• Transactions of Materials Processing
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• v.27 no.5
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• pp.314-322
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• 2018

AlSi12 is a heat-resistant aluminum alloy that is lightweight, corrosion-resistant, machinable and attracting attention as a functional material in aerospace and automotive industries. For that reason, AlSi12 powder has been used for high performance parts through 3D printing technology. The purpose of this study is to observe deposition characteristics of AlSi12 powder in a direct energy deposition (DED) process (one of the metal 3D printing technologies). In this study, deposition characteristics were investigated according to various process parameters such as laser power, powder feed rate, scan speed, and slicing layer thickness. In the single track deposition experiment, an irregular bead shape and balling or humping of molten metal were formed below a laser power of 1,000 W, and the good-shaped bead was obtained at 1.0 g/min powder feed rate. Similar results were observed in multi-layer deposition. Observation of deposited height after multi-layer deposition revealed that over-deposition occurred at all conditions. To prevent over-deposition, slicing layer thickness was experimentally determined at given conditions. From these results, this study presented practical conditions for good surface quality and accurate geometry of deposits.

• Transactions of Materials Processing
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• v.27 no.5
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• pp.289-295
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• 2018

The profile ring rolling process can realize various ring shapes unlike conventional rectangular cross-sectional ring products. In this paper, the defective groove in the bottom surface of L-shaped ring products was analyzed. Grooves are generated by non-uniform external forces due to profile main roll and initial blank shape. Process parameters such as the motion of dies and working temperature were determined. Mechanism of groove formation was analyzed by FE simulation on the basis of local external forces acting on the blank. Analysis results were similar to the groove actually occurring in the production line. Based on results of the analysis, two solutions were proposed for the groove. The position of the base plate supporting the blank was adjusted and edge length of the main roll was extended to suppress growth of grooves. It has been verified that groove was improved by applying two proposed methods in the shop-floor.

• Transactions of Materials Processing
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• v.27 no.5
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• pp.276-280
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• 2018

This paper has developed a forging process for conical shells for making aluminum cylindrical large shells. An incremental forging process was applied to reduce forging loads and die cost. The preform is designed based on the crosssectional area of the final forged shape. Inner diameter of the preform for mandrel forging is constant, and outer diameter is conical so that it matches the cross-sectional area of the product. However, simulation confirmed that the larger diameter is smaller than predicted and the length is larger than predicted because in the initial stage of forging, the large diameter portion first comes into contact with the anvil at the initial stage of forging and stretches in longitudinal direction. So, it has developed a rule to design the preform considering 3-D deformation instead of plane strain deformation at the beginning stage of mandrel forging. The developed mandrel forging process can be applied to more similar products and economic benefits may be obtained.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.276-280
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• 1999

It is well-known that onion and garlic of Allium family have been cultivated for major food since ancient times. Especially garlic is known for containing protective materials against cardiovascular disease, neoplasm and cancer, and decreasing cholesterol value. Hemolytic anemia was first reported by Goldsmith in onion-fed cattle in 1909. Subsequently, similar effects have been reported in cattle, horses, sheep, dogs and cats. This toxic effect has been attributed to npropyl disulfide which causes oxidant damage to erythrocyte cell membrane. There are few reports on overconsumption of garlic. Kim et al. reported in 1999 that 45% of Jindo dogs in korea have erythrocytes characterized by high Na-K-ATPase activity with high K and low Na concentrations (HK) which easily results in hemolytic anemia. The purpose of present report is to determine whether garlic-induced hemolytic anemia occurs in normal erythrocytes characterized by complete lack of Na-K-ATPase activity with low K and high Na concentrations (LK) when LK dogs are fed large amounts of garlics. We found in this experiment that Erythrocyte count, PCV and Hemoglobin concentration decreased significantly, and GSH and Met-hemoglobin concentrations increased. Consequently, we determined that overconsumption of garlic induces hemolytic anemia in LK dogs.

• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.139-147
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• 1986

In order to clarify the pathogenesis of perirenal edema, pigs and rabbits were administered with oxalate and nitrate, with oxalate nitrate and glycolic acid, with oxalate, nitrate and ascorbic acid and with oxalate, nitrate and calcium, respectively. The results obtained are summarized as follows; The pigs and rabbits administered with oxalate and nitrate with oxalate, nitrate and glycolic acid and with oxalate, nitrate and ascorbic acid, respectively, were not showed perirenal edema despite of observing the abundant oxalate crystals in the proximal convoluted tubles. But pigs and rabbits administered with oxalate, nitrate and calcium were histopathologically showed perirenal edema similar to those of pigs fed Amaranthus retroflexus. Therefore, author considered that oxalate, nitrate and calcium are main factors to cause perirenal edema. It was regarded that perirenal edema in pigs was caused by the reciprocal reactions of those materials including oxalate, nitrate and calcium which may produce vascular damage, decreased osmotic pressure by hypoproteinemia and increased vascular permeability in kidney, rather than the mechanical obstructions by the oxalate crystals in the proximal convoluted tubule.

• Journal of the Korean Wood Science and Technology
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• v.41 no.3
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• pp.181-186
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• 2013

In this work, charcoal making characteristics of Quercus phyllyaeoides (which has been known as one of best raw materials for charcoals) was investigated. Charcoal from Quercus phyllyaeoides had more than 85% of fixed carbon, which is 5~25% higher fixed carbon content than other charcoals. Also specific gravity of this charcoal was more than 1.0, which is quite higher than other black charcoals (average of commercial products: 0.52) or white charcoals (average of commercial products: 0.73). Methylene blue adsorption, pH, and adsorption of water vapour was lower than other commercial charcoals. Carolic value of this charcoal was similar to other commercial products. Far infrared ray's emission from this charcoal was higher than others. Application of charcoal from Quercus phyllyaeoides should be consider the characteristics of this product.

• Transactions of Materials Processing
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• v.15 no.1 s.82
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• pp.9-14
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• 2006

In the present research, the simultaneous punching of ultra small size hole of $2\~10\;{\mu}m$ in diameter on flat rolled thin metal foils was conducted with elastic polymer punch. Workpiece used in the present investigation were the rolled pure copper of $3{\mu}m$ in thickness and CP titanium of 1.5fm in thickness. The metal foils were punched with the dies and arrays of circular and rectangular holes were made. The process set-up is similar to that of the flexible rubber pad farming or Guerin process. Arrays of holes were punched successfully in one step forming. The punched holes were examined in terms of their dimensions. The effects of the wafer die hole dimension and heat treatment of the workpiece on ultra small size hole formation of the thin foil were discussed. The process condition such as proper die shape, pressure, pressure rate and diameter-thickness ratio (d/t) were also discussed. The results in this paper show that the present method can be successfully applied to the fabrication of ultra small size hole away in a one step operation.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.121-121
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• 2018

We previously showed that the root extract of Paeonia lactiflora Red Charm might have anti-oxidant activities, however it was not clear which components might be involved in this activity. Our boinformatics analysis indicated the root extracts of Paeonia lactiflora Red Charm has a couple of potential anti-oxidant materials. One of them is paeoniflorin. We hypothesized that one of components present in Paeonia lactiflora Red Charm, paeoniflorin and its derivatives might be related to anti-oxidant activity. In this study, we compared paeoniflorin and its derivatives with the root extract of Paeonia lactiflora Red Charm using DPPH assays to measure its antioxidant activities. Paeoniflorin showed the highest radical scavenging activity(%) in $1000{\mu}g/m{\ell}$. its derivative showed the high levels radical scavenging activity(%) in $600{\mu}g/m{\ell}$, $800{\mu}g/m{\ell}$, $1000{\mu}g/m{\ell}$ similar to ascorbic acid. Taken together, these results suggest that Paeoniflorin and its derivatives may play a role in anti-oxidant acitivity in the root extracts of Paeonia lactiflora. Much of future studies may be needed to develop a potential new anti-oxidant candidates with anti-aging and anti-cancer effects.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1125-1130
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• 2014

In this paper, we discuss the relation between the motion profile and pre-filter. As previously reported in various literatures [1-3], a tuned motion profile can effectively reduce residual vibration by placing inherent zeros of the motion profile at the vibratory pole of systems similar to the role of the input shaping technique. From the results, we factorize the motion profile into a basis function and an input shaper. In contrast to the previously reported impulse-sequence-based input shapers, the input shaper extracted from the motion profile has unique characteristics. Thanks to the characteristics of the input shaper extracted from the motion profile, it has advantages to reduce the vibrations caused by not only the modeled vibratory mode but also unmodeled dynamics which exist in higher frequency ranges.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.2739-2743
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• 2015

Background: More than 1 million cancer survivors reside in Korea. We here investigated activity limitations of cancer survivors compared to controls without a history of cancer. Materials and Methods: Using the 4th and 5th Korea National Health and Nutrition Examination Survey (2007-2012) data, we identified 1,155 adult cancer survivors. Activity limitations were defined as limitation in activities of daily living, experience of lying in a sickbed, and number of days lying in a sickbed during the last month. Descriptive analysis and multiple logistic regression compared these measures for survivors and controls by sex and age groups. Results: Approximately 29.4% of cancer survivors reported limitation in activities of daily living, 14.6% experienced lying in a sickbed, and 4.3% experienced more than 15 days lying in a sickbed during the last month. After controlling for demographic and health-related factors, cancer survivors were more likely to report activity limitation than controls. The associations were similar across sex and age groups. Conclusions: Cancer survivors have increased activity limitation compared to controls and these limitations persist across sex and age. Targeted interventions and improved management are essential for improving cancer survivor daily life.