Optimal operation of cogeneration system coordinated by aggregator for providing the demand and supply regulation capacity

Recent growth of renewable energy generations with natural variability, such as photovoltaic generation and wind turbine generation, would make the demand and supply control in a whole power system more difficult, and therefore, alternatives for demand and supply regulation resources would be required. The authors focus on cogeneration system (CGS) as one of regulation resources. In order to procure adequate volume of regulation capability, an aggregator coordinates a number of CGSs efficiently and flexibly considering the wide variety of electricity/thermal demands of CGS owners. This paper proposes a novel optimal operation strategy of CGS coordinated by the aggregator considering the energy balance and operation cost of individual CGS owner. This paper also demonstrates the availability of CGSs for regulation capability by numerical case studies in which the actual consumption profile is employed.     

Altered mucosa-associated microbiota in the ileum and colon of neonatal calves in response to delayed first colostrum feeding

The present study investigated whether delaying the first feeding of colostrum affected ileum and colon mucosa-associated microbiota in calves. Twenty-seven male Holstein calves were randomly assigned to 1 of 3 groups, fed colostrum at 45 min, 6 h, and 12 h after birth, respectively. Ileum and colon mucosa were collected at 51 h after birth, and their associated microbial profiles were assessed using amplicon sequencing. Both ileum and colon mucosa-associated microbiota were predominated by genus Escherichia-Shigella. The negative correlation between the molar proportion of short-chain fatty acids (SCFA) and ileum mucosa-associated opportunistic pathogens, and the positive correlation between the molar proportion of SCFA and colon mucosa-associated beneficial bacteria, suggest that SCFA might play an important role in maintaining the gut health of 2-d-old calves. A higher relative abundance of ileum mucosa-associated Enterococcus and Streptococcus was detected when the first colostrum feeding was delayed for 12 h. The relative abundance of colon mucosa-associated Lactobacillus tended to be lower in calves fed colostrum 12 h than those under the other 2 treatments, whereas that of Faecalibacterium tended to be lower in calves fed colostrum immediately after birth than those fed colostrum 6 and 12 h after birth, respectively. Our findings suggest that delayed first colostrum feeding affects the establishment of ileum and colon mucosa-associated bacteria, which may have long-term effects on gut health of calves.     

Spring bloom in a hypereutrophic lake, lake Kasumigaura, Japan—II Succession of phytoplankton species

Numerous phytoplankton species in Lake Kasumigaura were shown to comprise the Spring bloom in 1980. The predominant phytoplankton species that appeared during the Spring bloom belonged to 28 genera. A few species among them increased at any time to form a phytoplankton pulse, but the few species of phytoplankters that comprised a phytoplankton pulse did not exclude completely other phytoplankters. During the Spring bloom, one pulse was replaced by another pulse composed of a new grouping of different species. Throughout these replacements by natural selection in the bloom were numerous other species by phytoplankters at levels of abundance somewhat less than those which formed phytoplankton pulse.     

A study of reactor neutrino monitoring at the experimental fast reactor JOYO

We carried out a study of neutrino detection at the experimental fast reactor JOYO using a 0.76 tons gadolinium loaded liquid scintillator detector. The detector was set up on the ground level at 24.3 m from the JOYO reactor core of 140 MW thermal power. The measured neutrino event rate from reactor on-off comparison was 1.11±1.24(stat.)±0.46(syst.) events/day. Although the statistical significance of the measurement was not enough, backgrounds in such a compact detector at the ground level were studied in detail and MC simulations were found to describe the data well. A study for improvement of the detector for future such experiments is also shown.     

Grain Boundary Segregation Behavior of Boron in Low-Alloy Steel

The boron concentration profiles around prior austenite grain boundaries in Fe-0.05C-0.5Mo-0.001B (mass pct) are examined using aberration-corrected STEM-EELS. In order to obtain the precise distribution of boron around the boundaries, tilt series measurements with thin specimens (<30 nm) are performed and the EEL spectra are analyzed by principal component analysis (PCA) and multivariate curve resolution (MCR). The boron concentration profile changes with the cooling rate from the solid solution temperature. The concentration at grain boundaries is maximized at a medium rate (30 °C/s), where the concentration reaches 8 at. pct, and it decreases at a larger (250 °C/s) or smaller (5 °C/s) rate. On the other hand, the boron distribution becomes wider as the cooling rate becomes smaller. The current results suggest that the boron segregation in the alloy is formed by the “non-equilibrium segregation mechanism.”     

Analysis of spatial smoothing effect of short‐term fluctuation of global solar radiation based on data including quantization error

Photovoltaic (PV) systems are attracting attention as one of the promising countermeasures against global warming and the environmental issues. However, the generation output from PV systems is generally unstable and unpredictable. Therefore, large penetration of PV systems may cause some serious impacts on power system operation, such as load frequency control, voltage regulation, etc. Estimation of the influences of PV system installation is becoming important, but it requires simultaneous multipoint solar radiation measurements. The Japan Meteorological Business Support Center has provided 1‐minute meteorological data observed in Japan, but its solar radiation data includes quantization errors. This paper proposes a regeneration method for solar radiation data including quantization errors. It also analyzes the spatial smoothing effect of global solar radiation fluctuations. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(3): 55–63, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21274     

Traversable Region Estimation for Mobile Robots in an Outdoor Image

This paper describes a novel method to estimate appropriate traversable regions from an outdoor scene image. The traversable regions output by the proposed method reflect the common sense of people. For example, a candidate traversable region is “a paved road somewhat distant from the side ditch.” The input to the traversable region estimation is one color image. First, category is assigned to each pixel in the image. The categorization result is then input to the region estimator. Finally, the traversable region are estimated on the input image. An important aspect of this method is the application of two score functions in region estimation process. One score function places high value on categories selected as traversable paths by subjects. The other function places high value on categories that are not selected as traversable regions but are adjacent to categories with traversable paths. A combination of these two functions produces feasible estimation results. The effectiveness of the combined score functions was evaluated by experiments and a questionnaire.     

Activation Energy of Aggregation-Disaggregation Self-Oscillation of Polymer Chain

In this paper, we investigated the activation energies of the aggregation–disaggregation self-oscillation induced by the Belousov-Zhabotinsky (BZ) reaction by utilizing the nonthermoresponsive polymer chain in a wide temperature range. This is because the conventional type self-oscillating polymer chain, with thermoresponsive poly(Nisopropylacrylamide) (poly(NIPAAm) main-chain covalently bonded to the ruthenium catalyst (Ru(bpy)₃) of the BZ reaction, cannot evaluate the activation energy over the lower critical solution temperature (LCST). The nonthermoresponsive self-oscillating polymer chain is composed of a poly-vinylpyrrolidone (PVP) main-chain with the ruthenium catalyst (Ru(bpy)₃). As a result, we clarified that the activation energy of the aggregation–disaggregation self-oscillation of the polymer chain is hardly affected by the concentrations of the BZ substrates. In addition, the activation energy of the nonthermoresponsive self-oscillating polymer chain was found to be almost the same value as normal BZ reaction, i.e., not including the self-oscillating polymer system with Ru moiety.