Gas transport in partially-saturated sand packs

Understanding gas transport in porous media and its mechanism has broad applications in various research areas, such as carbon sequestration in deep saline aquifers and gas explorations in reservoir rocks. Gas transport is mainly controlled by pore space geometrical and morphological characteristics. In this study, we apply a physically-based model developed using concepts from percolation theory (PT) and the effective-medium approximation (EMA) to better understand diffusion and permeability of gas in packings of angular and rounded sand grains as well as glass beads. Two average sizes of grain i.e., 0.3 and 0.5 mm were used to pack sands in a column of 6 cm height and 4.9 cm diameter so that the total porosity of all packs was near 0.4. Water content, gas-filled porosity (also known as gas content), gas diffusion, and gas permeability were measured at different capillary pressures. The X-ray computed tomography method and the 3DMA-Rock software package were applied to determine the average pore coordination number z. Results showed that both saturation-dependent diffusion and permeability of gas showed almost linear behavior at higher gas-filled porosities, while deviated substantially from linear scaling at lower gas saturations. Comparing the theory with the diffusion and permeability experiments showed that the determined value of z ranged between 2.8 and 5.3, not greatly different from X-ray computed tomography results. The obtained results clearly indicate that the effect of the pore-throat size distribution on gas diffusion and permeability was minimal in these sand and glass bead packs

Temperature effects on geotechnical properties of kaolin clay: Simultaneous measurements of consolidation characteristics, shear stiffness, and permeability using a modified oedometer

The increased worldwide use of shallow geothermal energy systems including ground source heat pumps (GSHPs) have given concerns of possible temperature effects on soil geotechnical properties. In this study, the effects of temperature on mechanical characteristics such as consolidation settlement, shear stiffness, and permeability of kaolin clay were investigated. A modified oedometer apparatus which allows the simultaneous measurements of consolidation settlement, shear wave velocity, and hydraulic conductivity was developed and used. Consolidation tests on preconsolidated kaolin samples (two sample sizes: ϕ 6 cm x H 10 cm and ϕ 6 cm x H 2 cm) were performed under sequentially increasing consolidation pressures at three different temperatures (5 °C, 15 °C, and 40 °C). Larger apparent preconsolidation pressure, Pac, was seen at higher temperature (40 °C) for both sample sizes, but only for samples having relatively high initial void ratios between 1.53 and 1.62. Relatively higher shear modulus as a function of void ratio was observed for samples at higher temperature, suggesting that changes in fabric structure (likely caused by enhanced inter-particle forces between clay particles at higher temperature) resulted in the increased shear stiffness and, thus, higher Pac at 40 °C. Oppositely, temperature effects on theManuscript received February 5, 2013. This work was partly funded by a grant from the Research Management Bureau, Saitama University, the grant-in-Aid for Scientific Research of Japan Society for the Promotion of Science (JSPS) (No.22860012), and a JSPS bilateral research project. This work was also partially supported by a CREST project, a research grant from the Japan Science and Technology Agency (JST).E. E. Mon is with Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura ku, Saitama, 338-8570, Japan. (phone/fax: (+81) 48-858-3116; e-mail: [email protected]).S. Hamamoto, is with Graduate School of Science and Engineering, and Institute for Environmental Science and Technology, Saitama University, 255 Shimo-okubo, Sakura ku, Saitama, 338-8570, Japan. (e-mail: [email protected])K. Kawamoto is with Graduate School of Science and Engineering, and Institute for Environmental Science and Technology, Saitama University, 255 Shimo-okubo, Sakura ku, Saitama, 338-8570, Japan. (e-mail: [email protected]).T. Komatsu is with Graduate School of Science and Engineering, and Institute for Environmental Science and Technology, Saitama University, 255 Shimo-okubo, Sakura ku, Saitama, 338-8570, Japan. (e-mail: [email protected]).P. Mødrup is with Department of Biotechnology, Chemistry, and Environmental Engineering, Aalborg University, 9000 Aalborg, Denmark. (e-mail: [email protected]). permeability of kaolin clay were not significant within the studied temperature range between 5 °C and 40 °C

Geotechnical Properties of Kanto Alluvial Soils based on Geochemical Survey

Chemical properties of pore water in soils have a great influence on interparticle bonding among clayey particles and, as a result, not only on their soil structure but also on their geotechnical properties. In this study, we analyzed ionic compositions in pore water extracted from alluvial soils deposited under different sedimentary environments in Kanto lowland area, Japan, and investigated the effect of the chemical compositions of pore water on the geotechnical properties such as compressibility and sensitivity. The following results were obtained: The ion concentrations of pore water measured by different extraction methods showed that the concentration of Na+ by the dilution method was higher than that by the centrifugation method, while the concentrations of Ca2+, Cl- and SO42- by the dilution method are significantly smaller than those by centrifugation method. The centrifugation method was recommended for evaluating geochemistry of the soils since the rotation speeds in the centrifugation method did not significantly affect the pore-water compositions. The geotechnical properties were highly related to the ion concentrations of pore water. Higher compression index and sensitivity were observed for the alluvial soils with higher monovalent/divalent ion ratio. In addition, more strong dependency of monovalent/divalent ion ratio on geotechnical properties was obtained for the alluvial soils with plasticity index larger than 30

COPII-Coated Vesicle Formation Reconstituted with Purified Coat Proteins and Chemically Defined Liposomes

AbstractCOPII vesicle formation requires only three coat assembly subunits: Sar1p, Sec13/31p, and Sec23/24p. PI 4-phosphate or PI 4,5-bisphosphate is required for the binding of these proteins to liposomes. The GTP-bound form of Sar1p recruits Sec23/24p to the liposomes as well as to the ER membranes, and this Sar1p-Sec23/24p complex is required for the binding of Sec13/31p. Ultrastructural analysis shows that the binding of COPII coat proteins to liposomes results in coated patches, coated buds, and coated vesicles of 50–90 nm in diameter. Budding proceeds without rupture of the donor liposome or vesicle product. These observations suggest that the assembly of the COPII coat on the ER occurs by a sequential binding of coat proteins to specific lipids and that this assembly promotes the budding of COPII-coated vesicles

Minichromosome Maintenance Protein 7 is a potential therapeutic target in human cancer and a novel prognostic marker of non-small cell lung cancer.

BACKGROUND: The research emphasis in anti-cancer drug discovery has always been to search for a drug with the greatest antitumor potential but fewest side effects. This can only be achieved if the drug used is against a specific target located in the tumor cells. In this study, we evaluated Minichromosome Maintenance Protein 7 (MCM7) as a novel therapeutic target in cancer. RESULTS: Immunohistochemical analysis showed that MCM7 was positively stained in 196 of 331 non-small cell lung cancer (NSCLC), 21 of 29 bladder tumor and 25 of 70 liver tumor cases whereas no significant staining was observed in various normal tissues. We also found an elevated expression of MCM7 to be associated with poor prognosis for patients with NSCLC (P = 0.0055). qRT-PCR revealed a higher expression of MCM7 in clinical bladder cancer tissues than in corresponding non-neoplastic tissues (P < 0.0001), and we confirmed that a wide range of cancers also overexpressed MCM7 by cDNA microarray analysis. Suppression of MCM7 using specific siRNAs inhibited incorporation of BrdU in lung and bladder cancer cells overexpressing MCM7, and suppressed the growth of those cells more efficiently than that of normal cell strains expressing lower levels of MCM7. CONCLUSIONS: Since MCM7 expression was generally low in a number of normal tissues we examined, MCM7 has the characteristics of an ideal candidate for molecular targeted cancer therapy in various tumors and also as a good prognostic biomarker for NSCLC patients.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Two Secreted Proteoglycans, Activators of Urothelial Cell-Cell Adhesion, Negatively Contribute to Bladder Cancer Initiation and Progression.

Osteomodulin (OMD) and proline/arginine-rich end leucine repeat protein (PRELP) are secreted extracellular matrix proteins belonging to the small leucine-rich proteoglycans family. We found that OMD and PRELP were specifically expressed in umbrella cells in bladder epithelia, and their expression levels were dramatically downregulated in all bladder cancers from very early stages and various epithelial cancers. Our in vitro studies including gene expression profiling using bladder cancer cell lines revealed that OMD or PRELP application suppressed the cancer progression by inhibiting TGF-β and EGF pathways, which reversed epithelial-mesenchymal transition (EMT), activated cell-cell adhesion, and inhibited various oncogenic pathways. Furthermore, the overexpression of OMD in bladder cancer cells strongly inhibited the anchorage-independent growth and tumorigenicity in mouse xenograft studies. On the other hand, we found that in the bladder epithelia, the knockout mice of OMD and/or PRELP gene caused partial EMT and a loss of tight junctions of the umbrella cells and resulted in formation of a bladder carcinoma in situ-like structure by spontaneous breakdowns of the umbrella cell layer. Furthermore, the ontological analysis of the expression profiling of an OMD knockout mouse bladder demonstrated very high similarity with those obtained from human bladder cancers. Our data indicate that OMD and PRELP are endogenous inhibitors of cancer initiation and progression by controlling EMT. OMD and/or PRELP may have potential for the treatment of bladder cancer

Distorted wave impulse approximation analysis for spin observables in nucleon quasi-elastic scattering and enhancement of the spin-longitudinal response

We present a formalism of distorted wave impulse approximation (DWIA) for analyzing spin observables in nucleon inelastic and charge exchange reactions leading to the continuum. It utilizes response functions calculated by the continuum random phase approximation (RPA), which include the effective mass, the spreading widths and the \Delta degrees of freedom. The Fermi motion is treated by the optimal factorization, and the non-locality of the nucleon-nucleon t-matrix by an averaged reaction plane approximation. By using the formalism we calculated the spin-longitudinal and the spin-transverse cross sections, ID_q and ID_p, of 12C, 40Ca (\vec{p},\vec{n}) at 494 and 346 MeV. The calculation reasonably reproduced the observed ID_q, which is consistent with the predicted enhancement of the spin-longitudinal response function R_L. However, the observed ID_p is much larger than the calculated one, which was consistent with neither the predicted quenching nor the spin-transverse response function R_T obtained by the (e,e') scattering. The Landau-Migdal parameter g'_N\Delta for the N\Delta transition interaction and the effective mass at the nuclear center m^*(r=0) are treated as adjustable parameters. The present analysis indicates that the smaller g'_{N\Delta}(\approx 0.3) and m^*(0) \approx 0.7 m are preferable. We also investigate the validity of the plane wave impulse approximation (PWIA) with the effective nucleon number approximation for the absorption, by means of which R_L and R_T have conventionally been extracted.Comment: RevTex 3, 29 pages, 2 tables, 8 figure