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        검색결과 155

        21.
        2018.09 구독 인증기관·개인회원 무료
        Cold, salt and heat are most critical factors that restrict full genetic potential, growth and development of crops worldwide.. In this study, we applied an annealing control primer (ACP) based GeneFishing approach to identify differentially expressed genes (DEGs) in annual ryegrass (cv. Kowinearly) leaves under cold, salt and heat stresses. Two-week-old seedlings were exposed to cold (4°C), salt (NaCl 200 mM) and heat (42 °C) treatments for 6 h. A total 8 differentially expressed genes were isolated form ryegrass leaves. These genes were sequenced then identified and validated form National Center for Biotechnology Information (NCBI) database. We identified several promising genes encoding light harvesting chlorophyll a/b binding protein, alpha-glactosidase b, chromosome 3B, elongation factor 1-alpha, FLbaf106f03, complete genome, translation initiation factor SUI1, and glyceraldehyde-3-phosphate dehydrogenase. These genes were potentially involved in photosynthesis, plant development, protein synthesis and abiotic stress tolerance in plants. These genes might be useful for the enhancement of abiotic stress tolerance in fodder crops along with crop improvement under unfavorable environmental conditions.
        22.
        2018.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The annealing characteristics of a cold rolled Al-6.5Mg-1.5Zn alloy newly designed as an automobile material is investigated in detail. The aluminum alloy in the ingot state is cut to a thickness of 4 mm, a total width of 30 mm and a length of 100 mm and then reduced to a thickness of 1 mm (reduction of 75%) by multi-pass rolling at room temperature. Annealing after rolling is performed at temperatures ranging from 200 to 400 ℃ for 1 hour. The tensile strength of the annealed material tends to decrease with the annealing temperature and shows a maximum tensile strength of 482MPa in the material annealed at 200 ℃. The tensile elongation of the annealed material increases with the annealing temperature, while the tensile strength does not, and reaches a maximum value of 26 % at the 350 ℃ annealed material. For the microstructure, recovery and recrystallization actively occur as the annealing temperature increases. The recrystallization begins to occur at 300 ℃ and is completed at 350 ℃, which results in the formation of a fine grained structure. After the rolling, the rolling texture of {112}<111>(Cu-Orientation) develops, but after the annealing a specific texture does not develop.
        4,000원
        23.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigates the directional recrystallization behavior of Ni based oxide dispersion strengthened (ODS) alloy according to the zone annealing velocity. The zone annealing temperature is set as 1390oC, while the zone velocities are set as 2.5, 4, 6, and 10 cm/h, respectively. The initial microstructure observation of the as-extruded sample shows equiaxed grains of random orientation, with an average grain size of 530 nm. On the other hand, the zone annealed samples show a large deviation in grain size depending on the zone velocities. In particular, grains with a size of several millimeters are observed at 2.5-cm/h zone velocity. It is also found that the preferred orientation varies with the zone annealing velocity. On the basis of these results, this study discusses the role of zone velocities in the directional recrystallization of Ni base ODS alloy.
        4,000원
        24.
        2018.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Effects of annealing temperature on the microstructure and mechanical properties through thickness of a Cu-3.0Ni- 0.7Si alloy processed by differential speed rolling are investigated in detail. The copper alloy with a thickness of 3 mm is rolled to a 50 % reduction at ambient temperature without lubricant and subsequently annealed for 0.5 h at 200-900 oC. The microstructure of the copper alloy after annealing is different in the thickness direction depending on the amount of the shear and compressive strain introduced by the rolling; the recrystallization occurs first in the upper roll side and center regions which are largely shear-deformed. The complete recrystallization occurs at an annealing temperature of 800 oC. The grain size after the complete recrystallization is finer than that of the conventional rolling. The hardness distribution of the specimens annealed at 500-700 oC is not uniform in the thickness direction due to partial recrystallization. This ununiformity of hardness corresponds well to the amount of shear strain in the thickness direction. The average hardness and ultimate tensile strength has the maximum values of 250 Hv and 450 Mpa, respectively, in the specimen annealed at 400 oC. It is considered that the complex mode of strain introduced by rolling directly affects the microstructure and the mechanical properties of the annealed specimens.
        4,000원
        25.
        2018.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of the post annealing temperatures on the electrical and interfacial properties of a metal-semiconductor-metal photodetector(MSM-PD) device. The interdigitate type MSM-PD devices had the structure Al(500 nm) / Ti(200 nm) / poly-Si(500 nm). Structural analyses of the MSM-PD devices were performed by employing X-ray diffraction(XRD), scanning electron microscopy(SEM) and transmission electron microscope(TEM). Electrical characteristics of the MSM-PD were also examined using current-voltage(I-V) measurements. The optimal post annealing condition for the Schottky contact of MSM-PD devices are 350℃-30minutes. However, as the annealing temperature and time are increased, electrical characteristics of MSM-PD device are degraded. Especially, for the annealing conditions of 400℃-180minutes and 500℃-30minutes, the I-V measurement itself was impossible. These results are closely related to the solid phase reactions at the interface of MSM-PD device, which result in the formation of intermetallic compounds such as Al3Ti and Ti7Al5Si12.
        4,000원
        26.
        2018.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        N-type porous silicon (PS) layers and thermally oxidized PS layers have been characterized by various measuring techniques such as photoluminescence (PL), Raman spectroscopy, IR, HRSEM and transmittance measurements. The top surface of PS layer shows a stronger photoluminescence peak than its bottom part, and this is ascribed to the difference in number of fine silicon particles of 2~3 nm in diameter. Observed characteristics of PL spectra are explained in terms of microstructures in the n-type PS layers. Common features for both p-type and n-type PS layers are as follows: the parts which can emit visible photoluminescence are not amorphous, but crystalline, and such parts are composed of nanocrystallites of several nm’s whose orientations are slightly different from Si substrate, and such fine silicon particles absorb much hydrogen atoms near the surfaces. Light emission is strongly dependent on such fine silicon particles. Photoluminescence is due to charge carrier confinement in such three dimensional structure (sponge-like structure). Characteristics of visible light emission from ntype PS can be explained in terms of modification of band structure accompanied by bandgap widening and localized levels in bandstructure. It is also shown that hydrogen and oxygen atoms existing on residual silicon parts play an important role on emission stability.
        4,000원
        27.
        2018.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Effects of annealing temperature on the microstructure and mechanical properties through thickness of a cold-rolled Cu-3.0Ni-0.7Si alloy were investigated in detail. The copper alloy with thickness of 3 mm was rolled to 50 % reduction at ambient temperature without lubricant and subsequently annealed for 0.5h at 200~900 oC. The microstructure of the copper alloy after annealing was different in thickness direction depending on an amount of the shear and compressive strain introduced by rolling; the recrystallization occurred first in surface regions shear-deformed largely. The hardness distribution of the specimens annealed at 500~700 oC was not uniform in thickness direction due to partial recrystallization. This ununiformity of hardness corresponded well with an amount of shear strain in thickness direction. The average hardness and ultimate tensile strength showed the maximum values of 250Hv and 450MPa in specimen annealed at 400 oC, respectively. It is considered that the complex mode of strain introduced by rolling effected directly on the microstructure and the mechanical properties of the annealed specimens.
        4,000원
        29.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Salt stress is one of the most limiting factors that reduce plant growth, development and yield. However, identification of salt-inducible genes is an initial step for understanding the adaptive response of plants to salt stress. In this study, we used an annealing control primer (ACP) based GeneFishing technique to identify differentially expressed genes (DEGs) in Italian ryegrass seedlings under salt stress. Ten-day-old seedlings were exposed to 100 mM NaCl for 6 h. Using 60 ACPs, a total 8 up-regulated genes were identified and sequenced. We identified several promising genes encoding alpha-glactosidase b, light harvesting chlorophyll a/b binding protein, metallothionein-like protein 3B-like, translation factor SUI, translation initiation factor eIF1, glyceraldehyde-3-phosphate dehydrogenase 2 and elongation factor 1-alpha. These genes were mostly involved in plant development, signaling, ROS detoxification and salt acclimation. However, this study provides new molecular information of several genes to understand the salt stress response. These genes would be useful for the enhancement of salt stress tolerance in plants.
        4,000원
        31.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Data clustering determines a group of patterns using similarity measure in a dataset and is one of the most important and difficult technique in data mining. Clustering can be formally considered as a particular kind of NP-hard grouping problem. K-means algorithm which is popular and efficient, is sensitive for initialization and has the possibility to be stuck in local optimum because of hill climbing clustering method. This method is also not computationally feasible in practice, especially for large datasets and large number of clusters. Therefore, we need a robust and efficient clustering algorithm to find the global optimum (not local optimum) especially when much data is collected from many IoT (Internet of Things) devices in these days. The objective of this paper is to propose new Hybrid Simulated Annealing (HSA) which is combined simulated annealing with K-means for non-hierarchical clustering of big data. Simulated annealing (SA) is useful for diversified search in large search space and K-means is useful for converged search in predetermined search space. Our proposed method can balance the intensification and diversification to find the global optimal solution in big data clustering. The performance of HSA is validated using Iris, Wine, Glass, and Vowel UCI machine learning repository datasets comparing to previous studies by experiment and analysis. Our proposed KSAK (K-means+SA+K-means) and SAK (SA+K-means) are better than KSA(K-means+SA), SA, and K-means in our simulations. Our method has significantly improved accuracy and efficiency to find the global optimal data clustering solution for complex, real time, and costly data mining process.
        4,000원
        32.
        2017.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        ZnO film was prepared on a p-type Si wafer and then annealed at various temperatures in air and vacuum conditions to research the electrical properties and bonding structures during the annealing processes. ZnO film annealed in atmosphere formed a crystal structure owing to the suppression of oxygen vacancies: however, ZnO annealed in vacuum had an amorphous structure after annealing because of the increment of the content of oxygen vacancies. Schottky contact was observed for the ZnO annealed in an air. O 1s spectra with amorphous structure was found to have a value of 529 eV; that with a crystal structure was found to have a value of 531.5 eV. However, it was observed in these results that the correlation between the electronic characteristics and the bonding structures was weak.
        4,000원
        33.
        2017.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Dinickel-silicide (Ni2Si)/glass was employed as a counter electrode for a dye-sensitized solar cell (DSSC) device. Ni2Si was formed by rapid thermal annealing (RTA) at 700 oC for 15 seconds of a 50 nm-Ni/50 nm-Si/glass structure. For comparison, Ni2Si on quartz was also prepared through conventional electric furnace annealing (CEA) at 800 oC for 30 minutes. XRD, XPS, and EDS line scanning of TEM were used to confirm the formation of Ni2Si. TEM and CV were employed to confirm the microstructure and catalytic activity. Photovoltaic properties were examined using a solar simulator and potentiostat. XRD, XPS, and EDS line scanning results showed that both CEA and RTA successfully led to tne formation of nano thick- Ni2Si phase. The catalytic activity of CEA-Ni2Si and RTA-Ni2Si with respect to Pt were 68 % and 56 %. Energy conversion efficiencies (ECEs) of DSSCs with CEA-Ni2Si and RTA-Ni2Si catalysts were 3.66 % and 3.16 %, respectively. Our results imply that nano-thick Ni2Si may be used to replace Pt as a reduction catalytic layer for a DSSCs. Moreover, we show that nanothick Ni2Si can be made available on a low-cost glass substrate via the RTA process.
        4,000원
        34.
        2016.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Dy3+ and Eu3+-codoped SrWO4 phosphor thin films were deposited on sapphire substrates by radio frequency magnetron sputtering by changing the growth and thermal annealing temperatures. The results show that the structural and optical properties of the phosphor thin films depended on the growth and thermal annealing temperatures. All the phosphor thin films, irrespective of the growth or the thermal annealing temperatures, exhibited tetragonal structures with a dominant (112) diffraction peak. The thin films deposited at a growth temperature of 100 oC and a thermal annealing temperature of 650 oC showed average transmittances of 87.5% and 88.4% in the wavelength range of 500-1100 nm and band gap energy values of 4.00 and 4.20 eV, respectively. The excitation spectra of the phosphor thin films showed a broad charge transfer band that peaked at 234 nm, which is in the range of 200-270 nm. The emission spectra under ultraviolet excitation at 234 nm showed an intense emission peak at 572 nm and several weaker bands at 479, 612, 660, and 758 nm. These results suggest that the SrWO4: Dy3+, Eu3+ thin films can be used as white light emitting materials suitable for applications in display and solid-state lighting.
        4,000원
        35.
        2016.10 구독 인증기관·개인회원 무료
        무정형입자전분(Amorphous granular starch, AGS)은 호화되어 복굴절성 및 결정성을 손실되었으나 입자 모양을 그 대로 유지하고 있어 천연 및 호화전분과 다른 물리화학적 성질을 나타낸다. Annealing은 전분에 과량의 수분을 첨가하 여 호화온도보다 낮은 온도에서 일정기간 동안 열처리 하는 물리적 변성방법으로 전분입자내의 무정형 및 결정형영역 내의 결합을 통한 안정성 증가, 이중나선구조 형성, 호화 온도 증가 및 범위의 축소, 전분입자의 팽윤력 감소 등을 유 발한다. 본 연구에서는 무정형입자감자전분(Amorphous Granular Potato Starch, AGPS)을 annealing 처리하고 이들의 물 리화학적 특성을 알아보았다. 열과 에탄올 처리를 통하여 얻어진 AGPS를 (NH4)2SO4 (81.0 %RH)와 KNO3 (93.6 %RH) 포화염 용액이 들어있는 데시케이터 안에서 일정 기간 저장하여 수분함량 18%(d.b)와 29%(d.b)인 시료를 제조하였다. 또한 AGPS에 증류수를 첨가하여 수분함량 200%(d.b)의 시료를 만들었다. 이 시료들을 4, 25, 40 각각의 온도에서 저 장하면서 DSC를 이용하여 열적특성 분석, RVA를 통해 pasting 특성, XRD를 이용하여 결정도의 변화를 확인하였고, RS함량을 측정하여 소화도를 분석하였다. DSC 분석결과, 아무 처리를 하지 않은 AGPS의 경우 어떠한 peak도 관찰되 지 않는 반면 각각의 온도에 일정 기간 동안 annealing한 AGPS의 경우 peak이 관찰되었다. 이를 통해 annealing 동안 전분입자 내의 분자들간의 사슬 간에 상호작용에 영향을 주는 것을 확인 할 수 있었다. XRD 분석결과, AGPS, 4, 25 온도에서 저장한 시료들의 XRD pattern에는 유의적인 차이가 보이지 않았다. 그러나 40에서 저장한 시료들에서는 결 정도의 변화가 확인되어 annealing한 AGPS에서 재결정화가 이루어졌음을 확인할 수 있었다. RVA 측정 결과, AGPS의 경우 천연전분과 달리 전분의 전형적인 pasting curve를 나타내지 않고 95oC에서 점도가 증가하다가 온도를 50oC로 냉 각시키면서 점도가 지속적으로 증가하는 양상을 보였다. Annealling한 AGPS 또한 비슷하지만 상대적으로 낮은 점도 를 나타내었다. RS 함량측정 결과, annealling한 AGPS의 경우 RS 함량이 모두 증가한 것을 확인할 수 있었다. 따라서 무정형입자전분에 annealing 처리를 할 경우 현재까지 존재하지 않았던 독특한 특성을 가지는 새로운 전분소재를 만들 수 있다는 것을 확인할 수 있었으며 이들이 다양한 식품산업에 응용 될 수 있을 것으로 판단된다.
        36.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Copper (Cu) is a necessary microelement for plants. However, high concentrations of Cu are toxic to plants that change the regulation of several stress-induced proteins. In this study, an annealing control primer (ACP) based approach was used to identify differentially expressed Cu-induced genes in alfalfa leaves. Two-week-old alfalfa plants (Medicago sativa L.) were exposed to Cu for 6 h. Total RNAs were isolated from treated and control leaves followed by ACP-based PCR technique. Using GeneFishing ACPs, we obtained several genes those expression levels were induced by Cu. Finally, we identified several genes including UDP-glucuronic acid decarboxylase, transmembrane protein, small heat shock protein, C-type cytochrome biogenesis protein, mitochondrial 2-oxoglutarate, and trans-2,3-enoyl-CoA reductase in alfalfa leaves. These identified genes have putative functions in cellular processes such as cell wall structural rearrangements, transduction, stress tolerance, heme transport, carbon and nitrogen assimilation, and lipid biosynthesis. Response of Cu-induced genes and their identification in alfalfa would be useful for molecular breeding to improve alfalfa with tolerance to heavy metals.
        4,000원
        38.
        2016.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To observe the bonding structure and electrical characteristics of a GZO oxide semiconductor, GZO was deposited on ITO glasses and annealed at various temperatures. GZO was found to change from crystal to amorphous with increasing of the annealing temperatures; GZO annealed at 200 oC came to have an amorphous structure that depended on the decrement of the oxygen vacancies; increase the mobility due to the induction of diffusion currents occurred because of an increment of the depletion layer. The increasing of the annealing temperature caused a reduction of the carrier concentration and an increase of the bonding energy and the depletion layer; therefore, the large potential barrier increased the diffusion current dna the Hall mobility. However, annealing temperatures over 200 oC promoted crystallinity by the defects without oxygen vacancies, and then degraded the depletion layer, which became an Ohmic contact without a potential barrier. So the current increased because of the absence of a potential barrier.
        4,000원
        39.
        2016.04 구독 인증기관·개인회원 무료
        최근 다양한 방법으로 제조한 무정형입자전분에 대한 연구가 활발히 진행되고 있다. 무정형입자전분은 호화는 되 었지만 입자 모양을 그대로 유지하고 있어 pre-gelatinized starch와 다른 물리화학적 성질을 나타낸다. Annealing은 전 분에 과량의 수분을 첨가하여 호화 온도보다 낮은 온도에서 일정기간 동안 열처리 하는 물리적 변성방법으로 전분입 자내의무정형 및 결정형영역내의 결합을 통한 안정성 증가, 이중나선구조 형성, 호화 온도 증가 및 범위의 축소, 전분입 자의 팽윤력 감소 등을 유발한다. 본 연구에서는 무정형 감자전분(Amorphous Granular Potato Starch, AGPS)을 Annealing 처리하고 이들의 물리화학적 특성을 알아보았다. 열과 에탄올 처리를 통하여 얻어진 AGPS를 (NH4)2SO4(RH81.0%)와 KNO3 (RH 93.6%) 포화염 용액이 들어있는 데시케이터 안에서 일정 기간 저장하여 수분함량17.7%(d.b)와 29.2%(d.b) 인 시료를 제조하였다. 또한 AGPS에 증류수를 첨가하여 수분함량 67.0%(d.b)의 시료를 만들었다. 이 시료들을 4, 25, 40 각각의 온도에서 저장하면서 DSC를 이용하여 열적특성을 분석하였고, XRD를 이용하여 결정도의 변화를 확인하 였다. DSC 분석결과, 아무 처리를 하지 않은 무정형 감자 전분의 경우 어떠한 peak도 관찰되지 않는 반면 각각의 온 도에 일정 기간 동안 저장한 전분의 경우 peak이 관찰되었다. 4에서의 시료들의 peak은 일정하지 않은 반면 25, 40에 서 저장된 시료의 To, Tp, Tc, ΔH 모두 증가하였다. Annealing 처리는 낮은 온도보다 상대적으로 높은 온도에서 더 큰 영향을 주었고, 전분입자 내의 분자들 간의 상호결합에 영향을 준 것으로 보인다. XRD 분석결과, AGPS, 4, 25 온도에 서 저장한 시료들의 XRD pattern에는 유의적인 차이가 보이지 않았다. 그러나 40에서 저장한 시료들에서는 결정도의 변화가 확인되었다. 따라서 무정형전분에 annealing처리를 할 경우 독특한 특성을 가지는 새로운 전분소재를 만들 수 있다는 것을 확인할 수 있었으며 다양한 식품산업에 응용 될 수 있을 것으로 판단된다.
        40.
        2015.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated the effect of annealing conditions on the ferromagnetic resonance(FMR) of yttrium iron garnet (Y3Fe5O12, YIG) thin film prepared on gadolinium gallium garnet (Gd3Ga5O12, GGG) substrate. The YIG thin films were grown by rf magnetron sputtering at room temperature and were annealed at various temperatures from 700 to 1000 ˚C. FMR characteristics of the YIG thin films were investigated with a coplanar waveguide FMR measurement system in a frequency range from 5 to 20 GHz. X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) were used to characterize the phase formation, crystal structure and composition of the YIG thin films. Field dependent magnetization curves at room temperature were obtained by using a vibrating sample magnetometer(VSM). The FMR measurements revealed that the resonance magnetic field was highly dependent on the annealing condition: the lowest FMR linewidth can be observed for the 800 ˚C annealed sample, which agrees with the VSM results. We also found that the Fe and O composition changes during the annealing process play important roles in the observed magnetic properties.
        4,000원
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