나노입자란 직경 100nm 이하의 크기를 가진 입자로 가전, 기능성 화장품, 반도체, 항균제 및 광촉매제 등에 널리 사용되어 있어 본 연구는 9종류의 나노입자가 참굴 수정란에 미치는 영향을 살펴보았다. 나인입자를 첨가하지 않은 대조구에서는 인공 수정한 참굴 수정란의 78%가 D형 유생으로 발생하였다. 은(Ag)이 2% 함유된 AGZ020, Nano silver 및 P-25의 나노입자와 주석산화물인 SnO의 나노입자는 24시간 경과 후 0.05ppm 농도에서 각 각 22%, 52%, 58% 및 76%가 D형 유생으로 발생하였으나, 20ppm 농도에서 8시간 이내 참굴 수정란을 모두 파괴하였다. In, Sb, Sn, Zn 및 Ag-TiO2의 나노입자는 24시간 경과 후 0.05ppm 농도에서 모두 70%이상의 D형 유생으로 발생하여 상대적으로 낮은 농도에서 큰 영향을 받지 않는 것으로 나타났으나, 20ppm 농도에서 대조에 비해 D형 유생 발생율이 각 각 57%, 60%, 50%, 65% 및 64%로 저해되었다.

In this article a reliable and rapid method based on specific turbidimetry is proposed for the determination of sizes of nanoparticles. Conventionally in specific turbidimetry specific turbidities for a colloidal dispersion are measured as a function of light wavelength, and compared to theoretical values calculated from Mie scattering theory for presumed particle sizes. In contrast specific turbidity at a fixed wavelength is measured in the proposed method, and particle sizes are determined from the prepared calibration curve. The calibration curve is a plot of specific turbidity vs particle size and in this case the specific turbidities are measured for a couple of samples of known sizes.

The electrophoretic deposition process of Ni nano-particles in organic suspension was employed for self-repairing of heat exchanger tubes. For this purpose, Ni nano-particles prepared by levitational gas condensation method were dispersed into the solution of ethanol with the addition of dispersant Hypermer KD2. For electrophoretic deposition of Ni nano-particles on the Ni alloy specimen, constant electric fields of 20 and 100 V were applied to the specimen in Ni-dispersed solution. It was found that as electrophoretic deposition proceeds, the size of the pit or crack remarkably decreased due to the agglomeration of Ni nano-particles at the pit or crack. This strongly suggests that the electrophoretic mobility of the charged particles is larger for the damaged part with a higher current value rather than outer surfaces with a lower current value.

The magnetic alloys of Cu-Fe () were prepared by a mechanical alloying method and their structural and magnetic behaviors were examined by X-ray diffraction and Mossbauer spectra. The magnetization curves did not distinctly show the saturation at 70 kOe for the concentrated alloys of . The Mossbauer spectrum of at room temperature shows one Lorentzian line of the paramagnetic phase, whereas the Mossbauer spectrum of consists of sextet Lorentzian line at room temperature and a centered doublet line. The Mossbauer spectra of measured in the temperature ranges from 13 to 295 K, implies that to consists of two magnetic phases. One superimposed sextet corresponds to the ferromagnetic iron in Cu and the other one indicates the superparamagnetic iron rich phase.

The electrophoretic deposition process of Ni nano-particles was employed for self-repairing of heat exchanger tubes. For electrophoretic deposition of Ni nano-particles on pitted Ni alloy specimen, a constant electric field of 100 V was applied to the specimen for 180 s in Ni-dispersed solution. It was found that as electrophoretic deposition proceeded, the size of the pit remarkably decreased due to the agglomeration of Ni nano-particles at the pit. This strongly suggests that the electrophoretic mobility of the charged particles is larger for the pit with a higher current value rather than outer surfaces with a lower current value.

nano cubes with high catalase activity were synthesized by reduction of freshly prepared Cu in distilled water at and their catalase activities of were studied. Transmission electron microscopy (TEM) observation showed that most of these nanocubes were uniform in size, with the average edge length of 30 nm. Selected area electron diffraction of TEM revealed that the nanocube consisted of single crystalline , but it changed to CuO phase. The catalase activity depends on the amount of both cuprite phase and surface area.

Silver bromide particles from 50 to 200a in diameter are prepared by mixing two microemulsions contaning the precursor salts AgNO3 and KBr. The microemulsions are composed of AOT(bis(2-ethylhexyl) sodium sulfosuccinate), n-heptane and water. The particle diameters are measured on photomicrographs obtained by transmission electron microscopy. The size of the particles is generally larger than that of the water cores. The influence of both the concentration of precursor salts in the water cores of the microemulsoin and the size of these water cores on the size of the particles has been studied.

Nanoparticles of iron oxides have been prepared by the levitational gas condensation (LGC) method, and their structural and magnetic properties were studied by XRD, TEM and Mossbauer spectroscopy. Fe clusters were evaporated from a surface of the levitated liquid Fe droplet and then condensed into nanoparticles of iron oxide with particle size of 14 to 30 nm in a chamber filled with mixtures of Ar and gases. It was found that the phase transition from both - and -Fe to , which was evaluated from the results of Mossbauer spectra, strongly depended on the flow rate. As a result, - was synthesized under the flow rate of 0.1(Vmin)0.15, whereas was synthesized under the , flow rate of 0.15(Vmin)0.2.

Nanoparticles of with a mean particle size of 4-30 nm have been prepared by a pulsed wire evaporation method, and its structural and magnetic properties were studied by SQUID magnetometer and Mossbauer spectroscopy. From the main peak intensity of XRD and absorption rate of Mossbauer spectrum, the amounts of and in as-prepared sample are about 70% and 30%, respectively. The coercivity (53 Oe) and the saturation magnetization (14 emu/g) are about 20% of those of the bulk . The low value of coercivity and saturation magnetization indicate that the phase nearly shows the spin glass-like behavior. Analysis of the set of Mossbauer spectrum indicates a distribution of magnetic hyperfine fields due to the particle size distribution yielding 20 nm of average particle size. The magnetic hyperfine parameters are consistent with values reported of bulk and . A quadrupole line on the center of spectrum represents of superparamagnetic phase of with a mean particle size of 7 nm or below.

Background : Panos extract is a mixture of four Panax plant extracts namely Dendropanax morbifera, Panax ginseng, Acanthopanax senticosus and Kalopanax septemlobus. We intended to use Panos extract for ZnO nanoparticles(NPs) synthesis and application for waste water treatment. Methods and Results : In the present study, we have synthesized Panos ZnO nanoparticles via co precipitation method. Characterization of the NPs has been done using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and UV-Visible spectroscopy. An average of 75% efficacy in degrading the methylene blue dye has been observed. The nanoparticles showed antibacterial activity against E. coli and S. aureus. Conclusion : The results shows that Panos ZnO NPs can be a potential eco-friendly and economical tool for waste water management in the current scenario where there an intense urge to remediate the polluted environment through novel approaches such as Nanobiotechnology.

Background : Cu ion is an essential mineral of animal feed. But rapid degradation of Cu ion in animal intestine causes poor immune activity and potential environment hazard. Therefore, to enhance immune system and control metal ion deliverly in intestine, we developed Cu ion nano suspension. In animal feed, > 127 ㎎/g of Cu ion are found but only 5 - 7 ㎎ are used out of them. Therefore, huge loss of Cu ion causes environment, economy and animal health problem. Methods and Results : Seven formulation were prepared to prepare nano suspension (particle size < 200 ㎚) of CuSO4. The particle diameter, polydispersity index, and zeta potential values of the samples were measured using dynamic light scattering (DLS) and laser Doppler methods (ELS-Z1000; Otsuka Electronics, Tokyo, Japan). Absorbance and Cu ion concentration was measured using UV-VIS Spectrophotometer. Cu ion nano particle (< 200 ㎚) was found in a formulation comprised of Cu ion : surfactant (lipophilic : hydrophilic) and PEG. In consistence with this result, total absorbance and concentration was found higher in the same formulation compared to control. Conclusion : From our experiment we may conclude that mixture of Cu ion : surfactant (lipophilic : hydrophilic) and PEG successfully prepared nano suspension which slow down the degradation of Cu ion in intestine with improving feed quality, animal health and prevent potential environment pollution.

본 연구에서는 나노 입자와 시멘트로 보강된 조립토의 강도 특성에 관한 연구로서, 물과 시멘트의 수화 반응으로 발생하는 이산화칼슘과 나노 실리카 입자의 포졸란 반응을 통하여 강도 증진 효과 양상이 어떠하게 나타나는지 확인하였다. 실험은 상대밀도, 흙-시멘트비율, 시멘트-나노실리카비율, 물-시멘트 비율을 이용하여 배합하였다. 배합된 보강토는 직경과 높이가 50㎜×100㎜인 몰드를 이용하여 공시체로 제작하고 실내 일축압축시험을 진행하였다. 7일 양생 공시체의 일축압축강도의 경우 상대밀 도가 증가함에 따라 강도 증진 효과가 증가하는 것을 확인할 수 있었다. 이는 상대밀도가 증가하면서 첨가되는 나노 실리카의 양이 증가하여 초기 수화 반응을 촉진시켰기 때문이다. 반면 28일 양생 공시체의 일축압축강도의 경우 강도 증진 효과가 감소하는 것을 확인할 수 있었다. 장기간 양생의 경우 수화 반응에 의하여 모세관 공극이 형성되는데 공극 주변의 시멘트가 충분한 수분을 받지 못하여 완전한 수화가 이루어지지 않아 이와 같은 결과가 나타난다. 또한, 흙-시멘트비율이 일정할 때, 나노 실리카 함량의 최적값은 상대밀도 60% 이상에서는 3%임을 확인하였다.

This study was carried out to compare the toxicity of nano and micrometer particles with Cu and Zn on soil microbial community and metal uptake of buck wheat. In microcosm system, soil was incubated for 14 days after soil aliquots were artificially contaminated with 1,000 mg/kg Cu, Zn nano and micro particles, respectively. After then, buck wheat was planted in incubating soils and non incubating soils. After 14 days, we compared bioaccumulation of metal, and microbial carbon substrate utilization patterns between incubating soils and non-incubating soils. The enrichment factor (EF) values of incubating samples were greater than non-incubating soils. Dehydrogenase activity had been inhibited by Cu and Zn nanoparticles in non-incubating soil, as well as it had been inhibited by Zn micro particles in incubating soils. Results of biolog test, it was not significant different between nano particles and micro particles. It cannot be generalized that nanoparticles of metal are always more toxic to soil microbial activity and diversity than micrometer-sized particles and the toxicity needs to be assessed on a case-by-case basis.