Fuzzy logic switching of thyristor controlled braking resistorconsidering coordination with SVC

This paper presents a new switching control scheme for braking resistors (BR) using fuzzy logic to enhance overall stability of electric power systems. In addition, the coordination with an SVC is also considered to achieve a wider stable region. The braking resistor is set on one of the generator busbars, where the real power output from the generator is measured to determine the firing-angle of the thyristor switch. The switching control scheme is simple so as not to require heavy computation on the microcomputer based switching controller. An SVC is set on one of the busbars in the system. The switching of the SVC uses a similar fuzzy logic control scheme to the one for the BR. Simulation results show the effectiveness of the proposed fuzzy logic switching control scheme     

Evaluation of advanced fuzzy logic PSS on analog network simulatorand actual installation on hydro generators

This paper presents the experimental evaluation of an advanced fuzzy logic PSS on the analog network simulator at the Research Laboratory of Kyushu Electric Power Co., Inc. The proposed power system stabilizer (PSS) is set up by using a personal computer with A/D and D/A conversion interfaces. The personal computer based PSS was set on the analog network simulator to evaluate the effectiveness of the advanced fuzzy logic control scheme, and to provide sufficient data for the actual installation of the proposed PSS on hydro-units in the Kyushu Electric Power System. This paper also describes the actual installation of the proposed PSS on hydro-units in the Kyushu Electric Power System for the long term evaluation of the proposed PSS using its prototypes     

‘Lipase and protease production of dairy Penicillium sp. on milk‐protein‐based solid substrates’

The lipolytic and proteolytic activity of Penicillium camemberti PC TT033 and Penicillium roqueforti PR G3, cultured on the whey solids or simulated cheese media, were compared under several pH reaction conditions. Lipolytic activity was higher when both strains had been cultured on the whey medium than on the simulated cheese medium, whereas proteolytic activity was less influenced by the culture medium. The relationship between the reaction pH and these enzyme activities was dependent on the culture medium, which suggested that the expression level and balance of isozyme rely on the culture substrate.     

A GIS-based DRASTIC model for assessing aquifer vulnerability in Kakamigahara Heights, Gifu Prefecture, central Japan

Vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible resource management and land use planning. This contribution aims at estimating aquifer vulnerability by applying the DRASTIC model as well as utilizing sensitivity analyses to evaluate the relative importance of the model parameters for aquifer vulnerability in Kakamigahara Heights, Gifu Prefecture central Japan. An additional objective is to demonstrate the combined use of the DRASTIC and geographical information system (GIS) as an effective method for groundwater pollution risk assessment. The DRASTIC model uses seven environmental parameters (Depth to water, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and hydraulic Conductivity) to characterize the hydrogeological setting and evaluate aquifer vulnerability. The western part of the Kakamigahara aquifer was dominated by "High" vulnerability classes while the eastern part was characterized by "Moderate" vulnerability classes. The elevated north-eastern part of the study area displayed "Low" aquifer vulnerability. The integrated vulnerability map shows the high risk imposed on the eastern part of the Kakamigahara aquifer due to the high pollution potential of intensive vegetable cultivation. The more vulnerable western part of the aquifer is, however, under a lower contamination risk. In Kakamigahara Heights, land use seems to be a better predictor of groundwater contamination by nitrate. Net recharge parameter inflicted the largest impact on the intrinsic vulnerability of the aquifer followed by soil media, topography, vadose zone media, and hydraulic conductivity. Sensitivity analyses indicated that the removal of net recharge, soil media and topography causes large variation in vulnerability index. Moreover, net recharge and hydraulic conductivity were found to be more effective in assessing aquifer vulnerability than assumed by the DRASTIC model. The GIS technique has provided efficient environment for analyses and high capabilities of handling large spatial data.     

Design of AVS/RS under group constraint

Distribution centers, which are essential to our society, are becoming increasingly important. Although the efficiency of an AVS/RS (Autonomous vehicle storage and retrieval system) makes it a promising system, there is still much to be studied regarding its effective use and design. This paper proposes a method of designing AVS/RSs through a quantitative consideration of group constraint by utilizing probability theory. The proposed algorithm also deals with the problem of designing the sizes of several buffers, and considers the effect of load fluctuations, which are important for real-world operation, by use of queuing network theory. Effectiveness of the proposed algorithm is shown with simulations of various number of groups, those of various safety factors for fluctuations, and those of various evasion rates for buffer overflow. The design results are shown to be much different from those which do not consider those factors. The results prove that the proposed method provides an accurate quantitative assessment of the AVS/RS’s constraints.     

Scaling of land surface temperature using satellite data: A case examination on ASTER and MODIS products over a heterogeneous terrain area

Land surface temperature (LST) is a key parameter in numerous environmental studies. Surface heterogeneity induces uncertainty in pixel-wise LST. Spatial scaling may account for the uncertainty, however, different approaches lead to differences in scaled values. Satellite-retrieved LST may be representative of the pixel-wise LST and useful for scaling analysis, but the limited accuracy of retrieved values adds uncertainty into the scaled values. Based on the Stefan-Boltzmann (S-B) law, this study proposed scaling approaches for LST over flat and relief areas to explore the combined uncertainties in scaling using satellite-retrieved data. To take advantage of simultaneous, multi-resolution observations at coincident nadirs by the Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) and the MODerate-resolution Imaging Spectroradiometer (MODIS), LST products from these two sensors were examined for part of the Loess Plateau in China. 90-m ASTER LST data were scaled up to 1 km using the proposed approaches, and variation in the LST was generally reduced after scaling. Amongst the sources of uncertainties, surface heterogeneity (emissivity) and different scaling approaches resulted in very minor differences, with a maximum difference of 0.2 K for the upscaled LST. Terrain features, taken as an areal weighting factor, had negligible effects on the upscaled value. Limited accuracy of the retrieved LST was the major uncertainty. The overall LST increased 0.6 K on average with correction for terrain-induced angular effect and 0.4 K for both angular and adjacency effects over the study area. Accounting for terrain correction in scaling is necessary for rugged areas. With terrain correction, the upscaled ASTER LST achieved an agreement of − 0.1 ± 1.87 K and a root mean square error (RMSE) of 1.87 K overall with the 1-km MODIS LST rectified by Wan et al.'s approach [Wan, Z., Zhang, Y., Zhang Q., Li, Z.-L. (2002b), Validation of the land-surface temperature products retrieved from Terra Moderate Resolution Imaging Spectroradiometer data. Remote Sensing of Environment, 83, 163-180]. Refining the rectification approach resulted in a better agreement of − 0.2 ± 1.57 K and a RMSE of 1.58 K.     

A Single Mutation at the Ferredoxin Binding Site of P450 Vdh Enables Efficient Biocatalytic Production of 25‐Hydroxyvitamin D3

Vitamin D₃ hydroxylase (Vdh) from Pseudonocardia autotrophica is a cytochrome P450 monooxygenase that catalyzes the two‐step hydroxylation of vitamin D₃ (VD₃) to produce 25‐hydroxyvitamin D₃ (25(OH)VD₃) and 1α,25‐dihydroxyvitamin D₃ (1α,25(OH)₂VD₃). These hydroxylated forms of VD₃ are useful as pharmaceuticals for the treatment of conditions associated with VD₃ deficiency and VD₃ metabolic disorder. Herein, we describe the creation of a highly active T107A mutant of Vdh by engineering the putative ferredoxin‐binding site. Crystallographic and kinetic analyses indicate that the T107A mutation results in conformational change from an open to a closed state, thereby increasing the binding affinity with ferredoxin. We also report the efficient biocatalytic synthesis of 25(OH)VD₃, a promising intermediate for the synthesis of various hydroxylated VD₃ derivatives, by using nisin‐treated Rhodococcus erythropolis cells containing Vdh_T107A. The gene‐expression cassette encoding Bacillus megaterium glucose dehydrogenase‐IV was inserted into the R. erythropolis chromosome and expressed to avoid exhaustion of NADH in a cytoplasm during bioconversion. As a result, approximately 573 μg mL^?1 25(OH)VD₃ was successfully produced by a 2 h bioconversion.