• 한국분무공학회지
• /
• 제27권4호
• /
• pp.203-210
• /
• 2022

Combustion and performance of a spark-ignition engine fueled with propane and butane were analyzed under different compression ratio. The electricity efficiencies of propane and butane increased with increasing the electricity production. The heat release rates of propane and butane were similar at a compression ratio of 9:1 because both fuels had similar optimal ignition timings without knocking combustion. Therefore, the difference in electricity efficiencies of engine generators was insignificant. However, at a higher compression ratio of 11:1, the butane engine generator had a lower electricity efficiency than the propane engine generator because its ignition timing retarded to suppress the knocking combustion.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1996년도 춘계학술대회
• /
• pp.207-207
• /
• 1996

Through molecular cloning, five muscarinic receptors have been identified. The muscarinic receptors can be generally grouped according to their coupling to either stimulation of phospholipase C (m1, m3, and m5) or the inhibition of adenylate cyclase (m2 and m4). Each m1, m3, and m5 receptors has the additional potential to couple to the activation of phospholipase A$_2$, C, and D, tyrosine kinase, and the mobilization of Ca$\^$2+/. However, the differences in coupling efficiencies to different second messenger systems between these receptors have not been studied well. Ectopic expression of each of these receptors in mammalian cells has provided the opportunity to evaluate the signal transduction of each in some detail. In this work we compared the coupling efficiencies of the m1, m3 and m5 muscarinic receptors expressed in chinese hamster ovary (CHO) cells to the Ca$\^$2+/ mobilization and the stimulation of neuronal nitric oxide synthase (nNOS). Because G protein/PLC/PI turnover/[(Ca$\^$2+/])i/NOS pathway was supposed as a main pathway for the production of nitric oxide via muscarinic receptors, we studied on ml, m3 and m5 receptors. Stimulation of guanylate cyclase activity in detector neuroblastoma cells was used as an index of generation nitric oxide (NO) in CHO cells. The agonist carbachol increased the cGMP formation and the intracellular [Ca$\^$2+/] in concentration dependent manner in three types of receptors and the increased cGMP formation was significantly attenuated by scavenger of NO or inhibitor of NOS. m5 receptors was most efficiently coupled to stimulation of nNOS, And, the coupling efficiencies to the stimulation of neuronal nitric oxide synthase in three types of receptors were parallel with them to the Ca$\^$2+/ mobilization.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권9호
• /
• pp.1326-1330
• /
• 2001

This study analyzed the lowest production cost and the greatest profit to be obtained from marketing hogs to determine the optimal operation scale for family-owned farrow-to-finish farms. Data were collected from 39 farrow-to-finish farms with 500 to 5,000 inventories for two consecutive years, and treated with GLM and quadratic regression models using the REG procedure. Analysis results indicated that farms capable of marketing 2,933 and 3,286 hogs annually had the lowest production cost and the greatest profit, respectively. Further analysis attributed the lowest production cost or the highest return in farms with an optimal scale of 3,000 to a higher survival rate of the herd, as well as lower expenses in veterinary medicine, labor, utilities and fuel, transportation, and depreciation. A similar feed conversion efficiency was observed for all the farms studied. Obviously, the cost efficiencies were associated with the economy of the operation scale of hog production until it reached 3,000 hogs marketed annually for a family-run unit. Beyond the optimal scale of 3,000 hogs, good stockmanship was more difficult to maintain and the herd management deteriorated as increasing mortality confirms. It is conclude that, unless advanced management is applied, the operation scale should not expand beyond 3,000 hogs.

• 한국환경보건학회지
• /
• 제14권2호
• /
• pp.43-49
• /
• 1988

This study was conducted to evaluate the organic removal efficiencies and sludge production in aerobic and anaerobic digestion of swine manure. A laboratory single-stage, high-rate, anaerobic digester was operated at 5, 10, 25 and 30 day's HRT at the temperature of 35$\circ$C, and also aerobic digester operated at 10, 20 and 28.6 day's HRT at the temperature of 20$\circ$C. The conclusions from this study are as follows: 1. While the BOD removal efficiency by anaerobic digestion was 30 to 75%, it was 99% over by aerobic digestion. 2. The sludge production was similar in both aerobic and anaerobic digestion. 3. The gas production was 0.21 to 0.55 m$^3$/kg VS fed by anaerobic digestion.

• 설비공학논문집
• /
• 제24권9호
• /
• pp.671-678
• /
• 2012

The objective of this study is to analyze theoretically the performance of an open air-cycle refrigeration system in which environmental concerns increase. The pressure ratio of the external compressor and efficiencies of the components that compose of the system are selected as important parameters. As the pressure ratio of the external compressor increases, the pressure ratio of the ACM compressor is determined high, the refrigerating temperature and capacity increase, the COP decreases, and the total entropy production rate increases. The effect of heat exchanger effectiveness and turbine efficiency on the performance are greater than that of the ACM compressor efficiency. Also the performance of the air-cycle refrigeration system with two heat exchangers has been enhanced like high COP and low total entropy production rate, compared to the system with one heat exchanger.

• 상하수도학회지
• /
• 제10권2호
• /
• pp.80-87
• /
• 1996

Treatment efficiencies of water quality parameters such as $KMnO_4$ Demand, $UV_{254}$, Turbidity, and LAS(Linear Alkyl Sulfonate) were compared between DAF(Dissolved Air Flotation) and CGS(Conventional Gravitational Sedimentation). The experimental results showed that DAF is much more efficient in treatment of water quality parameters than CGS. The optimum pH was about 7, and optimum alum($Al_2(SO_4)_3$) dose was about 30 ppm for DAF treatment. Economic aspects were also analyzed for bath systems. Even though production cost per ton of drinking water is slightly higher in DAF than in CGS, it turned out that construction cost and land value of CGS far surpass the production cost. DAF system is superior in removal efficiency of impurities and in production cost as a whole to CGS system.

• Journal of Microbiology and Biotechnology
• /
• 제21권4호
• /
• pp.430-437
• /
• 2011

The effects of the agitation and aeration rates on the production of serratiopeptidase (SRP) in a 5-L fermentor (working volume 2-l) were systematically investigated using Serratia marcescens NRRL B-23112. The dissolved oxygen concentration, pH, biomass, SRP yield, and maltose utilization were all continuously measured during the course of the fermentation runs. The efficiencies of the aeration and agitation were evaluated based on the volumetric mass transfer coefficient ($K_La$). The maximum SRP production of 11,580 EU/ml with a specific SRP productivity of 78.8 EU/g/h was obtained with an agitation of 400 rpm and aeration of 0.075 vvm, which was 58% higher than the shake-flask level. The $K_La$ for the fermentation system supporting the maximum production (400 rpm, 0.075 vvm) was 11.3 $h^{-1}$. Under these fermentor optimized conditions, kinetic modeling was performed to understand the detailed course of the fermentation process. The resulting logistic and Luedeking-Piret models provided an effective description of the SRP fermentation, where the correlation coefficients for cell growth, SRP formation, and substrate consumption were 0.99, 0.94, and 0.84, respectively, revealing a good agreement between the model-predicted and experimental results. The kinetic analysis of the batch fermentation process for the production of SRP demonstrated the SRP production to be mixed growth associated.

• Asian-Australasian Journal of Animal Sciences
• /
• 제13권10호
• /
• pp.1367-1372
• /
• 2000

The present study was conducted to evaluate the efficiency of transgenic rabbit production by DNA microinjection using EGFP (Enhanced Green Fluorescent Protein) gene. In this experiment EGFP coding sequences fused to CMV promoter were microinjected into rabbit one-cell embryos, and then GFP expression and gene integration were evaluated in preimplantation embryos and fetuses recovered on day 15 of pregnancy to determine efficiency of transgenic rabbit production. Effect of DNA concentration was also tested on development in vitro following microinjection and transgene integration in fetuses. Development of embryos in vitro was decreased by DNA microinjection, but the rates of pregnancy and implantation were not significantly affected by microinjection. As development progressed in vitro percentage of GFP expression in rabbit embryos was decreased, resulting GFP expression detected in 37.5% of blastocysts. The efficiencies for production of transgenic fetuses were 4.0% and 7.6%, respectively, when $10ng/{\mu}l$ and $20ng/{\mu}l$ of DNA concentration were microinjected. Transgenic fetuses were confirmed by GFP expression and PCR analysis of fetus genomic DNA. These results indicated that DNA microinjection itself damaged embryo development and DNA concentration affected the efficiency of transgenic rabbit production.

• 자원ㆍ환경경제연구
• /
• 제11권3호
• /
• pp.345-375
• /
• 2002

The purpose of this paper is to measure the change of the production efficiency which may happen when environmental regulation incurs technological constraint in the process of production, and to compute the opportunity cost of pollution reduction with the lost products based on the change of efficiency. The patterns of production technoloy in the paper are divided into the technologies of strong disposability and weak disposabilty to grasp the effect of the technological constraint due to the environmental regulation. The endowment of the technolgical constraints in the process of production is considered to bring the greatest restriction on firm's production. When the environmental efficiencies of Korean regional manufactures were measured with linear programming model, the lost products related with the constraint of production technology that environmental regulation incurred, was average 148.1 billion dollar per year(5.87% of one year overall products) for total manufactures in 1991~1998. The ratio of the lost products for total products was spread from 0.78% to 1l.08%. The average lost products of 15 regions were changed from 4.66% to 18.35% of total products. Generally the environmental efficiency index of regional manufactures being decreased continuously since 1991, it is estimated that the environmental performance of Korean manufactures has been more and more deteriorating.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권4호
• /
• pp.605-614
• /
• 2007

Feeding pigs used to be a means of managing domestic resources that may otherwise have been wasted into valuable animal protein. Feeding pigs thus was a form of husbandry. Following recent rapid industrial development, pig rearing has changed from extensive to intensive, but this transformation has been associated with major concerns. The concentration of large amounts of pig manure in small arrears is environmentally hazardous. Moreover, high densities of animals in intensive production systems also impose a health threat for both animals and humans. Furthermore, the use of growth promoters and preventive medicines for higher production efficiencies, such as in-feed antibiotics, also induces microbial resistance thus affects human therapeutics. In addition, consumers are questioning the ethics of treating animals in intensive production systems. Animal welfare, environmental and bio-safe issues are re-shaping the nature of pig production systems. Feeding pigs thus involves not only the consideration of economic traits, but also welfare traits and environmental traits. Thus, a focus on technological feasibility, environmental sustainability and social desirability is essential for successful feeding operations. Feeding pigs now involves multiple projects with different sustainability goals, but goal conflicts exist since no pattern or scenario can fulfill all sustainability goals and the disagreements are complicated by reduced or even no use of in-feed antibiotics. Thus it is difficult to feed pigs in a manner that meets all goals of high quality, safe product, eco- and bio-sustainability, animal welfare and profit. A sustainable pig production system thus requires a prioritization of goals based on understanding among consumers, society and producers and needs to view from both a local and global perspective.