6 research outputs found
Quantitative analysis of mutans streptococci adhesion to various orthodontic bracket materials in vivo
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Όλ¬Έ(μμ¬) --μμΈλνκ΅ λνμ :μΉμνκ³Ό, 2009.2.Maste
ZnO nanorod heterostructures for light emitting device applications
Doctorμ°νμμ°μ μ²μμ λ°κ΄μμ¬λ‘ λ리 μ΄μ©λλ μ§νκ°λ₯¨κ³Ό μ μ¬ν κ²°μ ꡬ쑰μ μ§μ μ²μ΄ν λ°΄λκ°μ κ°μ§κ³ μμ΄μ μ°¨μΈλ κ΄μμ¬λ‘ μ£Όλͺ©λ°κ³ μλ€. νΉν μ°νμμ° λλ
Έμμ¬λ λ€μν κΈ°ν μμ λμ κ²°μ μ±μ μ§λκ³ μ±μ₯ν μ μμ΄μ μ λΉμ© κ³ ν¨μ¨ κ΄μμ κ°λ°μ κΈ°λ³Έ μμ¬λ‘ μ΄μ©λ κ°λ₯μ±μ΄ μλ€.μ°νμμ° λλ
Έμμ¬λ₯Ό μ΄μ©ν κ΄μμλ₯Ό κ°λ°νκΈ° μν΄μλ μμ¬μ λ¬Όμ±μ μ‘°μ νκ³ κ°λ³ λλ
Έμμ¬ κΈ°λ°μ μμλ€μ μ§μ ννλ κ³Όμ κ° ν΄κ²°λμ΄μΌ νλ€. λ³Έ νμλ
Όλ¬Έμ μ°νμμ° λλ
Έλ§λμ λ¬Όμ±μ λν, μΌλ‘μμ ν΅ν μΌμκ³ νν©λ¬Ό μ μ‘°, μ±μ₯μμΉκ° μ‘°μ λ μ΄μ’
ꡬ쑰 μ μ‘° κΈ°μ μ μ΄μ©νμ¬ μ μ΄νκ³ μ μ‘°λ μ΄μ’
ꡬ쑰λ€μ κ΄νμ νΉμ±μ μ λμ μΌλ‘ λΆμν λΏ μλλΌ μ°νμμ° λλ
Έλ§λ μ΄μ’
ꡬ쑰 μ΄λ μ΄λ₯Ό κΈ°λ°μΌλ‘ ν λ°κ΄λ€μ΄μ€λμ νμμ μ§λ₯Ό μμ°νλ κ²μ λ΄μ©μΌλ‘ νλ€.λ¨Όμ μ°νμμ° λλ
Έλ§λμ λνμ μν΄ μμ νλΌμ¦λ§ μ²λ¦¬μ κ°λ₯¨ μ ꡬ체μ νλ¦μ λ³μ‘°νλ κΈ°λ²μ κ°λ°νλ€. μ°νμμ° λλ
Έλ§λλ₯Ό μ μ ν 쑰건μμ μμ νλΌμ¦λ§ μ²λ¦¬ν κ²½μ° μ κΈ°μ λλκ° ν₯μλλ κ²μ κ΄μ°°νμΌλ©° κ΄λ°κ΄λΆμμ ν΅ν΄ μμκ° μ°νμμ° λ΄μ λλλ‘ μμ©νμμ νμΈνλ€. κ°λ₯¨ μ ꡬ체μ νλ¦μ λ³μ‘°νλ λ°©λ²μ μ°νμμ° λλ
Έμμ¬ λνμ ꡬ쑰λ³ν, κ²°ν¨ μ€μμ μ¦κ°μ κ°μ λΆμ μ μΈ ν¨κ³Όλ₯Ό μ΅μννλ©΄μ μ°νμμ° λλ
Έλ§λμ μ κΈ°μ , κ΄νμ νΉμ±μ μ‘°μ ν μ μλ λ°©λ²μμ΄ νμΈλμλ€. λν μ°νμμ°μ κΈ°λ°μΌλ‘ ν κ΄μμ κ°λ°μ μ£Όλ κ±Έλ¦ΌλμΈ pν μ°νμμ° μ μ‘°μ λν μ°κ΅¬λ₯Ό μννμ¬ μ°νμμ° λ°λ§ μ μ‘°μ μΈμ 첨κ°ν κ²½μ° pν μ κΈ°μ λνΉμ±μ 보μ΄λ κ²μ νμΈνμλ€.μ°νμμ° λλ
Έλ§λμ λ°΄λκ°μ μ‘°μ νκΈ° μν΄ μ°νμμ°λ§κ·Έλ€μ λλ
Έλ§λλ₯Ό λΉμ΄λ§€μ κΈ°κΈμννκΈ°μμ¦μ°©λ²μΌλ‘ μ±μ₯νλ μ°κ΅¬λ₯Ό μννμλ€. μ±μ₯λ μ°νμμ°λ§κ·Έλ€μ λλ
Έλ§λλ λ§κ·Έλ€μμ ν¨λμ λ°λΌ λ°κ΄ μλμ§κ° 200 meV κΉμ§ μ¦κ°λ¨μ 보μ¬μ£Όμλ€. λν μ°νμμ°λ§κ·Έλ€μ λλ
Έλ§λμ ꡬ쑰μ , κ΄νμ νΉμ±μ λΆμν κ²°κ³Ό μ°νμμ°λ§κ·Έλ€μμ λλ
Έλ§λ ννλ‘ μ μ‘°μ λ°λ§μ΄λ λ²ν¬μ λΉν΄ μ±λΆλΆν¬μ λΆκ· μΌλκ° νμ ν κ°μνλ κ²μ νμΈνμλ€.μ°νμμ° λλ
Έλ§λ κΈ°λ°μ κ΄μμ κ°λ°μ μν΄ λνκ³Ό λ°΄λκ° μ‘°μ μΈμλ λ¬Όμ±μ΄ μ‘°μ λ μ°νμμ° λλ
Έλ§λ μ΄μ’
ꡬ쑰λ₯Ό μ νμ±μ₯νμ¬ μμ μ§μ νμ μ΄μμ λ¦λ μ°κ΅¬λ₯Ό μννλ€. μ΄λ₯Ό μν΄ μ μλΉ λ¦¬μκ·ΈλνΌμ λΉμ΄λ§€μ κΈ°κΈμννκΈ°μμ¦μ°©λ²μ κ²°ν©νμ¬ μ°νμμ° λλ
ΈνλΈλ₯Ό μνλ μμΉμ μ νμ±μ₯νκ³ μ±μ₯λ λλ
ΈνλΈμ μ΄μ’
λ¬Όμ§μ μ½ν
ν λλ
Έλ§λ νΉμ λλ
ΈνλΈ μ΄μ’
ꡬ쑰 μ΄λ μ΄λ₯Ό μ±μ₯νλ€. λνμ μΌλ‘ μ°νμμ° λλ
ΈνλΈμ μ°νμμ°λ§κ·Έλ€μμΈ΅κ³Ό μ°νμμ°μΈ΅μ κ΅λλ‘ μ¦μ°©νμ¬ λμ¬λ°°μ΄ λ¨μΌμμμ°λ¬Όκ΅¬μ‘°λ₯Ό μ μ‘°νμ¬ μ νμ±μ₯λ μ°νμμ° λλ
ΈνλΈμ λ°κ΄ μλμ§λ₯Ό μ λ°νκ² μ‘°μ ν μ μμμ νμΈνλ€.μμ¬μ μ±μ₯κΈ°μ μ μ΄μ©ν λ¬Όμ± μ‘°μ μ°κ΅¬ μΈμλ μμ¬μ λ¬Όμ±μ μ ννκ² νκ°νλ μ°κ΅¬ λν μνλμλ€. κ΄μμ κ°λ°μ μν΄ μ°νμμ° λλ
Έλ§λμ λ¬Όμ±μ μ‘°μ νλ μ°κ΅¬λ₯Ό μ§νν λ° κ΄μμ¬μ μ€μν νΉμ±μΈ μμν¨μ¨μ νκ°νλ μ°κ΅¬λ₯Ό μννλ€. μ°νμμ°μ κ²½μ° μ¬κΈ°μ κ²°ν©μλμ§κ° 60 meVμ λ¬ν΄μ μμ¨μμμ κ΄νμ νΉμ±λ μ¬κΈ°μμ μν₯μ λ§μ΄ λ°λλ€. λ°λΌμ μ°νμμ° λλ
Έλ§λμ λλ
Έλ§λ μ΄μ’
ꡬ쑰μμ μ¬κΈ°μ μμ‘ νΉμ±μ μ λμ μΌλ‘ κ΄μ°°νκ³ μ¬κΈ°μ μμ‘ νΉμ±κ³Ό μμν¨μ¨κ³Όμ μκ΄κ΄κ³λ₯Ό μ‘°μ¬νμλ€. λλ
Έλ§λμμμ μ¬κΈ°μ μμ‘ νΉμ± κ΄μ°°μ μν΄ μκ·Ήμ λ°κ΄ λΆμκ³Ό λλ
Έλ§λ μμꡬ쑰λ₯Ό κ²°ν©ν μλ‘μ΄ λΆμλ²μ κ°λ°νμΌλ©° μ΄λ₯Ό ν΅ν΄ μ°νμμ° λλ
Έλ§λ λ΄μμμ μ¬κΈ°μ νμ°κ±°λ¦¬λ₯Ό μ ννκ² κ²°μ ν μ μμλ€. μ°νμμ° λλ
Έλ§λμ λλ
Έλ§λ μ΄μ’
ꡬ쑰μ μλΆν΄λΆκ΄νΉμ±μ μ°κ΅¬νμ¬ μ¬κΈ°μ μ¬κ²°ν©μ λμνμ μ‘°μ¬νμΌλ©° μλΆν΄λΆκ΄νΉμ±λΆμμ ν΅ν΄ μ°νμμ° λλ
Έλ§λμ λλ
Έλ§λ μ΄μ’
ꡬ쑰κ°μ μμν¨μ¨μ°¨μ΄λ₯Ό λ°νλ€. μ΄μ λνμ¬ μ¬κΈ°μ νμ°μ κ΄ν κ³΅κ° μ 보μ κ²°ν©ν΄μ μ°νμμ° λλ
Έλ§λμ λλ
Έλ§λ μ΄μ’
ꡬ쑰μμμ μμν¨μ¨μ°¨μ΄λ₯Ό μ¬κΈ°μ νμ°μ κ΄μ μμ μ€λͺ
νμλ€.μ°νμμ° λλ
Έλ§λμ λ¬Όμ±μ μ‘°μ νκ³ νκ°νλ μ°κ΅¬λ₯Ό λ°νμΌλ‘ μ νμ±μ₯λ μ°νμμ° λλ
ΈνλΈμ μΈμ΄ λνλ μ°νμμ°μΈ΅μ μ½ν
νμ¬ μμ§λ°°ν₯λ λλ
Έλ§λ μ΄μ’
ꡬ쑰 μ΄λ μ΄λ₯Ό μ μ‘°νκ³ μ κ·Ήμ νμ±νμ¬ λλ
Έλ§λ μ΄μ’
ꡬ쑰 κΈ°λ°μ λ°κ΄λ€μ΄μ€λμ νμμ μ§ μ΄λ μ΄λ₯Ό κ°λ°νμ¬ μ²μ μ κ³λ°κ΄κ³Ό κ΄μ νΉμ±μ κ΄μ°°νλ€.ZnO nanomaterials have great potential for highly-efficient and novel photonic device applications due to their high crystallinity, wide and direct band gap, peculiar physical properties such as large exciton binding energy. Semiconductor photonic devices can be realized by tuning structural, electrical, and optical properties of semiconducting materials. In this dissertation, the methods for controlling characteristics of ZnO nanorods are presented, and the physical understanding on the control of the properties are discussed. Finally, some photonic devices such as light-emitting devices and solar cells based on ZnO nanorod heterostructures are demonstrated.The physical properties of ZnO nanorods were controlled by doping, alloying for band gap engineering, and formation of heterostructures. Current-voltage characteristics measurements and transfer characterizations of field-effect transistors based on doped ZnO nanorods exhibited that the electrical conductivity of ZnO nanorods could be precisely controlled without deterioriation such as structural deformation and optical quality degradation. Alloying with MgO in ZnO nanorods made it possible to tune band gap energy of ZnO in the ultraviolet wavelength region. The structural characterizations and the temperature-dependent PL measurements revealed that ternary alloyed MgZnO nanorods had improved homogeneity of elements compared to bulk and thin films counterparts. Additionally, the photoluminescent properties of position-controlled ZnO nanotube arrays were finely tuned by formation of heterostructures along radial direction of ZnO nanotubes.The quantum efficiency of ZnO nanorod heterostructures was quantitatively investigated by study on exciton transport in ZnO nanostructures. The precise and quantitative analysis technique for determination of exciton diffusion length in ZnO nanorods was developed using cathodoluminescence spectroscopy and ZnO nanorod single-quantum-wells. The combination of cathodoluminescence spectroscopy and time-resolved photoluminescence spectroscopy enabled to investigate exciton transport and internal quantum efficiency of ZnO nanorods in the quantitative manner. Through a series of experimental results, it was revealed that ZnO coaxial nanorod heterostructures can give gain of internal quantum efficiency of ZnO nanorods.The demonstration of photonic devices such as light-emitting devices and photovoltaic cells based on position-controlled ZnO nanorod heterostructures is presented. ZnO nanoarchitecture LED arrays were fabricated by position-controlled growth of ZnO nanotubes, doping in ZnO via phosphorous incorporation, and metallization technique for three-dimensional structures. The ZnO nanoarchitecture LED arrays exhibited electroluminescence which can be observed with unaided eyes under dark condition. Additionally, the photovoltaic characteristics of ZnO-based coaxial nanorod p-n junction arrays, ZnO:P/ZnO, were also investigated
Quantitative analysis of mutans streptococci adhesion to various orthodontic bracket materials in vivo
λ²λμ§ ννλ κ΅μ μΉλ£ μ€μ λ°μνλ λνμ μΈ λΆμμ©μΌλ‘μ νΉν κ΅μ μ© λΈλΌμΌμ λν μΈκ· λΆμ°©μ΄ κ·Έ μμΈμ΄ λ μ μλ€. λ³Έ μ°κ΅¬μ λͺ©μ μ μλ‘ λ€λ₯Έ νλ©΄ νΉμ±μ κ°μ§ μΈ μ’
λ₯μ λΈλΌμΌμ κ΅¬κ° λ΄ μ₯μ°©νμ λ κ° μ¬λ£μ νλ©΄μ λν mutans streptococci λΆμ°© μ λλ₯Ό μΈ‘μ νμ¬ λΈλΌμΌ μ¬λ£μ λ°λ₯Έ λ²λμ§ νν λ° μΉμ μ°μ λ°μ κ°λ₯μ±μ λΆμνλ κ²μ΄μλ€. μνμ
λ° μΉμ λΆμλ³ mutans streptococci λΆμ°© μ λμ μ°¨μ΄λ₯Ό λ°°μ νκ³ λΈλΌμΌ μμ¬λ£μ λ°λ₯Έ μ°¨μ΄λ§μ κ²μΆνκΈ° μνμ¬ κ· νμμ λΈλ‘ μ€νκ³νμ μ€κ³νμλ€. νΌμ€νμμΈ 30μΈ μ¬μ±μ κ΅¬κ° λ΄μ μ₯μ°©ν μ μλ tooth positioner ννλ‘ 3μΈνΈμ νλΌμ€ν± λ§μΆ€ νΈλ μ΄λ₯Ό μ μνμμΌλ©°, μ΄ νΈλ μ΄μ μ§μ‘면체μ νν()λ‘ μ μν stainless steel, monocrystalline sapphire, polycrystalline alumina μ‘°κ°μ μΈνΈλ§λ€ μλ‘ λ€λ₯Έ μμλ‘ μ μΉλΆμ ꡬμΉλΆ μλ©΄μ λΆμ°©νμλ€ μ΄λ κ² μ μλ 3μ’
λ₯μ μ€νμ₯μΉλ₯Ό 12μκ° λμ νΌ μ€νμμ κ΅¬κ° λ΄μ μ₯μ°©ν ν, κ° λΈλΌμΌ μ¬λ£ νλ©΄μ νμ±λ μΉνλ₯Ό μ±μ·¨νμ¬ bacitracinμ΄ ν¬ν¨λ mitis salivariusλ°°μ§μμ 48μκ° λ°°μ ν colony countingμ ν΅ν΄ κ·Έ νλ©΄μ λΆμ°©λ mutans streptococci μμ λΉκ΅νμλ€. μ΄μ κ°μ λ°©λ²μΌλ‘ 3μΈνΈμ μ€νμ₯μΉμ λν΄μ κ°κ° 5νμ© μ΄ 15νμ μ€νμ μννμλ€. κ·Έ κ²°κ³Ό μνμ
λ° μΉμ λΆμλ³ λ° λΈλΌμΌ μ¬λ£λ³ μΈκ· λΆμ°© μ λλ λͺ¨λ μ μν μ°¨μ΄λ₯Ό 보μ΄μ§ μμλ€. κ²°λ‘ μ μΌλ‘ λ³Έ μ°κ΅¬μ κ²°κ³Ό in vivo conditionμμ λΈλΌμΌ μ¬λ£μ μ°¨μ΄λ mutans streptococci λΆμ°©μ μν₯μ λ―ΈμΉμ§ λͺ»νλ κ²μΌλ‘ 보μλ€.
Objective: To estimate the effects of bracket material type on enamel decalcification during orthodontic treatment, this study analyzed the adhesion level of mutans streptococci (MS) to orthodontic bracket materials in vivo. Methods: Three different types of orthodontic bracket materials were used: stainless steel, monocrystalline sapphire, and polycrystalline alumina. A balanced complete block design was used to exclude the effect of positional variation of bracket materials in the oral cavity. Three types of plastic individual trays were made and one subject placed the tray in the mouth for 12 hours. Then, the attached bacteria were isolated and incubated on a mitis salivarius media containing bacitracin for 48 hours. Finally, the number of colony forming units of MS was counted. The experiments were independently performed 5 times with each of the 3 trays, resulting in a total of 15 times. Mixed model ANOVA was used to compare the adhesion amount of MS. Results: There was no difference in colony forming units among the bracket materials irrespective of jaw and tooth position. Conclusions: This study suggested that the result of quantitative analysis of MS adhesion to various orthodontic bracket materials in vivo may differ from that of the condition in vitro