• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.80-84
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• 2005

An experiment was conducted to study the performance, carcass traits, serum lipid profile and immune competence in commercial broilers (2 to 42 d of age) fed graded levels (25, 50, 75 and 100%) of finger millet (FM) (Elusine coracana) in place (w/w) of yellow maize (YM). Each diet was fed to eight replicates (five female Vencobb broilers/replicate) housed in stainless steel battery brooders. The estimated metabolizable energy content of FM was about 540 kcal less than the YM. FM contained more protein (10.42 vs. 9.05%) and fibre (9.52 vs. 2.24%) compared to YM. Body weight gain, ready to cook yield, relative weights of giblet, liver, intestine and length of intestine at 42 d of age was not affected due to replacing YM with FM. But, the feed efficiency decreased in broilers fed diets containing 75 and 100% FM in place of YM at both 21 and 42 d of age. The amount of fat deposited in abdominal area decreased and the relative weight of gizzard increased with increase in level of FM in the diet. The serum HDL cholesterol at 21 and 42 d of age and serum triglycerides at 42 d of age decreased with increase in level of FM in diet. The relative weight of spleen and antibody titers against sheep red blood cells (SRBC) at 5 d post inoculation (PI) decreased in broilers fed FM at 100% of YM. However, the relative weight of bursa, SRBC titers at 10 d PI, antibody titers against ND virus and mortality were not affected due to incorporation of FM in place of YM in diet. The fat content in thigh muscle and liver decreased, while the protein content in these tissues increased with increase in the level of FM in broiler diet. Based on the results, it may be concluded that YM can be replaced with FM up to 25% on weight basis without affecting weight gain, carcass yields and immunity in commercial broiler diet (up to 42 d of age). Further, inclusion of finger millet reduced the fat deposition in thigh muscle, liver and in abdominal area compared to those fed maize as the principal source of energy.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.186-190
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• 2014

Nuclear Power Plants require the control ability of chemical condition (pH) because pH control during transient accident such as LOCA makes an able the fission product removal capability to be maintained, stress corrosion cracking of stainless steel equipment to be prevented and the production of hydrogen by aluminum and zinc to be minimized. An NPP is designed to control the pH of containment spray and sump coolant using the spray additives 30% NaOH in the event of loss of coolant accident. In this paper, the pH of sump coolant of an NPP during LOCA was analyzed and the fission products removal constant and decontamination factor were calculated according to Standard Review Plan 6.5.2 related to spray chemical conditions of pH. The calculated pH value of recirculation mode using the computer code corresponds to 8.09~9.67, which meets the chemical environment regulation requirements. The fission product removal capability caused by containment spray system is performed to provide input to radiation analysis.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1639-1645
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• 1991

Because of the important role LD converters play in the production of high quality steel, various dynamic models have been attempted in the past by many researchers not only to understand the complex chemical reactions that take place in the converter process but also to assist the converter operation itself using computers. And yet no single dynamic model was found to be completely satisfactory because of the complexity involved with the process. The process indeed involves dynamic energy and mass balances at high temperatures accompanied by complex chemical reactions and transport phenomena in the molten state. In the present study, a mathematical model describing the dynamic behavior of LD converter process has been developed. The dynamic model describes the time behavior of the temperature and the concentrations of chemical species in the hot metal bath and slag. The analysis was greatly facilitated by dividing the entire process into three zones according to the physical boundaries and reaction mechanisms. These three zones were hot metal (zone 1), slag (zone 2) and emulsion (zone 3) zones. The removal rate of Si, C, Mn and P and the rate of Fe oxidation in the hot metal bath, and the change of composition in the slag were obtained as functions of time, operating conditions and kinetic parameters. The temperature behavior in the metal bath and the slag was also obtained by considering the heat transfer between the mixing and the slag zones and the heat generated from chemical reactions involving oxygen blowing. To identify the unknown parameters in the equations and simulate the dynamic model, Hooke and Jeeves parttern search and Runge-Kutta integration algorithm were used. By testing and fitting the model with the data obtained from the operation of POSCO #2 steelmaking plant, the dynamic model was able to predict the characteristics of the main components in the LD converter. It was possible to predict the optimum CO gas recovery by computer simulation

• Journal of the Korean Society for Advanced Composite Structures
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• v.3 no.1
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• pp.21-28
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• 2012

In this paper, we present the analytical study results pertaining to the buckling of the orthotropic plates and local buckling of structural compression members composed of orthotropic plate components. Fiber reinforced polymeric plastic (FRP) materials, have many advantages over conventional structural materials such as steel and concrete. The advantages of the FRP materials are high specific strength and stiffness, high corrosion resistance, right weight, etc. Among the various manufacturing methods, pultrusion process is one of the best choices for the mass production of structural plastic members. Since the major reinforcing fibers are placed along the axial direction of the member, this material is usually considered as an orthotropic (tranversely isotropic, more specifically) material. However, pultruded fiber reinforced plastic structural members have low modulus of elasticity and are composed of orthotropic thin plate components the members are prone to buckle. Therefore, stability is an important issue in the design of the pultruded FRP structural members. In this paper, the buckling of orthotropic plates and the local buckling of pultruded FRP structural members are investigated by following the previous research results and the local buckling strength of the member produced in the domestic manufacturer is found.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.348-351
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• 2006

Bipolar plate, which forms about 50% of the stack cost, is an important core part with polymer electrolyte membrane in PEMFC. Bipolar plates have been commonly fabricated from graphite meterial having high electrical conductivity and corrosion resistance. Lately, many researchers have concentrated their efforts on the development of metallic bipolar plate and stainless steel has been considered as a potential material for metallic bipolar plate because of its high strength, chemical stability, low gas permeability and applicability to mass production. However, it has been reported that its inadequate corrosion behavior under PEMFC environment lead to a deterioration of membrane by dissolved metal ions and an increase in contact resistance by the growth of passive film therefore, its corrosion resistance as well as contact resistance must be improved for bipolar plate application. In this work, several types of coating were applied to 316L and their electrical conductivity and corrosion resistance were evaluated In the simulated PEMFC environment. Application of coating gave rise to low interfacial contact resistances below $19m{\Omega}cm^2$ under the compress force of $150N/cm^2$. It also made the corrosion potential to shift in the posit ive direct ion by 0.3V or above and decreased the corrosion current from ca. $9{\mu}A/cm^2$ to ca. $0.5{\mu}A/cm^2$ in the mixed solution of $0.1N\;N_2SO_4$ and 2ppm HF A coat ing layer under potentiostatic control of 0.6V and $0.75V_{SCE}$ for 500 hours or longer showed some instabilities, however, no significant change in coat Ing layer were observed from Impedance data. In addition, the corrosion current maintained less than $1{\mu}A/cm^2$ for most of time for potentiostatic tests. It indicates that high electrical conductivity and corrosion resistance can be obtained by application of coatings in the present work.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.5
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• pp.719-725
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• 2003

An experiment was conducted to study the requirement of calcium (Ca) and non-phytin phosphorus (NPP) in commercial broilers during starter phase. Seven hundred and twenty day-old Vencob male broiler chicks were randomly distributed into 144 stainless steel battery brooders, 5 birds in each. Four levels each of Ca (6, 7, 8, and 9 g/kg) and NPP (3, 3.5, 4, and 4.5 g/kg diet) were fed in a factorial design in a corn-soya basal diet. Levels of dicalcium phosphate and oyster shell grit were adjusted to obtain the desired levels of Ca and NPP. Each diet was fed ad libidum to chicks in 9 battery brooders from one d to 21 d of age. Body weight gain and feed intake were depressed (p<0.01) by increasing the dietary Ca level (8 and 9 g/kg) at lower levels of NPP (3 and 3.5 g/kg diet). The growth depression observed at lower NPP level was alleviated by reducing the Ca content to 6 g/kg diet. The tibia ash content and tibia breaking strength increased with increase in both Ca (>6 g/kg) and NPP (>3 g/kg) levels. The leg abnormality score decreased (p<0.01) with increase in NPP content in the diet at all levels of Ca tested. The serum Ca and inorganic P levels were increased with increase in the level of the respective mineral in the diet, but the serum concentration of Ca and P were inversely related to the level of NPP and Ca, respectively /kg diet. In general, the excretion of macro minerals (Ca, and P), and micro minerals {zinc (Zn), manganese (Mn), iron (Fe), and copper (Cu)} was significantly lower at lower levels of Ca and NPP tested (6 and 3 g/kg diet, respectively). The mineral excretion increased with increase in dietary Ca and NPP levels, more conspicuously at the disproportionate ratio of these minerals (>2:1, Ca and NPP). Similarly, the retention of Zn, Mn, and Fe in liver was significantly higher (p<0.01) at lower levels of Ca and NPP tested. Results from this study indicate that the commercial broilers do not require more than 3 g NPP and 6g Ca/kg diet during starter phase (up to 21 d of age) for optimum weight gain, feed efficiency and utilization of Ca, P, Zn, Mn, Fe and Cu. However, the requirements of these minerals for optimum bone mineralization were higher than the levels suggested above.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1580-1586
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• 2007

The objective of this study was to compare the bioefficacy of L-lysine sulfate relative to L-lysine${\cdot}$HCl for 10 to 20 kg pigs. Two experiments were conducted to determine the bioefficacy of the two sources of lysine using daily gain, feed conversion, plasma urea nitrogen and nitrogen retention as the response criteria. In experiment 1, 168 crossbred barrows ($Landrace{\times}Large$ White), weaned at $28{\pm}3$ d ($9.07{\pm}0.78$kg body weight), were allotted to one of seven dietary treatments in a $2{\times}3$ (two lysine $sources{\times}three $ lysine levels) factorial arrangement of treatments with an added negative control treatment group. The basal diet was based on corn, peanut meal and soybean meal and provided 0.67% lysine. The basal diet was supplemented with 0.1, 0.2 or 0.3% lysine equivalents supplied from either L-lysine sulfate or L-lysine${\cdot}$HCl. Each treatment was fed to six pens of pigs with four pigs per pen. The trial lasted 21 days. The relative bioefficacy value of lysine in L-lysine sulfate using daily gain, feed conversion and plasma urea nitrogen as response criteria was 1.01, 1.05 and 1.04 of the lysine in L-lysine${\cdot}$HCl, respectively. In experiment 2, 42 crossbred ($Landrace{\times}Large$ White) pigs ($16.03{\pm}1.58$ kg body weight) were housed in stainless steel metabolism cages for 10 d and fed the seven diets used in the nitrogen-balance trial. The relative bioefficacy value of L-lysine sulfate was estimated to be 0.95 as effective as L-lysine${\cdot}$HCl for nitrogen retention on an equimolar basis. The t-test analysis revealed that bioefficacy of lysine in L-lysine sulfate was not significantly different from lysine in L-lysine${\cdot}$HCl, which was set at 1.00. In conclusion, L-lysine sulfate can be used instead of L-lysine${\cdot}$HCl to fortify lysine-deficient diets fed to 10 to 20 kg pigs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.595-602
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• 2017

In Korea, much research and development have occurred to enhance the technological competitiveness of tuna purse seining fisheries. Due to these efforts, fishing efficiency has been improved with the development of radar, sonar and global positioning systems for fish detection and revisions to the hull forms of tuna purse seiners. However, for skiff boats, net boats and speed boats, which are auxiliary working boats mounted on tuna purse seiners, technology has lagged behind relative to the modernization of the main vessel. In this study, the hull of an existing propeller-based net boat with steel wire net to protect tuna was changed to the hull of a water jet propulsion vehicle to reduce resistance and improve maneuverability. As a result, a prototype of a water jet propulsion option was produced according to the aluminum structure strength standards specified by the Ministry of Oceans and Fisheries, and safety was confirmed by performing a drop test. Moreover, through a sea trial test, an existing net boat was shown to have a speed of 12.0knots and a towing force of 2,545 kgf at 2,500 RPM. The prototype had a speed of 26.7 knots and a towing force of 2,011 kgf at 3,200 RPM, which satisfied the towing capacity standards of auxiliary working boats mounted on tuna purse seiners.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.107-114
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• 2017

A turbocharger is an engine supercharger that is driven by exhaust gas. It improves the output and fuel efficiency by increasing the charging efficiency of the mixture gas, which is achieved by changing the rotatory power of the turbine connected to the exhaust passage. It is important to control the supercharging for this purpose. A nozzle slide joint is one of the core parts. Austenitic stainless steel is currently used as the material for this part, and its excellent mechanical properties include high heat resistance and corrosion resistance. However, because of its poor machinability, there are many difficulties in producing products with complicated shapes. Machining is used in the production of nozzle slide joints for high dimensional accuracy after metal powder injection molding. As design variables in this study, we investigated the sintering temperature, product stress, deformation rate, radius of curvature of the punch, and angle of the chamfer punch, which are related to the strain and shapes. The goal is to suggest a forming process using Nitronic 60 that does not require machining to manufacture a nozzle slide joint for a turbocharger. Accordingly, we determined the best process environment using finite-element analysis, the signal-noise ratio, and the Taguchi method for experiment design. The relative density and hydrostatic pressure of the final product were in accordance with the results of the finite element analysis. Therefore, we conclude that the Taguchi method can be applied to the design process of metal powder injection molding.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.8
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• pp.411-419
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• 2016

The objective of this study was to evaluate the application possibility of tube type electrolysis module system using recirculation process through removal organic matters and nitrogen in the pigment wastewater. The tube type electrolysis module consisted of a inner rod anode and an outer tube cathode. Material used for anode was titanium electroplated with $RuO_2$. Stainless steel was used for cathode. It was observed that the pollutant removal efficiency was increased according to the decrease of flowrate and increase of current density. When the retention time in tube type electrolysis module system was 180 min, chlorate concentration was 382.4~519.6 mg/L. The chlorate production was one of the major factors in electrochemical oxidation of tube type electrolysis module system using recirculation process used in this research. The pollutant removal efficiencies from the bench scale tube type electrolysis module system using recirculation operated under the electric charge of $4,500C/dm^2$ showed the $COD_{Mn}$ 89.6%, $COD_{Cr}$ 67.8%, T-N 96.8%, and Color 74.2%, respectively and energy consumption was $5.18kWh/m^3$.