• Food Science of Animal Resources
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• v.43 no.1
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• pp.170-183
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• 2023

This study evaluated the effects of milk fermented with Pediococcus acidilactici strain BE and Pediococcus pentosaceus strain M103 on diabetes in rats (Rattus norvegicus). The bacteria were separately used as starter cultures for milk fermentation, and the products were then fed to diabetic rats for 15 days. Blood glucose levels, immunohistochemical and histological indicators, lipid profiles, and total lactic acid bacterium counts were evaluated before and after treatment. The administration of milk fermented with P. acidilactici strain BE reduced blood glucose levels from 410.27±51.60 to 304.07±9.88 mg/dL (p<0.05), similar to the effects of metformin (from 382.30±13.39 mg/dL to 253.33±40.66 mg/dL, p<0.05). Increased insulin production was observed in diabetic rats fed milk fermented with P. acidilactici strain BE concomitant with an increased number and percentage area of immunoreactive beta-cells. The structure of insulin-producing beta-cells was improved in diabetic rats fed milk fermented with P. acidilactici strain BE or metformin (insulin receptor substrate scores of 5.33±0.94 and 3.5±0.5, respectively). This suggests that the administration of milk fermented with P. acidilactici BE potentially reduces blood glucose levels and improves pancreatic beta-cell function in diabetic rats.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.138-139
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• 2003

Sandwich sheet samples comprising AA1050/AA1050/AA1050, AA3003/AA1050/AA3003, AA3003 AA3003 AA3003. AA1050/AA3003/AA1050, SUS430/AA3003/SUS430, AA3003/SUS430/AA3003 and SUS430/SUS430/SUS430 were cold rolled in order to clarify the evolution of strain states md textures in the sandwich samples. To investigate the effect of stacking sequences of the samples on strain and texture, the relative contribution of each layer to the total reduction was measured and textures of the mid-layer sheet of sandwich samples were determined.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.31-34
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• 2002

A study on the method that can measure the internal strain of composite materials is performed to monitor the health status of composite structures. A fiber optic sensor was constructed using the total reflected extrinsic Fabry-Perot interferometer(TR-EFPI) probe with a broadband light source. Result obtained from electrical strain gage adhered on the aluminum beam specimen was compared with that from the fiber optic TR-EFPI sensor and showed a good agreement. It was found that fiber optic TR-EFPI sensor system was adequate for monitoring the strain and thus failure processes in the interior of composite materials.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.10
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• pp.1853-1860
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• 1992

The plane-strain stamping process is analyzed by a forming energy minimization method in order to obtain forming load, slip length and strain distribution in each step of punch stroke. All the developed programs are integrated into total CAD/CAE SYSTEM for the purpose of the practical usage in die design. The computed strain distribution and the amount of draw-in are compared with those of the actually developed panel It is found that there is a good agreement between theoretical and experimental results.

• Structural Engineering and Mechanics
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• v.46 no.1
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• pp.111-135
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• 2013

An experimental study has been carried out on square plain concrete (PC) and reinforced concrete (RC) columns strengthened with carbon fiber-reinforced polymer (CFRP) sheets. A total of 78 specimens were loaded to failure in axial compression and investigated in both axial and transverse directions. Slenderness of the columns, number of wrap layers and concrete strength were the test parameters. Compressive stress, axial and hoop strains were recorded to evaluate the stress-strain relationship, ultimate strength and ductility of the specimens. Results clearly demonstrate that composite wrapping can enhance the structural performance of square columns in terms of both maximum strength and ductility. On the basis of the effective lateral confining pressure of composite jacket and the effective FRP strain coefficient, new peak stress equations were proposed to predict the axial strength and corresponding strain of FRP-confined square concrete columns. This model incorporates the effect of the effective circumferential FRP failure strain and the effect of the effective lateral confining pressure. The results show that the predictions of the model agree well with the test data.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.203-209
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• 1994

The bacterial strain which utilizes phenol and degrade TCE was isolated from an industrial waste site. The bacterial strain was named as T5-7 and identified as an Acinetobacter species. After phenol-induction, the strain T5-7 removed TCE efficiently without cell growth. So, it seems that TCE degradation was not related to cell growth. TCE degradation increased when initial cell concentrations of phenol-grown T5-7 were high. In the presence of phenol, initial degradation of TCE was delayed but total amount of degradation was not affected at final stage. The strain cultured in 0.1% yeast extract did not degrade TCE, which indicates that phenol induction was essential to the TCE degradation.

• Fibers and Polymers
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• v.2 no.1
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• pp.140-143
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• 2001

To better understand the formation of necking in drawing processes of fibers, strain distributions during drawing processes have been analyzed. For simplicity, one-dimensional incompressible steady flow at a constant temperature was assumed and quasi-static model was used. To describe mechanical properties of solid polymers, non-linear visco-plastic material properties were assumed using the power law type hardening and rate-sensitive equation. The effects of various parameters on the neck formation were matematically analyzed. As material property parameters, strain-hardening parameter, visco-elastic coefficient and strain-rate sensitivity were considered and, for process parameters, the drawing ratio and the process length were considered. It was found that rate-insensitive materials do not reach a steady flow state and the rate-sensitivity plays a key role to have a steady flow. Also, the neck formation is mainly affected by material properties, especially for the quasi-static model. If the process length changes, the strain distribution was found to be proportionally re-distributed along the process line by the factor of the total length change.

• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.309-312
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• 2003

A bacterial strain NB01, isolated from wastewater, was found to utilize nitrobenzene (NB) as the sole source of nitrogen, carbon, and energy. The strain was classified as a member of a high G+C Gram-positive group and identified as Mycobacterium chelonae based on an analysis of its 16S rRNA gene sequence. The strain grew on NB with a concomitant release of about 63% of the total available nitrogen as ammonia, suggesting a reductive degradation mechanism. The optimal pH and temperature for degradation were PH 7.0-8.0 and $30^{\circ}C$, respectively. The cell growth was retarded at NB concentrations above 1.8 mM. The degradation of NB followed Michaelis-Menten kinetics within the tolerance range, and the $K_m$ and maximum specific removal rate for NB were 0.33 mM and $11.04\;h^{-1}$, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.612-615
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• 2005

Low cycle fatigue tests are performed on the Incollel 617 that be used fur a hot gas casing. The relation between strain energy density and numbers of cycles to failure is examined in order to predict the low cycle fatigue life of Inconel 617. The life predicted by the strain energy method is found to coincide with experimental data and results obtained from the Coffin-Mansun method. Also the cyclic behavior of Inconel 617 is characterized by cyclic hardening with increasing number of cycle at room temperature.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.1-12
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• 1995

Isothermal and thermal-mechanical fatigue characteristics of 12Cr heat resisting steel used for high temperature applications were investigated including hold time effects. Isothermal low cycle fatigue test at $600^{\circ}C$ and in-phase, out-of-phase thermal-mechanical fatigue test at 350 to $600^{\circ}C$ were conducted using smooth cylindrical hollow specimen under strain-control with total strain ranges from 0.006 to 0.015. Regardless of thermal-mechanical and isothermal fatigue tests, cyclic softening behavior was observed and much more pronounced in the thermal-mechanical fatigue tests with hold times due to the stress relaxation during the hold time. The phase difference between temperature and strain in thermal-mechanical fatigue tests resulted in significantly shorter fatigue life for out-of-phase compared to in-phase. The differences in fatigue lives were dependent upon the magnitudes of plastic strain ranges and mean stresses. During the hold time in the strain-controlled fatigue tests, the increase in the plastic strain range and the stress relaxation were observed. It appeared that the increase in plastic strain range per cycle and the introduction of creep damage made important contributions to the reduction of thermal-mechanical fatigue life with hold time, and the life reduction tendency was more remarkable in the in-phase than in the out-of-phase thermal-mechanical fatigue. Isothermal fatigue tests performed under the combination of fast and slow strain rates at $600^{\circ}C$ showed that the fatigue life decreased as the strain rate and frequency decreased,especially for the low strain ranges.