• The Korean Journal of Mycology
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• v.15 no.3
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• pp.149-157
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• 1987

This study was undertaken to investigate the differentiation, from spore germination to hyphae growth and phialide formation, of Aspergillus niger through the method of synchronous and submerged culture. Through continuous experiments by shake culture with potassium acetate medium, we observed the formation of spores at appropriate concentration and pH. Potassium acetate medium was set pH 5.5, 6.0, 6.5 and 7.0 on each scale, and control, 20 mM, and 40 mM, 80 mM and 160 mM concentrations on the other scale. Aspergillus niger was cultured in the defined media at $28^{\circ}C$, and mycelial dry weight, changes of pH and the onset of sporulation were checked. The mycelial dry weight, increased in potassium acetate medium, and pH increased during mycelial growth and gradually decreased after the spore formation. When pH increased excessively in Potassium acetate medium with pH 7.0, the mycelia could not adapt and mycelial dry weight decreased gradually. At pH 5.5, the onset of sporulation was done within one day at 20 mM it took, at 80 mM three days and at 160 mM concentration. in two days, at 40 mM one to four days were taken, 80 mM concentration respectively. At pH 6.5, the onset of sporulation was done in three days and four days at 80 mM concentrations respectively. Spore formation was not shown at pH 7.0. In controlled medium with all levels of pH, spore formation was not shown.

• Journal of the Chungcheong Mathematical Society
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• v.26 no.2
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• pp.275-285
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• 2013

In this paper a nonlinear matrix equation is considered which has the form $$P(X)=A_0X^m+A_1X^{m-1}+{\cdots}+A_{m-1}X+A_m=0$$ where X is an $n{\times}n$ unknown real matrix and $A_m$, $A_{m-1}$, ${\cdots}$, $A_0$ are $n{\times}n$ matrices with real elements. Newtons method is applied to find the skew-symmetric solvent of the matrix polynomial P(X). We also suggest an algorithm which converges the skew-symmetric solvent even if the Fr$\acute{e}$echet derivative of P(X) is singular.

• Nuclear Engineering and Technology
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• v.6 no.2
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• pp.73-79
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• 1974

The preparation method of the mortar-plastic composites(M P C) were studied with styrene, methyl methacrylate and vinyl acetate as monomers. Radiation, thermal-catalytic and radiation-catalytic methods were used as curing methods. Almost all of the above monomers and methods were possible to use for preparing M P C Although thermal-catalytic method was excellent to get M P C in a short time, the tensile strength of the product was less than those obtained by radiation method. It was possible to prepare the M P C which included up to about 10% plastics and was strengthened about ten times on the properties of acid resistandes and tensile strength comparing with the control. The improvement of the properties is much superior to concrete-plastic composite(C P C).

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.391-396
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• 1998

Modified product Consistency Test (M-PCT) has been developed as an alternative to other existing methods in determining the leachability of glass. M-PCT, the leaching method, is a hybrid of MCC-l and PCT, but can provide quicker sample preparation. Larger diameter glass sample (1.0-2.0 mm) than in the PCT method can be used so that the glass beads are more easily produced and cleaned. From the M-PCT, the total mass loss (ML) of glass, the normalized elemental release rate (NLi), pH value of leachate have been obtained. For some selected glasses in which leaching rates have been known, their chemical durablility have been tested using the M-PCT method. The results are compared to the literature data for the glasses. It is found that M-PCT method is reasonable and suitable in determining the leachability of Low and Intermediate level Radioactive Waste glass form, such as the pH, elemental loss and total mass loss.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.600-604
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• 2001

Immunoassay was used to study the detection method of irradiated shrimp. Sandwich ELISA was formatted with monoclonal antibody (Ab) (M-IgG) and polyclonal Abs (P-IgG) and polyclonal Abs (P-IgG) individually produced against brown shrimp tropomyosin (TPM) as an antigen. When M-IgG was used as a coating Ab to capture TPM, and P-IgG were used as reaction Ab against captured TPM could be detected in the range of 12.5 to 50 $\mu\textrm{g}$/mL. Detected concentrations of TPM from irradiated shrimp decreased dose-dependently, and the concentration of Ag by combination of irradiation with heating or freezing treatments also decreased. This results suggests the possibility for Sandwich ELISA, one of immunological analyses, to be applied for detecting irradiated shrimp.

• Journal of Korea Foundry Society
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• v.20 no.4
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• pp.254-259
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• 2000

Metal matrix composites(MMCs) reinforced with hard particles have many potential application in aerospace structures, auto parts, semiconductor package, heat resistant panels, wear resistant materials and so on. In this work, the effect of SiC partioel sizes(50 and 100 ${\mu}m$) and additional elements such as Si, Cu and Ti on the microstructure and the wear property of $Al-5Mg-X(Si,Cu,Ti)/SiC_p$ composites produced by pressureless infiltration method have been investigated using optical microscopy, scanning eletron microcopy(SEM) with EDS(energy dispersive spectrometry), hardness test, X-ray diffractometer(XRD) and wear test. In present study, the sound $Al-5Mg-X(Si,Cu,Ti)/SiC_p$(50 and 100 ${\mu}m$) composites were fabricated by pressureless infiltration method. The $Al-5Mg-0.3Si-O.1Cu-O.1Ti/SiC_p$ composite with $50 {\mu}m$ size of SiC particle has higher hardness and better wear property than any other composite with $100{\mu}m$ size of SiC particle produced by pressureless infiltration method. The hardness and wear property of $Al-5Mg/SiC_p$(50 and 100 ${\mu}m$) composites were enhanced by the addition of Si, Cu and Ti in Al-5%Mg matrix alloy.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.6
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• pp.17-28
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• 2002

XTR is a new method to represent elements of a subgroup of a multiplicative group of a finite field GF( $p^{6m}$) and it can be generalized to the field GF( $p^{6m}$)$^{[6,9]}$ This paper progress optimal extention fields for XTR among Galois fields GF ( $p^{6m}$) which can be aplied to XTR. In order to select such fields, we introduce a new notion of Generalized Opitimal Extention Fields(GOEFs) and suggest a condition of prime p, a defining polynomial of GF( $p^{2m}$) and a fast method of multiplication in GF( $p^{2m}$) to achieve fast finite field arithmetic in GF( $p^{2m}$). From our implementation results, GF( $p^{36}$ )longrightarrowGF( $p^{12}$ ) is the most efficient extension fields for XTR and computing Tr( $g^{n}$ ) given Tr(g) in GF( $p^{12}$ ) is on average more than twice faster than that of the XTR system on Pentium III/700MHz which has 32-bit architecture.$^{［6,10］/ ［6,10］/6,10］}$

• Journal of the Korean Chemical Society
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• v.46 no.2
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• pp.145-150
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• 2002

A Method to determine Cr(III)ion in aqueous solution by chemiluminescence method using a stopped flow system has been studied. The method is based on the increased chemiluminescence intensity with the addition of Cr(III) to a solution of lucigenin a nd hyrogen peroxide. The effects of pH, injection volumes of reagent and sample, and concentration of lucigenin and hyrogen peroxide on the chemiluminescence intensity have been investigated. The calibration curve for Cr(III) ion was linear over the range from 1.0${\times}$$10^{-6}$ to 1.0${\times}$$10^{-3}$M and the detection limit was 5.2${\times}$$10^{-8}$M under the optimal experimental condition of 437nm, 12.8,and 1.0${\times}$$10^{-6}$ and 2.0M for emission wavelength, pH, and concentration of lucigenin and hyrogen peroxide, respectively.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.58-60
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• 2001

Two experiments were conducted to study the effects of nutrient level and feeding method of split diets for a.m. and p.m. on laying hen performance. In both studies, ISA Brown layers were kept in laying hen cages and treatments were represented by three or four replicates each containing 25 or 34 birds. In Experiment 1, the control group(C) was fed a conventional single diet throughout the day and split diet groups(T1, T2 and T3) were offered high energy/protein - low Ca diet and low energy/protein - high Ca diets in a.m. and p.m., respectively. In split diet groups, ME and CP consumption, and feed cost required per day and per kg egg mass were significantly reduced(P＜0.05) compared to C group, while the hen-day egg production, average egg weight and daily feed intake were not different among treatments. In the second study, C and T1 groups were fed the diets same to the C and T2 groups in Experiment 1, respectively. And T2 group was fed the diet mixed with the split diets for a.m. in mash and p.m. in pellet used in T1 group. In T1 and T2 groups, daily feed intake and average egg weight were significantly reduced(P＜0.05), while the hen-day egg production was not influenced by the feeding system. Daily ME and CP consumption, and feed cost were reduced(P＜0.05) in T1 and T2, while the ME, CP and feed cost required per kg egg mass were not different to the C group. In both study, eggshell qualities were improved(P＜0.05) by split diet feeding. It was concluded the feed and nutrients consumption, feed cost per day or per kg egg mass could be spared by introducing split diets for a.m. and p.m., and the feeding method of mixed diet of split diets was also convenient and effective for sparing feed cost and improvement of eggshell quality.

• ETRI Journal
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• v.37 no.3
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• pp.523-532
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• 2015

Recently, we have witnessed the gradual miniaturization of electronic devices. In miniaturized devices, flip-chip bonding has become a necessity over other bonding methods. For the electrical connections in miniaturized devices, fine-pitch solder bumping has been widely studied. In this study, high-volume solder-on-pad (HV-SoP) technology was developed using a novel maskless printing method. For the new SoP process, we used a special material called a solder bump maker (SBM). Using an SBM, which consists of resin and solder powder, uniform bumps can easily be made without a mask. To optimize the height of solder bumps, various conditions such as the mask design, oxygen concentration, and processing method are controlled. In this study, a double printing method, which is a modification of a general single printing method, is suggested. The average, maximum, and minimum obtained heights of solder bumps are $28.3{\mu}m$, $31.7{\mu}m$, and $26.3{\mu}m$, respectively. It is expected that the HV-SoP process will reduce the costs for solder bumping and will be used for electrical interconnections in fine-pitch flip-chip bonding.