• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.167-175
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• 2000

This paper describes the magnetic orientation of bull sperm separated into the head and the flagellum treated by DTT or heparin in a 5,400G static field. Semen samples collected from four bulls (Japanese Black) were mixed to the same sperm density. One percentage triton X-100 was used to extract the plasma membrane. The intact and demembranated sperm suspensions were treated with 20, 200, 2,000 mM DTT, 100, 1,000 or 10,000 units heparin solutions at $4^{\circ}C$ for 6 days. The decondensation of the sperm nuclei treated by DTT or heparin was examined by measuring the head area at 1, 3 and 6 days. After measuring the area, each sample was exposed to a 5,400G static magnetic field generated by Nd-Fe-B permanent magnets for 24 hours at room temperature. Results showed that the sperms were separated into the head and the flagellum through the DTT treatment. Almost of the separated heads showed that their long axis oriented perpendicularly to the magnetic lines of force, and most of the long axis perpendicularly oriented heads showed that their flat plane oriented perpendicularly in a 5,400G magnetic field. Also, the demembranation of the head tended to increase those perpendicular orientations, while those perpendicular orientations of the head declined with the decondensation of the sperm nuclei. These findings suggest that strong magnetic anisotropy for the perpendicular orientation of the long axis and the flat plane of the head occurs in the sperm nuclei in a 5,400G magnetic field. The separated flagellum showed lower parallel orientation, and the separated and demembranated flagellum showed parallel orientation to the magnetic lines of force in this magnetic field. These findings suggest that weak magnetic anisotropy of the parallel orientation of the flagellum occurs in the inside components in a 5,400G field.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.5
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• pp.423-430
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• 2012

In this paper, the effect of wrinkling on the cut propagation direction of thin membrane was studied using geometrically nonlinear shell element post-buckling analysis. In the analysis, rectangular tensile membrane configuration with a slanted center cut was considered. The cut propagation direction was predicted by maximum energy release rate method, $K_{II}$-zero method, and maximum tangential stress method. The cut propagation angle and the $J$-integral values were calculated for the wrinkled and unwrinkled cases and the results were compared. Various initial cut orientation angles were considered and the effect on the propagation direction was studied. The cut propagation paths were also predicted by virtual cut extension approach.

• Membrane Journal
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• v.29 no.4
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• pp.202-215
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• 2019

Molecular sieve membranes separate molecules based on their size and/or shape and have been of high interest, due to their potentially high energy efficiency and high selectivity. Zeolite MFI membrane is one of the most-studied molecular sieve membranes and has affected following studies on other molecular sieve membranes. This review discusses the technical developments on the control of morphology, microstructure, and defect of MFI membranes, which have significantly improved xylene isomer separation performances. These include crystal morphology control, effective secondary growth, seed coating method, crystal orientation control, heteroatom doping, and defect healing method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.1968-1799
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• 2000

A warpage analysis program has been developed for fiber-reinforced injection molded parts. The warpage is predicted from the residual stress and anisotropic thermo-mechanical properties coupled with fiber orientation in the integrated injection molding simulation. A simple elastic model is used for the calculation of thermally and pressure-induced residual stresses which are employed as the initial conditions in the structural analysis. To improve the reliability of warpage analysis, a new triangular flat shell element superimposing well-known efficient plate bending and membrane element is presented. The numerical examples address the necessity to use anisotropic models for fiber-reinforced materials and show that predicted warpage is in good agreement with experimentally measured one.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.745-750
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• 2000

A warpage analysis program has been developed for fiber-reinforced injection molded parts. The warpage is Predicted from the residual stress and anisotropic thermo-mechanical properties coupled with fiber orientation in the integrated injection molding simulation. A simple elastic model is used for the calculation of thermally and pressure-induced residual stresses which are employed as the initial conditions in the structural analysis. To improve the reliability of warpage analysis, a new triangular flat shell element superimposing well-known efficient plate bending and membrane element is presented. The numerical examples address the neccesity to use anisotropic models for fiber-reinforced materials and show that predicted warpage is in good agreement with experimentally measured one.

• Journal of Biomedical Engineering Research
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• v.2 no.1
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• pp.3-14
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• 1981

A theoretical investigation of the origin of the spontaneous firing in the squid axon was done with a mathmatical computer modelling based on the Hodgkin-Huxley equation. It is strongly believed that the existence of calcium ions in the membrane is essential to cause firing. The results of the computer simulation of the modelling indicate that the sites of calcium ions in the membrane might be near the potassium channel and the leakage channel plays an important role in the firing. The orientation of the future research project was suggested. And also, a theoretical investigation of the origin of the firing in the propagating action potential was done in the same way.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.248-251
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• 1996

Langmuir-Biodgett(LB) method is known as a unique method for preparing organic thin films, which can control thickness of the films in molecular level, and many kinds of ultra thin films of functional molecules have been prepared using this method. In this study, The organization of phospholipid monolayers on a water surface was investigated by means of displacement current measurement technique.

• Polymer(Korea)
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• v.30 no.6
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• pp.563-567
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• 2006

Poly(vinyl alcohol) (PVA) and gelatin (GEL) blend membranes were prepared by solution casting method under a high electric field. SEM observation of the membrane showed that gelatin rich domains were elongated and oriented to the direction of the applied electric field in PVA matrix. This can be attributed to the electrostatic emulsifying effects due to a reduction in interfacial tension. In addition, it was observed through WAXD and swelling measurements that the degree of crystallinity of membranes increased with applied electric field strength. This may be interpreted to be caused by the orientation effect of GEL domains in the blend membrane, and the self-annealing effect due to some heat generated from high electric field during casting.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.181-181
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• 1996

The (Na, K) ATPase is a membrane ion transporting ATPase composed of an ${\alpha}$ catalytic subunit and a ${\beta}$ glycoprotein subunit. The topology of the rat ${\alpha}$1 and ${\beta}$1 subunits has been studied by insertion of epitope(s) : at the NH2-terminus and COOH-terminus and between Glu117 and Glul18, Lys828 and Arg829, Gln900 and Trp901, and Va1939 and Phe940 of the ${\alpha}$ subunit; and at the NH2-terminus and COOH-terminus and between Glu228 and Tyr229 of the ${\beta}$ subunit. The epitope-tagged ${\alpha}$l, constructs were expressed in HeLa cells to select for stable cell lines expressing a functional (Na, K)ATPase. All constructs, except for the one tagged between Gln900 and Trp901, resulted in ouabain-resistant colonies indicating that modified proteins retained functional integrity. The epitope-tagged ${\beta}$ constructs were transiently expressed in Cos-7 cells. The orientation of the epitopes with respect to the cell membrane was revealed by indirect immunofluorescence performed on permeabilized and non-permeabilized cells expressing the (Na, K)ATPase chains. The results indicate that the ${\alpha}$ subunit has 4 transmembrane segments in the COOH terminal membrane bound domain between residues 760 and 938, and that both the NH2-terminus and the COOH-terminus are in the cytosol; it was not determined whether there are more transmembrane segments between residue 938 and the COOH-terminus. The ${\beta}$ subunit has only one transmembrane spanning region with the NH2-terminus in the cytosol and the COOH-terminus on the extracytoplasmic surface of the plasma membrane.

• Journal of the Korean Chemical Society
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• v.42 no.2
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• pp.143-149
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• 1998

When anesthetics were added to a bacteriorhodopsin (bR) in the purple membranes, the 570 nm absorption band shifts to 480 nm. This anesthetic-induced spectroscopic change is reversible. The apparent pKa (6.3) of this equilibrium depends on the nature of the anesthetics in which bR is dispersed. The electric orientation measurements showed that the native bR is easily achieved by relatively small electric field which is oriented at $60^\circ$, while anesthetic-treated bR is not the case. These results demonstrate that the subtle changes in the chromophore and the protein structure surrounding the chromophore by anesthetics influence the spatial orientation of the charged residues in the protein matrix surrounding chromophore.