• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2009.10a
• /
• pp.239-239
• /
• 2009

We prepared Au nanoparticles by seed-mediated method and investigated the effects of process variables on the seed-mediated growth of Au nanoparticles. The monodispersed Au seed nanoparticles in the size range from 14.3 nm to 20.3 nm were prepared by the reduction reaction between $HAuCl_4$ and citrate. We added the $HAuCl_4$ precursors with citrates into the Au seed solution and prepared the Au nanoparticles in the size range from 16.8 and 37.8 nm with monodisperse distribution and could control the size of Au nanoparticles by changing the amount of $HAuCl_4$ precursor.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.3
• /
• pp.880-884
• /
• 2011

ZnO nanorods were grown by hydrothermal method. Two kinds of seed layers, Au film and island seed layers were prepared to investigate the effect of seed layer on ZnO nanorods. The ZnO nanorod on Au island seed layer has more unifom diameter and higher density compared to that of ZnO nanorod on Au film seed layer. The ZnO nanorods on Au island seed layer were annealed at various temperatures ranging from 300 to $850^{\circ}C$. The pinholes at the surface of the ZnO nanorods is formed as the annealing temperature is increased. It is noted that the pyramid structure on the surface of ZnO nanorod is observed at $850^{\circ}C$. The intensity of ZnO (002) diffraction peak in X-ray diffraction pattern and intensity of near band edge emission (NBE) peak in photoluminescence (PL) are increased as the ZnO nanorods were annealed at the temperature of $300^{\circ}C$.

• Journal of Electrochemical Science and Technology
• /
• v.3 no.2
• /
• pp.57-62
• /
• 2012

In this report, we demonstrate that the longitudinal localized surface plasmon resonance mode can be suppressed when the nanorods were in dumbbell shape. The seed nanorods were synthesized by electrochemical deposition of metals into the pores of anodic aluminum oxide templates. The dumbbell-like nanorods were grown from seed Au-Ni-Au nanorods by a rate-controlled seed-mediated growth strategy. The selective deposition of Au atoms onto Au blocks of Au-Ni-Au nanorods produced larger diameter of Au nanorods with bumpy surface resulting in dumbbell-like nanorods. The morphology of nanorods depended on the reduction rate of $AuCl_4^-$, slow rate producing smooth surface of Au nanorods, but high reduction rate producing bumpy surface morphology. Through systematic investigation into the UV-Vis-NIR spectroscopy, we found that the multiple localized surface plasmon resonance (LSPR) modes were available from single-component Au nanorods. And, their LSPR modes of Au NRs with bumpy surface, compared to the smooth seed Au NRs, were red-shifted, which was obviously attributed to the increased electron oscillation pathways. While the longitudinal LSPR modes of smoothly grown Au NRs were blue-shifted except for a dipole transverse LSPR mode, which can be interpreted by decreased aspect ratio. In addition, dumbbell-like nanorods showed an almost disappeared longitudinal LSPR mode. It reflects that the plasmonic properties can be engineered using complex nanorods structure.

• Journal of Korean Society of Forest Science
• /
• v.103 no.2
• /
• pp.153-158
• /
• 2014

To examine the natural regeneration in the natural mixed-broadlived forest, flowering, fruiting, seed-fall, and seed viabilities of Acer ukurunduense Trautv. & C.A. Mey. (AU) were investigated in Mt. Jungwang, Gangwon-do, from 2009 to 2013. The flower of AU consisited many male and bisexual flowers on the raceme (unusual panicle) and the arrangement of two sex morphs are differed for each inflorescence. Flowering dates are differed between sex morph in the same inflorescence. Stamens are stop growing and disappeared after pollinated pistil begin to grow in bisexual flowers, and male flowers have vestial pistil. The flowers of AU might be pollinated by Apis mellifera, Thyris fenestrella seoulensis, Cerambycidae sp., Andrenidae sp. and Ctenophora sp., and had some mechanism to prevent feom self pollination. The number of flower buds per inflorescence is 189 on June 8, and that of young samaras per inflorescence is 41.2 on June 21. At last ripened samaras per inflorescence is reduced 33.4 on September 5. Mean annual seedfall of AU was 6,720 ea/ha (ranged 670~17,930). Rates of sound seeds are highest 43.2%, and those of damaged or decayed seeds are 41.8%,. Those of undeveloped and empty seeds are 10.2% and 4.8%, respectively. Successful regeneration of AU might be in masting year and on the gap sites with proper conditions to germinate and grow. To understand the natural regeneration of the species, Genus Acer, further study on the fruiting habit, pre- and post-dispersal seed viability, and annual variation on these factor should be needed.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.7
• /
• pp.1485-1488
• /
• 2009

A facile, seed-mediated preparation method of trimetallic Au@Pb@Pt core-shell nanoparticles is developed. Au nanoparticles are the template seeds onto which sequentially reduced Pb and Pt are deposited. The trimetallic core-shell structure is confirmed by UV-Vis spectroscopy, TEM and EDS analysis, and cyclic voltammetry. The trimetallic Au@Pb@Pt core-shell nanoparticles show high electrocatalytic activity for formic acid and methanol electrooxidation.

• Korean Journal of Environment and Ecology
• /
• v.25 no.3
• /
• pp.358-364
• /
• 2011

To examine the possibility of natural regeneration of six Acer species in broadleaved mixed forest in Korean peninsula, samples of six Acer species' samaras were collected at several seed sources from September to October 2009 and 2010, and seed morphological characteristics and viability were studied using cutting method. Inflorescense type of Acer mandshuricum(AM), A. pseudosieboldianum(APS) and A. palmatum(AP) is corymb, that of A. pictum subsp. mono(APSM) and A. okamotoanum(AO) is flat-topped panicle, and that of A. ukurunduense(AU) is raceme. Number of seed-set per inflorescense proves the highest value 38.5 sets in AU and the lowest value 2.4 sets in APS. Diameter of the seeds proves highest value 13.5mm in AO, and the lowest value 4.7mm in APS. Angles between the wings proves the highest values $130.05^{\circ}$ in APS, and the lowest value $48.60^{\circ}$ in AU. Air dry weight of 20 seed-sets proves highest value 3,900mg, in AO, and the lowest value 404mg in AU. Viable seed ratio of AP proves 50%, and that of AU does 43.2%. Those of other four species ranges 8.6~22.2%. Considering postdispersal seed predators and disturbance of litter, viable seeds of APSM, AO, AM, and APS supplied in the natural forest in Korea might be insufficient for seedling establishment. This study showed that sound viable seed supply might be key factors of natural regeneration of major Acer species in Korea. The openings made by insect pests were observed on the seed-coat of APSM, AM, AU, and APS samara, and Bradybatus sharpi were observed in the samaras of APSM and AO. Further study on the seed insect fauna, pre- and post-dispersal seed viability, and annual variation on these factor should be needed.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2009.10a
• /
• pp.171-172
• /
• 2009

TSV(through via silicon)를 이용한 Via의 Cu 충전에서 Seed 층의 역할은 전류의 흐름을 가능하게 하는 중요한 역할을 하고 있다. Via에 각각 Ti/Au, Ti/Cu를 증착한 후 Ti/Cu가 Ti/Au를 대체 할 수 있는지를 알아보기 위해 먼저 실리콘 웨이퍼에 via를 형성하고, 형성된 via에 기능성 박막층으로 절연층(SiO2) 및 시드층을 형성하였다. 전해도금을 이용하여 Cu를 충전한 결과 Ti/Au 및 Ti/Cu를 증착한 두 시편 모두 via와 seed층 접합면에 박리 등의 결함이 없었고, via 내부 또한 void나 seam 등이 관찰되지 않고 우수하게 충전된 것을 확인할 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.463-463
• /
• 2013

This paper reports the synthesis and characterization of ZnO:Ga nano-structures deposited on Au/SiNx/Si(001) by radio-frequency sputtering. The effect of the temperature on the microstructure of the as-grown ZnO:Ga thin films was examined. The growth mode of ZnO:Ga nano-structures can be explained by the profile coating, i.e. the ZnO nano-structures were formed with a morphological replica of Au seeds. Initially, the ZnO:Ga nano-structures were overgrown on top of Au nano-crystals. Small ZnO:Ga nano-dots were then nucleated on hexagonal ZnO:Ga discs.

• Korean journal of food and cookery science
• /
• v.23 no.5
• /
• pp.685-695
• /
• 2007

The purpose of this study was to develop an excellent salad dressing using grape seed oil, which contains high levels of unsaturated fatty acids. First, a vinaigrette was made with grape seed oil and vinegar and divided into five portions. Then, five types of mirepoix au maigre ($M_1,M_2,M_3,M_4,M_5$) were made with apple, onion, carrot, garlic, tomato puree, and tomato ketchup by mixing in a main material vessel. The samples were then allowed to ripen for three days. The control group $M_1$ was named $GD_1$, and the experimental groups $M_2,\;M_3,\;M_4,\;and\;M_5$ were named $GD_2,\;GD_3,\;GD_4,\;and\;GD_5$. respectively. To measure receptiveness, a sensory test was conducted using a 7 point category scale. The test concentrated on flavor, taste, color, agreeability, aftertaste, and overall acceptability: the panel consisted of 15 subjects According to the results, $GD_4$ had the best flavor, color and agreeability. The samples with the most preferred taste and aftertaste were $GD_4\;and\;GD_5$. Between $GD_4\;and\;GD_5$, there were no noticeable differences in taste, aftertaste, or overall acceptability, but differences in color and agreeability did exist. Thus, $GD_4$ proved to be the most favorable product. To determine the best complementing vegetables for $GD_4$ yam($VE_1$), broccoli sprouts($VE_2$), mustard leaves($VE_3$), beet leaves($VE_4$), cucumber($VE_5$), and lettuce(VE6) were selected as samples, and a sensory test was conducted. Each vegetable has its own peculiarities. According to the results, $VE_2$ had the nicest vegetable fragrance recording the highest mean value. The vegetable with the most preferred taste, aftertaste, and agreeability were $VE_2\;and\;VE_6$. $VE_1\;and\;VE_6$ had the nicest color and contained the brightest color as well. The highest overall acceptability was awarded to $VE_2\;and\;VE_6$ and there was no remarkable difference between thorn at a level of 0.05. In conclusion, $VE_2\;and\;VE_6$ were the best complementing vegetables with grape seed oil dressing. However, to commercialize such a dressing, many follow-up studies must be conducted.

• Laser Solutions
• /
• v.2 no.3
• /
• pp.52-61
• /
• 1999

The laser induced forward transfer(LIFT) technique employs a pulsed laser to transfer parts of a thin metal film from an optically transparent target onto an arbitrary substrate in close proximity to the metal film on the target. In this work, a two-step method, the combination of LIFT process, in which a Au film deposited on the $Al_2$O$_3$ substrate by Nd:YAG laser and subsequent Au electroless metal plating on the by LIFT process generated Au seed, was presented. The influence of laser parameters, wavelength, laser power, film thickness and overlap ratio of pulse tracks, on the shapes of deposit and conductor line after electroless plating is experimentally studied. As a results, the threshold power densities for ablation, deposition and metallization were determined and comparison of threshold value between the wave length 1064nm and the second harmonic generated 532nm. In odor to determine a possible application in the electronic industry, a smallest conduct spot size, line width and isolated line space were generated.