• Title/Summary/Keyword: Twisted

Search Result 791, Processing Time 0.031 seconds

Properties in Strength of Raschel Netting (랏쉘그물감의 강도)

  • KIM Dai An
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.11 no.1
    • /
    • pp.39-48
    • /
    • 1978
  • 1) The decrease in strength of Raschel twines at Raschel joints is regarded to be due mainly to the frictional force between yarns and the unbalanced tensile distribution by the deformation of the joints. The rate of the decrease is about $13\%$ in lengthwise pull and 22 to $26\%$ in breadthwise pull. 2) The 3-course joint is less in deformation and stronger than the 2-course joint in all cases of pulls. 3) The variation of Raschel joint strength $T_R$ with the angle $\varphi$ between the adjacent bars is expressed as $T_R=T_{R0}-k\varphi$ where $T_{R0}$ is the strength at $\varphi=0^{\circ}$ and K is a constant. 4) The tensile strength ${\sigma}R$ and tile breaking energy $E_R$ of Raschel netting are given by $${\sigma}R=KN\;or\;${\sigma}R=T_RN$$ and $$E_R=AN$$ respectively, where N is the number of meshes at the pulling side, and K and A are constants. But the breaking energy of the netting is almost constant independent of tile variation of N. 5) The Raschel netting with some bars cut already breaks from tile joints of the bars next to the cut bars and its tensile strength, breaking energy, and breaking elongation decrease largily even if only one bar is in already cut state. 6) The tearing strength of Raschel netting is almost equal to the tensile strength of its single joint pulled by two bars. 7) The twisted joint is much more excellent in strength than the knot or the Raschel joint. The knot strength is 69 to $76\%$, and the Raschel joint strength is 71 to $74\%$ in lengthwise pull and 62 to $67\%$ in breadthwise pull, respectively, of the twisted joint strength.

  • PDF

A Study on Woman's Experience of Being Bereaved of Her Husband by an Accident (사고로 남편을 잃은 여성의 경험)

  • Park, Sung-Hark;Choi, Mi-Hye;Chung, Yeon-Kang
    • Research in Community and Public Health Nursing
    • /
    • v.7 no.2
    • /
    • pp.294-312
    • /
    • 1996
  • Relatively young widows, who are left with young children by a sudden death of their husbands, will be faced with not only psychological troubles such as individual anxiety and frustration but also the dual burden of playing both father and mother roles in a family, Also, family members have difficulty in adapting themselves to new circumstances of the family system, the training and raising of family members, and management of the family economy. In this study, the realistic resources on the experience of middle-aged women who are bereaved of their husbands by accidents were explored. The purpose of this study is to help widows adapt to life in society and live a more positive life by setting a new goals and recovering from a lost and twisted life. 11 women, who have experienced the loss their husbands and live in the Seoul metropolitan area were studied. The research took 116 days from December 15, 1995 to April 8, 1996. The method of research was direct interviews. While having interviews with them, the contents were recorded with their consent. The ground theory was that used by Strauss & Corbin(1990) in the analysis of the data. 81 concepts were analyzed and they were subdirided into 22 subordinate categories through the course of the analysis. These were then classified into 9 general categories. In the course of being categorized, 'absurdity' was showed as a core category. The subordinate categories 'surprise', 'gloom', 'grudge', 'helplessness', 'emptiness', and 'loss' were united in the core category 'absurdity'. Ominous presentiment, belated notice, death, surprise, gloom, grudge, helplessness, emptiness, loss, the situation of the children, lack of support from neighbors, support from neighbors, mulling over ways to live, choosing a job, strengthening, reinforcement, burden, sadness, smoldering, yearning, overcoming these 22 subordinate categories were re-composed into 9 general ones the husband's death, absurdity, presence of children, existence of support, self-support ability, preparation of countermeasures, self-reinforcement, toilsomeness, and overcoming. 'Absurdity' widows experience was shown in the results of 'toilsomeness' and 'overcoming' through reaction, confrontation, and adaptation. According to the analysis the central phenomenon was absurdity, the causal condition of the death of a husband, the presence of children and the existence of support, and the meditated situation of self-support. To solve absurdity, the preparation of countermeasures and self-reinforcements were shown resulting in toilsomeness and overcoming. Through the contrast in the data, the following statements were deduced: (1) If the death of the husband is expected, the more a widow will feel absurdity. (2) The more children she has and the younger she is, the more a widow will feel absurdity. (3) The lower support she is given, the more a widow will feel absurdity. (4) The larger self-ability she has, the more actively she will prepare countermeasures. (5) The smaller self-ability she has, the more passively she will prepare countermeasures. (6) The larger self-ability she has, the weaker self-reinforcement she will preform. (7) The smaller self-ability she has, the stronger self-reinforcement she will perform. (8) The more actively she prepares countermeasures for absurdity, the better she will overcome. (9) The more passively she prepares counter measure for absurdity, the worse she will overcome. (10) The stronger self-reinforcement for absurdity she performs, the better she will overcome. (11) The weaker self-reinforcement for absurdity she performs, the worse she will overcome. Through the results in this study, the following suggested: 1) A study whose object is all family members, and a comparative study on the case of a husband who has lost his wife should be done. These studies can be expected to develop a more refined theory. 2) Because of the collapse of the extended family system and the changes of family culture in Korea, a widow's status and position are apt to be ambiguous between her husband's home and her parent's. Therefore a new study on family culture should be made. 3) A continuous study on growing social Self Help Groups should be requested for the widows of this study to re-establish and recover from their twisted and scattered lives.

  • PDF

The moment generated by the torque of the orthodontic rectangular wire : Three-dimensional finite element analysis (교정용 각형선재에 부여된 torque가 브라켓에 발생시키는 모멘트에 관한 유한요소법적 분석)

  • Ha, Do-Won;Kim, Young-Suk;Sung, Jae-Hyun
    • The korean journal of orthodontics
    • /
    • v.31 no.3 s.86
    • /
    • pp.335-346
    • /
    • 2001
  • The purpose of this study was to investigate the ideal clinical torque(In the SWA rectangular wire, the torque by the angle between the plane part and twisted part to move the tooth) of the orthodontic rectangular wire which produce the proper labiolingual movement of the single tooth during finishing stage of the orthodontic treatment. The clinical torque is the sum of the play and the active torque which generates the moment at the bracket. The play is calculated by the formula and the active torque is calculated by the computer aided three-dimensional finite element method. The finite element model was consist of the three brackets which formed a row and 3 kinds of orthodontic rectangular wire(stainless steel, TMA, NiTi) which inserted in brackets. Both sides of the model were twisted and the moment generated in the center bracket was calculated. The sizes of seven wires which were used commonly were .016'X.022', .017'X.022', .017'X.025', .018'X.025', .019'X.025', .020'X.025', .021'X.025'. In 018' bracket, 016'X.022', .017'X.022', .017'X.025' wires were inserted and in 022' bracket, all the sizes of wires except .016'X.022' were inserted and tested. The following conclusions could be drawn from this study. 1. The moments generated on the same size of the wires by the same active torque were equal regardless of the bracket slot size. 2. The moments were increased with the size of the wires. The moment generated on the .021'X.025' wire was about 1.75 times as large as that on the .016'X.022' wire regardless of the material. 3. The moments were increased in the order of the NiTi, TMA stainless steel. The moment of the TMA wire was 0.35 times as small as that of the stainless steel wire and the moment of the NiTi was0.16 times as small as that of the stainless steel wire. 4. The moment was decreased as the interbracket distance was increased. 5. To get a desired moment with the specific size and material of the wire on the specific bracket slot, the formula and the results were displayed.

  • PDF

LCD 연구 개발 동향

  • 이종천
    • The Magazine of the IEIE
    • /
    • v.29 no.6
    • /
    • pp.76-80
    • /
    • 2002
  • 'Liquid Crystal의 상전이(相轉移)와 광학적 이방성(異方性)이 1888년과 1889년 F. Reinitzer와 O. Lehmann에 의해 Monatsch Chem.과 Z.Physikal.Chem.에 각각 보고된 후 부터 제2차 세계대전이 끝난 뒤인 1950년대 까지는 Liquid Crystal을 단지실험실에서의 기초학문 차원의 연구 대상으로만 다루어 왔다. 1963년 Williams가 Liquid Crystal Device로는 최초로 특허 출원을 하였으며, 1968년 RCA사의 Heilmeier등은 Nematic 액정(液晶)에 저주파(低周波) 전압(電壓)을 인가하면 투명한 액정이 혼탁(混濁)상태로 변화하는 '동적산란(動的散亂)'(Dynamic Scattering) 현상을 이용하여 최초의 DSM(Dynamic Scattering Mode) LCD(Liquid Crystal Display)를 발명하였다. 비록 150V 이상의 높은 구동전압과 과소비전력의 특성 때문에 실용화에는 실패하였지만 Guest-Host효과와 Memory효과 등을 발견하였다. 1970년대에 이르러 실온에서 안정되게 사용 가능한 액정물질들이 합성되고(H. Kelker에 의해 MBBA, G. Gray에 의한 Cyano-Biphenyl 액정의 합성), CMOS 트랜지스터의 발명, 투명도전막(ITO), 수은전지등의 주변기술들의 발전으로 인하여 LCD의 상품화가 본격적으로 이루어지게 되었다. 1971년에는 M. Shadt, W. Helfrich, J.L. Fergason등이 TN(Twisted Nematic) LCD를 발명하여 전자 계산기와 손목시계에 응용되었고, 1970년대 말에는 Sharp에서 Dot Matrix형의 휴대형 컴퓨터를 발매하였다. 이러한 단순 구동형의 TN LCD는 그래픽 정보를 표시하는 데에는 품질의 한계가 있어 1979년 영국의 Le Comber에 의해 a-Si TFT(amorphous Silicon Thin Film Transistor) LCD의 연구가 시작되었고, 1983년 T.J. Scheffer, J. Nehring, G. Waters에 의해 STN(Super Twisted Nematic) LCD가 창안되었고, 1980년 N. Clark, S. Lagerwall 및 1983년 K.Yossino에 의해 Ferroelectric LCD가 등장하여 LCD의 정보 표시량 증대에 크게 기여하였다. Color화의 진전은 1972년 A.G. Ficher의 셀 외부에 RGB(Red, Green, Blue) filter를 부착하는 방안과, 1981년 T. Uchida 등에 의한 셀 내부에 RGB filter를 부착하는 방법에 의해 상품화가 되었다. 1985년에는 J.L. Fergason에 의해 Polymer Dispersed LCD가 발명되었고, 1980년대 중반에 이르러 동화상(動畵像) 표시가 가능한 a-Si TFT LCD의 시제품(試製品) 개발이 이루어지고 1990년부터는 본격적인 양산 시대에 접어들게 되었다. 1990년대 초에는 STN LCD의 Color화 및 대형화(大型化) 고(高)품위화에 힘입어 Note-Book PC에 LCD가 본격적으로 적용이 되었고, 1990년대 후반에는TFT LCD의 표시품질 대비 가격경쟁력 확보로 인하여 Note-Book PC 시장을 독점하기에 이르렀다. 이후로는 TFT LCD의 대형화가 중요한 쟁점으로 부각되고 있고, 1995년 삼성전자는 당시 세계최대 크기의 22' TFT LCD를 개발하였다. 또한 LCD의 고정세(高情細)화를 위해 Poly Si TFT LCD의 개발이 이루어졌고, 디지타이져 일체형 LCD의 상품화가 그 응용의 폭을 넓혔으며, LCD의 대형화를 위해 1994년 Canon에 의해 14.8', 21' 등의 FLCD가 개발되었다. 대형화 방안으로 Tiled LCD 기술이 개발되고 있으며, 1995년에 Sharp에 의해 21' 두장의 Panel을 이어 붙인 28' TFT LCD가 전시되었고 1996년에는 21' 4장의 Panel을 이어 붙인 40'급 까지의 개발이 시도 되었으며 현재는 LCD의 특성향상과 생산설비의 성능개선과 안정적인 공정관리기술을 바탕으로 삼성전자에서 단패널 40' TFT LCD가 최근에 개발되었다. Projection용 디스플레이로는 Poly-Si TFT LCD를 이용하여 $25'{\sim}100'$사이의 배면투사형과 전면투사형 까지 개발되어 대형 TV시장을 주도하고 있다. 21세기 디지털방송 시대를 맞아 플라즈마디스플레이패널(PDP) TV, 액정표시장치 (LCD)TV, 강유전성액정(FLCD) TV 등 2005년에 약 1500만대 규모의 거대 시장을 형성할 것으로 예상되는 이른바 '벽걸이TV'로 불리는 차세대 초박형 TV 시장을 선점하기 위하여 세계 가전업계들이 양산에 총력을 기울이고 있다. 벽걸이TV 시장이 본격적으로 형성되더라도 PDP TV와 LCD TV가 직접적으로 시장에서 경쟁을 벌이는 일은 별로 없을 것으로 보인다. 향후 디지털TV 시장이 본격적으로 열리면 40인치 이하의 중대형 시장은 LCD TV가 주도하고 40인치 이상 대화면 시장은 PDP TV가 주도할 것으로 보는 시각이 지배적이기 때문이다. 그러나 이러한 직시형 중대형(重大型)디스플레이는 그 가격이 너무 높아서 현재의 브라운관 TV를 대체(代替)하기에는 시일이 많이 소요될 것으로 추정되고 있다. 그 대안(代案)으로는 비교적 저가격(低價格)이면서도 고품질의 디지털 화상구현이 가능한 고해상도 프로젝션 TV가 유력시되고 있다. 이러한 고해상도 프로젝션 TV용으로 DMD(Digital Micro-mirror Display), Poly-Si TFT LCD와 LCOS(Liquid Crystals on Silicon) 등의 상품화가 진행되고 있다. 인터넷과 정보통신 기술의 발달로 휴대형 디스플레이의 시장이 예상 외로 급성장하고 있으며, 요구되는 디스플레이의 품질도 단순한 문자표시에서 그치지 않고 고해상도의 그래픽 동화상 표시와 칼라 표시 및 3차원 화상표시까지 점차로 그 영역이 넓어지고 있다. <표 1>에서 보여주는 바와 같이 LCD의 시장규모는 적용분야 별로 지속적인 성장이 예상되며, 새로운 응용분야의 시장도 성장성을 어느 정도 예측할 수 있다. 따라서 LCD기술의 연구개발 방향은 크게 두가지로 분류할 수 있으며 첫째로는, 현재 양산되고 있는 LCD 상품의 경쟁력강화를 위하여 원가(原價) 절감(節減)과 표시품질을 향상시키는 것이며 둘째로는, 새로운 타입의 LCD를 개발하여 기존 상품을 대체하거나 새로운 시장을 창출하는 분야로 나눌 수 있다. 이와 같은 관점에서 현재 진행되고 있는 LCD기술개발은 다음과 같이 분류할 수 있다. 1) 원가 절감 2) 특성 향상 3) New Type LCD 개발.

  • PDF

Study on Fabric and Embroidery of Possessed by Dong-A University Museum (동아대학교박물관 소장 <초충도수병>의 직물과 자수 연구)

  • Sim, Yeon-ok
    • Korean Journal of Heritage: History & Science
    • /
    • v.46 no.3
    • /
    • pp.230-250
    • /
    • 2013
  • possessed by Dong-A University Museum is designated as Treasure No. 595, and has been known for a more exquisite, delicate and realistic expression and a colorful three-dimensional structure compared to the 'grass and insect painting' work and its value in art history. However, it has not been analyzed and studied in fabric craft despite it being an embroidered work. This study used scientific devices to examine and analyze the Screen's fabric, thread colors, and embroidery techniques to clarify its patterns and fabric craft characteristics for its value in the history of fabric craft. As a result, consists of eight sides and its subject matters and composition are similar to those of the general paintings of grass and insects. The patterns on each side of the 'grass and insect painting' include cucumber, cockscomb, day lily, balsam pear, gillyflower, watermelon, eggplant, and chrysanthemums from the first side. Among these flowers, the balsam pear is a special material not found in the existing paintings of grass and insect. The eighth side only has the chrysanthemums with no insects and reptiles, making it different from the typical forms of the paintings of grass and insect. The fabric of the Screen uses black that is not seen in other decorative embroideries to emphasize and maximize various colors of threads. The fabric used the weave structure of 5-end satin called Gong Dan [non-patterned satin]. The threads used extremely slightly twisted threads that are incidentally twisted. Some threads use one color, while other threads use two or mixed colors in combination for three-dimensional expressions. Because the threads are severely deterioration and faded, it is impossible to know the original colors, but the most frequently used colors are yellow to green and other colors remaining relatively prominently are blue, grown, and violet. The colors of day lily, gillyflower, and strawberries are currently remaining as reddish yellow, but it is anticipated that they were originally orange and red considering the existing paintings of grass and insects. The embroidery technique was mostly surface satin stitch to fill the surfaces. This shows the traditional women's wisdom to reduce the waste of color threads. Satin stitch is a relatively simple embroidery technique for decorating a surface, but it uses various color threads and divides the surfaces for combined vertical, horizontal, and diagonal stitches or for the combination of long and short stitches for various textures and the sense of volume. The bodies of insects use the combination of buttonhole stitch, outline stitch, and satin stitch for three-dimensional expressions, but the use of buttonhole stitch is particularly noticeable. In addition to that, decorative stitches were used to give volume to the leaves and surface pine needle stitches were done on the scouring rush to add more realistic texture. Decorative stitches were added on top of gillyflower, strawberries, and cucumbers for a more delicate touch. is valuable in the history of paintings and art and bears great importance in the history of Korean embroidery as it uses outstanding technique and colors of Korea to express the Shin Sa-im-dang's 'Grass and Insect Painting'.

AN EXPERIMENTAL STUDY OF THE IRRADIATION EFFECTS ON THE MICROVASCULATURE OF THE RAT SUBMANDIBULAR GLAND (방사선 조사가 백서 악하선 미세혈관계에 미치는 영향에 관한 실험적 연구)

  • Choi Karp Shik;Choi Soon Chul;Park Tae won
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
    • /
    • v.22 no.1
    • /
    • pp.43-53
    • /
    • 1992
  • The purpose of this study was to investigate the effects of irradiation on the microvascular structure of the submandibular gland in rats. For this study, 110 male rats were singly irradiated with the dose of 10Gy or 20Gy to their neck region by 6MV X-irradiation and sacrificed on the 1st, 3rd, 7th, 14th and 28th day after irradiation. The author observed distribution and structural changes of the microvasculature in rat submandibular glands using a scanning electron microscope by forming vascular resin casting. The author observed ultrastructural changes of the endothelial cells using a transmission electron microscope, and also histologic changes using a light microscope at Hematoxylin and Eosin staining and PAS staining process. The results of the irradiation effects on the microvasculature in rat submandibular gland were as follows: By light microscopic examination, the dilation of small vessels were observed until the 7th day after irradiation. After then, the vascular constriction and decrease in number of small vessels were noticed. Changes were greater on 20Gy irradiated group than on lOGy irradiated group. The reaction to PAS staining at acinar cells was decreased just after irradiation, but gradually recovered with days. There was no specific difference between two irradiated groups. By scanning electron microscopic examination, general findings on the two irradiated groups were similar. The dilation of conduits and meandering were observed on the 3rd day after irradiation. Decrease of capillary density and blunt ended small vessels were appeared on the 7th day after irradiation. After that, findings of the tortuous and twisted vascular running and coarseness of capillary lumen were increased. Changes were greater on 20Gy irradiated group than on l0Gy irradiated group. By transmission electron microscopic examination, increase of the formation of cytoplasmic process was observed on the 3rd day after irradiation. After that, swelling of endothelial cell and bridge formation of cytoplasmic processes were also observed, but destruction of endothelial cell and loss of basement membrane were observed only on 20Gy irradiated group on the 28th day after irradiation.

  • PDF

The effect of temperature on morphological of fruiting body and cultivated characteristics of oyster mushroom (생육온도에 따른 느타리버섯 자실체의 형태 및 재배적 특성변화)

  • Jhune, Chang-Sung;Yun, Hyung-Sik;Jang, Kab-Yeul;Kong, Won-Sik;Lee, Kang-Hyo;Lee, Chan-Jung;Yoo, Young-Bok
    • Journal of Mushroom
    • /
    • v.9 no.4
    • /
    • pp.155-160
    • /
    • 2011
  • Changes of fruiting body yield and morphology according to growing temperatures in Pleurotus strains were investigated. In this study, twelve commercial strains divided into low, medium and high temperature groups were tested. On the basis of fruiting body yield, they showed best in their own temperature properties. On the other hand, they didn't have any fixed tendency to growing temperatures on morphological characteristics. Thicknesses of pilei were best at $10^{\circ}C$, having nothing to do with strains. Lengths of stipes were increased with the progress of cultivation temperatures in five strains including 'Sambok'. The other strains showed differences on this trait. Thicknesses of stipes were decreased with the progress of cultivation temperatures in other strains excepting 'Sambok and ASI2029'. Days for harvest were extended as temperature decreased, even though the shortest days were different according to strains. Sometimes there were abnormal shapes of fruiting bodies in response to temperatures in some strains. In 'Suhan-1', white cilia fully covered onto the surface of pilei were observed macroscopically at the early stage and then disappeared or remained a little later at $10^{\circ}C$ cultivation. In 'Chunchu-2', their stipes were twisted and bent over $20^{\circ}C$ cultivation.

Treatment of Spontaneous Serial Lung Lobe Torsion Using Self-Cutting Linear Endoscopic Stapler in a Pekingese Dog under Total Intravenous Anesthesia (페키니즈견에서 발생한 연속적 폐염전의 전정맥마취하 자가 절단식 선형 복강경 스테플러를 이용한 치료)

  • Park, JiYoung;Lee, Young Won;Jeong, Seong Mok
    • Journal of Veterinary Clinics
    • /
    • v.30 no.6
    • /
    • pp.490-495
    • /
    • 2013
  • A 9-year old, castrated male Pekingese dog weighing 6.9 kg was referred with one week history of dyspnea, depression, yellow vomiting and abdominal distension. Refractory right lung field opacity was diagnosed as spontaneous right cranial lung lobe torsion (LLT) with collapsed middle lobe on the computed tomography. Four days after diagnosis, right fourth intercostal thoracotomy was performed under propofol-remifentanil based total intravenous anesthesia (TIVA). Right cranial and middle lung lobes were twisted together in a clockwise direction. ENDOPATH-ETS-FLEX-45, an articulating endoscopic linear cutting stapler was applied at the hilus and there were no complications after resection. The patient recovered favorably and has been doing well up to one year follow up. Lung lobe torsion is an uncommon condition in small breed dogs, this case report suggests serial lung lobe torsion of cranial lobe followed by middle lobe in small breed dog, and immediately after diagnosis surgical intervention is beneficial to prevent progression of LLT. Furthermore, using self cutting stapling device and TIVA technique will be helpful for lung lobectomy in dogs.

A Study on the policy of activate Baekje Cultural goods -focus on Gongju-Buyeo national museum- (백제문화상품 활성화 정책에 관한 연구 -공주.부여 국립박물관 중심으로-)

  • Shin, Dae-Teak;Park, Seung-Chul
    • Journal of Digital Convergence
    • /
    • v.10 no.5
    • /
    • pp.333-338
    • /
    • 2012
  • Cultural goods is carrying nature and value above-mentioned a commodity to what a cultural element was commercialized. And it produced for the purpose of manufacture for popular sales and supply, and holding commercial character. Specially, cultural goods of a museum keeps a good memory to a sightseer, and broaden an educational experience, and the source of profit becomes it to a seller a producer. This cultural goods as they all include the artistic historical figurative background that they are displayed directly and got twisted up to collection have background which became a motive. Cultural goods can acquire cultural difference in globalization and have to be based on the soil of cultural heritage, starting around various cultural materials through practical value to a modern life. Internationally, cultural goods using a culture material development have competitiveness of nation as in it. Therefore, Baekje cultural goods need national and positive aid from the government with the customer satisfaction index considering the modern design, an age group, an internal and external commodity as the difficulty of various commodity development and managing museum shop. Furthermore, like overseas museum shop, if we are practically using on-off line, continuous promoting our commodity, and marketing strategy such as a membership system when buy our cultural goods, a special discount event etc., we can contribute to activate local economy as a museum shop when we have responsibility of the function and the part.

Characterization of the a-Se Film for Phosphor based X-ray light Modulator (형광체 기반 X선 광 변조기를 위한 비정질 셀레늄 필름 특성)

  • Kang, Sang-Sik;Park, Ji-Koon;Cho, Sung-Ho;Cha, Byung-Youl;Shin, Jung-Wook;Lee, Kun-Hwan;Mun, Chi-Woong;Nam, Sang-Hee
    • Journal of Biomedical Engineering Research
    • /
    • v.28 no.2
    • /
    • pp.306-309
    • /
    • 2007
  • PXLM(Phosphor based x-ray light modulator) has a combined structure by phosphor, photoconductor, and liquid crystal and it can realize x-ray image of high resolution in clinical diagnosis area. In this study, we fabricated a photoconductor and investigated electrical and optical properties to confirm application possibility of radiator detector of PXLM structure. As photoconductor, amorphous selenium(a-Se), which is used most in DR(Digital radiography) of direct conversion method, was used and for formation of thin film, it was formed as $20{\mu}m-thick$ by using thermal vacuum evaporation system. For a produced a-Se film, through XRD(X-ray diffraction) and SEM(Scanning electron microscope), we investigated that amorphous structure was uniformly established and through optical measurement, for visible light of 40 $0\sim630nm$, it had absorption efficiency of 95 % and more. After fabricated a-Se film on the top of ITP substrate, hybrid structure was manufactured through forming $Gd_2O_3:Eu$ phosphor of $270{\mu}m-thick$ on the bottom of the substrate. As the result to confirm electrical property of the manufactured hybrid structure, in the case of appling $10V/{\mu}m$, leakage current of $2.5nA/cm^2$ and x-ray sensitivity of $7.31nC/cm^2/mR$ were investigated. Finally, we manufactured PXLM structure combined with hybrid structure and liquid crystal cell of TN(Twisted nematic) mode and then, investigated T-V(Transmission vs. voltage) curve of external light source for induced x-ray energy. PXLM structure showed a similar optical response with T-V curve that common TN mode liquid crystal cell showed according to electric field increase and in appling $50\sim100V$, it showed linear transmission efficiency of $12\sim18%$. This result suggested an application possibility of PXLM structure as radiation detector.