A Two‐Stage Stochastic Mixed‐Integer Programming Approach to the Smart House Scheduling Problem

A “smart house” is a highly energy‐optimized house equipped with photovoltaic (PV) systems, electric battery systems, fuel cell (FC) cogeneration systems, electric vehicles (EVs), and so on. Smart houses are attracting much attention recently because of their enhanced ability to save energy by making full use of renewable energy and by achieving power grid stability despite an increased power draw for installed PV systems. Yet running a smart house's power system, with its multiple power sources and power storages, is no simple task. In this paper, we consider the problem of power scheduling for a smart house with a PV system, an FC cogeneration system, and an EV. We formulate the problem as a mixed‐integer programming problem, and then extend it to a stochastic programming problem involving recourse costs to cope with uncertain electricity demand, heat demand, and PV power generation. Using our method, we seek to achieve the optimal power schedule running at the minimum expected operation cost. We present some results of numerical experiments with data on real‐life demands and PV power generation to show the effectiveness of our method. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 48–58, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22336     

Experimental study on relationship between heat parameter and angular distortion

It is well known that weld residual stress and distortion should be controlled appropriately for structural integrity. Recently, it has become much more necessary to control weld distortion to highly improve manufacturing efficiency. Various studies on control of weld distortion had been conducted based on clarification of influential dominant factors for that. The influential dominant factors had been studied from a viewpoint of temperature distribution in plate thickness section. Without considering moving the weld heat source, the temperature distribution is controlled by weld heat input (Q_net) per weld length. Angular distortion, which is controlled by temperature distribution along the direction of plate thickness (h), is controlled by heat input parameter (Q_net/h²). However, it has recently become known that the conventional results cannot be applied to all welding processes because such processes are becoming more diversified. It is significant for more accurate control of angular distortion to investigate once again the relationship between the heat input parameter and angular distortion. In this study, a series of experiments on the relationship between heat input parameter and angular distortion are carried out. The effects of welding current and welding speed are investigated individually in both TIG and MAG welding. The difference between these welding methods is also investigated. Based on the result, the effects of them are discussed in relation to temperature distribution during welding. It is considered that angular distortion is affected by temperature distribution not only in plate thickness section but also along welding direction. So, angular distortion is not always controlled by only the conventional heat input parameter because the heat input parameter is proposed as the influential dominant factor for temperature distribution in plate thickness section. It is concluded that generation characteristics of inherent strain should be considered in relation to three-dimensional temperature distributions during welding for more accurate control of angular distortion.     

New Natural Pigment Fraction Isolated from Saw Palmetto: Potential for Adjuvant Therapy of Hepatocellular Carcinoma

For the first time, we discovered a small proportion of aqueous fraction from Saw Palmetto apart from the fatty acid-rich fraction exhibited pharmacological activity. Therefore, this study aims to explore the anti-tumor potential of red pigmented aqueous fraction of Saw Palmetto, NYG on human hepatocellular carcinoma and its possible targets. Subcutaneous xenograft and orthotopic implantation models of HCC were used to evaluate the tumor inhibitory effect of NYG. Human hepatocellular carcinoma (HCC) cell lines and human umbilical vein endothelial cells (HUVEC) were used as in vitro model. The mRNA expression was conducted by qPCR. Protein expression was monitored by immunoblotting and immunohistochemistry. Cell migration and blood vessel formation were determined by chamber assay and tube formation assay, respectively. Significant tumor inhibition of NYG in dose-dependent manner was observed on subcutaneous xenograft and orthotopic HCC model. NYG has no direct action on cell viability or VEGF secretion of HCC cells. However, NYG reduced in vitro migration and vessel formation activities of HUVEC cells, as well as in vivo intratumoral neovascularization. NYG attenuated extracellular signal-regulated kinases (ERK) activation in endothelial cells, which may be associated with the suppression of migration and tube formation of HUVEC. NYG suppressed tumor expansion of HCC via inhibiting neovascularization, and may be potential adjuvant treatment for HCC.     

Mechanical properties of drawn poly(methyl methacrylate) filled with ultrafine particles

The elastic and yield properties of drawn poly(methyl methacrylate) (PMMA) filled with ultrafine SiO₂ are described as functions of filler content and size. The drawn PMMA composites were made by uniaxially drawing to x4.0 at 100°C and at a rate of 20 mm/min. Four compliance values, i.e., S₃₃, S₁₁, S₁₃, and S₄₄ were determined. These values decreased with filler content and decreasing filler size. The relative compliance values S^de/S^do(S^de is the compliance of drawn PMMA composites and S^do is that of drawn unfilled PMMA) are almost equivalently changed with changes in filler content. The elastic properties of drawn PMMA composites are thus reinforced isotopically. This is characteristic of PMMA which has a large side group. The yield behavior of drawn PMMA composites have similar filler size and content dependence to those of elastic properties except that the transverse yield stresses become more brittle with filler content. The anisotropy in yield stress is relatively larger than that of elastic properties. This is probably because the anti-reiforcing effect, such as fibrillation becomes prominent with increasing filler content in the perpendicular direction.     

Wave venation in downward gas-liquid two-phase flow (part I,time-spatial behavior chart of interface and analysis of main wave-vein)

Time-series information on both the cross-sectional mean liquid holdup along a tube axis and the gas-liquid phase distribution along a tube diameter was obtained by means of supermultiple cross-sectional mean liquid holdup probes (S-CHOP) and semi-supermultiple point-electrode probes (SS-PEP) for vertical downward gas-liquid two-phase flow. Typical time-spatial behavior charts of interface and gas-liquid interfacial profiles are presented. Close inspection of these results reveals that a huge wave and a disturbance wave appear in downward two-phase flow as well as upward flow. It was clarified that the huge wave flow region covers a wide range of superficial gas velocities. Wave velocity, wave width and maximum liquid holdup of individual waves were examined by wave-vein analysis. Histograms of these flow parameters were also studied. It was found that there exist distinct differences in wave width between the huge wave and the disturbance wave. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(8): 499–510, 1996     

Characteristics of interfacial profiles in upward and downward gas-liquid two-phase plug flow

Gas-liquid interfacial profiles in plug flow for both upward and downward flows were obtained using semi-supermultiple point-electrode probes, comprising 67 sensing tips arranged on a tube diameter. Typical interfacial profiles are demonstrated for both flows. Close inspection of the profiles reveals that four zones exist in a pair of gas and liquid slugs for upward plug flow and a high slip velocity region in downward plug flow. The lengths of the swelling liquid front zone and the wake zone were determined. The length of the wake zone strongly depends on the relative velocity between the liquid film around the gas slug and the liquid phase in the liquid slug. Characteristic distributions of bubbles within liquid slugs were found, i.e., three types of radial distributions of void fraction, namely saddle-shaped, trapezoidal and bullet-shaped distributions, exist for upward flow. The two types for downward flow exclude the saddle-shaped distribution. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25 (8): 568–579, 1996     

Source identification of nitrous oxide on autotrophic partial nitrification in a granular sludge reactor

Emission of nitrous oxide (N₂O) during biological wastewater treatment is of growing concern since N₂O is a major stratospheric ozone-depleting substance and an important greenhouse gas. The emission of N₂O from a lab-scale granular sequencing batch reactor (SBR) for partial nitrification (PN) treating synthetic wastewater without organic carbon was therefore determined in this study, because PN process is known to produce more N₂O than conventional nitrification processes. The average N₂O emission rate from the SBR was 0.32 ± 0.17 mg-N L⁻¹ h⁻¹, corresponding to the average emission of N₂O of 0.8 ± 0.4% of the incoming nitrogen load (1.5 ± 0.8% of the converted NH₄⁺). Analysis of dynamic concentration profiles during one cycle of the SBR operation demonstrated that N₂O concentration in off-gas was the highest just after starting aeration whereas N₂O concentration in effluent was gradually increased in the initial 40 min of the aeration period and was decreased thereafter. Isotopomer analysis was conducted to identify the main N₂O production pathway in the reactor during one cycle. The hydroxylamine (NH₂OH) oxidation pathway accounted for 65% of the total N₂O production in the initial phase during one cycle, whereas contribution of the NO₂⁻ reduction pathway to N₂O production was comparable with that of the NH₂OH oxidation pathway in the latter phase. In addition, spatial distributions of bacteria and their activities in single microbial granules taken from the reactor were determined with microsensors and by in situ hybridization. Partial nitrification occurred mainly in the oxic surface layer of the granules and ammonia-oxidizing bacteria were abundant in this layer. N₂O production was also found mainly in the oxic surface layer. Based on these results, although N₂O was produced mainly via NH₂OH oxidation pathway in the autotrophic partial nitrification reactor, N₂O production mechanisms were complex and could involve multiple N₂O production pathways.     

Long Crack R-Curve of Aligned Porous Silicon Nitride

Long crack R -curve of a porous Si₃N₄ with aligned fibrous grains was investigated, using a chevron-notched beam technique. A crack was constrained to propagate normal to the grain alignment. The crack growth resistance of aligned porous Si₃N₄ was much larger compared with that of dense Si₃N₄ ceramics. Microstructure observations showed that pullouts of fibrous grains in aligned porous Si₃N₄ markedly increased during crack propagation relative to those of dense Si₃N₄, due to the existence of pores. The efficient grain pullouts in porous Si₃N₄ increased the bridging stress at the crack wake.     

The kinetics of phenol decomposition under UV irradiation with and without H2O2 on TiO2, Fe–TiO2 and Fe–C–TiO2 photocatalysts

H₂O₂ used in the photo-Fenton reaction with iron catalyst can accelerate the oxidation of Fe²⁺ to Fe³⁺ under UV irradiation and in the dark (in the so called dark Fenton process). It was proved that conversion of phenol under UV irradiation in the presence of H₂O₂ predominantly produces highly hydrophilic products and catechol, which can accelerate the rate of phenol decomposition. However, while H₂O₂ under UV irradiation could decompose phenol to highly hydrophilic products and dihydroxybenzenes in a very short time, complete mineralization proceeded rather slowly. When H₂O₂ is used for phenol decomposition in the presence of TiO₂ and Fe–TiO₂, decrease of OH radicals formed on the surface of TiO₂ and Fe–TiO₂ has been observed and photodecomposition of phenol is slowed down. In case of phenol decomposition under UV irradiation on Fe–C–TiO₂ photocatalyst in the presence of H₂O₂, marked acceleration of the decomposition rate is observed due to the photo-Fenton reactions: Fe²⁺ is likely oxidized to Fe³⁺, which is then efficiently recycled to Fe²⁺ by the intermediate products formed during phenol decomposition, such as hydroquinone (HQ) and catechol.