218 research outputs found
Thermodynamic stability of H2 + tetrahydrofuran mixed gas hydrate in nonstoichiometric aqueous solutions
Phase equilibria (pressure - temperature relations) of the H2 + tetrahydrofuran mixed gas hydrate system have been measured for various concentrations of tetrahydrofuran aqueous solutions. The three-phase equilibrium lines obtained in the present study are shifted to the low-temperature or high-pressure side from that of the stoichiometric THF solution. Each three-phase equilibrium line of H2 + tetrahydrofuran hydrate converges at the three-phase equilibrium line of the pure tetrahydrofuran hydrate. At the cross point on the lines, the tetrahydrofuran concentration of mother aqueous solution agrees with each other. The Raman spectra of H 2 and tetrahydrofuran for the H2 + tetrahydrofuran mixed gas hydrate do not change with the variation of tetrahydrofuran mole fraction from 0.010 to 0.130 in the aqueous solution. © 2007 American Chemical Society.Shunsuke Hashimoto, Takeshi Sugahara, Hiroshi Sato et al. Thermodynamic Stability of H2 + Tetrahydrofuran Mixed Gas Hydrate in Nonstoichiometric Aqueous Solutions. Journal of Chemical & Engineering Data, 52 (1), 517-520, March 1, © 2007 American Chemical Society. https://doi.org/10.1021/je060436
Relativistic Hartree approach with exact treatment of vacuum polarization for finite nuclei
We study the relativistic Hartree approach with the exact treatment of the
vacuum polarization in the Walecka sigma-omega model. The contribution from the
vacuum polarization of nucleon-antinucleon field to the source term of the
meson fields is evaluated by performing the energy integrals of the Dirac Green
function along the imaginary axis. With the present method of the vacuum
polarization in finite system, the total binding energies and charge radii of
16O and 40Ca can be reproduced. On the other hand, the level-splittings in the
single-particle level, in particular the spin-orbit splittings, are not
described nicely because the inclusion of vacuum effect provides a large
effective mass with small meson fields. We also show that the derivative
expansion of the effective action which has been used to calculate the vacuum
contribution for finite nuclei gives a fairly good approximation.Comment: 15 pages, 8 figure
SPR METHOD : REHABILITATION TECHNOLOGIES TO REVIVE DECREPIT PIPELINES
Abstract In the SPR (Sewage Pipe Renewal) method, a rigid PVC liner is formed inside an existing pipe by using a specially designed winding machine that is placed inside the existing pipe. A rigid PVC profile strip is fed through a manhole entrance above ground, and the winding machine is used to wind and interlock the profiles together to form a liner. Rehabilitation technologies are needed that can cope with various existing installation site conditions; i.e. long or curved pipelines, with round, square or horseshoe shaped crossections. Under such circumstances, we have developed a new technology to form the PVC liner in which self running winding machenes travel around a frame that is set inside the existing pipeline, and which is made to conform to the interior cross sectional shape of the pipe
Exploring the Interplay between Mythology and âBeyond the Horizonâ: A Memorandum
application/pdfdepartmental bulletin pape
Identification of amino acid residues of mammalian mitochondrial phosphate carrier important for its functional expression in yeast cells, as achieved by PCR-mediated random mutation and gap-repair cloning
The mitochondrial phosphate carrier (PiC) of mammals, but not the yeast one, is synthesized with a presequence. The deletion of this presequence of the mammalian PiC was reported to facilitate the import of the carrier into yeast mitochondria, but the question as to whether or not mammalian PiC could be functionally expressed in yeast mitochondria was not addressed. In the present study, we first examined whether the defective growth on a glycerol plate of yeast cells lacking the yeast PiC gene could be reversed by the introduction of expression vectors of rat PiCs. The introduction of expression vectors encoding full-length rat PiC (rPiC) or rPiC lacking the presequence (ÎNrPiC) was ineffective in restoring growth on the glycerol plates. When we examined the expression levels of individual rPiCs in yeast mitochondria, ÎNrPiC was expressed at a level similar to that of yeast PiC, but that of rPiC was very low. These results indicated that ÎNrPiC expressed in yeast mitochondria is inert. Next, we sought to isolate ârevertantsâ viable on the glycerol plate by expressing randomly mutated ÎNrPiC, and obtained two clones. These clones carried either of two mutations, F267S or F282S; and these mutations restored the transport function of ÎNrPiC in yeast mitochondria. These two Phe residues were conserved in human carrier (hPiC), and the transport function of ÎNhPiC expressed in yeast mitochondria was also markedly improved by their substitutions. Thus, substitution of F267S or F282S was concluded to be important for functional expression of mammalian PiCs in yeast mitochondria
Big Three Dragons: A [N II] 122 m Constraint and New Dust-continuum Detection of A Bright Lyman Break Galaxy with ALMA
We present new Atacama Large Millimeter/submillimeter Array Band 7
observational results of a Lyman break galaxy at , B14-65666 ("Big
Three Dragons"), which is an object detected in [OIII] 88 , [CII]
158 , and dust-continuum emission during the epoch of reionization.
Our targets are the [NII] 122 fine-structure emission line and
underlying 120 dust continuum. The dust continuum is detected with
a 19 significance. From far-infrared spectral energy
distribution sampled at 90, 120, and 160 , we obtaine a best-fit
dust temperature of K ( K) and an infrared luminosity of () at the emissivity index (1.0). The [NII] 122 line is not detected. The 3 upper limit of the [NII] luminosity is . From the [NII], [OIII], and [CII] line luminosities, we use the
Cloudy photoionization code to estimate nebular parameters as functions of
metallicity. If the metallicity of the galaxy is high (), the ionization parameter and hydrogen density are and -,
respectively, which are comparable to those measured in low-redshift galaxies.
The nitrogen-to-oxygen abundance ratio, , is constrained to be
sub-solar. At , the allowed drastically
increases as the assumed metallicity decreases. For high ionization parameters,
the constraint becomes weak. Finally, our Cloudy models predict the
location of B14-65666 on the BPT diagram, thereby allowing a comparison with
low-redshift galaxies.Comment: 17 pages, 13 figures, 2 tables. accepted for publication in Ap
Comprehensive Analysis of Inflammatory Immune Mediators in Vitreoretinal Diseases
Inflammation affects the formation and the progression of various vitreoretinal diseases. We performed a comprehensive analysis of inflammatory immune mediators in the vitreous fluids from total of 345 patients with diabetic macular edema (DME, nâ=â92), proliferative diabetic retinopathy (PDR, nâ=â147), branch retinal vein occlusion (BRVO, nâ=â30), central retinal vein occlusion (CRVO, nâ=â13) and rhegmatogenous retinal detachment (RRD, nâ=â63). As a control, we selected a total of 83 patients with either idiopathic macular hole (MH) or idiopathic epiretinal membrane (ERM) that were free of major pathogenic intraocular changes, such as ischemic retina and proliferative membranes. The concentrations of 20 soluble factors (nine cytokines, six chemokines, and five growth factors) were measured simultaneously by multiplex bead analysis system. Out of 20 soluble factors, three factors: interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) were significantly elevated in all groups of vitreoretinal diseases (DME, PDR, BRVO, CRVO, and RRD) compared with control group. According to the correlation analysis in the individual patient's level, these three factors that were simultaneously increased, did not show any independent upregulation in all the examined diseases. Vascular endothelial growth factor (VEGF) was significantly elevated in patients with PDR and CRVO. In PDR patients, the elevation of VEGF was significantly correlated with the three factors: IL-6, IL-8, and MCP-1, while no significant correlation was observed in CRVO patients. In conclusion, multiplex bead system enabled a comprehensive soluble factor analysis in vitreous fluid derived from variety of patients. Major three factors: IL-6, IL-8, and MCP-1 were strongly correlated with each other indicating a common pathway involved in inflammation process in vitreoretinal diseases
Large Population of ALMA Galaxies at z>6 with Very High [OIII]88um to [CII]158um Flux Ratios: Evidence of Extremely High Ionization Parameter or PDR Deficit?
We present our new ALMA observations targeting [OIII]88um, [CII]158um,
[NII]122um, and dust continuum emission for three Lyman break galaxies at
z=6.0293-6.2037 identified in the Subaru/Hyper Suprime-Cam survey. We clearly
detect [OIII] and [CII] lines from all of the galaxies at 4.3-11.8sigma levels,
and identify multi-band dust continuum emission in two of the three galaxies,
allowing us to estimate infrared luminosities and dust temperatures
simultaneously. In conjunction with previous ALMA observations for six galaxies
at z>6, we confirm that all the nine z=6-9 galaxies have high [OIII]/[CII]
ratios of L[OIII]/L[CII]~3-20, ~10 times higher than z~0 galaxies. We also find
a positive correlation between the [OIII]/[CII] ratio and the Lya equivalent
width (EW) at the ~90% confidence level. We carefully investigate physical
origins of the high [OIII]/[CII] ratios at z=6-9 using Cloudy, and find that
high density of the interstellar medium, low C/O abundance ratio, and the
cosmic microwave background attenuation are responsible to only a part of the
z=6-9 galaxies. Instead, the observed high [OIII]/[CII] ratios are explained by
10-100 times higher ionization parameters or low photodissociation region (PDR)
covering fractions of 0-10%, both of which are consistent with our [NII]
observations. The latter scenario can be reproduced with a density bounded
nebula with PDR deficit, which would enhance the Lya, Lyman continuum, and C+
ionizing photons escape from galaxies, consistent with the [OIII]/[CII]-Lya EW
correlation we find.Comment: 20 pages, 18 figures, Accepted for publication in Ap
Charge- and parity-projected Hartree-Fock method for the strong tensor correlation and its application to the alpha particle
We propose a new mean-field-type framework which can treat the strong
correlation induced by the tensor force. To treat the tensor correlation we
break the charge and parity symmetries of a single-particle state and restore
these symmetries of the total system by the projection method. We perform the
charge and parity projections before variation and obtain a Hartree-Fock-like
equation, which is solved self-consistently. We apply the Hartree-Fock-like
equation to the alpha particle and find that by breaking the parity and charge
symmetries, the correlation induced by the tensor force is obtained in the
projected mean-field framework. We emphasize that the projection before the
variation is important to pick up the tensor correlation in the present
framework.Comment: 21 pages, 2 figure
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