This study was focused on the optimization of low-pressure ultrasonic spraying process for synthesis of pure nanoparticles. As process variables, pressure in the reactor, precursor concentration, and reaction temperature were changed in order to control the chemical and microstructural properties of iron oxide nanoparticles including crystal phase, mean particle size and particle size distribution. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies revealed that pure nanoparticles with narrow particle size distribution of 5-15 nm were successfully synthesized from iron pentacarbonyl () in hexane under 30 mbar with precursor concentrations of 0.1M and 0.2M, at temperatures over . Also magnetic properties, coercivity () and saturation magnetization () were reported in terms of the microstructure of particles based on the results from vibration sampling magnetometer (VSM).

The mushroom production reached to 1000 billion won in monetary value in Korea. We, however, do not have systematic terminology dictionary published yet. Recently new varieties of medicinal mushrooms in addition to culinary mushrooms are being introduced steadily through out the world. This makes the necessity of coordinated and consistent arrangement of terms involved in culture, cultivation and physiological aspects of mushrooms. Various components in relation to the medicinal and physiological functionality also poses ambiguity in terminology along with the terms used in breeding and genetic researches. Moreover, some of the scientific terms are being used erroneously. In order to help mushroom cultivators, students, and mushroom business personnel in understanding the terms on mushroom science and technology we intended to collect and organize all the terms related to mushroom morphology and cultivation, poison and medicinal functionality, processing and utilization, and so on. Thirteen professionals from each field participated in this project. The fields included here are : 1) Genetics and breeding of mushrooms, 2) Cultivation and physiology of mushrooms, 3) Taxonomy and ecology of mushrooms, 4) Processing and functional components, 5) Blight and insects of mushrooms

본 연구는 쥐노래미과(Hexagrammidae)에 속하고 양식산업에서 중요한 위치를 차지하고 있는 노래미, Hexagrammos otakii(Jordan et Starks)와 쥐노래미, H. agrammus(Temminck et Schlegel)의 미토콘드리아 cytochrome b(cyt b)유전자의 염기서열을 서로 비교 분석하였다. 총 489 bp크기의 cyt b 염기서열에서 종간의 변이는 거의 없었다(96%의 유사성).Neighbor-joining

The effect of Cu content on hydrogen reduction behavior of ball-milled -CuO nanocomposite powders was investigated. Hydrogen reduction behavior and reduction percent() of nanopowders were characterized by thermogravimetry (TG) and hygrometry measurements. Activation energy for hydrogen reduction of nanopowders with different Cu content was calculated at each heating rate and reduction percent(). The activation energy for reduction of obtained in this study existed in the ranging from 129 to 139 kJ/mol, which was in accordance with the activation energy for powder reduction of conventional micron-sized

Through the volume change of Sn in a low-temperature phase transformation, the Sn nanopowder with high, purity, was fabricated by an economic and eco-friendly process. The fine cracks were spontaneously generated. in, Sn ingot, which was reduced to powders in the repetition of phase transformation. The Sn nanopowder with 50 run in size was obtained by the 24th repetitions of phase transformation by low-temperature and ultrasonic treatments. Also, the powder was fabricated by the oxidation of the produced Sn powder to the ingot and milled by the ultrasonic milling method. The nanopowder of 20 nm in size was fabricated after the milling for 180 h

The brazing adhesion properties of Ag coated W-Ag electric contact on the Cu substrate have been investigated in therms of microstructure, phase equilibrium and adhesion strength. Precoating of Ag layer ( in thickness) on the contact material was done by electro-plating method. Subsequently the brazing treatment was conducted by inserting BCuP-5 filler metal (Ag-Cu-P alloy) layer between Ag coated W-Ag and Cu substrate and annealing at in atmosphere. The optimum brazing temperature of was semi-empirically calculated on the basis of the Cu atomic diffusion profile in Ag layer of commercial electric contact produced by the same brazing process. As a mechanical test of the electric contact after brazing treatment the adhesion strength between the electric contact and Cu substrate was measured using Instron. The microstructure and phase equilibrium study revealed that the sound interlayer structure was formed by relatively low brazing treatment at . Thin Ag electro-plated layer precoated on the electric contact ( in thickness) is thought to be enough for high adhesion strength arid sound microstructure in interface layer.

Successful implementation of the powder forming process requires a detailed understanding of several interacting phenomena. The aim is to better control the process variables and to optimize the design parameters. A number of studies were carried out using various constitutive models that take the density change during powder forming into account. Most of them were developed for powders and sintered porous metals, but few of them can describe powder agglomerates, whose behaviour is different from that of uniformly arranged powders. The modification is needed to account for the effect of agglomeration on densification behaviour. Incorporating powder agglomeration into a constitutive model is of considerable importance, as it provides a possibility of relating the powder densification response to microstructural characteristics of powder particles, especially in case of nano powders. In this paper, we proposed a new powder agglomerate model in order to describe the unique densification behaviour of nano powders. The proposed model was applied to the densification of powder agglomerates during cold isostatic pressing.

The chloroacetanilide herbicide alachlor (2-chloro-2', 6'-diethyl-N-(methoxymethyl)-acetanilide) and organochlorine insecticide endosulfan (6, 7, 8, 9, 10, 10-hexachloro-l, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 3, 4-benzodioxathiepin-3-oxide)are the h

A study on the recognition on the mushrooms by elementary school pupils, middle school students and school dietitians were-carried out. The ways of cooking mushrooms by school dietitians were also investigated. Most students and dietitians highly recognized mushrooms as good food. The most favorite mushroom was Flammulina velutipes, the cooking of mushrooms with meat and the hot mushroom soup with meat(Jungol) being the most preferred cooking methods. School ditetitians like to use mushrooms in school lunch and generally use medium or high duality mushrooms. Students, however, do not tend to prefer mushrooms compared to other vegetables. Mushroom dishes that can promote the consumption by students are mushroom bulgogi, mushroom pizza, sweet and sour mushroom in the order.