• Transactions of Materials Processing
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• v.13 no.4
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• pp.359-364
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• 2004

In the multi-stage former, a manufacture of hexagonal fitting nut was generated in a defective products about 70∼80% in the industry field. Products generated in defects manufactured to be a machining about 60%. Additional process increased a product cost and decreased a product rate. Therefore, it is important to predict and design a preform reducing defective products in the early stage of process design. So in the study Defects for manufacturing hexagonal fitting nut verified a cause through the finite element simulation. To reduce a defective generation. a preform designed and a designed preform verified through the finite element simulation. In conclusion, a generated defects when a hexagonal fitting nut manufactured should reduce if a round dimension of preform reduced and a part of opposition angle distributed in plenty a volume.

• Journal of Power System Engineering
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• v.21 no.2
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• pp.41-47
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• 2017

Boron steel (51B20) was cold forged using by new designed dies to apply for automotive aluminum wheel nut. The formability and mechanical properties of boron steel were compared with carbon steel(S45C) which has been used up to date for the wheel nut material. The formability was investigated on the dies designed with various types of punch nose using by FEM. The metal flow and compressive stress on the dies during cold forging were investigated and compared each other. The forging process with a new designed die showed the improved metal flow with a reduced forging load which resulted in the significant increase of the die life. It was recommended that the carbon steel for automotive wheel nut material could be substituted by the boron steel.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1858-1861
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• 2005

Automatic nut sorting machine used to calculate the size of inserted nut and detect the black spot defection is introduced in this paper. Because most of farm products are imported from the underdeveloped countries, domestic farm products have no place to be sold in market. To overcome this critical situation, lowering the productivity cost is strongly demanded to compete with foreign corps. Imaged processed nut sorting algorithm is developed to the automatic nut sorting machine to remove the sorting time which takes lots of man power. This system is composed of mainly two parts, mechanical parts and vision system. The purpose of mechanical part is supplying the nuts automatically to make computer system capture the images of objects. Simplified mechanical system was assembled followed by 3D simulation by Pro/E design for the adaptive cost effects. Several image processing algorithms are designed to detect the spot defects and calculate the size of nuts. Test algorithm shows good results to the designed automatic nut sorting system.

• Journal of Korean Society of Steel Construction
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• v.12 no.2 s.45
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• pp.143-150
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• 2000

Depending upon the combination of tolerances specified in the standards on bolt, nut and washer for high tension bolt sets, there arises center-to-center deviation between bolt and washer. This deviation nay cause loss of effective contact area between nut- and washer-faces, which leads to some dispersion of the torque coefficient K. By adapting circular arc surface instead of flat surface for the nut, it is shown through numerical analyses that the dispersion of the torque coefficient can be minimized. In this way, optimum radius of curvature of the nut bearing surface is proposed.

• Transactions of Materials Processing
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• v.21 no.8
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• pp.493-498
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• 2012

A wheel nut wrench is one of the hand tools used to loosen and tighten lug nuts on automobile wheels and it has generally a solid-type geometry for commercial vehicles. However, the solid-type wheel nut wrenches manufactured by hot forging processes exhibit several drawbacks such as heavy weight and rough surface finish. Thus, many efforts have been devoted to change the part geometry and improve the manufacturing process. For this purpose, the weight of the final product can be reduced drastically using a hollow tube as the initial stock, which can be manufactured by the more economical manufacturing process of cold forging. In this study, the cold forging of a hollow-type wheel nut wrench for commercial vehicles was designed based on the results of fundamental experiments and CAE analyses using the commercial finite element code DEFORM-3D. In addition, cold forging experiments were conducted on a special-purpose forming machine for hollow wheel nut wrenches in order to validate the designed process sequence. As results, it was found that the final products with a weight reduction of 39% and better surface appearance can be manufactured without any defect with the newly designed cold forging process.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.353-361
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• 1989

A parametric study of load distribution in bolt-nut joints is performed by the method of finite element contact analysis. The contacting surface is assumed unbonded and frictionless. Multi-body contact analysis is performed in elastic region under the assumption of axi-symmetric stress state. Load acting on the first thread from the fastened plate is much greater than that on the other threads in the standard setting. But the load distribution is shown to be improved by making the center of contact force acting on the nut surface move outwards. Such a modification is possible by enlarging the gap between bolt shank and fastened plate or by inserting suitable washers. Shape modification of the standard nut by the making a groove and a step on the nut surface is also suggested, which results in almost uniform load distribution and considerable decrease in the maximum stress of the joint.

• Food Science and Preservation
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• v.17 no.3
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• pp.376-383
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• 2010

Including crude fat content, triacylglycerol species, tocopherols and phytosterols were analyzed in 8 kinds of nuts (sunflower seed, cashew nut, walnut, pistachio, pumpkin seed, ginkgo, hazel nut and pecan). The extracted crude fats showed 0.63~39.60 wt%, among which hazel nut showed the highest amount of fat content. Oleic acid (C18:1) was major fatty acids at sn-2 position in cashew nut, pistachio, hazel nut, and pecan while sunflower seed, walnut, and pumpkin seed showed linoleic acid (C18:2) as a major fatty acids at sn-2 position. Especially, ginkgo contained 10.72 wt% of vaccenic acid (C18:1-n7) at sn-2 position. The TAG species of 8 kinds of nuts were analyzed by reverse-phase HPLC, from which PN value ranged 40~52. Among the analyzed nuts, higher content of tocopherols were observed in ginkgo (48.57 mg/100 g), sunflower seed (38.35 mg/100 g), and pumpkin seed(31.43 mg/100 g). Total phytosterols were observed with the range of 88.60~947.20 mg/100 g.

• Korean Journal of Food Science and Technology
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• v.10 no.2
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• pp.119-123
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• 1978

Lipids, extracted with chloroform-methanol (2:1 by vol.) and purified, from nut and leaf of Ginkgo biloba were identified and quantitatived by column, thin layer and gas liquid chromatography. The results were summarized as follow: 1) The total content of purified lipids in the nut and leaf on the fresh weight basis were 1.32% and 2.24%, respectively. 2) The lipid fractions in the nut obtained by silicic acid colum chromatography were found to be composed of about 89% neutral lipids and about 10% compound lipids, and in the leaf were found to be composed of about 28% neutral lipids and about 72% compound lipids. 3) Among the neutral lipid fractions, triglycerides (86.2%) were the major component in the nut, but esterified sterols (53.3%) were the major component in the leaf. 4) The main fatty acids of the total lipids were oleic(37.5%) and linoleic acid(44.5%) in the nut, but linolenic(45.2%) and palmitic acid (25.1%) were main fatty acids in the leaf. The patterns of fatty acid composition of the neutral lipid fractions in the nut and leaf were found to be similar, and oleic, linoleic and palmitic acid were the predominant. A large amount of oleic and linoleic acid in the glycolipid fractions was found in the nut compared with those in the leaf, but linolenic acid content in the leaf was significantly higher than in the nut. And patterns of fatty acid composition of the phospholipid fractions in the nut and leaf were found to be similar to that of glycolipid fractions.

• Journal of Welding and Joining
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• v.34 no.2
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• pp.1-10
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• 2016

The use of materials for modern lightweight auto-bodies is becoming more complex than hitherto assemblies. The high strength materials nowadays frequently used for more specific fields such as the front and rear sub frames, seat belts and seats are mounted to the assembled body structure using bolt joints. It is desirable to use nuts attached to the assembled sheets by projection welding to decrease the number of loose parts which improves the quality. In this study, nut projection welding was carried out between a nut of both boron steel and carbon steel and ultra-high strength hot-stamped steel sheets. Then, the joints were characterized by optical and scanning electron microscope. The mechanical properties of the joints were evaluated by microhardness measurements and pullout tests. An indigenously designed sample fixture set-up was used for the pull-out tests to induce a tensile load in the weld. The fractography analysis revealed the dominant interfacial fracture between boron steel nut weld which is related to the shrinkage cavity and small size fusion zone. A non-interfacial fracture was observed in carbon steel nut weld, the lower hardness of HAZ caused the initiation of failure and allowed the pull-out failure which have higher in tensile strengths and superior weldability. Hence, the fracture load and failure mode characteristics can be considered as an indication of the weldability of materials in nut projection welding.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.171-182
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• 2002

This study wa performed to investigate the effect of dired powder of chestnut and acorn on lipid metabolism, antioxidative capacity and antithrombotic effect in rats. Fifty-four male Sprague-Dawley rats weighing 199$\pm$17g were blocked into nine groups according to their body weight. Rats were raised with diets containing only flesh or flesh with inner skin of 5% and 10% dried nut powders for four weeks. Food intake, body weight gain, food efficiency ratio and organ weight were no different among the experimental groups. The plasma and liver lipid levels of all the nut diet groups were lover than those of the control group. The nut diets showed hypolipidenic effect in the plasma and liver. Plasma and liver thiobarbituric acid reactive substance (TBARS) concentrations were significantly decreased in all the nut diet groups. The plasma TBARS levels of the inner skin groups were significantly different from the control group dose-dependently. Superoxide dismutase(SOD) activity was significantly different among the experimental groups, and all the nut groups showed higher activity than the control group. There were significant differences in SOD activity between the chestnut and acorn groups and the chestnut groups showed higher erythrocyte SOD activity and the acorn groups showed higher liver SOD activity than the other groups. Whereas catalase and GSH-Px activities in the erythrocyte and liver of both nut groups showed a tendency to increase, they were not significantly different among the experimental groups. The bleeding time and whole blood clotting time tended to be extended by feeding both types of nut but they were not significantly different among the experimental groups. Production of TX $B_2$ and PG $F_{1{\alpha}}$ was no different among the experimental groups. These results suggest that chestnut and acorn diets have the effect of lowering plasma and liver lipid levels, inhibiting lipid peroxide formation and increasing antioxidative enzymes activity. Thus, it is plausible that chestnut and acorn could be recommended in the treatment and prevention of cardiovascular diseases.