• Title/Summary/Keyword: type of defects

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Reverse-bias Leakage Current Mechanisms in Cu/n-type Schottky Junction Using Oxygen Plasma Treatment

  • Kim, Hogyoung
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.2
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    • pp.113-117
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    • 2016
  • Temperature dependent reverse-bias current-voltage (I-V) characteristics in Cu Schottky contacts to oxygen plasma treated n-InP were investigated. For untreated sample, current transport mechanisms at low and high temperatures were explained by thermionic emission (TE) and TE combined with barrier lowering, respectively. For plasma treated sample, experimental I-V data were explained by TE or TE combined with barrier lowering models at low and high temperatures. However, the current transport was explained by a thermionic field emission (TFE) model at intermediate temperatures. From X-ray photoemission spectroscopy (XPS) measurements, phosphorus vacancies (VP) were suggested to be generated after oxygen plasma treatment. VP possibly involves defects contributing to the current transport at intermediate temperatures. Therefore, minimizing the generation of these defects after oxygen plasma treatment is required to reduce the reverse-bias leakage current.

결함 제어를 통한 금속산화물 소재의 전기화학 특성 제어

  • Jeong, Hyeong-Mo;Sin, Won-Ho
    • Ceramist
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    • v.21 no.2
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    • pp.49-58
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    • 2018
  • Metal oxide based materials have been widely used to fields of electrochemical applications. Recently, various type of defects from microstructures of metal oxides and their nanocomposites have been raised as the important material design factors for realizing highly improved electrochemical properties. Previous experimental and theoretical works have suggested that controlling the reaction activity and kinetics of the key electrochemical reactions by activated interfaces originating from the defect sites can play an important role in achieving the robust energy storage and conversion. Therefore, this paper focuses on the role of defect-controlled metal oxide materials such as doping, edge-sites, grain boundaries and nano-sized pores for the high performances in energy storage devices and electrocatalysts. The research approaches demonstrated here could offer a possible route to obtain noble ideas for designing the metal oxide materials for the energy storage and conversion applications.

Familial Hearine Loss (가족성 난청)

  • 전광수;장선문;박찬일
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1978.06a
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    • pp.7.2-7
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    • 1978
  • There are over 60 types of hereditary hearing loss in man and most of these are distinguished from one another by outstanding associated defects caused the same gene producing hearing loss. However, there are at least 12 types of hereditary hearing loss with no known associated defects. The authors experienced two similar families with hereditary hearing loss. The affected offsprings had inevitably an affected parent in type of transmissin (autosomal dominant) and the hearing loss developed in childhood and progressed. Audiologic findings showed bilateral symmetrical moderate to severe sensori-neural hearing loss with flattened configuration on the audiogram. Vestibular function tests showed no abnormal findings and the associated anomalies could'nt be observed in history or clinical examinations.

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Geometrical Defect Detection of Secondary Battery Using 3-Dimensional CAD Model (3D CAD 모델을 이용한 이차 전지의 형상 결함 검출)

  • Yeong-Ho Jo;Keun-Ho Rew;Sang-Yul Lee
    • Journal of Information Technology Applications and Management
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    • v.29 no.6
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    • pp.135-144
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    • 2022
  • In this study, we transformed 4680 type lithium-ion batteries to 3-dimensional CAD models and present a methodology to detect defects using Radon inverse transformation. Transparency was applied to the model to make it look like a CT image when viewed from the front. One normal and three defect models were created and analyzed. The models were saved as image files while rotating at a certain angle. Then, we used the Radon inverse transformation to reconstruct the original 3D geometry from the image files. Finally, we successfully found defects in the defect models for three cases.

Dependence of Thermal Annealing Conditions on Photoluminescence in $SiO_2$ films

  • Lee, Jae-Hee;Lee, Weon-Sik;Kim, Kwang-Il
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.102-102
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    • 1999
  • Visible photoluminescence(PL) in si-implanted SiO2 films on crystaline silicon were observed. Thermal oxide films of 1 ${\mu}{\textrm}{m}$ thickness on P-type crystal silicon were made and si+ ions were implanted with 200keV acceleration voltage on ti. Argon laser (wavelength 488nm) and PM tube were used for PL measurements. As annealing time increased at low temperature, the visible PL intensity are increased and the peak positions are changed. On the other hand, with increasing annealing time at high temperature, the visible PL intensity are disappeared. From the PL peaks and intensity changes, XRD results, and TEM observations, we will discuss the origin of PL in Si+-implanted SiO2 films with oxygen righ defects and silicon rich defects.

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A COMPARATIVE STUDY OF EFFECTS OF THE BIOCERAMICS ON HEALING PROCESSES OF THE ALVEOLAR BONE DEFECTS IN DOGS (수종의 합성골이식재가 성견 치조골 결손의 치유에 미치는 영향에 관한 비교연구)

  • Park, Yang-Jae;Kwon, Young-Hyuk
    • Journal of Periodontal and Implant Science
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    • v.23 no.3
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    • pp.422-441
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    • 1993
  • The purpose of this study was to compare effects of the bioceramics on healing processes of the alveolar bone defects in dogs. Five adult dogs aged 1 to 2 years were used in this study. Experimental alveolar bone defects were created surgically with a #1/2 round bur at the furcation area of the buccal surface of the mandibular 3rd, 4th premolars and 1st molar. Fifteen experimental alveolar bone defects were devided into three groups according to the type of graft materials. The groups were as follows : 1) flap operation with dense hydroxyapatite( DHA group ) 2) flap operation with porous hydroxyapatite( PHA group ) 3) flap operation with natural coral ( NC group ) At 1, 2, 4, 6, and 12 weeks, dogs were serially sacrificed and specimens were prepared with Hematoxylin-Eosin stain and Mallory stain for light microscopic evaluation. The results of this study were as follows : 1. In every group, inflammatory cell infiltrations were seen at 1st weeks due to surgical trauma, however inflammatory response owing to graft materials were not seen. 2. In every group, the appearance of connective tissue around graft materials was loosely formed at the initial stages, however the connective tissue was densely formed at 2 weeks. 3. The presence of osteocytes were observed at 2 weeks in the natural coral group, however the osteocytes were appeared at 6weeks in the dense hydroxyapatite group. 4. A new bone was formed from the base and walls of the defect and gradually expanded toward the graft materials. 5. A resorption of the natural coral occurred irregularly at the periphery of the material, therefore the size and shape of the natural coral were reduced at 6 weeks. 6. At 12 weeks, the porous hydroxyapatite and natural coral were surrounded by newly formed bone most completely, however dense hydroxyapatite was surrounded by newly formed bone in part.

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SPARING EFFECTS OF COBALT OR NICKEL ON ZINC NUTRITION AND THE DIFFERENCE IN ZINC ABSORPTION BETWEEN ANCONA AND NEW HAMPSHIRE X LEGHORN CROSS CHICKS

  • Chung, A.S.;Sunde, M.L.;Grummer, R.H.;Hoekstra, W.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.1 no.2
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    • pp.73-79
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    • 1988
  • Experiments were conducted to determine whether supplemental cobalt (Co) or nickel (Ni) would prevent the signs of zinc (Zn) deficiency in chicks fed a high calcium (1.5%) corn-soybean diet and to examine the difference in $^{65}Zn$ absorption rates between inbred Ancona and crossbred New Hampshire X Single Comb White Leghorn chicks. In the initial experiment, the supplementation of 27 ppm Ni, 27 ppm Co or 54 ppm Co to a basal diet increased weight gain and reduced feather defects; 54 ppm Ni tended to increase weight gain but did not reduce feather defects. In further experiments, chicks fed the diet supplemented with 54 ppm Co usually showed increased weight gain and reduced feather defects; however, chicks fed a diet supplemented with 54 ppm Ni less frequently showed these effects. In another test, Ancona chicks fed a diet supplemented with 30 ppm Zn (except during a $^{65}Zn$ absorption study period) showed lower weight gain, more feather defects and less $^{65}Zn$ absorption than did New Hampshire X Leghorn cross chicks. Similar results were achieved with two strains of chicks fed the basal and 54 ppm Ni, 54 ppm Co or 60 ppm Zn supplemented diets. The sparing effects of Co on Zn which were commonly observed and the lesser effect of Ni or Zn were shown to be, at least in part, the result of increased availability of dietary Zn. That Ancona chicks required more Zn than New Hampshire cross chicks for the development of feathers and for growth is partly the result of decreased Zn absorption from the type of diets fed.

A morphologic evaluation of defects created by a piezoelectric ultrasonic scaler on casting gold alloy (압전방식초음파치석제거기의작업조건에따른치과주조용합금의삭제결손부 양상에 관한 고찰)

  • Kim, Young-Sung;Kim, Soo-Hwan;Kim, Won-Kyung;Lee, Young-Kyoo
    • Journal of Periodontal and Implant Science
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    • v.39 no.4
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    • pp.385-390
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    • 2009
  • Purpose: In this study we evaluated the morphologic aspects of defects created by a piezoelectric ultrasonic scaler with scaler tip on casting gold alloy using scanning electron microscope (SEM) images and defect surface profiles. Methods: 54 blocks of type III casting gold alloy (Firmilay, Jellenko Inc, CA, USA) were scaled by a piezoelectric ultrasonic scaler (P-MAX, Satelec, France) with scaler tip (No. 1 tip) on a sledge device. 2-dimensional profiles of defects on all samples were investigated by a surface profilometer (a-Step 500, KLA-Tencor, CA, USA). The selected working parameters were lateral force (0.5 N, 1.0 N, 2.0 N), mode (P mode, S mode), and power setting (2, 4, 8). SEM images were obtained. Defect surface profiles were made on Microsoft Excel program using data obtained by a surface profilometer. Results: Among P mode samples, there were similarities on defect surface profiles and SEM images regardless of lateral force. The defects created in P mode were narrow and shallow although the depth and the width increased as power setting changed low (2) to high (8). In P mode samples, the defect depth was the greatest when lateral force of 0.5 N was applied. However all the depths were smaller than 1 m. SEM images of Lateral force of 0.5 N, S mode, power setting 2 and 4 were similar to that of P mode, but the other SEM images of S mode showed discernible changes. Defect depth of S mode samples was the greatest when lateral force of 1.0 N was applied. Conclusions: Within the limitations of this study, it can be concoluded that removing capability of piezoelectric scaler with scaler tip becomes maximized as power level becomes higher but the capability is restricted when excessive lateral force is applied on scaler tip.

Evaluation of an Amniotic Membrane-Collagen Dermal Substitute in the Management of Full-Thickness Skin Defects in a Pig

  • Kim, Hyunji;Son, Daegu;Choi, Tae Hyun;Jung, Samhyun;Kwon, Sunyoung;Kim, Junhyung;Han, Kihwan
    • Archives of Plastic Surgery
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    • v.40 no.1
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    • pp.11-18
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    • 2013
  • Background To minimize the inflammatory reaction and improve healing, a new modified dermal substitute composed of an atelocollagen, chondroitin-6-sulfate, and amniotic membrane (AM) was applied to full-thickness skin defects in a pig. Atelocollagen was extracted from bovine skin, and two modified dermal substitutes were generated according to the cross-linking type. Methods The AM-collagen dermal substitutes were characterized and compared with currently used dermal substitutes in a pig skin defect model. There were five experimental groups: dehydrothermal (DHT) cross-linking atelocollagen with the AM on the top (AM-DHT), DHT and chemical cross-linking atelocollagen with the AM on the top (AM-DHT/chemical), Terudermis, Integra, and AlloDerm. After $3{\times}3cm$ full-thickness skin defects on the back of a pig were created, each dermal substitutes dermal substitutes was randomly grafted on the defects. Two weeks after grafting, autologous partial-thickness skin was over-grafted on the neodermis. The take rate of the dermal substitutes, skin, and histological sections were all assessed at 1, 2, and 4 weeks postoperatively. Results More rapid healing and a higher take rate were evident in the AM-DHT and Terudermis groups. Histological examination revealed fewer inflammatory cells and more fibroblast hyperplasia in these two groups. Four weeks after surgery, the amount of newly formed collagen was significantly more appropriate in the AM-DHT group. Conclusions These observations provide supporting evidence that a newly developed amniotic-collagen dermal substitute may inhibit inflammatory reactions and promote wound healing.

Refinements of Adipofascial flap for Small Defects of Fingers and Toes: Indication and Surgical Tips

  • Chung, Yoon-Kyu;Choi, Jin-Hee;Kim, Jiye;Chung, Seum
    • Archives of Reconstructive Microsurgery
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    • v.25 no.2
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    • pp.25-28
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    • 2016
  • Purpose: Reconstruction of small defects of the dorsal fingers and toes is a challenging task. Although adipofascial flap is widely used for these areas, additional refinements are warranted. In this paper, we define the appropriate defect size in the finger and toes that can be treated with the adipofascial flap, refine its surgical indications and present a few surgical tips. Materials and Methods: Twelve patients with dorsal defects of the fingers and toes were treated with a random-type adipofascial turn-over flap and skin graft. If the defect area exceeded the size that could be covered by a conventional design, the flap base was designed in oblique or curvilinear fashion to lengthen the flap. For accurate defect coverage, the width of the flap base was designed in an asymmetrical shape depending on the defect configuration, varying the width from 0.3 to 1.0 cm, as opposed to the standard 0.5 to 1.0 cm width. Moreover, the lateral limit of the flap was defined as the lateral axial line. The size of the defect ranged from $3.0{\times}1.7cm$ to $1.5{\times}1.3cm$. Results: All flaps survived completely. Gliding function of the hand was well preserved and there was no evidence of tendon adhesion. Conclusion: The small defect in the dorsal finger and toe can be defined as less than one phalanx-length, measuring about $3.0{\times}2.0cm$ in size. If the defect exceeds this dimension, it is recommended that a different option be considered. We believe the adipofascial flap is an excellent option for treating small defects.