• Title/Summary/Keyword: 절단섬유

Search Result 124, Processing Time 0.028 seconds

Investigating the Partial Substitution of Chicken Feather for Wood Fiber in the Production of Wood-based Fiberboard (목질 섬유판 제조에 있어 도계부산물인 닭털의 목섬유 부분적 대체화 탐색)

  • Yang, In;Park, Dae-Hak;Choi, Won-Sil;Oh, Sei Chang;Ahn, Dong-uk;Han, Gyu-Seong;Oh, Seung Won
    • Korean Chemical Engineering Research
    • /
    • v.56 no.4
    • /
    • pp.577-584
    • /
    • 2018
  • This study was conducted to investigate the potential of chicken feather (CF), which is a by-product in poultry industry, as a partial substitute of wood fiber in the production of wood-based fiberboard. Keratin-type protein constituted the majority of CF, and its appearance did not differ from that of wood fiber. When the formaldehyde (HCHO) adsorptivities of CF compared by its pretreatment type, feather meal (FM), which was pretreated CF with high temperature and pressure and then grounded, showed the highest HCHO adsorptivity. In addition, there was no difference between the adsorbed HCHO amounts, which was measured by dinitrophenylhydrazine method, of scissors-chopped CF and CF beated with an electrical blender. Mechanical properties and HCHO emission of medium-density fiberboards (MDF), which were fabricated with wood fiber and 5 wt% CF, beated CF or FM based on the oven-dried weight of wood fiber, were not influenced by the pretreatment type of CF. However, when the values compared with those of MDF made with just wood fiber, thickness swelling and HCHO emission of the MDF were improved greatly with the addition of CF, beated CF or FM. Based on the results, it might be possible to produce MDF with improved dimensional stability and low HCHO emission if CF, beated CF or FM is added partially as a substitute of wood fiber in the manufacturing process of MDF produced with the conventional urea-formaldehyde resin of $E_1$ grade. However, the use of CF or FM in the production of MDF has a low economic feasibility at the current situation due to the securing difficulty and high cost of CF. In order to enhance the economic feasibility, it requires to use CF produced at small to medium-sized chicken meat plants. More importantly, it is considered that the technology developed from this research has a great potential to make provision for the prohibition of animal-based feed and to dispose environmentally avian influenza-infected poultry.

Changes in Physicochemical Characteristics of Green Barley according to Days after Heading (출수 후 일수에 따른 쌀보리 종실의 이화학적 특성 변화)

  • Ju, Jung-Il;Lee, Ka-Soon;Min, Hee-Il;Lee, Byung-Jin;Kwon, Byung-Gu;Gu, Ja-Hyeong;Oh, Man-Jin
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.52 no.1
    • /
    • pp.36-44
    • /
    • 2007
  • In order to evaluate the utilization of immature green barley kernels as food processing material, these experiments were carried out to analyze free sugars, free amino acids, mineral contents and color of two naked barley varieties according to their heading dates. Contents such as moisture, protein, fat, ash, and free sugars were gradually decreased according to the days after heading of the nonwaxy naked barley 'Saessalbori' and waxy naked barley 'Hinchalssalbori', while crude fiber and starch were gradually increased. Contents like maltose and maltotriose in immature green kernels were high, but free amino acids showed a tendency to decrease, among which the alanine content was the highest. As barley matured, beta-glucan content, redness and yellowness increased, while lightness decreased. Considering chemical composition and color, the immature green cereals were produced through blanching the spikes harvested before the yellow ripe stage around $26{\sim}27$ days after heading. The optimum duration of harvest was very limited to produce green whole grains. The harvested green barley cereals is able to eat raw barley or cook it as food processing material.

Physical and Mechanical Properties of The Lignin-based Carbon Nanofiber-reinforced Epoxy Composite (에폭시 강화 리그닌 기반 나노탄소섬유 복합재료의 특성)

  • Youe, Won-Jae;Lee, Soo-Min;Lee, Sung-Suk;Kim, Yong Sik
    • Journal of the Korean Wood Science and Technology
    • /
    • v.44 no.3
    • /
    • pp.406-414
    • /
    • 2016
  • The lignin-based carbon nanofiber reinforced epoxy composite has been prepared by immersing carbon nanofiber mat in epoxy resin solution in order to evaluate the physical and mechanical properties. The thermal and mechanical properties of the carbon nanofiber reinforced epoxy composite were analyzed using thermogravimetric analysis (TGA), differential scanning calorimeter (DSC) and tensile tester. It was found that the thermal properties of the carbon nanofiber reinforced epoxy composite improved, with its glass-transition temperature ($T_g$) increased from $90.7^{\circ}C$ ($T_g$ of epoxy resin itself) to $106.9^{\circ}C$. The tensile strengths of carbon nanofiber mats made from both lignin-g-PAN copolymer and PAN were 7.2 MPa and 9.4 MPa, respectively. The resulting tensile strength of lignin-based carbon nanofiber reinforced epoxy composite became 43.0 MPa, the six times higher than that of lignin-based carbon nanofiber mats. The carbon nanofibers were pulled out after the tensile test of the carbon nanofiber reinforced epoxy composite due to high tensile strength (478.8 MPa) of an individual carbon nanofiber itself as well as low interfacial adhesion between fibers and matrices, confirmed by the SEM analysis.

On the Composites of poly(ethylene 2,6-naphthalate) with a Thermotropic Block Copolyester(I) (열방성 블록 코폴리에스테르와 poly(ethylene 2,6-naphthalate)의 복합재료 연구(I))

  • Choi, Jae Kon
    • Applied Chemistry for Engineering
    • /
    • v.8 no.3
    • /
    • pp.454-462
    • /
    • 1997
  • Thermotropic block copolyester(TLCP-b-PBN) based on poly(tetramethylene 2,6-(naphthaloyldioxy)dibenzoates)(TLCP) and poly(butylene 2,6-naphthalate)(PBN) was synthesized by solution polycondensation and melt-blended with poly(ethylene 2,6-naphthalate)(PEN) for in-situ composites. The TLCP domains showed nematic behavior in melt. The composition of block copolymer was determined from $^1H-NMR$ spectroscopy. The DSC thermogram of block copolymer revealed the presence of two major melting transitions, corresponding to the separete melting of PBN and TLCP domains. The glass transition temperature(Tg) of the PEN in the blends decreased with increasing the content of TLCP-b-PBN and the TLCP-b-PBN acted as a nucleating agent for the matrix polymers. In the 20% TLCP-b-PBN blend, well oriented TLCP fibriles were observed at temperature above the melting point of the PEN by optical microscopy. By scanning electron micrographs of cryogenically fractured surfaces of extruded blends, the TLCp domains were found to be finely and uniformely dispersed in 0.15 to $0.2{\mu}m$ size. Interfacial adhesion between the TLCP and matrix polymer was seemed to be good. Under certain condition TLCP formed a fiver structure in the PEN matrix, with thin oriented TLCP fibril in the skin region and spherical TLCP domains in the core.

  • PDF

Characteristics of Processed Food for Improvement Utilization of Sweet Persimmon (단감의 이용성 증진을 위한 특성 검토)

  • Choi, Yoon-Hee;Kim, Eun-Mi;Cho, Yong-Sik;Park, Shin-Young;Yang, Jeong-Min
    • Proceedings of the Korean Society of Community Living Science Conference
    • /
    • 2009.09a
    • /
    • pp.88-88
    • /
    • 2009
  • 단감은 우리나라가 세계에서 가장 많은 양을 생산하는 대표 과일로 과잉생산과 수확기에 일시적인 홍수출하로 인한 가격이 하락하고, 기상이변에 의한 비상품 과일의 생산이 많아지나 전량 폐기되고 있으며, 유통 및 저장 중에 연화현상과 생리적장애로 품질이 저하되어 경제적 손실이 발생되므로 안정적 생산과 소비를 위하여 다양한 형태의 식품개발이 절실히 요구된다. 국내 감 생산량은 352,822톤이며 이 중 떫은감은 146,233톤(41.45%), 단감은 206,589톤(58.55%)으로 단감 생산량이 떫은감에 비하여 많으며 국내 단감 생산지는 진영, 순천, 문산, 담양, 장성 등 집단화 되어 있고, 원료확보가 유리하나 저장은 수확기인 10월 중순, PE필름 봉지에 넣고 밀봉하여 박스 등에 넣어 $0{\sim}1^{\circ}C$의 저온저장고에 이듬해 4월 중순까지 6개월 정도 저장 가능하나 저장비용이 많이 들고, 4월 이후에는 생리적 장해로 보관이 어렵다. 단감은 다른 과일에 비하여 높은 감미와 비타민 A, 비타민 B1, 비타민 C, 식이섬유 및 리코핀 성분이 다량 함유되어 있고, 노화와 암 발생을 억제하는 폴리페놀물질이 풍부하여 건강 기능성 과일로 알려져 있다. 본 연구에서는 시중에서 구입한 단감의 저온저장 중 감모율 및 이용성 구명을 위하여 관련특성을 검토하였다. 단감을 3월에 구입하여 $5^{\circ}C$에 저온저장하여 보관기간별 감모율을 조사하였고, 단감의 전 처리 후 당도, pH, 색도, 수분함량 등을 조사하였다. 3월에 시중에서 구입하여 PE필름에 봉한 채 종이박스 넣어 $5^{\circ}C{\pm}2$ 저온저장고에 저장하여 1개월 후에 조사한 결과 정상과가 75.47%, 25%미만 장해과가 14.37%, 50%이상 장해과가 10.16% 이었고, 2개월 후는 정상과가 41.52%, 25%미만 장해과가 42.88%, 50%이상 장해과가 15.61%이었다. 단감을 꼭지제거, 박피, 제핵 후 절단하여 파쇄 후의 당도는 14.8 $^{\circ}Brix$, pH는 6.0, 수분은 56.7%, 색도 L값은 39.8, a값이 12.6, b값이 22.7이었다. 파쇄한 단감을 $-20^{\circ}C$에 1차 냉동하여 해동 후 당도는 냉동 전 $14.8^{\circ}Brix$에서 $14.2^{\circ}Brix$로, 2차 냉동 해동 후는 $12.6^{\circ}Brix$로 감소하였으며, 색도 L값과 a값 및 b값은 냉동 전에 비하여 감소하였고, 수분함량은 냉동 전 64.4%, 1차 냉동 해동 후에 82.78%, 2차 냉동 해동 후에는 84.09%로 증가하였다.

  • PDF

Generation of antibodies against N-terminus fragment of AgI/II protein from Streptococcus mutans GS-5 (연쇄상구균(Streptococcus mutans GS-5)의 항원단백질 AgI/II의 N-terminus절편에 대한 항체형성)

  • Han, Ji-Hye;Baik, Byeong-Ju;Yang, Yeon-Mi;Park, Jeong-Yeol;Kim, Jae-Gon
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.33 no.3
    • /
    • pp.401-410
    • /
    • 2006
  • Dental caries results from localized demineralization of tooth enamel by acids of bacterial origin produced from the fermentation of dietary sugars. A group of related oral bacteria, collectively known as mutans streptococci, are implicated as the primary etiological agents of human caries. Within this group, Streptococcus mutans has been known as a causative agent for dental caries. As well as acid production yielding the demineralization of tooth enamel, adherence and colonization of S. mutans to the teeth are also important for their virulence Cell-surface fibrillar proteins, which mediate adherence to the salivary pellicle are virulence components of mutans streptococci, and primary candidates for a human caries vaccine. Here we report that the AgI/II gene from S. mutans GS-5 were cloned by PCR amplification of the bacterial chromosomal DNA and the integrity of cloned genes were confirmed by nucleotide sequencing. Sequence analyses showed the sequence alignment of 280 nucleotides between the cloned AgI/II and the reported sequence of S. mutans GS-5 showed the perfect match The cloned genes which signal nucleotide was truncated, were transferred into bacterial expression vector and the recombinant proteins were purified as His-tag fusion proteins In order to generate polyclonal antibodies against the recombinant proteins, AgI/II mr, some $100{\mu}g$ of the proteins was injected into mice three times. It can be used for an effective vaccine production to prevent dental caries caused by pathogenic S. mutans.

  • PDF

Effect of Formic acid and Caproic acids on the Quality and Aerobic Deterioration of Reed Canarygrass Silage (Formic acid와 Caproic acid 첨가가 Reed Canarygrass Silage의 품질과 호기적 변패에 미치는 영향)

  • 김재황;고영두
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.14 no.2
    • /
    • pp.132-141
    • /
    • 1994
  • In order to study the effects of silage additive on the quality and in preventing aerobic deterioration, reed canarygrass silages were made with various levels of formic acid, caproic acid and a mixture of the two acids. Preparation of silages cutted into about 1.5 cm length with the forage cutter and packed in vinyl bags(50 kg of capacity, 0.1 mrn of thickness), and it also divided nine types of experimental treatments. Aerobic deterioration in the silages were investigated for 7 days of aerobic exposure periods, and the plastic vessel of diameter 25 cm, a height 30 cm used as a tool. The results obtained from this experiment are summarized as fellow. 1. Crude protein and NFE contents at the time if opening were increased in the silage with mixture of formic and caproic acids(P<0.01). Crude fiber and ADF contents during the 7 days of aerobic exposure periods were the decreased in the sslages with mixture of two acods treatment(P<0.01). 2. Temperature of the silage treated with fromic acid alone during the 2 days of aerobic exposure period reached$34.4^{\circ}C$, while that of the silage with caproic acid and mixture formic and caproic acids were not rapidly increased resulting by reduced aerobic deteriorarion. 3. The pH of silages treated with formic acid alone during 7 days of aerobic exposure was not effectively changed, while solages treated with caproic acid were effectively stabilized. 4. The ratio of amminia nitrogen to total nitrogen was significantly decreased in silages with formic acid>caproic acid>mixture of both in the order(P<0.01). 5. Microbiological population of the silage were positively changed during the 7 days of aerobic exposure period. Solages with formic acid were deteriorated at ensiling observed, while applicarion of 1.2% caproic acid was partially reduced deteriorarion by precenting of the growth moulds.

  • PDF

Tooth preparation design of dental laminate veneer: a review article (라미네이트 치아형성 디자인에 관한 문헌고찰)

  • Jo, Eun-Hye;Ko, Kyung-Ho;Park, Chan-Jin;Cho, Lee-Ra;Huh, Yoon-Hyuk
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.32 no.3
    • /
    • pp.149-157
    • /
    • 2016
  • Tooth preparation design is essential for successful laminate veneer treatment. Preservative tooth preparation limited on enamel, supra-margin advantageous for plaque control, and maintaining contact points known as a standard concept. However, the tooth preparation design has been the controversial issue. In biomechanical considerations, the incisal coverage should be decided on esthetic needs and necessity for the anterior guidance reconstruction. In occasion for sufficient enamel thickness, preparation can prolong to the palatal side but not recommended at palatal concavity. Elongation to contact point is selective option according to the cases. If an old resin restoration located at contact area, laminate veneer should cover over half area of that after surface treatment. The laminate veneer can be also selected at a partially discolored tooth root canal therapy (RCT) and at this occasion, the fiber-reinforced composite (FRC) posts are recommended.

T800/AD6005계 복합재의 습기투과에 관한 연구

  • 박명규;류백능;최영보
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 1997.11a
    • /
    • pp.35-36
    • /
    • 1997
  • 복합재는 강도가 높고 가볍기 때문에 최근 로켓의 연소관으로 널리 사용되고 있다. 그런데 이 복합재 로켓 연소관은 제조 후 대기 환경에 장기적으로 노출되어 있기 때문에 금속 연소관과는 달리 온도 또는 습도 등의 환경에 대한 영향을 고려해야 한다. 더구나 연소관은 내부에 추진제가 충전되어 있으므로 추진제의 기계적 특성이 습도에 민감함을 생각할 때 강도뿐만 아니라 습기의 투과도 또한 매우 중요한 고려 요소가 된다. 그러나 온/습도 변화에 따른 복합재 자체의 재료 특성 변화에 대한 연구는 많이 보고되었으나 습기의 투과 정도에 관한 연구는 자료가 미흡한 실정이다. 한편, 포화 함수율은 복합재에 따라서 차이가 있으나 T300/5208의 경우 문헌을 참조하면 20-$50^{\circ}C$에서 복합재 무게의 약 1.5% 정도이며 포화에 걸리는 시간은 약 100일 정도로 나타나 있다.본 연구에서는 수분이 복합재를 통하여 투과되는 정도를 고찰하기 위하여 $20^{\circ}C$,95%RH의 온/습도를 유지하는 수조를 제작하였고, 이 수조내에 보관한 복합재 연소관의 실린더 벽면으로 투과되는 습기를 측정하기 위하여 연소관 내에 습도 센서를 투입하여 상대습도를 직접 측정하였다. 복합재 연소관이 로켓에 사용될 때는 연소관 외부에 페인트로 피막 처리하고 연소관 내부에도 추진제와의 사이에 라이너가 접착되어 있어서 수분 침투 및 온도 등의 외부 환경조건에 견디기에 더 양호한 조건이나 본 연구에서는 복합재 자체의 특성을 고찰하기 위하여 섬유를 에폭시에 함침시켜 winding한 상태 그대로의 복합재 연소관 시료를 사용하였다. 습기의 투과는 내부에 라이너/인슐레이션이 피복되거나 또는 추진제가 충전된 경우 많은 감소효과를 보였다. 순수 복합재 연소관의 경우 수조에 넣고 평형에 도달한 후로부터 약 8개월의 습기 투과 상태를 볼대 벽면을 통하여 들어가는 water vapor flux는 $20^{\circ}C$,95%RH 에서 평균적으로 9.3163$\times$$10^{-8}$g/$m^2$sec로 나타났다. 이때 습기가 투과되는 연소관이 국지점을 평판으로 가정하고 Fick's law를 이용하여 구한 습기에 대한 복합재의 확산계수는 D=2.5$\times$$10^{-6}$$mm^2$sec였으며, 이는 다른 graphite/epixy 복합재의 확산계수와 유사한 값을 나타내고 있다. 또한 추진제가 충전된 연소관을 절단하여 밀폐한 후 95%RH 습도 조건에 보관함으로써 연소관 내부의 추진제 기계적 특성에 미치는 침투된 습기의 영향도 함께 고찰하였다. 추진제에 따라 차이는 있겠으나 추진제가 충전된 연소관은 순수 복합재 연소관에 비해 습기의 투과 정도가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.

  • PDF

Primary bone tumors of fibula (비골에 발생한 원발성 골 종양)

  • Park, Jang-Won;Lee, Seung-Hwan;Shin, Kyoo-Ho
    • The Journal of the Korean bone and joint tumor society
    • /
    • v.12 no.2
    • /
    • pp.112-117
    • /
    • 2006
  • Purpose: The purpose of this study was to investigate on primary bone tumors of fibula. Materials and Methods: Patients who received operative treatment from January 1993 to December 2005 for primary bone tumors of fibula were analyzed for clinical outcomes. Results: There were 17 patients(10 males, 7 females) who were diagnosed for primary bone tumors of fibula. Osteochondroma was the most common diagnosis and others were osteosarcoma, fibrous dysplasia. The malignant bone tumors were 10.5% of all fibula tumors. There were 12 cases on proximal, 4 cases on mid shaft, and 1 cases on distal part of fibula. At the final follow up, 14 patients reported patient satisfaction of either excellent or good. Conclusion: Bone tumor of fibula doesn't need reconstruction after the resection unless it invades tibia or its site distal, which enables easy surgical resection. However, generally it is rare and accompany with vague symptoms, so careful approach to diagnosis is necessary because late diagnosis can mean the needs for amputation.

  • PDF