• Title/Summary/Keyword: Fiber Type

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Improvement of CF/ABS Composite Properties by Anodic Oxidation of Pitch based C-type Carbon Fiber

  • Yang, Xiao Ping;Wang, Cheng Zhong;Yu, Yun Hua;Ryu, Seung-Kon
    • Carbon letters
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    • v.3 no.2
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    • pp.80-84
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    • 2002
  • The surface treatment of C-type isotropic pitch-based carbon fiber was carried out by anodic oxidation in 5 wt% $NH_4NO_3$ electrolyte. The changes of fiber surface and carbon fiber/ABS resin composites were characterized by SEM, XPS and mechanical properties test. The oxygen functional groups on the surface, such as hydroxyl (-C-OH), carboxyl (-COOH) groups etc., increased after oxidation. Tensile strength, flexural strength and modulus of carbon fiber/ABS composites were also enhanced. However, the impact strength decreased with the improvement of the surface adhesion between CF and matrix.

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Development of Ultrasonic Active Fiber Sensor for Structural Health Monitoring (구조물 안전진단을 위한 초음파능동형광섬유 센서의 개발)

  • Lim, Seung-Hyun;Lee, Jung-Ryul;Oh, Il-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.747-752
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    • 2008
  • Fiber-guided sensor system using a generator and a receiver can detect the amplitude of load or pressure. However, this type of sensor can show some difficulties in detecting the location of damages and pressure loadings. To overcome this weakness of this type, the ultrasonic active fiber sensor, which has an integrated ultrasonic generator and sensing part, was developed in this study. By using this sensor system, the location of mechanical loads can be exactly detected. Moreover, the ultrasonic active fiber sensor is more cost-effective than an ultrasonic fiber sensor using two piezoelectric transducers which are used as a generator and a receiver, respectively. Two applications of the ultrasonic active fiber sensor are demonstrated: cure monitoring of lead and measurement of liquid level. Present results showed that the active fiber sensor can be applied for various environmental sensing.

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Effects of Morphological Characteristics of Muscle Fibers on Porcine Growth Performance and Pork Quality

  • Lee, Sang Hoon;Kim, Jun-Mo;Ryu, Youn Chul;Ko, Kwang Suk
    • Food Science of Animal Resources
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    • v.36 no.5
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    • pp.583-593
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    • 2016
  • The aim of this study was to investigate the effects of morphological characteristics of porcine muscle fibers on growth performance, muscle fiber characteristics, and pork quality taken from the longissimus dorsi muscle. A total of 239 crossbred pigs (164 castrated males and 75 females) were used in this study. Experimental pigs were categorized by the total number of muscle fiber (TNF: High and Low) and cross sectional area of muscle fiber (CSAF: Large, Middle, and Small). Their combinations were classified into six groups (High-Large, HL; High-Middle, HM; High-Small, HS; Low-Large, LL; Low-Middle, LM; Low-Small, LS). The TNF and CSAF were significantly (p<0.05) correlated with growth rate and carcass productivity, while the only of the type I number had no meaningful relationships excluding the correlation with loin area (p<0.001). The proportion of type I area was positively correlated with pH45 min while the proportion of type IIB area was negatively correlated with pH45 min and pH24 h (p<0.05). Drip loss and protein denaturation had strong relationships with the proportion of type IIB number or area. The HL group exhibited the greatest growth performance. In addition, the HL group had significantly greater values in protein solubility than the other groups. In conclusion, this study suggest that high TNF combined to large CSAF improve the ultimate lean meat productivity and assure normal meat quality simultaneously with increased both proportion of number and area of type I, type IIA muscle fibers and lowered proportion of number and area of type IIB.

Seismic Performance of Piloti-Type Structures with Columns Strengthened with Aramid Fiber Sheets (아라미드 섬유시트로 기둥 보강된 필로티 구조물의 내진성능 평가)

  • Keun-Hyeok Yang;Ju-Hyun Mun;Chae-Rim Im;Kwang-Geun Rho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.201-210
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    • 2023
  • This study is to evaluate the ductility strengthening effect of aramid fiber sheets on piloti-type structures. Two piloti-type structure specimens were prepared and tested under statical cyclic lateral loads. The ductility strengthening effect was validated from the analysis of lateral load-displacement relationship, displacement ductility ratio, work damage index and torsion behavior. Test results showed that the post-peak behavior of piloti-type structures with columns strengthened with aramid fiber sheets tended to be ductile resulting from preventing shear failure and minimizing torsion due to the effective lateral confinement of column concrete by aramid fiber sheet. Consequently, the displacement ductility ratio and work damage index of piloti-type structures with columns with strengthened with aramid fiber sheets were 4.63 and 42.81 times higher than those of non strengthened piloti-type structures.

A Study on the Hemisphere-Type Compression Molding for Continous Fiber-Reinforced Polymeric Composites (연속섬유강화 플라스틱 복합재료의 반구형 압축성형성에 관한 연구)

  • 임용진;오영준;김이곤
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 1999.11a
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    • pp.149-153
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    • 1999
  • During a hemisphere-type compression molding, the wrinkles are caused by complex stress condition. It is very important to clarify the degree of wrinkles in order to have good products. In this paper, the effects of numbers of needling and initial area on the degree of wrinkles are studied. the degree of wrinkle is expressed as nonhomogeneity.

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Effect of Endurance Exercise Prior to Occurrence of Muscle Atrophy on the Mass, Myofibrillar Protein Content and Fiber Crossectional Area of Atrophied Hindlimb Muscles of Rats (근위축 발생전의 지구력 운동이 쥐의 위축뒷다리근의 질량, 근원섬유 단백질 함량 및 근섬유 단면적에 미치는 영향)

  • 최명애
    • Journal of Korean Academy of Nursing
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    • v.27 no.1
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    • pp.96-108
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    • 1997
  • The purpose of this study was to determine the effect of endurance training prior to occurrence of muscle atrophy on the mass, myofibrillar protein content and fiber crossectional area of atrophied hindlimb muscles of rats. Adult female Wistar rats were trained prior to occurrence of muscle atrophy induced by hindlimb suspension. Training began on the 1st day for 10min /day at 15m /min on a 0% grade, training exercise increased daily in time and intensity so that by the 4th week rats were running 60min /day, at 34m /min on a i3.5% grade. Wet weight and relative weight of soleus, plantaris and gastrocnemius muscle decreased significantly after seven days of hindlimb suspension. Wet weight and relative weight of soleus tended to increase and that of plantaris and gastrocnemius tended to decrease in the exercise group as compared to the control group. Myofibrillar protein content of soleus and gastrocnemius tended to increase and that of plantaris tended to decrease in the endurance trained group as compared to the control group. Fiber crossectional area of Type I, II fiber in soleus and plantaris muscle tended to increase in the exercise group as compared to the control group. Wet weight and relative weight of soleus. plantaris and gastrocnemius decreased significantly, myofibrillar protein content of soleus, plantaris and gastrocnemius increased in hindlimb suspended rats following endurance training as compared to the control group. There was no change in fiber type percentage and crossectional area of type I and II fiber in soleus muscle and that of type I and IIfiber in plantaris muscle decreased in the hindlimb suspended rats following endurance training as compared to the control group. Wet weight and relative weight of soleus and plantaris tended to increase, that of gastrocnemius increased significantly, myofibrillar protein content of soleus and plantaris muscle increased significantly and that of gastrocnemius tended to increase in the hindlimb suspended rats following endurance training as compared to sedentary rats following endurance training. Crossectional area of type I fiber of soleus muscle tended to increase. that of type I fiber of plantaris muscle increased significantly and that of type II fiber tended to increase in hindlimb suspended rats following endurance training as compared to sedentary rats following endurance training. The results suggest that endurance training prior to occurrence of muscle atrophy can attenuate the decrease of mass, myofibrillar protein content and fiber crossectional area induced by hindlimb suspension.

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A Study on the Processing of Long Fiber-Reinforced Composite Materials for Thermoforming On the Correlation Coefficient between Separation and Orientation (Thermoforming용 長纖維强化 複合材料의 成形工程에 관한 硏究 分離$\cdot$配向의 相關계수)

  • 이동기;김정락;김상필;이우일;김이곤
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1106-1114
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    • 1993
  • A composite material is composed of a reinforcement and a matrix, which determine mechanical characteristics of the molded part. There is no doubt that the properties of a composite material depend not only on the characteristics of the matrix but also on the structure of glass fiber mat and a fiber type of reinforcement. Therefore it is very important to study the composites of reinforcement and the matrix, and to control the fiber type in the process of molding of composite materials. In this study, the specimen was made of a glass fiber mat of 6-7mm thickness by scattering it in the air after cutting the glass fiber mat with needle punching makes change according to the type of needle and the number of times of stretching. First the sheet was made by means of a hot-press after accumulating a matrix and a glass fiber according to each mat structure of glass fiber. It was heated the manufactured sheet with the dry oven and molded it a secondary high temperature compression by a 30 ton oilhydraulic press. A definition of a correlation coefficient is showed up during this period and find it out with the relation of the fiber-matrix separation and the fiber orientation. We studied effects of the glass fiber mat structures on the correlation coefficient.

Alkaline Weight Reduction and Physical Properties of 0.01d Polyester Ultramicro Fiber (0.01d 폴리에스테르 초극세 섬유의 알칼리 감량과 물성)

  • Park, Jae-Min;Jeong, Dong-Seok;Rho, Hwan-Kown;Lee, Mun-Cheul
    • Textile Coloration and Finishing
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    • v.18 no.4
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    • pp.37-42
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    • 2006
  • Two kinds of sea-island type polyester ultramicro fibers (fiber fineness : 0.01 and 0.05 denier) were treated with NaOH varying time and concentration. Surface morphology of the treated fibers with alkaline weight loss was observed by SEM. The treated effects were investigated by measuring density, melting temperature, and X-ray diffraction patterns. The surface morphology of the polyester ultramicro fiber was changed by NaOH concentration. Weight loss of 0.01d fiber was much larger than that of 0.05d fiber. Density and crystallinity were increased with weight loss of fiber. After the weight loss had finished, the density and crystallinity were decreased because of attack of island partition of the fiber. A melting temperature$(T_m)$ is $250^{circ}$ at untreated fiber on the whole and in 0.05d fiber the $(T_m)$ is $252^{circ}$ at untreated. In 0.01d fiber the $(T_m)$ was increased with weight loss of fiber.

Shear Failure Behaviour of Reinforced Concrete Deep Beam Strengthened by Carbon Fiber Sheets (탄소섬유시트로 보강된 춤이 큰 철근콘크리트 보의 전단파괴거동(剪斷破壞擧動))

  • Cho, Su-Je;Son, Sung-Hun;Park, Sung-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.4
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    • pp.145-153
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    • 1999
  • The major objective of this study is to investigate experimentally the shear strengthening effect of carbon fiber sheets upon reinforced concrete deep beam and shear failure behavior variation of reinforced concrete deep beam strengthened by carbon fiber sheets. Tests are carried out with 6 specimens were shear failure at first loading tests, and with parameters including the types of shear strengthening of carbon fiber sheets (I type, S type, U type), and plies of sheets (2 ply and 1 ply). From the results of test, analyzed load-deflection of midspan, strain variation of main bars and transverse reinforcement, maximum load capacity of strengthened specimens, and compared with the previous test results.

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Evaluation on Spalling Properties of Polypropylene Fiber reinforced Concrete by Restrained Ring-type Test (구속 링형 시험에 의한 PP섬유 혼입 콘크리트의 폭렬 특성 평가)

  • Han, Cherl-Hwan;Kim, Gyu-Yong;Yoon, Min-Ho;Hwang, Eui-Chul;Baek, Jae-Uk;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.124-125
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    • 2017
  • In this study, the spalling properties of Polypropylene reinforced concrete were evaluated by the restrained ring-type test. As a result of the experiment with the fiber mixture ratio set at 0, 0.15 vol.%, The PP fiber reinforced specimen showed lower water vapor pressure as a whole than the Plain specimen, but the restraint stress was measured to be higher. This is thought to be due to the fact that higher thermal stresses were applied in the PP fiber reinforced test specimen.

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