Airborne microorganisms in the indoor environment of Syowa Station in Antarctica

Airborne bacterial and fungal numbers in the buildings of Syowa Station in Antarctica were examined for 9 months in 2001. The number of bacteria or fungi was less than 20 or 70/m^3 in the dining room and washroom. The average number of bacteria or fungi was less than 1/50 or 1/5 of those in Japan and Europe, respectively, and remained constant regardless of season. The number of airborne microorganisms appeared to depend on drying of the indoor environment by the use of air-conditioners

Infrared and Raman spectroscopic investigation of the reaction mechanism of cytochrome c oxidase

AbstractRecent progress in studies on the proton-pumping and O2 reduction mechanisms of cytochrome c oxidase (CcO) elucidated by infrared (IR) and resonance Raman (rR) spectroscopy, is reviewed. CcO is the terminal enzyme of the respiratory chain and its O2 reduction reaction is coupled with H+ pumping activity across the inner mitochondrial membrane. The former is catalyzed by heme a3 and its mechanism has been determined using a rR technique, while the latter used the protein moiety and has been investigated with an IR technique. The number of H+ relative to e− transferred in the reaction is 1:1, and their coupling is presumably performed by heme a and nearby residues. To perform this function, different parts of the protein need to cooperate with each other spontaneously and sequentially. It is the purpose of this article to describe the structural details on the coupling on the basis of the vibrational spectra of certain specified residues and chromophores involved in the reaction. Recent developments in time-resolved IR and Raman technology concomitant with protein manipulation methods have yielded profound insights into such structural changes. In particular, the new IR techniques that yielded the breakthrough are reviewed and assessed in detail. This article is part of a Special Issue entitled: Vibrational spectroscopies and bioenergetic systems

Study of Various Flow Regimes in the Water Intrusion Process into Porous Media under Different Upstream Boundary Conditions

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Solute distribution in porous rhyolite as evaluated by sequential centrifugation

International audiencePore water in a porous rhyolite, having a porosity of 27% and pore radii ranging from >25 μm to 0.008 μm, was centrifugally extracted stepwise with increasing centrifugal speed to examine the potential variations of the compositions of pore water and their relationships to reaction and transport occurring in the rock. The rock was soaked for from 1 h to 7 days in an aqueous solution prior to centrifugation. To evaluate the effect of adsorption under minimum effect of dissolution, Li+ and Br− were added to the solution as tracer ions. As centrifugal speed increased, water was extracted in order of large to small pores and the thickness of residual water film became thinner. The concentrations of ions dissolving from the rock (Na+, K+, Ca2+, etc.) after 7 days of immersion were relatively constant in pores of 1−10 μm radii and exponentially increased by 3−100 fold with decreasing pore radius to 0.1 μm. These ions are dissolved from the rock and transported toward the exterior of the rock by diffusion. The calculation using a reactive-transport equation showed that the observed concentration changes reflect the change in solute distribution profile with pore size. The concentration of Si after 7 days of immersion was approximately constant or slightly decreased with increasing centrifugal speed, which appears to be controlled by the solubility. The concentration of Li+ decreased with increasing centrifugal speed after 1 h of immersion but the trend changed after 7 days of reaction. Initial behaviour of Li+ is explained by adsorption on pore walls, and the change of trend is explained by desorption of that previously adsorbed, slight amounts of dissolution, and inflow from the outside of the rock. The change in concentration of Br− with increasing centrifugal speed was small, probably because Br− was not adsorbed on the surfaces. The sequential centrifugation thus provides information on the solute distribution associated with reaction and transport occurring in rock pores

Assessing the Geomechanical Responses of Storage System in CO2 Geological Storage: an Introduction of Research Program in the National Institute for Advanced Industrial Science and Technology (AIST)

AbstractThis paper overviews studies being conducted in the National Institute for Advanced Industrial Science and Technology (AIST) on the fluid-rock mechanical interaction associated with CO2 geological storage (CGS). Our studies include the extension of TOUGH-FLAC simulator developed in LBNL to CGS under the geologic conditions of Japan where the young sedimentary basins underlain by so-called “soft rocks” are postulated to be the place of CO2 storage. Experimental studies and basic studies on the petrophysical properties of “soft rocks” are also the important parts of the whole research program to elucidate their mechanical behaviors under the conditions in and around a CO2 reservoir and its caprock