• Transactions of Materials Processing
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• v.29 no.5
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• pp.257-264
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• 2020

This paper is concerned with the influence of the plastic property of the rivet on the numerical prediction of the Self-Piercing Rivet (SPR) Joining. In order to predict the plastic property of the rivet, a ring compression specimen was directly fabricated from the rivet used for the mechanical joining of dissimilar materials, and the FE analysis together with the ring compression test was iteratively carried out by changing the plastic property of the rivet. For reliable FE analysis, a friction coefficient was estimated based on a friction calibration curve, measuring the reductions in inner diameter and height of the ring specimen after the compression test. From each simulation result, the force-displacement curves were then compared from each other so as to obtain the rivet plastic property that shows good agreement with the experimental result. The SPR joining between GA590 1.0t and Al5052 2.0t was conducted, and the numerical prediction was performed with the use of the plastic property evaluated based on the inverse analysis and the one referred from Mori et al. [11]. Comparison of the experiment and the numerical predictions in terms of the interlock and bottom thickness revealed that the reliable evaluation of the plastic property of the rivet is necessary for the trustworthy numerical prediction of the SPR joining.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.76-84
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• 2021

In this study, an optimal stiffness model of the C-frame, which was supporting the mold and tool load, was proposed to obtain quality self-piercing riveting (SPR) joining. First, the load path acting on the C-frame structure was identified using topology optimization. Then, a final suggested model was proposed based on the load path results. Stiffness and strength analyses were performed for a rivet pressing force of 7.3 [t] to compare the design performance of the final proposed model with that of the initial model. Moreover, to examine the reliability of continuous and repeated processes, vibration analysis was performed and the dynamic stiffness of the final proposed model was reviewed. Additionally, fatigue analysis was performed to ascertain the fatigue characteristics due to simple repetitive loading. Finally, stiffness test was performed for the final proposed model to verify the analysis results. The obtained results differed from the analysis result by 2.9%. Consequently, the performance of the final proposed model was superior to that of the initial model with respect to not only the SPR fastening quality but also the reliability of continuous and repetitive processes.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.28-33
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• 2008

The expression vector (pWHM3-TR1R2) for sprT gene encoding Streptomyces griseus trypsin (SGT) followed by two regulatory genes, sgtR1 and sgtR2, was introduced into Streptomyces lividans TK24 and Streptomyces griseus IFO 13350. Various media with different compositions were used to maximize the productivity of SGT in the recombinant trains. he SGT productivity was best when the transformant of S. lividans TK24 was cultivated in R2YE medium (0.74 unit/mL) at 5 days of cultivation. C5/L (0.66 unit/mL) medium also gave a good productivity, but Livid (0.08 unit/mL) and NDSK (0.06 unit/mL) yielded poor productivities. S. griseus IFO 13350/pWHM3-TR1R2 produced SGT by 1.518 unit/mL (C5/L), 1.284unit/mL (R2YE),0.932 unit/mL (NDSK), and 0.295 unit/mL (Livid) at 7 days of cultivation, which was much higher than those from S. lividans TK24/TR1R2. The SGT protein was purified from the culture broth of S. griseus IFO 13350/pWHM3-TR1R2 in C5/L to homogeneity via ammonium sulfate fractionation, and CM-sepharose and SP-sepharose column chromatographies. The specific activity of purified SGT was 69,252 unit/mg, and the final purification fold and recovery yield were 6.5 and 1.4%, respectively.

• 전기의세계
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• v.28 no.7
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• pp.60-66
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• 1979

In this paper we deal with a hardware redundency, using the replications of an original module to enhance the reliability of the system in view of static and dynamic redundancy. As results of the study the following facts have been proved that (1) if the mission time is small (T .neq. 0.5), the effect of spare modules cannot be expected significantly, (2) for the small mission time (0.1 .neq. T .neq. 0.3) the SPR system is more reliable than the other redundant systems. In addition to above facts, it is also proved that for the large mission time (T=1), the dynamic redundant system is more reliable than the static redundant system, and that the SR system is more reliable than the HR system in the dynamic redundant system.

• BMB Reports
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• v.40 no.5
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• pp.832-838
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• 2007

A novel inhibitory protein against blood coagulation factor Va (FVa) was purified from muscle protein of granulated ark (Tegillarca granosa, order Arcoida, marine bivalvia) by consecutive FPLC method using anion exchange and gel permeation chromatography. In the results of ESI-QTOF tandem mass analysis and database research, it was revealed that the purified T. granosa anticoagulant protein (TGAP) has 7.7 kDa of molecular mass and its partial sequence, HTHLQRAPHPNALGYHGK, has a high identity (64%) with serine/threonine kinase derived from Rhodopirellula baltica (order Planctomycetales, marine bacteria). TGAP could potently prolong thrombin time (TT), corresponding to inhibition of thrombin (FIIa) formation. Specific factor inhibitory assay showed that TGAP inhibits FVa among the major components of prothrombinase complex. In vitro assay for direct-binding affinity using surface plasmon resonance (SPR) spectrometer indicated that TGAP could be directly bound with FVa. In addition, the binding affinity of FVa to FII was decreased by addition of TGAP in dose-dependant manner ($IC_{50}$ value = 77.9 nM). These results illustrated that TGAP might interact with a heavy chain of FVa ($FVa_H$) bound to FII in prothrombin complex. The present study elucidated that non-cytotoxic T. granosa anticoagulant protein (TGAP) bound to FVa can prolong blood coagulation time by inhibiting conversion of FII to FIIa in blood coagulation cascade. In addition, TGAP did not significantly (P < 0.05) show fibrinolytic activity and cytotoxicity on venous endothelial cell line (ECV 304).

• BMB Reports
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• v.32 no.1
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• pp.86-91
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• 1999

The sprT gene encoding Streptomyces griseus trypsin (SGT) was introduced into Streptomyces lividans TK24 and Streptomyces lividans 1326 to study which strain would be better to overexpress the extracellular proteinase. Various media with different compositions were also used to maximize the productivity of SGT in heterologous hosts. The SGT productivity was best when the transformants of S. lividans TK24 and 1326 were cultivated in R2YE medium, and their relative trypsin activity of the culture broth measured with an artificial chromogenic substrate, N-${\alpha}$-benzoyl-DL-arginine-${\rho}$-nitroanilide, were 382 units/ml and 221 units/ml, respectively. They produced high levels of SGT in GYE medium but relatively lower than those in R2YE medium, and negligible amount of SGT was produced in Ferm, RASF, LIVID, and NDSK media. Considering non-SGT associated activity in Pronase powder, it was estimated that the transformant of S. lividans TK24 can produce SGT in R2YE 3.5 times more than the amount by S. griseus 10137 from which the sprT gene had been originated. The growth of S. lividans reached the maximum level of cell mass at 5 d of culture, but SGT production started in the stationary phase of cell growth and kept increasing until the ninth day of culture in R2YE medium, but in GYE media the productivity reached at the maximum level at 7 d of cultivation.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.630-633
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• 2003

Transfer of an electron from one site to another in a molecular or between molecules and/or electrodes is one of the most fundamental and ubiquitous processes in chemistry, biology and physics. In this study fusion proteins composed by green fluorescent protein(GFP) and cytochrome b562 were used in fabricating molecular array as an electron sensitizer and electron acceptor, Protein formation onto the substrate was performed by the self-assembly technique. The fusion protein film were analyzed using scanning probe microscope(SPM), Surface Plasmon Resornance(SPR) and hybrid STM/I-V. The results suggest that the proposed molecular photodiode can be used as a basic unit of the memory device.

• Journal of Magnetics
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• v.3 no.3
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• pp.74-77
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• 1998

A method to analyze the anisotropy constants of a two sublattice system with uniaxial anisotropy has been investigated by extending the Sucksmith and Thompson's method to higher order anisotropy terms. Using the method, a set of anisotropy constants for Pr-sublattice of $Pr_2Fe_{14}B at 4.2K has been obtained as K_{1Pr}=5210 J/kg, K_{2Pr}=-7200 J/kg, K_{3Pr}=-770 J/kg, K_{4Pr}=4940 J/kg and K_{SPr}=700 J/kg for N_{PrFe}=2.2 T/Am^2kg^{-1}.$ The magnetization calculated by an energy minimum method by using the sublattice anisotropy constants well reproduced the experimental results and satisfied the simulation assumptions.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.65-68
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• 2004

Molecular imprinting, which was first proposed by Wulff and Sarhan in 1972 [1], is a facile way to construct molecular recognition sites by applying a simple radical polymerization [2]. Since 1994, the authors have proposed an alternative molecular imprinting method in which polymeric materials are directly converted into molecular recognition materials [3].(omitted)

• Journal of the Korean Mathematical Society
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• v.60 no.2
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• pp.407-464
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• 2023

Let R be a commutative ring with identity. The structure theorem says that R is a PIR (resp., UFR, general ZPI-ring, π-ring) if and only if R is a finite direct product of PIDs (resp., UFDs, Dedekind domains, π-domains) and special primary rings. All of these four types of integral domains are Krull domains, so motivated by the structure theorem, we study the prime factorization of ideals in a ring that is a finite direct product of Krull domains and special primary rings. Such a ring will be called a general Krull ring. It is known that Krull domains can be characterized by the star operations v or t as follows: An integral domain R is a Krull domain if and only if every nonzero proper principal ideal of R can be written as a finite v- or t-product of prime ideals. However, this is not true for general Krull rings. In this paper, we introduce a new star operation u on R, so that R is a general Krull ring if and only if every proper principal ideal of R can be written as a finite u-product of prime ideals. We also study several ring-theoretic properties of general Krull rings including Kaplansky-type theorem, Mori-Nagata theorem, Nagata rings, and Noetherian property.