevisiae broth. By treating the fermentation broth with activated carbon, bioethanol was concentrated as efficiently as with binary mixtures of ethanol/water. The total flux was improved upto 56% of that obtained from the separation of binary mixtures, compared with 43% before the addition of activated carbon. Nutrients such as peptone, yeast extract and corn steep liquor had a negative effect on pervaporation, but this response was distinct from that caused by succinate. CONCLUSION: For consistent separation of bioethanol from C. krusei IA‐1 fermentation broth by pervaporation, it is useful to treat the low nutrient broth with activated carbon. To further improve pervaporation performance, it will be necessary to suppress the accumulation of glycerol. Copyright © 2009 Society of Chemical Industry