• The Korean Journal of Pain
• /
• v.19 no.2
• /
• pp.253-256
• /
• 2006

Cervical disc herniation is one of the most common causes of neck, shoulder and arm pain. There are many treatments for a cervical disc herniation, such as rest, physical therapy, medication, epidural steroid injection and surgery. However, conservative treatments sometimes have limited effectiveness, and a surgical discectomy is often associated with numerous complications. Nowadays, a percutaneous discectomy, using a $Dekompressor^{(R)}$, has been used in herniated disc patients, but a posterolateral extruded disc is not an indication. Herein, our experience using a 19 G $Dekompressor^{(R)}$, on a 52 year-old male patient with a left C6-⁣7 posterolateral extruded disc, is reported. Decompression was successfully performed, and the pain and range of motion was immediately improved.

• Transactions of Materials Processing
• /
• v.6 no.4
• /
• pp.346-356
• /
• 1997

The fiber orientation distribution and interface bonding in hot extrusion process have an effect on the maechanical properties of metal matrix composites(MMC's). Aluminium alloy matrix composites reinforced with alumina short fibers are fabricated by compocasting method. MMC's billets are extruded at high temperature through conical and curved shaped dies with various extrusion ratios and temperature. This present study was directed to describe the systematic correlation between extrusion die shape and subsequent results such as fiber breakage, fiber orientation and tensile strength to hot extruded MMC's billet. Extrusion load, tensile strength and hardness for variation of extrusion ratios and temperature are investigated to examine mechanical properties of extruded MMC's SEM fractographs of tensile specimens are observed to analyze the fracture mechanism.

• Transactions of Materials Processing
• /
• v.12 no.6
• /
• pp.566-571
• /
• 2003

The metal forming behavior and defect formation in Ti-6Al-4V tube during hot backward extrusion were investigated. Dynamic material model(DMM) including Ziegler's instability criterion was employed to predict the forming defects such as shear band, inner and/or surface cracks. This approach was coupled to the internal variables generated from FE analysis. The simulation results fur the backward extrusion were compared with the experimental observation. The chilling effect and friction indicated a great influence on the deformation mode of the tube and the formation of surface cracks. The formation of forming defects in the extruded tube was attributed to non-uniform distribution of strain, strain rate and temperatures in the extruded tubes for the given test conditions.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.91-97
• /
• 2003

In many countries such as Japan, France and so on, the number of double-deck trains has been dramatically increased for the purpose of public traffic. Several researchers have performed feasiblilty studies related to the operations of double deck rolling stock vehicles in Korea since 2001. In recent years, rolling stock vehicles are required to have light weight to save energy consumption and maintenance costs. For these reasons, the standard EMU vehicle developed by KRRI and Kwan-Ju EMU(Electric Multi Unit) are made of aluminum extruded panels. The concept model of a double-deck rolling stock vehicle investigated in this study is also designed to use AEP(Aluminum Extruded Panel). In this paper, the methods related to the structural strength improvements of the car body are proposed through careful modifications of thicknesses and shapes of AEP.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.2
• /
• pp.306-310
• /
• 2005

The comparison in release rate constant and properties of extracts from extruded raw ginseng and extruded white ginseng was conducted to apply extrusion process for manufacturing of released ginseng tea bag. Dry raw ginseng and white ginseng powder were extruded at 20∼30% moisture content and 200∼300 rpm by using an experimental twin-screw extruder. Browness and redness (both indicated the releasing of saponin and ginsenosides) were increased with the increase in the screw speed and the decrease of moisture content. Crude saponin and water solubility index (WSI) of both ginseng also share the same behaviour against the level of screw speed and moisture content, as well as browness and redness. The particle size effects of extruded raw ginseng at 20% and 28% moisture content on absorbance of released extract at 260 up to 560 nm, WSI, and water absorption index were determined. While particle size decreased from 800∼1000 nm to 200∼500 nm, absorbance and WSI are decreased. Absorbance and WSI shown increasing level while moisture content was decreased. In conclusion, the formation of pores by expansion and disruption of cell wall in extrusion cooking were obviously responsible to increase the amount of released extract of extruded ginseng and its WSI as well. The extrusion process turns out be the efficient process for manufacturing of commercial ginseng tea product than those of other thermal processes.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.9
• /
• pp.1263-1271
• /
• 2000

A total of 80 piglets ($5.85{\pm}0.62kg$ BW; 21 d of age) were used to study the effect of carnitine addition to extruded full-fat soybean (EFS) diets on the growth of weaned pigs. Pigs were allotted into five treatments based on body weight, in a completely randomized block design. Each treatment has 4 replicates of 4 heads each. Treatments were 1) SBM (positive control), 2) EFS without carnitine (negative control), 3) EFS with 50 ppm carnitine, 4) EFS with 100 ppm carnitine and 5) EFS with 150 ppm carnitine. During d 0 to 14, piglets were fed diets containing 3,400 kcal ME, 23% crude protein, 1.65% lysine, 0.9% Ca and 0.8% P and for the period of d 15 to 28, piglets were fed diets supplying 3,300 kcal ME, 20% crude protein, 1.55% lysine, 0.9% Ca and 0.8% P. The urease activity of EFS (0.18) were three times higher than SBM (0.07). During d 0-14, pigs fed SBM had greater ADG and ADFI compared to pigs fed extruded full-fat soybean diets (p<0.05). Feed conversion ratio was not different among treatments. No linear or quadratic effect of carnitine addition was found in growth performance. During d 15-28, piglets fed SBM diet also showed better ADG and FCR with no significant differences among treatments. Feed intake tended to increase as carnitine addition level was increased (p=0.10). For overall period (d o to 28), the best performance was observed in pigs fed SBM diet. CP digestibility was higher in pigs fed SBM diet than piglets fed EFS diet at d 14, and DM and CP digestibility tended to be higher in pigs fed SBM diet at d 28. Blood metabolites (BUN, glucose and cholesterol)were not affected by treatments. In conclusion, based on the results of this study piglets at 21 d of age appeared to be not ready for extruded full-fat soybean (FFSB) in their diets. Piglets fed extruded FFSB showed decreased growth rate compared to piglets fed SBM diet. Nutrient utilization was also poor in piglets fed extruded FFSB diets. L-carnitine addition at the level of 50 to 150 ppm was not effective in improving the growth performance of pigs fed EFS diets.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.2
• /
• pp.247-254
• /
• 2005

The objective of this study is to compare the chemical properties of red ginseng, white ginseng, and extruded ginseng. Six kinds of samples were prepared and examined their chemical components. The comparison among crude ash, crude lipid, and total sugar resulted insignificant difference. White ginseng had lower content of reducing sugar than those of extruded ginseng and red ginseng. Total amino acid was found relatively low in treatment A (sliced whole root and dried at 7$0^{\circ}C$). Total amino acid of treatment C (extruded dry whole root ginseng slices, moisture content 30%, barrel temperature 11$0^{\circ}C$, and screw speed 200 rpm) was higher than that of treatment B (extruded dry whole root slices, moisture content 25%, barrel temperature 11$0^{\circ}C$, and screw speed 200 rpm). Crude saponin of treatments A, B, C, D (white ginseng with skin), E (skinless white ginseng), and F (red ginseng) were 4.02, 4.77, 4.12, 3.56, 3.25, and 4.02%, respectively. Ginsenoside was contained similarly as crude saponin. The amount of ginsenoside in the treatment of A, B, C, D, E, and F was recorded respectively at 6.031, 8.108, 6.876, 7.978, 5.591, and 9.834 mg/g. A specific component in red ginseng, $R_{g3}$ was detected in treatment F. Maltol was detected in treatment Band F. Acidic polysaccharide was increased 2∼3% by extrusion process. In conclusion, extruded ginseng had similar components to those of red ginseng.

• Korean Journal of Food Science and Technology
• /
• v.44 no.4
• /
• pp.411-416
• /
• 2012

This study was carried out to investigate the effects of the extrusion process on the change of components in ginseng. The extraction yields from ginseng by distilled water extraction were highest in the extruded ginsengs, whereas it was lowest in the white ginseng. The contents of crude saponin were highest in the extruded ginseng, and they increased as the extrusion temperature was raised. The total contents of 11 kinds of ginsenosides increased in the order of red, white and extruded ginsengs. In particular, red ginseng showed higher contents of Rg1, Rg3 and Rb2, whereas Re was highest in white ginseng. In addition, the contents of Rg2, Rh1, Rh2 and Rg3 in the extruded white ginseng became higher. Free sugar contents were greatest in red ginseng. However, they were lowest in the extruded ginseng. White ginseng had a greater L value, whereas extruded ginseng demonstrated higher a and b values. In conclusion, the extraction yields, the contents of saponin, and ginsenoside-Rg2, Rh1, Rh2 and Rg3 were increased through the extrusion process.

• Korean Journal of Materials Research
• /
• v.30 no.10
• /
• pp.542-549
• /
• 2020

Effects of Sc addition on microstructure, electrical conductivity, thermal conductivity and mechanical properties of the as-cast and as-extruded Al-2Zn-1Cu-0.3Mg-xSc (x = 0, 0.25, 0.5 wt%) alloys are investigated. The average grain size of the as-cast Al-2Zn-1Cu-0.3Mg alloy is 2,334 ㎛; however, this value drops to 914 and 529 ㎛ with addition of Sc element at 0.25 wt% and 0.5 wt%, respectively. This grain refinement is due to primary Al₃Sc phase forming during solidification. The as-extruded Al-2Zn-1Cu-0.3Mg alloy has a recrystallization structure consisting of almost equiaxed grains. However, the as-extruded Sc-containing alloys consist of grains that are extremely elongated in the extrusion direction. In addition, it is found that the proportion of low-angle grain boundaries below 15 degree is dominant. This is because the addition of Sc results in the formation of coherent and nano-scale Al₃Sc phases during hot extrusion, inhibiting the process of recrystallization and improving the strength by pinning of dislocations and the formation of subgrain boundaries. The maximum values of the yield and tensile strength are 126 MPa and 215 MPa for the as-extruded Al-2Zn-1Cu-0.3Mg-0.25Sc alloy, respectively. The increase in strength is probably due to the existence of nano-scale Al₃Sc precipitates and dense Al₂Cu phases. Thermal conductivity of the as-cast Al-2Zn-1Cu-0.3Mg-xSc alloy is reduced to 204, 187 and 183 W/MK by additions of elemental Sc of 0, 0.25 and 0.5 wt%, respectively. On the other hand, the thermal conductivity of the as-extruded Al-2Zn-1Cu-0.3Mg-xSc alloy is about 200 W/Mk regardless of the content of Sc. This is because of the formation of coherent Al₃Sc phase, which decreases Sc content and causes extremely high electrical resistivity.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.05a
• /
• pp.254-257
• /
• 2007

In this study, hydroformability and mechanical properties of pre- and post- heat treated Al6061 tubes at different extrusion type were investigated. For the investigation, as-extruded, full annealed and T6-treated Al 6061 tubes at different extrusion type were prepared. To evaluate the hydroformability, uni-axial tensile test and free bulge test were performed at room temperature and $200^{\circ}C$. Also mechanical properties of hydroformed part at various pre- and post-heat treatments were estimated by tensile test. And the tensile test specimens were obtained from hexagonal prototype hydroformed tube at $200^{\circ}C$. As for the heat treatment, hydroformability of full annealed tube is 25% higher than that of extruded tube. The tensile strength and elongation were more than 330MPa and 12%, respectively, when hydroformed part was post-T6 treated after hydroforming of pre- full annealed tube. However, hydroformed part using T6 pre treated tube represents high strength and low elongation, 8%. Therefore, the T6 treatment after hydroforming for as-extruded tube is cost-effective. Hydroformability of Al6061 tube showed similar value for both extrusion types. But flow stress of seam tube showed $20{\sim}50MPa$ lower value.