Proceedings of the Korean Vacuum Society Conference
/
2000.02a
/
pp.64-64
/
2000
Since its discovery in 1991, the carbon nanotube has attracted much attention all over the world; and several method have been developed to synthesize carbon nanotubes. According to theoretical calculations, carbon nanotubes have many unique properties, such as high mechanical strength, capillary properties, and remarkable electronical conductivity, all of which suggest a wide range of potential applications in the future. Here we report the synthesis in the catalytic decomposition of acetylene at ~65 $0^{\circ}C$ over Ni deposited on SiO2, For the catalyst preparation, Ni was deposited to the thickness of 100-300A using effusion cell. Different approaches using porous materials and HF or NH3 treated samples have been tried for synthesis of carbon nanotubes. It is decisive step for synthesis of carbon nanotubes to form a round Ni particles. We show that the formation of round Ni particles by heat treatment without any pre-treatment such as chemical etching and observe the similar size of Ni particles and carbon nanotubes. Carbon nanotubes were synthesized by chemial vapour deposition ushin C2H2 gas for source material on Ni coated Si substrate. Ni film gaving 20~90nm thickness was changed into Ni particles with 30~90nm diameter. Heat treatment of Ni fim is a crucial role for the growth of carbon nanotube, High-resolution transmission electron microscopy images show that they are multi-walled nanotube. Raman spectrum shows its peak at 1349cm-1(D band) is much weaker than that at 1573cm-1(G band). We believe that carbon nanotubes contains much less defects. Long carbon nanotubes with length more than several $\mu$m and the carbon particles with round shape were obtained by CVD at ~$650^{\circ}C$ on the Ni droplets. SEM micrograph nanotubes was identified by SEM. Finally, we performed TEM anaylsis on the caron nanotubes to determine whether or not these film structures are truly caron nanotubes, as opposed to carbon fiber-like structures.
The purpose of this study was to assess the energy value of breakfast and its relation to total daily nutrient intake and serum lipid. Dietary intakes were evaluated through the 3-day dietary recalls(interview for 1day and self-report for 2 days) from 333 Korean urban adults aged 20-49 year. Serum lipids in fasting blood samples were measured form 98 of those 333 adults. Low energy breakfast(<15% of daily energy intake) was consumed by 22.6% of males and 18.5% of females. 59.4 of males and 43.3% of females consumed a breakfast of average energy intake(15-25% daily energy intake) ; and 18.1 of males and 38.2% of females consumed a significant contribution to a total daily nutrient intake. The daily nutrient intake except crude fiber and vitamin A, B, B, and C in males and except vitamin C in females significantly increased as the energy value of breakfast increased. The differences in energy and nutrient intakes at breakfast were not made up for by other meals. To make matters worse, the satisfactory-energy breakfast group took more energy at dinner compared with the low-energy and average-energy breakfast group took more energy at dinner compared with the low-energy and average-energy breakfast groups in females. Among serum lipid parameters, TG was negatively correlated with energy provided at breakfast, and total cholesterol and LDL-cholesterol had a negative correlation with energy and carbohydrates provided at breakfast in males. For females TG was positively correlated with the ratio of carbohydrates to energy at breakfast but negatively correlated with the ratio of fat to energy at breakfast. These results suggest that satisfactory energy intakes at breakfast have positive effects on the adequacy of daily nutrient intake and may positively affect the serum lipid status.
To study the effect of prosomillet (Panicum milaceum) on lipid metabolism, male Sprague-Dawley rats weighing 190$\pm$8g were fed six experimental diets for four weeks. The six diets based on AIN-76 composition consisted of one cholesterol-free(normal) and five 1%(w/w) cholesterol diets, i.e. control, two diets containing additional 0.3 and 0.6%(w/w) methanol extracts of prosomillet and another two diets containing 15 and 30% (w/w) prosomillet powder. There was no difference in weight gains between the groups but relative liver weights increased under the cholestrol diets. Plasma levels of total cholesterol and triglyceride(TG) decreased by 23-27% and by 37-52%, respectively, in the four prosomillet diet groups compared to those of the normal and control groups. Whereas in the liver, only TG levels decreased in the prosomillet diet groups. Fecal excretions of bile acid and cholesterol significantly with methanol extracts of prosomillet. There was a significant increase in the activity of hepatic microsomal cholesterol 7$\alpha$-hydroxylase when feeding 1% cholesterol but prosomillet in the diet, either as in the form of powder or methanol extract, appeared to have only slight additional effects, namely increases in enzyme activity. The activity of liver cytosolic glucose-6-phophate dehydrogenase (G6PDH) tended to be reduced with high cholesterol diets and dropped markedly by 15% using additional prosomillet powder. Those of the liver cytoxolic malic enzyme had a similar tendency to those of G6PDH. The results indicate that certain active components in prosmillet other than fiber have the potential to exert hypolipidemic effects via regulating cholesterol excretions and lipogenesis.
Fibroin is a biopolymer available in large quantity from silk fiber and has a long history of use as a suture proving biocompatibility. In this report, fibroin microspheres has been fabricated for biomaterial applications. W/O emulsion of regenerated fibroin droplets in a continuous phase of decane with mixed surfactants was dried to facilitate fibroin gelation and the condensed fibroin microspheres were harvested. The ratio of mixed surfactants and their proportions to decane were determined to prepare a stable W/O emulsion. A spherical form of fibroin gels was obtained from the W/O emulsion agitated at 600 rpm. Scanning electron microscopy revealed that number average sizes of the fibroin microspheres were 21.6 and 8.5 ${\mu}m$ when dried under ambient conditions or under vacuum, respectively. Tomography of the spheres revealed that their internal structures are packed or hollowed. Hollow and hemispherical forms of microspheres were also prepared by using porogen.
Kim, Yang Seok;Na, Young Cheon;Yoon, Hyun Sik;Huh, Woo Hoe;Kim, Ji Min
Archives of Craniofacial Surgery
/
v.20
no.1
/
pp.10-16
/
2019
Background: Physicians tend to overcorrect when applying the acellular dermal matrix for reconstructive option because of volume decrement problem after absorption comparing with initial volume. However, there are no studies on the exact volume decrement and absorption rate with commercial products in South Korea. To figure out absorption rate of acellular dermal matrix product in South Korea (Megaderm), authors designed this experiment. Methods: Nine mice were used and randomly divided into three groups by the time with sacrificing. The implant (Megaderm) was tailored to fit a cuboid form ($1.0cm{\times}1.0cm$ in length and width and 2.0 mm in thickness). A skin incision was made at anterior chest with blade #15 scalpel with exposing the pectoralis major muscle. As hydrated Megaderm was located upon the pectoralis major muscle, the skin was sutured with Ethilon #5-0. After the surgical procedure, each animal group was sacrificed at 4, 8, and 12 weeks, respectively, for biopsies and histological analysis of the implants. All samples were stained with routine hematoxylin and eosin staining and Masson's trichrome staining and the thickness were measured. A measurements were analyzed using Friedman test. Statistically, the correlation between thicknesses of Megaderm before and after implantation was analyzed. Results: After sacrificing the animal groups at postoperative 4, 8, 12 weeks, the mean tissue thickness values were $2.10{\pm}1.03mm$, $2.17{\pm}0.21mm$, and $2.40{\pm}0.20mm$ (p= 0.368), respectively. The remaining ratios after absorption comparing with after initial hydrated Megaderm were 82.7%, 85.4%, and 94.5%, respectively. In histopathological findings, neovascularization and density of collagenous fiber was increased with time. Conclusion: Author's hypothesis was absorption rate of implant would be increased over time. But in this experiment, there is no statistical significance between mean absorption thickness of implant and the time (p= 0.368). Also it can be affected by graft site, blood supply, and animals that were used in the experiment.
Yim, Shi On;Lee, Jung Moo;Lee, Sang Kwan;Park, Yong Ho;Park, Ik Min
Korean Journal of Metals and Materials
/
v.50
no.9
/
pp.697-702
/
2012
In this study, unidirectional and plain woven carbon fiber reinforced magnesium matrix composite laminates were fabricated by the liquid pressing infiltration process, and evolutions of the microstructure and compressive strength of the composite laminates under corrosion were investigated by static immersion tests. In the case of the unidirectional composite laminate, the main microstructural damage during immersion appeared as a form of corrosion induced cracks, which were formed at both CF/Mg interfaces and the interfaces between layers. On the otherhand, wrap/fill interface cracks were mainly formed in the plain woven composite laminate, without any cracks at the CF/Mg interface. The formation of these cracks was considered to be associated with internal thermal residual stress, which was generated during cooling after the fabrication process of these materials. As a consequence of the corrosion induced cracks, the thickness of both laminates increased in directions vertical to the fibers with increasing immersion time. With increasing immersion time, the compressive strengths of both composite laminates also decreased continuously. It was found that the plain woven composite laminates have superior corrosion resistance and stability under a corrosive condition than unidirectional laminates.
In this study, the sales status of female ball-jointed dolls and their parts were investi- gated and analyzed. Baseline data from 194 products and 54 brands on domestic and international Internet sites was gathered for the manufacture of ball-jointed dolls and the development of prototype costumes for them. The results are as follows. First, the sizes used for ball-jointed dolls are SD, USD, MSD, 13SD, and 70SD together with height. This study analyzed 39 sizes (15~70cm) by classifying them into numbered groups: 1 (15~22cm), 2 (23~33cm), 3 (35~51cm), 4 (53~62cm), and 5 (63~70cm). The price varied depending on the size; for example, 50cm dolls were approximately 45,000 won, while limited editions were sold at high prices, regardless of their size. They were classified into designs according to their body proportions and facial features as follows: 7- or 8-head-figure, 5-head figure, and 3-head figure, and were presented proportionally as images of women, adolescents, and infants. Second, the head was incised so that the top could be removed horizontally or the facial region vertically, allowing attachment of the eyeballs (which were either glass, resin, or acrylic) to the inside. More than 30 different colors were sold. Various wig styles were provided, including cut, short hair, and perm. These were made from human hair, heat-resistant fiber, and artificial hair. For the hands, there was a design expressing human hand gestures. For the feet, heels were in the form of wearing either high-heels or flat soles.
While the shielding substances of radiation shields in medical institutions are beginning to be replaced by environmentally friendly materials, radiation protection according to the shielding properties of environmentally friendly substances is becoming an important factor rather than the existing lead shielding properties. Tungsten and barium sulfate are representative shielding materials similar to lead, and are made in sheets or fiber form with eco-friendly materials. Ytterbium is an impermeable material used as a fluorine compound in the dental radiation field. This study aims to evaluate the shielding performance in the x-ray shielding area by comparing the shielding properties of ytterbium by energy band and that of existing eco-friendly materials. When three types of shielding sheets were fabricated and tested under the same process conditions, the shielding performance of the medical radiation area was about 5 % difference from tungsten. Furthermore, shielding performance was superior to barium sulfate. In the cross-sectional structure of the shielding sheet, there was a disadvantage that the arrangement of particles was not uniform. Ytterbium oxide showed sufficient potential as a medical radiation shielding material, and it is thought that it can improve the shielding performance by controlling the particle arrangement structure and particle size.
Seok, Yong-Joo;Zo, Sun-Mi;Choi, Soon-Mo;Han, Sung Soo
Textile Coloration and Finishing
/
v.34
no.4
/
pp.284-301
/
2022
The limitations of food production caused by global warming, consumption of soil fertility, and land shortage have demanded the development of alternative foods. Their market has been increasing, and in particular, there is an urgent need for an alternative meat. Among them, the non-slaughtered cell-cultured meat that can be manufactured in the laboratory, that is, cultured meat, is in the spotlight, which can solve the problem of meat consumption while including the advantages of meat. It is classified into minced cultured meat and structured one with a structure similar to that of real meat. The latter is currently facing limitations related scaffolds, cells, and the multiplicative problems, and many attempts are being made to solve them. The complex problem is related to secure texture and taste as well as structural similarity to actual meat. To solve the problems, it is necessary to lay emphasis on cells, there are fat cells and vascular cells, and the most fundamental cells, muscle cells. These are the main cells that control the texture and nutrients of meat, and unlike other cells, they grow in the form of fibers. A myofibril (also known as a muscle fibril) is a basic rod-like organelle of a muscle cell, which is a quantitatively major component of meat, and one of the tissues that maintain the appearance of the body and bones. In this review article, we focused on the growth of muscle cells into long, tubular cells known as muscle fibers using the fabricated fibrous scaffold, and reviewed not only research results for muscle tissue engineering but also various results in the related fields for the last five years.
Although his mythic poetry deals with the fall and resurrection of Albion as the origin of humankind, William Blake (1757-1827) simultaneously links it to the professionalization and unification of disciplinary knowledge itself. He particularly takes a great interest in the cross-referential relation of poetry to science. He argues for the communication of poetry and science on equal footing with each other without the former's prioritization over the latter, or vice versa. In his works Vala, or The Four Zoas (1797-1807) and Jerusalem: The Emanation of the Giant Albion (1804-1820), on which I focus in this essay, Blake's primary problematic is to display strong conflicts among different systems of knowledge. I approach this issue in light of the ideological clash of Newtonian thought, Romantic thought, and postmodern thought. In his poetry, Blake thematizes the very clashes of these different thought patterns. From the standpoint of Romantic thought, first of all, Blake problematizes Newtonian Enlightenment. He criticizes abstract universalization both in poetry and science, which Urizen, one of four Zoas, propagates. Protesting against Urizen's Newtonism, Los values "living form." Thus, Blake demonstrates, through this figure, that poetic imagination and scientific organicism are discursively communicative. Blake, however, also questions the network of Romantic science and Romantic poetry so as to suggest what current critics would call postmodern thought. Blakean postmodernism pursues the self-similarity of organic structure in science and poetry. Precisely, Blake sees polypus as a proliferation of organic body; he arranges four Zoas' self-repetitive stories in a non-linear way. Blake aspires for the conflicting coexistence of different thought patterns.
이메일무단수집거부
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.