• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.137-145
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• 2009

The steady-state kinetics of the selective catalytic reduction (SCR) of $NO_X$ with $NH_3$ has been investigated over a commercial ${V_2}{O_5}/TiO_2$ catalyst. In order to account for the influence of transport effects the kinetics are coupled with a fully transient two-phase 1D+1D monolith channel model. The Langmuir-Hinshelwood (L-H) mechanism is adopted to describe the steady-state kinetic behavior of the ${V_2}{O_5}/TiO_2$ catalyst. The reaction rate expressions are based on previously reported papers and are modified to fit the experimental data. The steady-state chemical reaction scheme used in the present mathematical model has been validated extensively with experimental data of selective $NO_X$ reduction efficiency for a wide range of inlet conditions such as space velocity, oxygen concentrations, water concentration, and $NO_2/NO$ ratio. The parametric investigations are performed to examine how the $NH_3$ slip from a SCR $DeNO_X$ catalyst and the conversion of $NO_X$ are affected by the reaction temperature, $NH_3/NO_X$ feed ratio, and space velocity for feed gas compositions with $NO_2/NO_X$ ratios of 0 and 0.5.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.473-482
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• 2013

The desulfurization ability of Sphingomonas subarctica T7b was evaluated using resting and immobilized cells with dibenzothiophene (DBT), alkyl DBTs, and commercial light gas oil (LGO) as the substrates. The resting cells of S. subarctica T7b degraded 239.2 mg of the initial 250 mg of DBT/l (1.36 mM) within 24 h at $27^{\circ}C$, while 127.5 mg of 2-hydroxybiphenyl (2-HBP)/l (0.75 mM) was formed, representing a 55% conversion of the DBT. The DBT desulfurization activity was significantly affected by the aqueous-to-oil phase ratio. In addition, the resting cells of S. subarctica T7b were able to desulfurize alkyl DBTs with long alkyl chains, although the desulfurization rate decreased with an increase in the total carbon number of the alkylated DBTs. LGO with a total sulfur content of 280 mg/l was desulfurized to 152 mg/l after 24 h of reaction. Cells immobilized by entrapment with polyvinyl alcohol (PVA) exhibited a high DBT desulfurization activity, including repeated use for more than 8 batch cycles without loss of biodesulfurization activity. The stability of the immobilized cells was better than that of the resting cells at different initial pHs, higher temperatures, and for DBT biodesulfurization in successive degradation cycles. The immobilized cells were also easily separated from the oil and water phases, giving this method great potential for oil biodesulfurization.

• Journal of Pharmaceutical Investigation
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• v.34 no.6
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• pp.443-452
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• 2004

Habit is the description of the outer appearance of a crystal. If the environment of a growing crystal affects its external shape without changing its internal structure, a different habit results. Crystal habit and the internal structure of a drug can affect bulk and physicochemical properties, which range from flowability to chemical stability. A polymorph is a solid crystalline phase of a given compound resulting from the possibility of at least two different arrangements of the molecules of that compound in the solid state. Chemical stability and solubility changes due to polymorphism can have an impact on a drug's bioavailability and its development program. During crystallization from a solution, crystals separating may consist of a pure component or be a molecular compound. Solvates are molecular complexes that have incorporated the crystallizing solvent molecule in their lattice. When the solvent incorporated in the solvate is water, it is called a hydrate. To distinguish solvates from polymorphs, which are not molecular compounds, the term pseudopolymorph is used. Identification of possible hydrate compounds is important since their aqueous solubilities can be significantly less than their anhydrous forms. Conversion of an anhydrous compound to a hydrate within the dosage form may reduce the dissolution rate and extent of drug absorption. An amorphous solid may be treated as a supercooled liquid in which the arrangement of molecules is random. Amorphous solids lack the three-dimensional long-range order found in crystalline solids. Since amorphous forms are usually of higher thermodynamic energy than corresponding crystalline forms, solubilities as well as dissolution rates are generally greater. A study on crystal form includes characterization of (l)crystal habit, (2)polymorphism, (3)pseudopolymorphism, (4)amorphous solid.

• Animal Bioscience
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• v.34 no.2
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• pp.265-275
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• 2021

Objective: The study developed mushroom stalk residues as feed additives in the broiler diet for improving the growth performance and immunity of broilers as well as to increase the value of mushroom stalk residues. Methods: In total, 300 ROSS 308 broilers were randomly allocated into fifteen pens with five dietary treatments: i) control, basal diet; ii) CMWM, supplemented with 1% Cordyceps militaris waster medium (CM); iii) CMPE, supplemented with 0.5% CM+0.5% Pleurotus eryngii stalk residue (PE); iv) CMPS, supplemented with 0.5% CM+0.5% Pleurotus sajorcaju stalk residue (PS); v) CMFV, supplemented with 0.5% CM+0.5% Fammulina velutipes stalk residue (FV). Results: The chemical analysis results showed that CM extracts, PE extracts, PS extracts, and FV extracts contain functional components such as polysaccharides and phenols and have both 2, 2-diphenyl-1-picryl-hydrazyl-hydrate scavenging and Ferrous scavenging capacities. The group CMWM saw increased body weight gain and feed conversion rate and the promotion of jejunum villus growth, but there is no significant difference in the intestinal bacteria phase. Antioxidant genes in the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)- antioxidant responsive element pathway among the groups are significantly higher than that of the control group, especially in group CMWM. Conclusion: The mushroom stalk residues have antioxidant functional components, can improve the intestinal health and body weight gain of chickens, and can activate the antioxidant pathway of Nrf2 to increase the heme oxygenase-1 expression. The treatment with 1% CM was the most promising as a feed additive.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.4
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• pp.375-383
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• 2021

The intestinal barrier function disrupted in sepsis, while little is known about the variation in different phases of sepsis. In this study, mouse models of sepsis were established by caecal ligation and puncture (CLP). The H&E staining of sections and serum diamine oxidase concentration were evaluated at different timepoint after CLP. TUNEL assay and EdU staining were performed to evaluate the apoptosis and proliferation of intestinal epithelium. Relative protein expression was assessed by Western blotting and serum concentrations of pro-inflammatory cytokines was measured by ELISA. The disruption of intestinal barrier worsened in the first 24 h after the onset of sepsis and gradually recovered over the next 24 h. The percentage of apoptotic cell increased in the first 24 h and dropped at 48 h, accompanied with the proliferative rate of intestinal epithelium inhibited in the first 6 h and regained in the later period. Furthermore, the activity of nuclear factor kappa B (NF-κB) presented similar trend with the intestinal barrier function, shared positive correction with apoptosis of intestinal epithelium. These findings reveal the conversion process of intestinal barrier function in sepsis and this process is closely correlated with the activity of NF-κB signaling.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.21-30
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• 1998

The effects of compost inoculation on the degradation of cellulosic fraction in composting of food waste and paper mixture were investigated by bench-scale composting. With the increase of seed inoculation, the time to reach the peaks of temperature, $CO_2$ evolution rate, and ammonia evolution rate was reduced, indicating that seed compost had beneficial effects on the enhanced degradation of organic materials at the early stage of composting. However, the final conversion of organic matters and the loss of ammonia were not affected by the amount of seed compost inoculated. The increasing of seed inoculum also resulted in the higher level of cellulase activity at initial stages and rapid rise to the maximums, suggesting that initial supply of sufficient cellulolytic microorganisms might facilitate the evolution of cellulase activity. The cellulose was degraded substantially during the increasing phase of cellulase activity, while they showed similar values at the end of 20 days composting. As a result, the seed inoculation seemed to be effective to the enhanced evolution of cellulase activity and cellulose degradation at initial stage of composting. But it did not contribute to increase the final degradation of cellulose after the entire composting reaction of 20 days.

• KSBB Journal
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• v.20 no.6
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• pp.458-463
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• 2005

[ $H_2$ ] from CO and water was continuously produced in a trickle bed reactor(TBR) using Citrobacter amalonaticus Y19. When the strain C. was cultivated in a stirred-tank reactor under a chemoheterotrophic and aerobic condition, the high final cell concentration of 13 g/L was obtained at 10 hr. When the culture was switched to an anaerobic condition with the continuous supply of gaseous CO, CO-dependent hydrogenase was fully induced and its hydrogen production activity approached 16 mmol/g cell/hr in 60 hr. The fully induced C. amalonaticus Y19 cells were circulated through a TBR packed with polyurethane foam, and the TBR was operated for more than 20 days for $H_2$ production. As gas retention time decreased or inlet CO partial pressure increased, $H_2$ production rate increased but the conversion from CO to $H_2$ decreased. The maximum $H_2$ production rate obtained was 16 mmol/L/hr at the gas retention time of 25 min and the CO inlet partial pressure of 0.4 atm. The high $H_2$ production rate was attributed to the high cell density in the liquid phase circulating the TBR as well as the high surface area of polyurethane foam used as packing material of the TBR.

• Resources Recycling
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• v.14 no.5 s.67
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• pp.13-17
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• 2005

As a basic study for recycling molten converter slag as an ordinary portland cement (OPC) by a conversion process, the reaction mechanism and the rate of the formation of $C_4AF$ which is one of the main components of OPC were investigated. The converter slag whose basicity was controlled by adding reagent grade $SiO_2$ was melted and hold for 30 minutes in MgO crucible at $1300^{\circ}C{\sim}1350^{\circ}C$. Then, the sintered CaO pellet heated at the same temperature was dipped into the molten slag and hold for $10{\sim}30$minutes. After the reaction, the crucible was cooled in air and the specimen was cut off to the horizontal direction of the crucible. The dissolution rate of $C_3A$ pellet was measured by the change of radius of the sintered $C_3A$ pellet, and the formed phase of $C_4AF$ was observed by SEM/EDX. As a result, the dissolution rate of $C_3A$ pellet into molten slag was increased from $0.75{\times}10^{-4}(cm/sec)$ at $1300^{\circ}C$ to $1.67{\times}10^{-4}(cm/sec)$ at $1350^{\circ}C$, and the mixed layer of $C_4AF$ and $C_{12}A_7$ was found between slag and $C_3A$ pellet.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.2
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• pp.217-223
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• 1997

This study was performed to determine if women with day 3 serum inhibin-B concentrations <45pg/ml (conversion factor to SI unit, 1.00) demonstrate a poor response to ovulation induction and assisted reproductive technology outcome to women with inhibin-B${\ge}45pg$/ml, independant of day 3 FSH, E2 and patient age. From Jan 1996 to Dec 1996, 16 volunteers patients who underwent 25 IVF cycles with luteal phase GnRH agonist suppression and HMG stimulation were allocated to the study group. We evaluated day 3 serum inhibin-B, FSH, E2, peak E2, cancellation rate per initiated cycle (%) and clinical pregnancy rate per initiated cycle (%) according to the above two groups and independent of patient age, day 3 FSH, day 3 E2 and all of above combined. Women with day 3 serum inhibin-B${\ge}45pg$/ml demonstrated higher average day 3 inhibin-B level, clinical pregnancy rate per initiated cycle ($20.3{\pm}2.5$ pg/ml vs $80.9{\pm}5.0$ pg/ml, p<0.05; 24.8% vs 8.5%, p<0.05) and lower day 3 FSH level, cancellation rate per initiated cycle ($6.9{\pm}0.3$ mIU/ml vs $8.5{\pm}0.5$ mIU/ml, p<0.05; 1.5% vs 9.0%, p<0.05). Women with day 3 serum inhibin${\ge}45pg$/ml and age<40 year demonstrated higher pregnancy rate per initiated cycle (28.2% vs 7.4%, p<0.05) and lows. day 3 FSH level, cancellation rate per initiated cycle ($6.9{\pm}0.5$ mIU/ml vs $8.2{\pm}0.7$ mIU/ml, p<0.05; 1.0% vs 9.0%, p<0.05). Women with day 3 serum inhibin${\ge}45pg$/ml and day 3 FSH<15mIU/ml demonstrated higher pregnancy rate per initiated cycle (33.5% vs 9.5%, p<0.05) and lower day 3 FSH level, cancellation rate per initiated cycle ($7.7{\pm}0.2$ mIU/ml vs $8.5{\pm}0.5$ mIU/ml, p<0.05; 1.5% vs 10.0%, p<0.05). Women with day 3 serum inhibin${\ge}45pg$/ml and day 3 E2<50pg/ml demonstrated higher pregnancy rate per initiated cycle (30.0% vs 9.5%, p<0.05) and lower cancellation rate per initiated cycle (1.5% vs 9.5%, p<0.05). Women with day 3 serum inhibin${\ge}45pg$/ml, age<40 year, day 3 FSH<15mIU/ml and day 3 E2<50pg/ml demonstrated higher pregnancy rate per initiated cycle (30.0% vs 10.8%, p<0.05) and lower day 3 FSH level, cancellation rate per initiated cycle ($6.8{\pm}0.6$ mIU/ml vs $8.4{\pm}0.9$ mIU/ml, p<0.05; 1.5% vs 7.8%, p<0.05). Therefore women with low day 3 serum inhibin-B concentrations demonstrate a poorer response to ovulation induction and are less likely to conceive a clinical pregnancy though ART relative to women with high day 3 inhibin-B and day 3 serum inhibin-B, in addition to a day 3 FSH, E2 and patient age, appears helpful in prediction in IVF-ET outcome.

• Journal of the Korean Society of Radiology
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• v.2 no.3
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• pp.19-25
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• 2008

Commercial analog x-ray detectors based on film cassettes have been showing problems such as with image storage and image transmission. Recently direct conversion material, photoconductor whit flat panel have been researched which generate the electron hole-pair (EHP). In this paper, we researched the electrical properties of the PbO and Lead(II) oxide PbO. film which fabricated by Particle-In-Binder(PIB) method. We compared tetragonal ${\alpha}$-PbO with orthorhombic ${\beta}$-PbO physical property. Tetragonal material was more than orthorhombic material in other paper. The solution was Poly Vinyl Butyral(PVB) in the PIB. We discussed about the sample of x-ray sensitivity, leakage current, Signal to Noise Rate and investigated SEM for the physical property of sample. We need to think more research ${\alpha}$-PbO material fabrication.