• Journal of Powder Materials
• /
• v.12 no.4 s.51
• /
• pp.239-248
• /
• 2005

1990년도 초반에 개발되어 나노분말의 제조 공정으로 집중적으로 연구되어온 화학기상응축공정은 고강도용 나노분말 소재이외에 기능성 자성재료로의 응용에 주로 이용되어 왔다. 최근에는 이러한 응용이외에 나노분말의 표면을 다양한 이종 소재로 응용하고자하는 나노캡슐(혹은 core/shell)화 제조 공정으로 진보되어 다양한 합금 시스템으로 발전하게 되었다. 특히 최근 Particles 2005, Surface Modification in Particle Technology 학회에서는 나노금속 혹은 세라믹 분말에 PMMA, PE등 polymer의 유기화합물의 코팅하여, DNA나 RNA를 부착하거나 추출해내는 나노캡슐화 공정 연구가 매우 활발하게 진행됨을 보여주고 있으며, 이들 나노 캡슐의 개발은 약물전달계(Drug delivery system), 온열치료용 및 MRI 조영제 등의 바이오재료로의 응용가능성이 크게 기대되어 이에 대한 연구들이 활발하게 진행될 것으로 예상된다.

• Journal of the Korean Applied Science and Technology
• /
• v.30 no.3
• /
• pp.504-517
• /
• 2013

The purpose of this study was to process extraction and separation for polyglucose porpyran from pophyra yezoensis as high yield. The acidic porphyran solution was extracted with 0.1~1N of ${\alpha},{\beta}$-dichloromaleic acid or ${\alpha}$-chloromaleic acid of 2% solution as organic acid instead of inorganic acid at $60^{\circ}C$ and then porphyran was collection of high yield to acidic solution and it was neutralization treated with 0.1N of $d-Ca(OH)_2$ solution and the mixture was conversion to porphyran salt form and treated with a shell powder of ouster and then added of ethanol as precipitator. It recovery porphyran contained of violet purple laver coloring matter was obtained as a crystalline and used for the next step without future purification to prepare of porphyran laver jam. so, The resulting porphyran and porphyran jam was characterized by it component and physical properties.

• Korean Journal of Organic Agriculture
• /
• v.6 no.1
• /
• pp.127-132
• /
• 1997

This experiment was carried out to examine the effect of various functional materials such as bioceramic podwers, crushed shells and elvanites supplemented to the each substrate on the seedlings growth of rices. The rice seedlings were grown in pots filled with substrates supplemented with bioceramic podwers, crushed shells and elvanites. The growth of rice seedlings in terms of plant height, stem diameter, root length and leaf width, plant fresh and dry weight was promoted by adding the bioceramic powders (2 to 3g/kg), crushed shells (10g/kg) or elvanites (20 to 40g/kg). Plant height was also promoted by the adding of bioceramic powder from 16 days after treatment, whereas crushed shells and elvanites from 10 days after treatment. Especially, root growth was greatly influenced by bioceramic powder, whereas the shoot growth(leaves and stem) was stimulated by the crushed shells and elvanites supplemented into each substrate. In the field, plant growth in terms of plant height, leaf length and leaf width were also influenced by crushed shells and elvanites at 74 days after treatment. The growth of rices in terms of tiller number, spikelets, panicles and spikelets/panicle was incresed by adding the crushed shells and elvanites from 100 to 200g per m2.

• Journal of Sericultural and Entomological Science
• /
• v.19 no.1
• /
• pp.9-13
• /
• 1977

This experiment was carried out to know relationship between economical characters and kinds of extracted cellulose powders, extracting methods and cellulose composition. The results obtained are summarized as follows; 1. Among the matters for cellulose resources, mulberry branch is the most useful in economical characters such as larval weight, ratio of cocoon shell and mortality, followed by pine branch. 2. Though both PA-method and NaOH-treatment are equally effective in the larval growth, the latter may be more recommendable because of its economical convenience. 3, It may be desirable to add 15 to 22.5 per cent of cellulose powder per dry matter in the diet composition

• Korean Journal of Materials Research
• /
• v.31 no.7
• /
• pp.375-381
• /
• 2021

Chitosan powder is synthesized by a deasetylation process of chitin, obtained from processing of dried shrimp shell powder. Subsequently, chitosan (CS) membranes filled by montmorillonite (MMT) particles and phosphotungstic acid are prepared, and characterized by FT-IR and SEM. The morphology, obtained by SEM for the composite membrane, showed that MMT filler is successfully incorporated and relatively well dispersed in the chitosan polymer matrix. Water and methanol uptake for the CS/MMT composite membranes decrease with increasing MMT loadings, but IEC value increases. In all prepared CS/MMT composite membranes, the CS membrane filled by 5 wt% MMT particles exhibits the best proton conductivity, while that with 10 wt% MMT loading exhibits the lowest methanol permeability; these values are 2.67 mS·cm^-1 and 3.40 × 10^-7 cm²·s^-1, respectively. The best membrane selectivity is shown in the CS/MMT10 composite membrane; this shows that 10 wt% filled MMT is the optimum loading to improve the performance of the chitosan composite membrane. These characteristics make the developed chitosan composite membranes a promising electrolyte for direct methanol fuel cell (DMFC) application.

• Journal of Aquaculture
• /
• v.11 no.1
• /
• pp.31-38
• /
• 1998

A 20-week growth trial was conducted in flow-through aquarium system to investigate the effects of supplemental macroalgae and spirulina in the diets on growth and body cmposition in juvenile abalone (Haliotis discus hannai). Four replicate groups of the abalone averaging 65mg were fed one of ten isonitrogenous (34%) and isolipidic (7.5%) diets containing 8.1% Ulva, 7.5% Undaria, 11% Laminara, 11% Sargassum, spirulina (5, 10 and 15%), or dried Undaria powder (10 and 20%). In addition, these formulated diets were compared with natural food(dried Undaria). Survival rate of abalone were not significantly affected by the different dietary macoralgae sources, spirulina or dried Undaria powder levels (P>0.05). Weight gain and soft body weight of abalone fed the diet containing Sargassum was significantly higher (P<0.05) than those of abalone fed the diets containing Laminaria, 20% dried Undaria powder and natural food. Survival rate, weight gain, soft body weight and shell length of abalone fed natural food were lowest (P<0.05) among all diet. Moisture, protein and lipid contents of soft body were not influenced by experimental diets except natural food. Lipid content of abalones fed natural food was significantly lower than those of abalone fed other diets (P<0.05). These data indicate that abalone can more efficiently utilize Sargassum than Ulva, Undaria, Laminaria or spirulina.

• Journal of Radiation Protection and Research
• /
• v.41 no.3
• /
• pp.185-190
• /
• 2016

Background: In order to measure neutron energy spectra, the conventional Bonner Sphere Spectrometers (BSS) are widely used. In this spectrometer, several measurements with different size Bonner spheres are required. Operators should, therefore, place these spheres in several times to a measurement point where radiation dose might be relatively high. In order to reduce this effort, novel neutron energy spectrometer using an onion-like single Bonner sphere was proposed in our group. This Bonner sphere has multiple sensitive spherical shell layers in the single sphere. In this spectrometer, a band-shaped thermal neutron detection medium, which consists of a LiF-ZnS mixed powder scintillator sheet and a wavelength-shifting (WLS) fiber readout, was looped to each sphere at equal angular intervals. Amount of LiF neutron converter is reduced near polar region, where the band-shaped detectors are concentrated, in order to uniform the directional sensitivity. The LiF-ZnS mixed powder has an advantage of extremely high light yield. However, since it is opaque, scintillation photons cannot be collect uniformly. This type of detector shows no characteristic shape in the pulse height spectrum. Subsequently, it is difficult to set the pulse height discrimination level. This issue causes sensitivity fluctuation due to gain instability of photodetectors and/or electric modules. Materials and Methods: In order to solve this problem, we propose to replace the LiF-ZnS mixed powder into a flexible and Transparent RUbber SheeT type $LiCaAlF_6$ (TRUST LiCAF) scintillator. TRUST LiCAF scintillator can show a peak shape corresponding to neutron absorption events in the pulse height spectrum. Results and Discussion: We fabricated the prototype detector with five sensitive layers using TRUST LiCAF scintillator and conducted basic experiments to evaluate the directional uniformity of the sensitivity. Conclusion: The fabricated detector shows excellent directional uniformity of the neutron sensitivity.

• The Korean Journal of Mycology
• /
• v.42 no.4
• /
• pp.328-332
• /
• 2014

For mass production of entomopathogenic fungus Beauveria bassiana 149, isolated from moth larva, by two-phase fermentation, we performed selection of carbon and nitrogen sources for liquid culture and examined solid fermentation on carrier, ingredient, temperature, and water content. Spore production with rice powder, corn powder, and starch from sweet potato was higher than that of sucrose and dissolvable starch for liquid fermentation as first-phase fermentation. As a nitrogen source, addition of peptone and yeast powder showed higher spore production than $NaNO_3$, fish powder, and soybean powder. The isolate produced more conidia in sawdust + wheat bran + corn powder, sawdust + wheat bran and rice shell + wheat bran as carrier and ingredient than vermiculite as carrier. Conidia production of B. bassiana 149 in solid-phase fermentation was twice higher at 30 than 20. Conidia yield was higher at 60% and 70% water content ($26.9{\times}10^8$ and $38.6{\times}10^8conidia/g$) than 40% and 50% ($13.9{times}10^8 $and $11.6{\times}10^8conidia/g$), respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.2
• /
• pp.109-117
• /
• 1986

For the purpose of obtaining basic data which can be applied to processing of retort pouched shellfishes, retort pouched seasoned ark shell, Anadara broughtonii, was prepared. The frozen ark shell was thawed and seasoned with a mixed seasoning powder prepared with $10.0\%$ of sorbitol, $2.0\%$ of table salt and $0.5\%$ of monosodium glutamate at $5^{\circ}C$ for 10 hours, and then dried at $45^{\circ}C$ for 4 hours. The dried seasoned ark shell was coated with $1.0\%$ sodium alginate solution, dried with cola air blast for 2 hours and then vacuum-packed in the laminated plastic film bag (polyester/casted polypropylene= $12{\mu}m/70{\mu}m,\;15{\times}16cm$), and finally sterilized up to Fo=6.0 in hot water circulating retort at $121^{\circ}C$ for 10 minutes. The major fatty acids of raw ark shell and retort pouched seasoned ark shell products were 16:0, 20:5, 22:6, 18:0 and 18:3, and predominant free amino acids of those were lysine, arginine, glycine, alanine, glutamic acid and leucine. In nucleotides and its related compounds of raw ark shell and retort pouched seasoned ark shell products, the most abundant one was AMP, and total extract-N of those was chiefly consisted of free amino acids, betaine and nucleotide and its related compounds. During the processing procedure such as drying and sterilization, unsaturated fatty acids slightly decreased while saturated fatty acids increased, and total extract-N content decreased about a half. From the results of chemical and microbial experiments during storage, it was concluded that the products could be preserved in a good condition for 100 days at room temperature, and their duality could be improved by the coating treatment of sodium alginate solution.

• Clean Technology
• /
• v.21 no.1
• /
• pp.68-75
• /
• 2015

In this study, we investigated the structure and properties of a highly heat conductive metal-ceramic core-shell CoAl₂O₄@Al micro-composite for heterogeneous catalysts support. The CoAl₂O₄@Al was prepared by hydrothermal surface oxidation of Al metal powder, which resulted in the structure with a high heat conductive Al metal core encapsulated by a high surface area CoAl₂O₄ shell. For comparison, CoAl₂O₄ was also prepared by co-precipitation method and also utilized for a catalyst support. Rh catalysts supported on CoAl₂O₄@Al and CoAl₂O₄ were prepared by incipient wetness impregnation and characterized by N₂ adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), CO chemisorption, and temperature-programmed reduction (TPR). The properties of catalysts were investigated for glycerol steam reforming reaction for hydrogen production at 550 ℃. Rh/CoAl₂O₄@Al exhibited about 2.8 times higher glycerol conversion turnover frequency (TOF) than Rh/CoAl₂O₄ due to facilitated heat transport through the core-shell structure. The CoAl₂O₄@Al and CoAl₂O₄ also showed some catalytic activities due to a partial reduction of Co on the support, and a higher catalytic activity was also found on the CoAl₂O₄@Al core-shell than CoAl₂O₄. These catalysts, however, displayed deactivation on the reaction stream due to carbon deposition on the catalysts surface.