• Journal of Fisheries and Marine Sciences Education
• /
• v.20 no.1
• /
• pp.90-94
• /
• 2008

Growth and water quality in Japanese eel, Anguilla japonica ($6.0{\pm}0.9g$) fed extruded and paste type diets were compared for 8 weeks. Fish in the duplicate tanks were fed with one of three experimental diets: two different extruded pellet diets and one paste type diet. Six FRP tanks were used with stocking density of 3.6 kg per tank (3 m3). Restricted feeds (ca. 2% of body weight) were served twice daily. Weight gains were checked at the end of every two-week interval, and water qualities in terms of NH4-N and NO2-N were determined daily one hour after feeding in the morning. Water temperature, dissolved oxygen, and pH were constantly kept within the optimum range, while fifty percent of total water volume was changed daily. Eels fed the extruded pellet diets showed significantly better (P<0.05) growth performance than did eels fed the paste type diet. The amount of feed waste from the paste type diet was significantly greater than those from the extruded pellet diets (P<0.05). Ammonia (NH4-N) waste was significantly higher from the paste diet than from the extruded pellet diets (P<0.05). These results show that extruded pellet diets are better than the paste type diet for growth and water quality management in eel culture.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.2
• /
• pp.523-528
• /
• 2013

In this experiment, we investigated the performance of two types of heat sink, swaged- and extruded-type, used in the inverter of industrial electricity generator. The swaged-type heat sink has 62 fins, and the extruded-type has 38 fins having the same dimension as that of the swaged-type. But the extruded-type heat sink maintains the same heat transfer area by the laterally waved surface which has 1 mm in radius. As a result, the swaged- and extruded-type heat sinks released 70.7% and 63.8% of the heat incoming to the heat sink, respectively. The other incoming heat were naturally convected and radiated to the ambient. In spite of 40% decrease in number of fins, the heat release performance of the extruded-type heat sink was lowered only 6.9% than that of the swaged-type. We believe that, this shows the increment of effective heat transfer area by the laterally waved surface of fins and the better heat transfer property of the extruded-type heat sink.

• Journal of Acupuncture Research
• /
• v.18 no.4
• /
• pp.68-81
• /
• 2001

Herniated lumbar intervertebral disc(H.I.V.D) is the most common reason causing low back pain and leg radiating pain. Objective : The purpose of this report is to observe the effects of oriental medical conservative treatment in the different herniated type. Methods : We investigated 30 patients suffering from low back pain with sciatica which were admitted to Taejon Cheonan O. M. hospital from Nov 1, 2000 to Apr 30, 2001. 30 patients had a diagnosis of herniated lumbar interver tebral disc by Lumbar-C.T and Lumbar-M.R.I. we treated 30 patients by oriental medical conservative treatment (Ex: acupuncture, herb-med, physical theraphy, bed-rest, etc.) Results : 1. The mean hospitalization of patients was 21.1 days. that in the bulging type was l4days, protruded type 21days, mixed type 27days, extruded type 30days. that shows the less herniation of lumbar intervertebral disc, the mean hospitalization was more short. 2. In the distribution of the clinical symptoms admitted at that time, low back pain, leg radiating pain were showed in the all types(29patients, 96.6%). and sensory disorder, muscle powerlessness were showed least in the bulg ing type(0%, 37.5%), but that were showed most in the extruded type(50%,75%). 3. In the result of treatment due to clinical syptoms, bulging type was more execellent than any other other types. 4. The less herniation of lumbar intervertebral disc, angle of straight leg raising test was higher. In the result of treatment due to angle of straight leg raising test, bulging type was more execellent than any other other types. 5. In the distribution of physical. test, positive case in the Peyton sign, Ankle Dorsiflexion were showed least in the bulging type(25%, 12.5%), but that were showed most in the extruded type(100%, 75%). 6. In the result of treatment due to physical.test, bulging type was more exec ellent than any other other types. 7. The efficacy of total treatment was 90%(when we set a standard things more than fair), that in the bulging type was 100%, protruded 92%, mixedtype 80%, extruded type 75%. Bulging type had a more remakable effectsthan any other types. Conclusions : The less herniation of lumbar intervertebral disc, clinical syptoms were slighter, physical. test were better, and efficacy of oriental medical conservative treatme nt was remakable high.

• Transactions of Materials Processing
• /
• v.31 no.5
• /
• pp.253-260
• /
• 2022

In this study, the microstructural characteristics of a high-speed-extruded Mg-5Bi-3Al (BA53) alloy and its tensile, compressive, and high-cycle fatigue properties are investigated. The BA53 alloy is successfully extruded at a die-exit speed of 16.6 m/min without any hot cracking using a large-scale extruder for mass production. The homogenized BA53 billet has a large grain size of ~900 ㎛ and it contains fine and coarse Mg₃Bi₂ particles. The extruded BA53 alloy has a fully recrystallized microstructure with an average grain size of 33.8 ㎛ owing to the occurrence of complete dynamic recrystallization during high-speed extrusion. In addition, the extruded BA53 alloy contains numerous fine lath-type Mg₃Bi₂ particles, which are formed through static precipitation during air cooling after exiting the extrusion die. The extruded BA53 alloy has a high tensile yield strength of 175.1 MPa and ultimate tensile strength of 244.4 MPa, which are mainly attributed to the relative fine grain size and numerous fine particles. The compressive yield strength (93.4 MPa) of the extruded BA53 alloy is lower than its tensile yield strength, resulting in a tension-compression yield asymmetry of 0.53. High-cycle fatigue test results reveal that the extruded BA53 alloy has a fatigue strength of 110 MPa and fatigue cracks initiate at the surface of fatigue test specimens, indicating that the Mg₃Bi₂ particles do not act as fatigue crack initiation sites. Furthermore, the extruded BA53 alloy exhibits a higher fatigue ratio of 0.45 than other commercial extruded Mg-Al-Zn-based alloys.

• Transactions of Materials Processing
• /
• v.24 no.5
• /
• pp.317-322
• /
• 2015

A process for the concurrent welding and extruding of pipe was designed for continuous production of fin tubes. Unlike a conventional pipe extrusion, the new process is able to extrude a pipe continuously without limit of length by using spring type wire material. The current paper provides the basic research for welding during the extrusion using a spring type wire material. The object of the current study is to investigate the possibility that the spring type wire material could be extrude into a welded pipe. The appropriate extrusion ratio was selected through investigation of loads using computer simulations. As a result, experiments showed that pipe could be welded and simultaneously extruded with spring type wire material of aluminum. The tensile strength of the welded and extruded aluminum pipe can reach 80% of tensile strength of original aluminum feedstock.

• 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.

• Journal of radiological science and technology
• /
• v.23 no.2
• /
• pp.21-26
• /
• 2000

The classification of herniated intervertebral cervical disc types are clinically important, as treatment methods would be slightly different according to the specific type of the herniated disc. 423 patients who suffered from herniated intervertebral cervical discs were tested with Magnetic Resonance Imaging (MRI), to distinguish the type of the herniated discs. The followings are the results ; 1) The age of the patients tested ranged from 16 to 75 years old and the mean age of the patients was 41.4 years of age. 2) There were twice as many male patients, with a ratio of 288 : 135 men to women. 3) 101 patients suffered from single herniated discs, while 322 patients suffered from multi-herniated discs. 4) Of single herniated disc injuries, 52 patients had protruded discs (52%), while 25 patients had extruded discs (25%). 21 Patients (21%) had herniated intervertebral discs between $C_4{\sim}C_5$, and 51 patients (50%), and had the same injury between $C_5$ and $C_6$. 5) Of multi-herniated disc injuries, 140 patients had protruded discs(44%). while 45 patients had extruded discs (14%). 54 patients had both protruded and extruded discs(17%). 36 patients(11%), herniated discs $C_3{\sim}C_6$ ; 69 patients (21%), herniated discs $C_3{\sim}C_7$ ; 47 patients(15%) herniated discs $C_4{\sim}C_6$ and 67 patients(20%) herniated discs $C_5{\sim}C_7$.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.10a
• /
• pp.132-135
• /
• 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 Al6061 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 $250^{\circ}C$. 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 $250^{\circ}C$. 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.

• The Journal of Korea CHUNA Manual Medicine
• /
• v.3 no.1
• /
• pp.43-53
• /
• 2002

Objectives : The object is to study a clinical effect regarding the conservative treatment of the patient who was diagnosed as the herniated Intervertebral lumbar disc(HIVD) and hospitalized in the oriental medical hospital and clinical study about the type of the HIVD. Methods. The clinical studies were done on 65 cases (hospitalized in Dept. of Oriental Rehabilitation Medicine, jaseng on oriental medical hospital from June 2001 to May 2002) who complained of low back pain or sciatica and diagnosed as HIVD on CT(computerized tomography) or MRI(magnetic resonance imaging). They were given both oriental conservative treatment and exercise during the hospitalization period. We investigated and observed 20 items about sex, age, weight, height, occupation, smoking. obesity, duration of disease, clinical symptom and treatment duration in basis of medical recording which was drawn up at patient hospitalization. We classified HIVD with 4 types(Bulging. Protruded. Extruded, Sequestered) and decided the case which simultaneously had 2 overs with Mixed type. The treatment evaluation standard was classified with 4 branches; Excellent. Good, Fair and Poor. Results & Conclusions : The treatment result of over 'fair' is bulging type 85%, protruded type 92.7%, extruded type 100% and the mixed type was 85.1 %. The effect was good in order of bulging, mixed, protruded and extruded type. It appeared most plentifully with 30 people in L4-5 and L5-S 1 disc herniation type.

• Journal of Aquaculture
• /
• v.10 no.2
• /
• pp.163-169
• /
• 1997

An experiment was conducted to determine the effects of feeding extruded-floating (EP), slow-sinking (SP), fast-sinking (FP) or moist (MP) prepared with two different levels of fish meal, respectively, on the growth, feed efficiency and body composition in Korean rockfish (Sebastes schlegeli). Triplicate groups of the 50 fish averaging 75g were fed each of the following diets : high fish meal (72% in diet)-EP, low fish meal SP, low fish meal-FP and low fish meal-MP for 15 weeks. Dietary fish meal levels or pellet types did not influence weight gain, feed efficiency and bo요 composition of the fish (P>0.05). Findings showed that each of EP, SP or FP can by used as a practical type of diet for Koran rockfish.