Soil gas investigation by detection tube

Pollution of groundwater and soil caused by volatile organic chloride such as trichloroethylene (TCE) is normally detected by measurement of the groundwater, but a pollution source and a pollution range could not be specified only by the measurement of the groundwater. A soil gas investigation by a detection tube method detects components contained in soil gas of a surface layer by utilizing high volatility such as TCE, and surface pollution and range are estimated. Here, a soil gas investigation is performed and pollution source points are estimated by considering ground water science and geochemical examination in tetrachloroethylene (PCE).

PCE in ground water in a polluted district is measured and its change is observed. Furthermore, ion components in the ground water are measured, hexadiagram and trilinear diagrams are made and determination of quality of the groundwater is carried out.

From the gas investigation result concentration contours are made on the points on a map made by the previous hearing investigation.     

Combined modeling and experimental studies of hydroxylated silica nanoparticles

Nanotechnology offers several opportunities to solve problems related with Oil and Gas industry. One of them is the possibility to use hard nanoparticles to control the wettability phenomena between the three-phase system (oil–water–minerals) at reservoir conditions of temperature, pressure, and salinity. Here, we present a combined experimental and modeling study of hydroxylated silica nanoparticles as candidate for improved oil recovery applications. In this work, we mainly focus on development of more realistic SiO₂-nanoparticle models and validating them against the experimental data. An efficient Monte Carlo scheme is proposed to generate realistic SiO₂ nanoparticle atomistic models (3–5 nm). Structural and spectroscopic properties such as Raman and Infrared were obtained through Molecular Dynamics (MD) calculations using a force field that mimics an ab initio data. We have also used Fourier transform infrared spectroscopy to identify chemical functional groups present in 5 nm unmodified (bare) silica nanoparticle dispersions. A good agreement between the MD simulations and experiments has been observed.     

Surface coating with a high resistance to hydrogen entry under high-pressure hydrogen-gas environment

Development of a surface coating with high resistance to hydrogen entry under a high-pressure hydrogen-gas environment is presented. Two aluminum-based coatings were developed on the basis of preliminary tests: two-layer (alumina/Fe–Al) and three-layer (alumina/aluminum/Fe–Al) coatings, deposited onto cylindrical and pipe (Type 304 austenitic stainless steel) surfaces by immersion into a specially blended molten aluminum alloy. The coated specimens were exposed to hydrogen gas at 10–100 MPa at 270 °C for 200 h. Specimen hydrogen content was measured by thermal desorption analysis; hydrogen distributions were analyzed by secondary ion mass spectroscopy. Both coatings showed high hydrogen-entry resistance at 10 MPa. However, resistance of the two-layer coating clearly decreased with an increase in pressure. In contrast, the three-layer coating showed excellent hydrogen-entry resistance at a wide pressure range (10–100 MPa), achieved by the combined effect of alumina, aluminum, and Fe–Al layers.     

Formation of Ni-aluminide Coating Containing Hf by Molten-Salt Electrodeposition and Cyclic-Oxidation Resistance

The formation of a coating layer consisting of Ni-aluminide containing Hf on a Ni–10at.%Cr–8at.%Al alloy substrate was attempted by the electrodeposition of Hf, Ni, and Al. The cyclic-oxidation resistance for the alloy covered with this coating was then evaluated in air at 1,423 K. Ni was deposited by aqueous solution electrolysis. Hf and Al were deposited by molten-salt electrolysis. For the sample first treated with the Hf-deposition, subsequently treated with the Ni-deposition, followed by Al-deposition, a coating consisting of Ni₂Al₃ of about 40-μm thickness was uniformly formed on the alloy. At the center region of this coating, a Hf-concentration layer was formed. The cyclic-oxidation test showed that, for the untreated sample and the sample with only Ni and Al depositions, a mass reduction due to spallation of a scale took place during the initial oxidation period. On the contrary, for the sample with Hf, Ni, and Al depositions, a mass reduction due to spallation of a scale scarcely took place. The cross-sectional observation using SEM showed that, for the sample with Hf, Ni, and Al depositions after the oxidation test, an adhesive scale having a spiked shape was formed. This scale mainly consisted of α-Al₂O₃, and contained HfO₂ particles. It was postulated that, for this sample, the Hf in the Hf-concentration layer diffused into the surface region of the Ni-aluminide layer, contributing to improvement in the exfoliation resistance of the scale.     

Temperature Coefficient of Electrical Resistivity in Individual Single-Crystal Bismuth Nanowires

The temperature dependence of electrical resistivity and the crystal orientation of single-crystal bismuth nanowires each encapsulated in a quartz template were studied. The electrical resistivities of four bismuth nanowires with diameter of 356 nm, 376 nm, 622 nm, and 633 nm were measured in the temperature range from 4.2 K to 300 K. The temperature coefficient of resistivity of 376-nm- and 633-nm-diameter nanowires was negative in the low-temperature region. On the other hand, a positive temperature coefficient appeared in 356-nm- and 622-nm-diameter nanowires. The positive temperature coefficient was not explained by carrier mean free path limitation. Thus, the crystal orientation of the bismuth nanowires was observed by x-ray diffraction measurements to study the relationship between electrical resistivity and crystal orientation. It was confirmed that the temperature dependence of electrical resistivity strongly depended on the crystal orientation of the bismuth nanowire.     

Sediment transport and depth variation study of the Gulf of Kutch using remote sensing

Ocean Colour Monitor (OCM) data gathered onboard Indian Remote Sensing satellite (IRS P4), in eight VNIR bands covering Gulf of Kutch and adjoining regions were digitally processed using an image processing system. False colour composite images of actual data and principal components were generated to study sediment transport, depth variation and associated processes by mapping coastal and underwater geomorphic features and suspended sediment plumes. Submerged shoals, located as deep as 20 m below water level, were correctly marked. By studying turbidity distribution patterns and sediment transport indicators, sediment distribution and dispersion have been inferred. The study demonstrates that OCM data have been derived from up to 20 m water depth in the high-energy tide dominated Gulf and hence are useful for mapping underwater bedforms, sediment plumes, and other geomorphic features. The study indicates that the sediments are transported to the Gulf from the north as well as from the south and are mainly season dependent. It is concluded that the OCM data can be used for depth variation and sediment distribution studies.     

A multiagent approach to distribution system restoration

This paper proposes a multiagent approach to decentralized power system restoration for a distribution system network. The proposed method consists of several feeder agents (FAGs) and load agents (LAGs). LAG corresponds to the customer load, while a FAG is developed to act as a manager for the decision process. From the simulation results, the proposed multiagent system was able to reach the right solution by making use of only local information. This means that the proposed multiagent restoration system is a promising approach to more large‐scale distribution networks. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(3): 21–28, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20065     

New control for HVDC system connected to large windfarm

HVDC consisting of self‐commutated inverters is able to be applied for power transmission connecting from a remote large windfarm to a weak AC system. Most self‐commutated HVDC is applied for connection between two AC systems that have synchronous power sources, but it is not suitable for a windfarm that consists of induction generators without synchronous power source. This paper presents new control for the self‐commutated HVDC system connected to a large windfarm of induction generators. The effect of the proposed control is shown by EMTP simulation. ©2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(4): 31–39, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20539