• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.1-8
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• 2001

Paper consists of fiber network and paper properties were highly affected by fiber characteristics. Many researchers have tried to relate fiber and paper properties. Softwood and hardwood fiber's are quite different in their properties. Generally, softwood fiber's are longer and more flexible than hardwood fibers. At present, many paper mills make mixed paper with softwood and hardwood fibers except for special grade. During fracture some fiber's are broken and others are pulled out. In this paper, the number of broken and pulled out fiber's during fracture is analyzed depending on the mixing ratio of softwood and hardwood fiber's. Fiber length, curl, kink, coarseness, WRV and formation index were measured. Double-edged strength samples were prepared to observe the number of broken and pulled out fiber's. Mixed paper strength was decreased with increasing hardwood fibers ratio. During fracture, softwood fiber's were more likely broken and hardwood fibers were more likely pulled out. The strength of paper which consists of softwood fibers was determined by fiber's broken strength and that of hardwood fibers by fiber's debonding strength. Paper strength was changed depending on the fiber's bonding capability. If the fiber is longer and more flexible, the fiber network becomes stronger and stiffer.

• Journal of the Korean Arthroscopy Society
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• v.2 no.1
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• pp.85-92
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• 1998

Various methods for fixation of graft have been widely used for reconstruction of anterior cruciate ligament. However, the biomechanical strength of each fixation techniques are not fully understood. The purpose of this study is to compare the pull out strength of different fixation techniques which is probably the most important factor for the success at the initial stage of healing. Biomechanical test was carried out to measure and compare the pull out tensile strength of five different fixation techniques in 35 pig(Yorkshire) knees. ANOVA and Duncan multiple comparison test was applied for statistical analysis. In the two fixation techniques with bone patellar tendon bone graft, the mean maximum tensile strength was $1333.4{\pm}148.5N$ with titanium interference screw, while it was $1310.1{\pm}168.9N$ with biodegradable interference screw. The failure mode were pulled out of bone plugs from the femoral tunnel in majority cases. In the fixations with hamstring tendon, the mean maximum tensile strength were $1405.9{\pm}135.1N$ with SemiFix screw, $820.3{\pm}104.5N$ with biodegradable interference screw, and $682.1{\pm}54.2N$ with Endobutton. The mode of failure was variable in each technique. The tendon was pulled out from the tunnel in biodegradable interference screw fixation, the screw was bent in the SemiFix system, and the polyester tape were ruptured or the buttons were pulled into tunnel in Endobutton fixation. The mean maximum tensile strength of two interference screws with bone patellar tendon bone was statistically comparable to that of SemiFix with hamstring tendon. However biodegradable interference screw and Endobutton with hamstring tendon showed weaker maximum tensile strength than above three fixation techniques (P<0.05).

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.37-42
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• 2003

Physical properties of paper can be explained in terms of the changes in fiber's morphological properties. As the paper machine speed increases, the basis weight decreases and the mixing ratio of inferior recycled fibers increases, paper break becomes important than ever before. One of the objectives of this study is to analyze paper's physical, mechanical and fracture mechanical properties depending on softwood(SW) and hardwood(HW) mixing ratios and recycling. Fibers were refined by Valley beater to 450 mL CSF. Handsheets of 30 g/$\textrm{m}^2$ were prepared at different mixing ratios. Fracture toughness was measured as the amount of energy applied to cracked sample before total failure. Fracture toughness showed different trend to other strength properties. At the mixing ratio of SW 80: HW 20, papers showed the maximum fracture toughness. At this mixing ratio, flexible softwood fibers were mostly broken and stiff hardwood fibers were mostly pulled out.

• Journal of Korean Orthopaedic Sports Medicine
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• v.1 no.2
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• pp.118-123
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• 2002

Purpose: To report modified technique of inside-out suture in repair of tear of postero medial corner of medial meniscus. Operative technique: Arthroscope is placed through anterolateral portal. Suture hook is delivered through anteromedial portal. By rotating the suture hook, it penetrates the inner portion of the torn meniscus from femoral surface to tibial surface of the meniscus for vertically oriented suture. A PDS suture is delivered through the lumen of suture hook, and the suture hook is withdrawn. The both ends of the suture are retrieved through anteromedial portal by a retriever, either grasper or crochet hook.A Zone-specific cannula is positioned below the inferior surface of the meniscus through anterolateral portal. The Looped Needle designed by the authors is delivered through the lumen of the Zone-specific cannula. The suture end of the tibial surface is placed in the loop of the Looped Needle and pulled out to the surface of posteromedial joint line. The suture end of the femoral surface is pulled out in same manner. A transverse skin incision of 1cm size is made adjacent to pulled out suture and the suture is tied. Discussion: Even though modified inside-out suture technique requires longer operation time than conventional inside-out technique, it provides vertically oriented suture and good tissue coaptation. The authors recommend this modified inside-out suture technique to be good alternative in repairing tear of the posteromedial corner of medial meniscus.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.289-289
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• 1999

• 전기의세계
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• v.21 no.2
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• pp.20-24
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• 1972

The transient stability of the synchronous motor is generally improved by damper winding or flywheel. However the synchronous motor at full load will be pulled out from normal operation state when the period of power failure exceeds approximately ten cycle per second. This paper studies the method of improving the stability of synchronous motor by equipping the phase slipping switch between the motor and power source. This paper shows the motor does not pull out, which results from the decrease of power angle to about 30 electrical degrees by means of the switch even when the relatively long period of power failure brings the power angle to some 150 electrical degrees.

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.147-155
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• 1998

Acupuncture and Radix Astragali aqua-acupuncture stimuli have long been used to cure human diseases. However, it still remains to be unkown on its action mechanism, physiolosical and biochemical aspects. Thus, many attempts were made to show the scientific background covering the above mentioned mechanisms. Most recent studies show that these tests improve blood circulatory system and increase leucocyte counts. In this study, we have applied the acupuncture stimuli to mouse Sinsu(BL-23), which is a stimulative point of oriental medicine, to see if cytokine such as IL-6 can be detected. Mice were treated with lipopolysaccharide(LPS) for inflammation induction, and then reverse transcriptase-polymerase chain reaction (RT-PCR) using each primer set was performed to trace the amounts of mRNA. The results are summarized as follows ; 1. IL-6 was not temporarily expressed in normal mice 15 min after the acupuncture was pulled out. But, it started to show a feeble expression at 30 min after the removal of acupuncture and it started to reduce at 1h. after the acupuncture was pulled out 2. IL-6 was specifically expressed in LPS-treated mouse 30 min after the acupuncture was pulled out. The transcriptional expressions of LPS-treated mice were more effective than those of normal mice at 30 min after the removal of acupuncture 3. IL-6 was not temporarily expressed in normal mice 15 min after Radix Astragali aqua-acupuncture. But it expressed most highly at 30 min, and the transcriptional expressions of IL-6 was continued to 3 h. 4. IL-6 was not expressed in all the time after Radix Astragali aqua-acupuncture in LPS-treated mice. Therefore, a follow-up of cytokine IL-6 can be used not only a basis of the effect of acupuncture and Radix Astragali aqua-acupuncture but a diagnosis giude through the immunological action of thats. And, it is suggested that cytokine's expression by Acupuncture and Radix Astragali aqua-acupuncture stimulation should be continuously elucidated.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.40-46
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• 2015

Many construction equipment or supporting structure should be installed in a field without appropriate anchorage to cause a collapse of those. Anchor length, anchor diameter, hooked or non hooked will be made and tested in the study. This one will be analyzed and compared with the previous study in order to find out some difference, strength by strength, based on this study. Embedded re-bar and the resistant capacity against pulled out force of re bar have been tested and analyzed by concrete design strength and rebar diameter in the study. 21Mpa and 24MPa compressive strength which are used in construction practice have been applied as variables. Those rebars are composed of D13, D16. D22 which are mostly used at construction sites. The followings are summarized as conclusions.1) ductility is not increased as rebar diameter becomes larger under the condition of non-hooked anchorage.2) those are two times of displacement difference between small diameter of rebar and large one with hooked anchorage of rebar while being 1/10 times difference with non-hooked condition but, only 10% difference of maximum load are shown, not conspicuously between hooked and non-hooked condition.3) displacement related to ductility can be three(3) times decreased if only concrete compressive strength and rebar diameter become larger with heavy support weight.

• Journal of Korea Water Resources Association
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• v.30 no.3
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• pp.211-223
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• 1997

This study was focused on the investigation of the distribution of trees which is an important factor for the improvement of the river environment, and the experimental examination of resistant force of trees to the external forces. The investigation of plant distribution performed in 11 major rivers in Korea showed that the willow family grows spontaneously over the whole country. The field experiments on the resistant force of trees were carried out on the 78 trees of 8 species in 3 different sites to estimate whether pulled out trees damage downstream hydraulic structure. The experiments were performed by the method that a backhoe drew trees and the forces were measured when the trees were overturned and pulled out. The analysis of the experimental results showed that there is a linear correlation between the resistant force and DHB (diameter at breast height).

• KCI Concrete Journal
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• v.12 no.1
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• pp.91-99
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• 2000

A new type of retrof=t anchor bolt that uses deformed reinforcing bars and a commercial adhesive was developed and then an experimental study was carried out to determine the behavior of the anchors in direct shear. The steel-to-concl몫ete interface was tested. Plain concrete slabs with about 20-MPa compressive strength were used for 23 direct shear tests performed Test variables were anchor diameters (D16, D22. and D29) and edge effect. Three different shear tests were completed: simple shear, edge shear where anchors were pulled against the concrete core, and edge shear where anchors were pushed against the concrete cover In the simple and the edge shear tests where the anchors were pulled against the core, the theoretical dowel strength determined by (equation omitted) was achieved but with relatively large displacements. The shear resistances increased with the increasing displacements. In the edge shear test where the anchors were pushrd against the cover, the peak shear strengths signif=cantly lower than the theoretical dowel strength were determined due to cracks developed in concrete when the edge distance was 80 mm. The peak strengths were about 50% of the dowel strength for Dl6 bar. and about 25% or less of the dowel strength for D22 and D29 bars. Test results revealed that the edge shear where the anchor was pushed against the cover controled.