• Title/Summary/Keyword: Intrinsic defect

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Effect of Hydrogen Radicals for Ion Implanted CVD Diamond Using Remote Hydrogen Plasma Treatment(RHPT)

  • Won, Jaihyung;Hatta, Akimitsu;Yagi, Hiromasa;Wang, Chunlei;Jiang, Nan;Jeon, Hyeongmin;Deguehi, Masahiro;Kitabatake, Makoto;Ito, Toshimichi;Sasaki, Takatomo;Hiraki, Akio
    • The Korean Journal of Ceramics
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    • v.4 no.1
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    • pp.15-19
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    • 1998
  • Defects formation of Chemical Vapor Deposition (CVD) diamond on $^4He^{2+}$ irradiation and after remote hydrogen plasma treatment(RHPT) were investigated by cathodoluminescence(CL). As calculated in the TRIM simulation, the light elements of $^4He^{2-}$ can be penetrated into the diamond bulk structure at 3~4 $\mu\textrm{m}$ depth. The effects of the implantation region were observed when 5 keV~20 keV electron energy (insight 0.3~4.0$\mu\textrm{m}$) of CL measurement was irradiated to diamond at temperature 80 K. After the RHPT, rehybridization of irradiation damaged diamond was studied. The intensity of 5RL center(intrinsic defect of C) was diminished. The 2.16 eV center (N-V center) occurring usually by annealing could not be seen after RHPT. The diamond was rehybridized by hydrogen radicals without etching and thermal degradation by the RHPT.

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Defect Analysis via Photoluminescence of p-type ZnO:N Thin Film fabricated by RF Magnetron Sputtering

  • Jin, Hu-Jie;So, Soon-Jin;Park, Choon-Bae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.3
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    • pp.202-206
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    • 2007
  • ZnO is a promising material to make high efficient ultraviolet(UV) or blue light emitting diodes(LEDs) because of its large binding energy and energy bandgap. In this study, we prepared ZnO thin films with p-type conductivity on silicon(100) substrates by RF magnetron sputtering in the mixture of $N_2$ and $O_2$. The process was accompanied by low pressure in-situ annealing in $O_2$ at $600^{\circ}C$ and $800^{\circ}C$ respectively. Hall effect in Van der Pauw configuration showed that the N-doped ZnO film annealed at $800^{\circ}C$ has p-type conductivity. Photoluminescence(PL) spectrum of the film annealed at $800^{\circ}C$ showed UV emission related to exciton and bound to donor-acceptor pair(DAP) as well as visible emission related to many intrinsic defects.

Prestack migration using seismic interferometry (탄성파 간섭파를 이용한 중합전 구조보정)

  • Kim, Young-Wan;Jang, Seong-Hyung;Yoon, Wang-Jung;Suh, Sang-Yong
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.203-207
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    • 2008
  • Prestack depth migration is used to image for complex geological structure such as faults, folds, and subsalt. In this case, it is widely used the surface reflection data as a input data. However, the surface reflection data have intrinsic problems to image the subsalt and the salt flank due to the complex wavefields and multiples which come from overburden. For overcoming the structural defect of the surface reflection data in the imaging, I used the virtual sources in terms of seismic interferometry to image the subsurface and suppress the multiples using the velocity model of the lower part of the virtual sources. The results of the prestack depth migration using virtual source gathers and velocity model below receivers are similar geological interfaces to the results from shot gathers of the conventional ocean bottom seismic survey. And especially artificial interfaces by multiples were suppressed without applying any other data processing to eliminate multiples. This study results by numerical modeling can make a valuable imaging tool when it is applied to satisfied field data for specific condition.

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The Free Musculocutaneous Flap in the Treatment of Chronic Osteomyelitis (유리 근피부판을 이용한 만성 골수염의 치료)

  • Chung, Duke-Whan;Cho, Chang-Hyun;Jung, Ki-Woong
    • Archives of Reconstructive Microsurgery
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    • v.8 no.2
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    • pp.163-169
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    • 1999
  • Purpose : To evaluate the efficacy of free musculocutaneous flap in the treatment of chronic osteomyelitis with drain sinus. Materials and Methods : Eighteen patients (sixteen male and two female) whose average age was 42.6 years were followed for an average of 3.5 years after free musculocutaneous flap for chronic osteomyelitis with drain sinus tract. The period of time between the initial injury and this procedure was average 10.6 years. The patients had an average of 4.1 prior surgical procedure before it. Results : Sixteen(88.9%) of the eighteen free musculocutaneous flap survived, including thirteen of latisimus dorsi flap, three of scapular free flap with muscle, two of medial plantar flap with abductor muscle. Sixteen cases had no evidence of recurrence at follow up. Conclusion : Free musculocutaneous flap is an extremely successful and reliable procedure for the treatment of chronic osteomyelitis with drain sinus. This flap with microvascular anastomses is highly vascularized through its own intrinsic blood vessels, which has the advantage of obliterating dead space and providing improved vascularity to the relatively ischemic recipient site and covering the skin defect.

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The Technology of Sloped Wall SWAMI for VLSI and Analysis of Leakage Current (고집적 회로를 위한 경사면 SWAMI 기술과 누설전류 분석)

  • 이용재
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.15 no.3
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    • pp.252-259
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    • 1990
  • This paper present new scheme for a Side Wall Masked Isolation(SWAMI) technology which take all the advatages provided by conventional LOCOS process. A new SWAMI process incorporates a sloped sidewall by reactive ion etch and a layer of thin nitride around the side walls such that both intrinsic nitride stress and volume expansion induced stress are greatly reduced. As a fabricate results, a defect-free fully recessed zero bird's beak local oxidation process can be realized by the sloped wall anisotropic oxide isolation. No additional masking step is required. The leakage current of PN diodes of this process were reduced than PN diode of conventional LOCOS process. On the other hand, the edge junction part was larger than the flat juction part in the density of leakage current.

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Effective Oxygen-Defect Passivation in ZnO Thin Films Prepared by Atomic Layer Deposition Using Hydrogen Peroxide

  • Wang, Yue;Kang, Kyung-Mun;Kim, Minjae;Park, Hyung-Ho
    • Journal of the Korean Ceramic Society
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    • v.56 no.3
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    • pp.302-307
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    • 2019
  • The intrinsic oxygen-vacancy defects in ZnO have prevented the preparation of p-type ZnO with high carrier concentration. Therefore, in this work, the effect of the concentration of H2O2 (used as an oxygen source) on the oxygen-vacancy concentration in ZnO prepared by atomic layer deposition was investigated. The results indicated that the oxygen-vacancy concentration in the ZnO film decreased by the oxygen-rich growth conditions when using H2O2 as the oxygen precursor instead of a conventional oxygen source such as H2O. The suppression of oxygen vacancies decreased the carrier concentration and increased the resistivity. Moreover, the growth orientation changed to the (002) plane, from the combined (100) and (002) planes, with the increase in H2O2 concentration. The passivation of oxygen-vacancy defects in ZnO can contribute to the preparation of p-type ZnO.

Bronchial compression in an infant with isolated secundum atrial septal defect associated with severe pulmonary arterial hypertension

  • Park, Sung-Hee;Park, So-Young;Kim, Nam-Kyun;Park, Su-Jin;Park, Han-Ki;Park, Young-Hwan;Choi, Jae-Young
    • Clinical and Experimental Pediatrics
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    • v.55 no.8
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    • pp.297-300
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    • 2012
  • Symptomatic pulmonary arterial hypertension (PAH) in patients with isolated atrial septal defect (ASD) is rare during infancy. We report a case of isolated ASD with severe PAH in an infant who developed airway obstruction as cardiomegaly progressed. The patient presented with recurrent severe respiratory insufficiency and failure to thrive before the repair of the ASD. Echocardiography confirmed volume overload on the right side of heart and severe PAH (tricuspid regurgitation [TR] with a peak pressure gradient of 55 to 60 mmHg). The chest radiographs demonstrated severe collapse of both lung fields, and a computed tomography scan showed narrowing of the main bronchus because of an intrinsic cause, as well as a dilated pulmonary artery compressing the main bronchus on the left and the intermediate bronchus on the right. ASD patch closure was performed when the infant was 8 months old. After the repair of the ASD, echocardiography showed improvement of PAH (TR with a peak pressure gradient of 22 to 26 mmHg), and the patient has not developed recurrent respiratory infections while showing successful catch-up growth. In infants with symptomatic isolated ASD, especially in those with respiratory insufficiency associated with severe PAH, extrinsic airway compression should be considered. Correcting any congenital heart diseases in these patients may improve their symptoms.

A Clinical Study on Childhood Hemolytic Anemia According to Etiological Classification (소아 용혈성 빈혈 환자에서 원인에 따른 임상적 분석)

  • Kwon, Hae-Sik;Kang, Jung-Chul;Won, Sung-Chul;Oh, Seung-Hwan;Lyu, Chuhl-Joo
    • Clinical and Experimental Pediatrics
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    • v.46 no.9
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    • pp.883-888
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    • 2003
  • Purpose : The etiology of hemolytic anemia can be classified as either cellular or extracellular defects of red blood cells. The aim of this study was to investigate the clinical and laboratory findings of hemolytic anemia concerning its etiological classification. Methods : Clinical and laboratory findings of the patients with hemolytic anemia treated from January 1987 to May 2002 at Severance Hospital were analyzed retrospectively. They were divided into two groups based on the types of red cell defects(group I : erythrocytic defect, group II : extraerythrocytic defect). Results : Twenty one cases were included in group I, thirty four cases in group II, and three cases were unclassified. In group I, nineteen cases(90.5%) were diagnosed as hereditary spherocytosis and were proved to have red cell membrane disorders while two cases(9.5%) were shown to have red cell enzyme deficiencies. In group II, thirteen cases(38.2%) were noted as autoimmune hemolytic anemia, eleven cases(32.4%) as traumatic or microangiopathic hemolytic anemia, four cases(11.8%) as drug induced hemolytic anemia, two cases(5.9%) were related with systemic lupus erythematosus and one case(2.9%) with malignancy. Hemoglobin at the time of diagnosis(7.5 g/dL vs. 6.2 g/dL, P<0.05) and the incidence of splenomegaly(85.7% vs. 18.2%, P<0.05) were higher in group I though blood urea nitrogen(9.0/0.4 mg/dL vs. 27.8/1.6 mg/dL, P<0.05) was higher in group II. Conclusion : Comparing the clinical features of pediatric hemolytic anemia, we concluded as following : In cases associated with extraerythrocytic defect, blood tests revealed significant initial lower hematocrit with higher level of BUN and Cr while cases with erythrocytic defect, splenomegaly were more common noted.

A High-Resolution Transmission Electron Microscopy Study of the Grain Growth of the Crystalline Silicon in Amorphous Silicon Thin Films (비정질 실리콘 박막에서 결정상 실리콘의 입자성장에 관한 고분해능 투과전자현미경에 의한 연구)

  • 김진혁;이정용;남기수
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.7
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    • pp.85-94
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    • 1994
  • A high-resolution transmission electron microscopy study of the solid phase crystallization of the amorphous silicon thin films, deposited on SiOS12T at 52$0^{\circ}C$ by low pressure chemical vapor deposition and annealed at 55$0^{\circ}C$ in a dry N$_{2}$ ambient was carried out so that the arrangement of atoms in the crystalline silicon and at the amorphous/crystalline interface of the growing grains could be understood on an atomic level. Results show that circular crystalline silicon nuclei have formed and then the grains grow to an elliptical or dendritic shape. In the interior of all the grains many twins whose{111} coherent boundaries are parallel to the long axes of the grains are observed. From this result, it is concluded that the twins enhance the preferential grain growth in the <112> direction along {111} twin planes. In addition to the twins. many defect such as intrinsic stacking faults, extrinsic stacking faults, and Shockley partial dislocations, which can be formed by the errors in the stacking sequence or by the dissociation of the perfect dislocation are found in the silicon grain. But neither frank partial dislocations which can be formed by the condensation of excess silicon atoms or vacancies and can form stacking fault nor perfect dislocations which can be formed by the plastic deformation are observed. So it is concluded that most defects in the silicon grain are formed by the errors in the stacking sequence during the crystallization process of the amorphous silicon thin films.

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A literature study about the comparison of Oriental-Occidental medicine on the Atopic dermatitis (아토피 피부염의 東西醫學的 文獻 考察)

  • Park, Min-Cheol;Kim, Jin-Man;Hong, Cheol-Hee;Hwang, Chung-Yeon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.15 no.1
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    • pp.226-252
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    • 2002
  • The results of a literature study about the comparison of Oriental-Occidental medicine on the Atopic dennatitis were as follows. 1. In Oriental medicine, Atopic dermatitis belongs to the category of the Naesun(내선), Taeryumchang(胎斂瘡), Eczema(濕疹), Chimumchang(浸淫瘡). In Occidental medicine, the other names of Atopic dermatitis are allergic eczema, IgE dermatitis, flexual eczema etc. 2. In Oriental medicine, the definition of atopic dermatitis includes chang(瘡), sun(선), and pung(風). Occidental medicine, is one of the intrinsic eczema classifications. In fact eczema term circumscribes dermatitis in atopic patients. 3. In Oriental medicine, the etiology and pathogenesis of Atopic dermatitis arose from the state of cogenital defect(稟賦不足), internal accumulation of damp and heat(濕熱內蘊) at first, and then invaded pathogenic wind, damp, heat factors again, and combined endo-exoteric pathogenic factors. So it appears in skin. In Occidental medicine, the etiology and pathogenesis of Atopic dermatitis approaches in genetic, allergic and immunologic, pharmacophysioloic aspects. It is only a hypothesis but there is no known facts about radical aetiology. 4. In Oriental medicine, differentiation of syndromes classifies manifestation aspects, etiology and pathogenesis, and invasion period. In Occidental medicine, it divides into an invasion period, and clinical aspect etc. 5. In Oriental medicine, Internal theraphys of Atopic dermatitis are decoction of ingredients(湯劑), pills(丸), and tablet(片). So, it prescribes as treatments on the ground of differentition of syndrome. In Occidental medicine, there is no radical therapy because Atopic dispositions don't change. But steroid, antihistamine as symptomatic tre atments are generally used in Occidental medicine. 6. In Oriental medicine, external therapies are wet dressings(濕敷), lotion(洗劑), powder(散劑), adhesive plasters(膏劑), oil(油劑), smoking(烟薰法), warm over fire therapy(熱烘療法), acupunture and moxibustion therapy(鍼灸療法).

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