• 제목/요약/키워드: III-V materials

검색결과 255건 처리시간 0.026초

강천산(전북.순창)의 자원식물상 연구 (A Floristic Study of the Economic Plants in Mt. Gangcheon(Sunchang-gun Jeollabuk- do))

  • 김중현;윤창영
    • 한국자원식물학회지
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    • 제20권5호
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    • pp.409-423
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    • 2007
  • 2005년 3월부터 11월까지 전북 강천산 군립공원에 자생하는 유관속식물을 대상으로 조사한 결과 조사지역내에 분포하는 식물은 97과 253속 328종 45변종 6품종 등 총 379분류군으로 관찰되었다. 조사 지역에서 분포하고 있는 379종류의 식물자원의 유용도를 분석한 결과 총 315종류의 자원식물로 분류되었으며, 식용자원(E)은 161종류(51.1%), 초지자원(P)은 121종류(38.4%), 약용자원(M)은 147종류(46.6%), 관상자원(O)은 82종류(26.0%), 목재자원(T)은 11종류(3.4%), 공업원료자원(I)은 14종류(4.4%)로 나타났다. 한국특산식물은 14과 16속 16분류군으로 조사지역내 분포하는 총 379분류군 중 약 4.2%이었으며, 특정식물 중 $III{\sim}V$등급 식물은 9과 9속 9분류군으로 소산식물 379분류군의 약 2.3%로 나타났으며, 진화식물은 11과 15속 14종 1변종의 15분류군으로 우리나라 전체 귀화식물 225 종류의 6.7%에 해당되었다.

Orange Phosphorescent Organic Light-emitting Diodes Using a Spirobenzofluorene-type Phospine Oxides as Host Materials

  • Jeon, Young-Min;Lee, In-Ho;Lee, Chil-Won;Lee, Jun-Yeob;Gong, Myoung-Seon
    • Bulletin of the Korean Chemical Society
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    • 제31권10호
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    • pp.2955-2960
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    • 2010
  • Spiro-type orange phosphorescent host materials, 9-diphenylphosphine oxide-spiro[fluorene-7,9'-benzofluorene] (OPH-1P) and 5-diphenylphosphine oxide-spiro[fluorene-7,9'-benzofluorene] (OPH-2P) were successfully prepared by a lithiation reaction followed by a phosphination reaction with diphenylphosphinic chloride. The EL characteristics of OPH-1P and OPH-2P as orange host materials doped with iridium(III) bis(2-phenylquinoline)acetylacetonate ($Ir(pq)_2acac$) were evaluated. The electroluminescence spectra of the ITO (150 nm)/DNTPD (60 nm)/NPB (30 nm)/OPH-1P or OPH-2P: $Ir(pq)_2acac$ (30 nm)/BCP (5 nm)/$Alq_3$ (20 nm)/LiF (1 nm)/Al (200 nm) devices show a narrow emission band with a full width at half maximum of 75 nm and $\lambda_{max}$ = 596 nm. The device obtained from OPH-1P doped with 3% $Ir(pq)_2acac$ showed an orange color purity of (0.580, 0.385) and an efficiency of (14 cd/A at 7.0 V). The ability of the OPH-P series to combine a high triple energy with a low operating voltage is attributed to the inductive effect of the P=O moieties and subsequent energy lowering of the LUMO, resulting in the enhancement of both the electron injection and transport in the device. The overall result is a device with an EQE > 8% at high brightness, but operating voltage of less than 6.4 V, as compared to the literature voltages of ~10 V.

전국 보건소 물리치료실 운영 실태와 활성화 방안 (Improving Physical Therapy Services of Health Centers in Korea)

  • 장은주
    • 대한물리치료과학회지
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    • 제3권2호
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    • pp.1021-1036
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    • 1996
  • The purpose of this study are ( i ) to examine operating situation of physical therapy department and job satisfaction of physical therapists in health centers, (ii) to analyze utilization patterns and patient satisfaction of physical therapy services among health center visitors, and finally, (iii) to suggest policy implications in facilitating improvement on physical therapy services of health centers. The materials are collected from 105 physical therapists among nationwide health centers and 203 patients of 5 health centers in Pusan, Korea. The survey is conducted from February 13 to March 30, 1996 with a structured self - administered questionnaire. Major results of the study are as follows. First, the result of regression analysis between job satisfaction and affecting factors identify following variables as the significant determinants; self-development(+), job itself(+), and co-worker support (+). Second, the current operating situation of physical therapy department shows such problem as; i )shortage and unstable job security of physical therapists, ii )absence of rehabilitation specialist, iii )lack of understanding on physical therapy of co-workers, iv)shortage of physical therapy equipment and facility, v)burdensome task of physical therapists, and vi) inappropriate purchase process of equipment. Third, patient satisfaction for physical therapy services are revealed relatively high. And the result of regression analysis between patient satisfaction and affecting factors identify following variables as the significant determinants; credibility of physical therapist(+), satisfaction for waiting time(+), cleanliness(+). Fourth, the patients appeal about physical therapy services such problem as; i) shortage of physical therapists, physical therapy equipment, and facility, ii) inconvenient administrative procedure for utilization physical therapy services. Fifth and last, recommendations for the improvement of physical therapy services of health centers are as follows; i )recruiting more physical therapists, ii )regular employment of physical therapists instead of daily use employment, iii )re-arrangement of facility for patient's convenience, iv )establishing reasonable purchasing system of equipment for physical therapy, v) reforming administrative procedure for patient focused care.

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개인피폭 선량 측정을 위한 필름 배지 선량계의 새로운 알고리즘 개발 및 특성 (The Development and It′s Characteristics of New Film Dosimetry Algorithm for Personal Dosimetry)

  • 이병용;장혜숙;봉정균;권수일
    • 한국의학물리학회지:의학물리
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    • 제6권2호
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    • pp.35-40
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    • 1995
  • 목적 : 필름배지를 이용하여 개인 피폭 선량을 측정하는 방법을 개발하고 그 특성을 알아보고자 한다. 재료 및 방법 : 필름으로는 Agfagaevart Personal monitoring 2/10 을 사용하였고, 필터로는 구리 0.3mm, 플라스틱 1.5mm, 알루미늄 0.6mm, 주석 0.8mm를 사용하였으며, 필름은 표준기관에서 교정하였다. 사용에너지는 ANSI N13.11 Category III, IV였고, 현상기는 수동현상기를, 농도계는 Xrite 농도계를 사용하였다. H&D 곡선을 선량에 따라 구한 뒤 다항식 전개를 이용하여 선량에 대해 직선성을 갖도록 변환하였다. 이후 필터와 방사선 에너지 관계를 구하여 선량 및 에너지를 추정할 수 있는 알고리즘을 개발하였다. 결과 : 본 연구에서 개발된 선량 평가 알고리즘은 해당 Category 의 전에너지에 대해 30% 이내의 정확도를 만족시켜 이 알고리즘이 개인 피폭 선량 측정에 이용될 수 있음을 알았다. Category I, II , V에 대하여 보완한다면 완벽한 선량 평가 알고리즘이 될 것으로 기대된다.

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Comparison of Core Needle Biopsy and Repeat Fine-Needle Aspiration in Avoiding Diagnostic Surgery for Thyroid Nodules Initially Diagnosed as Atypia/Follicular Lesion of Undetermined Significance

  • Leehi Joo;Dong Gyu Na;Ji-hoon Kim;Hyobin Seo
    • Korean Journal of Radiology
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    • 제23권2호
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    • pp.280-288
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    • 2022
  • Objective: To compare core needle biopsy (CNB) and repeat fine-needle aspiration (rFNA) to reduce the rate of diagnostic surgery and prevent unnecessary surgery in nodules initially diagnosed as atypia/follicular lesions of undetermined significance (AUS/FLUS). Materials and Methods: This study included 231 consecutive patients (150 female and 81 male; mean age ± standard deviation, 51.9 ± 11.7 years) with 235 thyroid nodules (≥ 1 cm) initially diagnosed as AUS/FLUS, who later underwent both rFNA and CNB. The nodules that required diagnostic surgery after the biopsy were defined using three different scenarios according to the rFNA and CNB results: criterion 1, surgery for low-risk indeterminate (categories I and III); criterion 2, surgery for high-risk indeterminate (categories IV and V); and criterion 3, surgery for all indeterminate nodules (categories I, III, IV, and V). We compared the expected rates of diagnostic surgery between CNB and rFNA in all 235 nodules using the three surgical criteria. In addition, the expected rates of unnecessary surgery (i.e., surgery for benign pathology) were compared in a subgroup of 182 nodules with available final diagnoses. Results: CNB showed significantly lower rates of nondiagnostic, AUS/FLUS, and suspicious for malignancy diagnoses (p ≤ 0.016) and higher rates of follicular neoplasm or suspicious for a follicular neoplasm (p < 0.001) and malignant diagnoses (p = 0.031). CNB showed a significantly lower expected rate of diagnostic surgery than rFNA for criterion 1 (29.8% vs. 48.1%, p < 0.001) and criterion 3 (46.4% vs. 55.3%, p = 0.029), and a significantly higher rate for criterion 2 (16.6% vs. 7.2%, p = 0.001). CNB showed a significantly lower expected rate of unnecessary surgery than rFNA for criterion 1 (18.7% vs. 29.7%, p = 0.024). Conclusion: CNB was superior to rFNA in reducing the rates of potential diagnostic surgery and unnecessary surgery for nodules initially diagnosed as AUS/FLUS in a scenario where nodules with low-risk indeterminate results (categories I and III) would undergo surgery.

닭의 정자선(精子腺) 기능(機能) 향상(向上)을 위한 연구(硏究) 1. 조직화학적(組織化學的) 및 전자현미경적(電子顯微鏡的) 관찰(觀察) (Study on functional elevations of sperm-host glands in domestic hens 1. Histochemical and electron microscopical observations)

  • 곽수동;우호춘;최상용
    • 대한수의학회지
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    • 제31권1호
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    • pp.1-10
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    • 1991
  • The present investigation was focussed on histochemical and electron microscopical observations of utero-vaginal(U-V) glands in U-V junctions of domestic hens. In histochemical observations, fine granules by PAS technique for mucopolysaccharides and nile blue stain for acidic lipids were slightly stained on the cytoplasm of U-V glandular epithelium. Larger granules by Sudan black B stain for neutral fat and phospholipids and Sudan III stain for neutral fat were heavily stained on the perinuclear region of the U-V gland epithelial cells. These positive materials were heavily stained on the U-V glandular epithelium of lowfecundity hens and non-laying hens. In scanning electron microscopic findings of the U-V junction surface, the orifices of U-V glands are seen as the crater-like invagination. The neck of the U-V gland and the epithelium of U-V iunction were covered by ciliated epithelial cells. Aggregates of spermatozoa are observed often to be on the necks of the U-V gland. These spermatozoa heads are embedded in the glandular tubules and many spermatozoa tails are free on the epithelium of uterine surface. In transmission electron microscopic findings, the epithelial cells of the U-V glandular orifices were ciliated, columnar cells. The apical regions of these cells contained numerous electrondense, round secretory granules of uniformly size. The epithelial cells of the U-V glandular tubule were columnar or pyramid shape with round or oval nuclei. These epithelial cells have numerous microvilli and also contained electron-dense, round secretary granules of uniformly size and electron-lucent vesicles of various size. Spermatozoa are seen as the cross-sections of various regions of heads and tails in glandular tubules. Also spermatozoa arranged longitudinally parallel within the glandular tubules.

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경관의 선호도 결정인자 모형 -골프장을 배경으로- (A Model on the Determinants of Visual Preference at Golf courses)

  • 서주환;이철민;맹상빈
    • 한국조경학회지
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    • 제29권1호
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    • pp.1-10
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    • 2001
  • The purpose of this thesis is to classify landscape-type of golf course, and t provide a better understanding of landscape of existing golf courses, seek a developed method for landscape, and other useful knowledge. In order to classify landscape type of the golf course, and analyze the preference for the determinants, we have selected 4 golf courses in Yongin, Kyonggi Province. The analysis in this study shows that a variable, 'familiarity' is the most potent influence of visual preference, (Sig 0.01), and it can be divided into five classes of landscape-type in golf course. More specifically, we conducted the analysis of the image of views and visual preference to bring out major factors which could decide visual preference in golf courses. The results between visual preference and physical variable are as follows; 1. It implies that a factor for a image of the view in golf course is analyzed by 4 districts from factor 1 to factor 4. An ability explaining those factors in the whole of variable quantity is 51.742%, implying factors for the image of the scene in golf courses are appeared as familiarity, changeableness, spaciousness, and naturalness. Among those factors, since familiarity(C.V.; 26.783%) and changeableness(C.V.; 112.200%) took high rank, this represents the fact that familiarity or changeableness highly affects the forming of image. 2. Defending on degree of image ability in golf course, we could classify as five types such as Type I, Type II, Type II, Type IV, and Type V. 3. As a result of calculating type of factor score, Type I had the lowest ranking in naturalness, and rather lower than others such as organization and spaciousness. The II is a top-ranked one in familiarity and naturalness, while it has the lowest ranking in spaciousness. Type III has the highest ranking in organization and preference. Type IV is the lowest-ranked one in familiarity and preference. Type IV is the lowest-ranked one is familiarity and preference. Type V has the highest ranking in spaciousness, but the lowest ranking in organization. 4. As a result of preference, Type III, Type II, Type V, Type I, and Type IV come out in order. That water-seen place type charges the highest rank shows the importance of changeable materials. 5. These factors-familiarity, organization, spaciousness and naturalness- are the major materials of the scene of view in golf courses. The possibility of how to use those for designing and making enhanced golf courses should be reinvestigated through these factors. Especially, it is acknowledged that the duction of changeableness, which is not mentioned in the study of informational approach, is much stimulating for the designing use. A further research on this theme should be made in the future, not limiting to the golf courses in Yongin.

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Marginal microleakage of single step adhesives

  • Lee, Dong-Kyun;Jeong, Jin-Ho;Cho, Young-Gon
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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    • pp.614-614
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    • 2003
  • I. Objectives The purpose of this study was to compare the marginal microleakage of Prompt L-Pop, AQ Bond, One-Up Bond F, Futurabond, and Xeno III in Class V cavity. II. Materials and Methods One hundred Class V direct resin restorations were placed in the buccal and lingual surfaces of 50 extracted human molars. Each cavity had occlusal margin in enamel and gingival margin in dentin. Teeth were randomly divided into five groups and restored using one of the single step adhesives and composite resins.(omitted)

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$(SR.Ca)TiO_3$세라믹의 하전입자 거동에 관한 연구 (A study on the behavior of charge particles of $(SR.Ca)TiO_3$ ceramic)

  • 김진사;최운식;신철기;김성열;박현빈;김태성;이준응
    • E2M - 전기 전자와 첨단 소재
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    • 제10권2호
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    • pp.97-104
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    • 1997
  • In this paper, in order to investigate the behavior of charged particles on (Sr.Ca)TiO$_{3}$ ceramics with paraelectric properties, the characteristics of electrical conduction and thermally stimulated current was measured respectively. As a result, the conduction mechanism is divided into three regions having different mechanism as the current increased. The region I below 200[V/Cm] shows the ohmic conduction. The region B between 200[V/cm] and 2000[V/cm] can be explained by the Poole-Frenkel emission theory, and the region III above 2000[V/cm] is dominated by the tunneling effect. The three peaks of TSC were obtained at the temperature of -20[.deg. C], 20[.deg. C] and 80[.deg. C], respectively. The origins of these peaks are that the .alpha. peak observed at -20[.deg. C] looks like to be ascribed to the ionization excitation from donor level in the grain, and the .alpha.' peak observed at 20 [.deg. C] appears to show up by hopping conduction of the trapped carrier of border between the oxidation layer and the grain, and the .betha. peak observed at 80[.deg. C] seems to be resulted from hopping conduction of existing carrier in the trap site of the border between the oxidation and second phase.

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$(Sr_{1-x}.Ca_x)TiO_3$입계층 세라믹의 유전 및 전기전도특성에 관한 연구 (A study on the dielectric and electrical conduction properties of$(Sr_{1-x}.Ca_x)TiO_3$ grain boundary layer ceramics)

  • 최운식;김충혁;이준웅
    • E2M - 전기 전자와 첨단 소재
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    • 제8권5호
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    • pp.611-618
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    • 1995
  • The (Sr$_{1-x}$ .Ca$_{x}$)TiO$_{3}$+0.6[mol%]Nb$_{2}$O$_{5}$ (0.05.leq.x.leq.0.2) ceramics were fabricated to form semiconducting ceramics by sintering at about 1350[.deg. C] in a reducing atmosphere(N$_{2}$ gas). Metal oxides, CuO, was painted on the both surface of the specimens to diffuse to the grain boundary. They were annealed at 1100 [.deg. C] for 2 hours. The 2nd phase formed by thermal diffusing from the surface lead to a very high apparent dielectric constant. According to increase of the frequency as a functional of temperature, all specimens used in this study showed the dielectric relaxation, and the relaxation frequency was above 106 [Hz], it move to low frequency with increasing resistivity of grain. The specimens showed three kinds of conduction mechanisms in the temperature range 25-125 [.deg. C] as the current increased: the region I below 200 [V/cm] shows the ohmic conduction. The region rt between 200 [V/cm] and 2000 [V/cm] can be explained by the Poole-Frenkel emission theory, and the region III above 2000 [V/cm] is dominated by the tunneling effect.fect.

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