• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.98-102
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• 1996

This study investigated performance of the phenol degradation and reaction characteristics according to variation of phenol volumetric loading rates and dilution rates in suspension and PACT reactors using Pseudomonas sp. B3. 1. Removal efficiencies of the PAC unit indicated about 100 % with phenol volumetric loading rates from 0.4 phenol $kg/ma^3\cdot d$ to 1.2 phenol $kg/m^3\cdot d$, however, which of the suspension reactor showed about 100% with from 0.2 phenol $kg/m^3\cdot d$ to 0.75 phenol $kg/ma^3\cdot day$. 2. The cell density slightly was decreased from 298.2 mg/l to 272 mg/l, when dilution rate for suspension was reactor increased from 0.4 to 1.41 1/d, and also the cell density suddenly was decreased to 145.5 mg/l and was washed out at the dilution rate higher than 1.60 1/d. But the cell density for the PAC unit was linearly decreased with dilution rate of from 0.8 to 3.0 1/d, and showed 220.75 mg/l at maximum dilution rate. 3. The phenol utilization rate was increased from 0.008 to 0.031 phenol g/l$\cdot$h, when dilution rate for suspension reactor was increased from 0.4 to 1.5 1/d, however, the rate for the PAC unit was linearly increased from 0.017 to 0.061 phenol g/l$\cdot$h as variation changes from 0.017 to 0.061 phenol g/l$\cdot$h dilution rate.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.129-133
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• 1995

Continuous fermentations were performed in order to investigate the effect of culture condition on the yeast RNA accumulation and autolysis efficiency. The content of intracellular RNA increased with increasing dilution rate, showing its maximum value of 14.8% at D=0.35 $h^{-1}$. Also, both RNA productivity and specific RNA productivity tended to increase with the increase of dilution rate. The maximum biomass was obtained at $30^{\circ}C$ in the fixed dilution rate of 0.2 $h^{-1}$, whereas the maximum RNA content appeared at the lowest temperature experimented. Growth rate affected significantly on the yeast autolysis efficiency such that the extraction ratio(TN/TN) increased with increasing growth rate, whereas the hydrolysis ratio(AN/TN) was reversed. On the other hand, its efficiency was little affected by cultivation temperature.

• Journal of Sensor Science and Technology
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• v.24 no.1
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• pp.29-34
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• 2015

This study aimed to evaluate the characterization of a metal oxide semiconductor and electrochemical gas sensor array for measuring wastewater odor. The sensitivity of all gas sensors observed in sampling method by stripping was 6.7 to 20.6 times higher than that by no stripping, except sensor D (electrochemical gas sensor). The average reduction ratio of sensor signal as a function of initial dilution rate of wastewater was in the order of food plant > food waste reutilization facility > plating plant. The sensitivity of gas sensors was dependent on both the type of wastewater and the dilution rate. The sensor signals observed by the gas sensor array were correlated with the dilution factor (OU) calculated by the air dilution sensory test with several wastewater ($r^2=0.920{\sim}0.997$), except the sensor signals of sensor D measured in the plating plant wastewater. It seems likely that the gas sensor array plays a role in the evaluation of odor in wastewater and is useful tool for on-site odor monitoring in the wastewater facilities.

• Animal Bioscience
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• v.37 no.2
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• pp.203-209
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• 2024

Objective: This study aimed to assess the impact of the dilution ratio of Tris diluent, storage at 0℃, and long-distance transportation on the spermatozoa of Simmental cattle. It also validated the feasibility of the regional distribution of fresh semen. Methods: In experiment 1, semen was diluted at four dilution ratios (1:6, 1:9, 1:12, and 1:15) to determine the optimal dilution ratio of Tris diluent. In experiment 2, we assessed sperm viability, progressive motility (objectively assessed by computer-assisted sperm analyzer), and acrosome intactness in Tris dilutions kept at constant 0℃ for 1, 3, 6, 9, and 12 days. We compared them to Tianshan livestock dilutions (Commercial diluent). In experiment 3, semen was diluted using Tris diluent, and sperm quality was measured before and after long-distance transport. Artificial insemination of 177 Simmental heifers compared to 156 using Tianshan Livestock dilution. Results: The outcomes demonstrated that 1:9 was the ideal Tris diluent dilution ratio. The sperm viability, Progressive Motility, and acrosome integrity of both Tris and Tianshan dilutions preserved at 0℃ gradually decreased over time. sperm viability was above 50% for both dilutions on d 9, with a flat rate of decline. The decrease in acrosome integrity rate was faster for Tianshan livestock dilutions than for Tris dilutions when stored at 0℃ for 1 to 6 days. There was no significant difference (p>0.05) in sperm viability between semen preserved in Tris diluent after long-distance transportation and semen preserved in resting condition. The conception rates for Tris dilution and Tianshan livestock dilution were 49.15% and 46.15% respectively, with no significant difference (p>0.05). Conclusion: This shows that Tris diluent is a good long-term protectant. It has been observed that fresh semen can be successfully preserved for long-distance transport when stored under 0℃ conditions. Additionally, it is feasible to distribute semen regionally.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.557-562
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• 2002

Physiological characteristics such as specific productivity, morphology of Streptomyces cells Immobilized on celite beads, and operational stability at different dilution rates were investigated in continuous immobilized-cell cultures for the production of kasugamycin. At a dilution rate (D) of 0.05 $h^{-1}$, a relatively high specific productivity was attained and the loss of cell-loaded beads was negligible. At D=0.1 $h^{-1}$, a higher specific productivity and cell concentration could be obtained, resulting in a significantly improved volumetric kasugamycin productivity. However, no stable operation could be maintained due to a significant loss of cell-loaded beads from the reactor that was caused by their fluffy morphology developed in the later stage. At D=0.2 $h^{-1}$, the production of kasugamycin and cell growth were observed to be severely inhibited by the high concentration of residual maltose.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1399-1406
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• 2000

A continuous culture study was conducted to determine the impact of ruminal degradable soy protein (S-RDP) level and dilution rate (D) on growth of ruminal non-structural carbohydrate-fermenting microbes. Corn starch, urea and isolated soy protein (ISP) were used to formulate three diets with S-RDP levels of 0, 35 and 70% of total dietary CP. Two Ds were 0.03 and $0.06h^{-1}$ of the fermenter volume in a single-effluent continuous culture system. As S-RDP levels increased, digestibilities of dietary dry matter (DM), organic matter (OM) and crude protein (CP) linearly (p=0.001) decreased, whereas digestion of dietary starch linearly (p=0.001) increased. Increasing D from 0.03 to $0.06h^{-1}$ resulted in decreased digestibilities of dietary DM and OM, but had no effect on digestibilities of dietary starch (p=0.77) and CP (p=0.103). Fermenter pH, the concentration of volatile fatty acids (VFA) and daily VFA production were unaffected (p=0.159-0.517) by S-RDP levels. Molar percentages of acetate, propionate and butyrate were greatly affected by S-RDP levels (p=0.016-0.091), but unaffected by D (p=0.331-0.442). With increasing S-RDP levels and D, daily bacterial counts, daily microbial N production (DMNP) and microbial efficiency (MOEFF; grams of microbial N produced per kilogram of OM truly digested) were enhanced (p=0.001). The increased microbial efficiency with increasing S-RDP levels is probably the result of peptides or amino acids that served as a stimulus for optimal protein synthesis. The quantity of ruminal degradable protein from soy proteins required for optimum protein synthesis of non-structural carbohydrate-fermenting microbes appears to be equivalent to 9.5% of dietary fermented OM.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.2
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• pp.75-81
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• 1985

Inhibitory effects of ammonium nitrogen on the nightsoil digestion were investigated in this study by using laboratory digesters. Inhibitory effects were observed even at a concentration less than 1.5g/1 $NH_3N$. This would suggest dilution of influent nightsoil would be one of the applicable methods, however, increased microbial washout due to the dilution limited applicable organic loading rate. The study results indicated 1 : 1 dilution would be most likely applicable to minimize inhibitory effect up to a loading rate of $5kg\;COD/m^3/d$.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.589-596
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• 2020

Many components in the assembly section of Sodium-cooled Fast Reactor are made of good corrosionresistant 316 LN Stainless Steel material. To avoid self-welding of the components with the coolant sodium at elevated temperature, hardfacing is inevitable. Ni-based colmonoy-5 is used for hardfacing due to its lower dose rate by Plasma Transferred Arc process due to its low dilution. Since Ni-Cr-B-Si alloy becomes very fluidic while depositing, the major height of the weld overlay rests inside the groove. Hardfacing is also done over the plain surface where grooving is not possible. Therefore, grooved and ungrooved hardfaced specimens were prepared at different travel speeds. Fe content at every 100 ㎛ of the weld overlay was studied by Energy Dispersive Spectroscopy and also the micro hardness was determined at those locations. A correlation between iron dilution from the base metal and the micro hardness was established. Therefore, if the Fe content of the weld overlay is known, the hardness at that location can be obtained using the correlation and vice-versa. A new correlation between micro hardness and dilution coefficient is obtained at different locations. A comparative study between those specimens is carried out to recommend the optimum travel speed for lower dilution.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.202-204
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• 2009

Erosion is a common failure mode of materials frequently encountered in plant and power industry. Although the erosion resistance of Fe-base alloy has been inferior to the other expensive materials, it is expected that the strain-induced martensitic transformation can impart high erosion resistance to Fe-base alloy. The key technology to develop Fe-base metal cored welding wire for erosion resistant overlay welding may include the strain-induced metallurgy for hardening rate control and the welding flux metallurgy for dilution control. Sophisticated studies showed that the strain-induced martensitic transformation behavior was related to the critical strain energy which was dependent on the alloy composition. Dilution and bead shape of overlay weld were proved to be affected by metal transfer mode during gas tungsten arc welding and elements in welding fluxes. It was considered that the highly erosion resistant Fe-base overlay weld could be achieved by precise control of alloy composition to have proper level of critical strain energy for energy absorption and welding flux formulation to have small amount of deoxidizing metallic elements for dilution.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.716-721
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• 1999

It has been known that continuous cultivation of hairy root is difficult to maintain for a long period of time compared to the microbial and callus cultures. Chemostat cultivation was successfully carried out in order to economically produce a plant-based colorant, betacyanin, from red beet hairy root for more than 85 days in a 14-1 fermentor. The result from the chemostat cultivation was compared to those of the batch and fed-batch cultivations of red beet hairy roots. It was shown that hairy root reached its steady state within 50 days of the cultivation, and then maintained for about 25-30 days in a wide range of dilution rates. Total betacyanin production from the continuous process was also calculated to be 2.65g at 0.28(l/d) of dilution rate, compared to 0.196g from fed-batch cultivation. It was found that betacyanin production was a partially growth related process, yielding 0.376 mg/g-fresh wt. cell and $1.89{\times}10^{-5}$ mg/g-fresh wt. cell/d, with 0.92 of correlation factor in a partial growth-product model. It was also shown that the cell growth required was relatively large for maintenance amount of energy at a low dilution rate. The growth of hairy root was inhibited by high light intensity in following a photo-inhibition model. The growth parameters were estimated to be 0.3(l/d), $10.56kcal/\textrm{m}^2/h$,{\;}and{\;}35.81kcal/\textrm{m}^2/h$ for the maximum specific growth rate, half saturation light intensity, and inhibition light intensity, respectively.