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1.
The liquid membrane prepared with oleyl alcohol was used in pervaporation of dilute aqueous butanol solutions. The selectivity of this liquid membrane was found to be superior than that of silicone rubber membrane, and the separation factor for butanol was 180. Energy saving effect of pervaporation in butanol purification was investigated by comparing the energies required to purify a butanol solution of 0.5 wt.% in the following three separation systems; a conventional distillation system, a separation system combining pervaporation with distillation, and a pervaporation system using a hydrophobic membrane and a hydrohylic membrane in series. When the pervaporation using oleyl alcohol liquid membrane was employed as a pretreatment process of butanol purification, the energy requirement was found to be around one-tenth of that of conventional distillation.List of Symbols
E
D
MJ/kg
Specific energy requirement of butanol purification by distillation
-
J kg/(m2 · h)
Total permeation flux
-
J
B
kg/(m2 · h)
Permeation flux of butanol
-
P
1, P
2 MPa
Pressure at inlet and outlet of vacuum pump
-
Q kJ/h
Energy transfer rate
-
Q
C
Q
W
kJ/h
Energy consumption rate of condenser and vacuum pump
-
R J/K · mol
Gas constant
-
t, T °C, K
Temperature
-
W-g/h
Mass flow rate of butanol/water binary mixture
-
(W)
F1
,-kg/h
Mass flow rate of aqueous butanol solution
-
(W)
F2
at inlet and outlet of permeation cell
-
W* kJ/mol
Energy requirement of adiavatic expansion
-
X
B
Butanol mass fraction of aqueous butanol solution
-
(X
B
)
F
Butanol mass fraction of aqueous butanol solution supplied into distillation column
-
(X
B
)
F1
Butanol mass fraction of aqueous butanol
-
(X
B
)
F2
solution at inlet and outlet of permeation cell
-
Y
B
Butanol mass fraction in permeate
-
Separation factor of butanol
-
Adiavatic constant 相似文献
2.
Summary We have developed a bioreactor system for aerobic fermentation, using a new ceramic carrier APHROCELL which has a suitable shape for liquid and gas passage. In acetic acid fermentation byAcetobacter cells from ethanol, as a typical example of aerobic fermentation, a productivity of 17.25 g/l h was attained at continuous production of 23 g-acetic acid/l; at an acetic acid concentration around 53 g/l, the productivity was 6.4 g/l h. Thus a marketable vinegar can be obtained continuously by this bioreactor system. Because of the simplicity of the APHROCELL reactor, scale up should be relatively easy. 相似文献
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4.
Atsuko Yamazaki Akane Yamamoto Junko Yaguchi Shunsuke Yaguchi 《Genesis (New York, N.Y. : 2000)》2019,57(6)
The specification of anterior neuroectoderm is controlled by a highly conserved molecular mechanism in bilaterians. A forkhead family gene, foxQ2, is known to be one of the pivotal regulators, which is zygotically expressed in this region during embryogenesis of a broad range of bilaterians. However, what controls the expression of this essential factor has remained unclear to date. To reveal the regulatory mechanism of foxQ2, we performed cis‐regulatory analysis of two foxQ2 genes, foxQ2a and foxQ2b, in a sea urchin Hemicentrotus pulcherrimus. In sea urchin embryos, foxQ2 is initially expressed in the entire animal hemisphere and subsequently shows narrower expression restricted to the anterior pole region. In this study, as a first step to understand the foxQ2 regulation, we focused on the later restricted expression and analyzed the upstream cis‐regulatory sequences of foxQ2a and foxQ2b by using the constructs fused to short half‐life green fluorescent protein. Based on deletion and mutation analyses of both foxQ2, we identified each of the five regulatory sequences, which were 4–9 bp long. Neither of the regulatory sequences contains any motifs for ectopic activation or spatial repression, suggesting that later mRNA localization is regulated in situ. We also suggest that the three amino acid loop extension‐class homeobox gene Meis is involved in the maintenance of foxQ2b, the expression of which is dominant during embryogenesis. 相似文献
5.
6.
Larissa Wakefield Valerie Cornish Hilary Long Akane Kawamura Xiaoyan Zhang David W. Hein 《Biomarkers》2013,18(1):106-118
Arylamine N-acetyltransferase (NAT) genes in humans and in rodents encode polymorphic drug metabolizing enzymes. Human NAT1 (and the murine equivalent mouse Nat2) is found early in embryonic development and is likely to have an endogenous role. We report the detailed expression of the murine gene (Nat2) and encoded protein in mouse embryos, using a transgenic mouse model bearing a lacZ transgene inserted into the coding region of mouse Nat2. In mouse embryos, the transgene was expressed in sensory epithelia, epithelial placodes giving rise to visceral sensory neurons, the developing pituitary gland, sympathetic chain and urogenital ridge. In Nat2+/+ mice, the presence and activity of Nat2 protein was detected in these tissues and their adult counterparts. Altered expression of the human orthologue in breast tumours, in which there is endocrine signalling, suggests that human NAT1 should be considered as a potential biomarker for neuroendocrine tissues and tumours. 相似文献
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8.
9.
Tsukasa Ikemura Akane Miyaji Hideaki Kashima Yuji Yamaguchi Naoyuki Hayashi 《Journal of physiological anthropology》2013,32(1):23
Background
Heat stress induces various physiological changes and so could influence ocular circulation. This study examined the effect of heat stress on ocular blood flow.Findings
Ocular blood flow, end-tidal carbon dioxide (PETCO2) and blood pressure were measured for 12 healthy subjects wearing water-perfused tube-lined suits under two conditions of water circulation: (1) at 35°C (normothermia) for 30 min and (2) at 50°C for 90 min (passive heat stress). The blood-flow velocities in the superior temporal retinal arteriole (STRA), superior nasal retinal arteriole (SNRA), and the retinal and choroidal vessels (RCV) were measured using laser-speckle flowgraphy. Blood flow in the STRA and SNRA was calculated from the integral of a cross-sectional map of blood velocity. PETCO2 was clamped at the normothermia level by adding 5% CO2 to the inspired gas. Passive heat stress had no effect on the subjects’ blood pressures. The blood-flow velocity in the RCV was significantly lower after 30, 60 and 90 min of passive heat stress than the normothermic level, with a peak decrease of 18 ± 3% (mean ± SE) at 90 min. Blood flow in the STRA and SNRA decreased significantly after 90 min of passive heat stress conditions, with peak decreases of 14 ± 3% and 14 ± 4%, respectively.Conclusion
The findings of this study suggest that passive heat stress decreases ocular blood flow irrespective of the blood pressure or arterial partial pressure of CO2. 相似文献10.
Exposure to high‐concentration oxygen in the neonatal period induces abnormal retinal vascular patterning in mice
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Akane Morita Hiroko Ushikubo Asami Mori Kenji Sakamoto Tsutomu Nakahara 《Birth defects research. Part B, Developmental and reproductive toxicology》2016,107(6):216-224
The interruption of vascular development could cause structural and functional abnormalities in tissues. We have previously reported that short‐term treatment of newborn mice with vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors induces abnormal retinal vascular growth and patterns. An exposure of neonatal mice to high‐concentration oxygen disturbs normal retinal vascular development. The present study aimed to determine (1) whether vascular abnormalities are observed in the retina of newborn mice exposed to high concentrations of oxygen, and (2) how astrocyte network formation is affected following the exposure to hyperoxia. Newborn (postnatal day 0) mice were exposed to 75% oxygen for 48 or 96 hr. During hyperoxia exposure, VEGF expression decreased, and the onset of retinal vascularization was completely suppressed. After completion of the hyperoxic period, retinal vascularization occurred, but it was delayed in a hyperoxic exposure duration‐dependent manner. In retinas of hyperoxia‐exposed mice, dense capillary plexuses were found, and the number of arteries and veins decreased. The astrocyte network formation was slightly delayed under hyperoxic conditions, and the network became denser in retinas of mice with an episode of hyperoxia. Expression of VEGF levels in the avascular retina of mice that were exposed to hyperoxia was higher than that of control mice. These results suggest that short‐term interruption of the onset of vascular development resulting from the reduction in VEGF signals induces abnormal vascular patterns in the mouse retina. The abnormalities in retinal astrocyte behavior might contribute to the formation of an abnormal retinal vascular growth. 相似文献