• Title/Summary/Keyword: ambient drying

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Effect of Acid Catalyst Kinds on the Pore Structural Characteristics of Water Glass based Silica Aerogel (산 촉매가 물유리 기반 실리카 에어로겔의 기공구조에 미치는 영향)

  • Nah, Ha-Yoon;Jung, Hae-Noo-Ree;Lee, Kyu-Yeon;Ku, Yang Seo;Park, Hyung-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.24 no.3
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    • pp.13-18
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    • 2017
  • Water glass is much cheaper than silicon alkoxide, so it has advantage for commercialization. A condensation by acid catalyst makes considerable effect about the properties of water glass based silica aerogel among many factors in silica aerogel process. The pore structural properties of water glass based silica aerogel such as specific surface area and pore size distribution have been investigated through the changes in the amount and the kinds of acid catalyst. It has been confirmed that water glass based silica aerogel is affected by various conditions of catalyst in the condensation reaction such as the kind, concentration, and the amount of mole of acid catalyst on the properties of final products. Especially, it is checked that the effect of mole of acid is more prominent than that of concentration. In the case for conventional method with introducing 4M HCl in condensation step, the silica aerogel could be synthesized which has $394m^2/g$ of specific surface area, 2.20 cc/g of pore volume, 22.3 nm of average pore size, and 92.53% of porosity. On the other hand, when 4M sulfuric acid was used with 73 mmol at the condensation step of water glass based silica aerogel, the pore structural characteristics of water based silica aerogel showed better properties than the case of using HCl, for example, specific surface area was measured as $516m^2/g$, and pore volume, average pore diameter, and porosity were obtained as 3.10 cc/g, 24.1 nm, and 96.1%, respectively.

Quality Characterization of Salmon Oil Microencapsulated with Various Wall Materials (다양한 피복물질을 이용한 연어 오일의 미세캡슐화 및 품질 특성)

  • LIM, Hyun-Jung;PARK, Seul-Ki;KIM, Min-Jeong;LEE, Won-Kyung;MIN, Jin-Ki;CHO, Young-Je
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.5
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    • pp.1334-1342
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    • 2015
  • The aim of this study was to investigate the quality characterization of salmon oil microencapsulated with maltodextrin (MD), cyclodextrin (CD), sodium caseinate (SC), arabic gum (AG) and WPI. After spray drying to ambient temperature, the salmon oil powders were packed (single package) and placed at room temperature ($25^{\circ}C$) for 30 day. The quality characterization of salmon oil powder including total oil (%), extractable oil (%), encapsulation efficiency (%), fatty acid, SEM, pH, acid value (AV), peroxide value(POV) were investigated. Salmon oil was microencapsulated with a high power yield (> 80%); including the formulation MD/SC and MD/SC/WPI. The microencapsules of MD/SC/WPI presented spherical shapes, smooth texture and non-porous surfaces. The pH of MD/SC/WPI varied from 6.11 to 5.99 (p>0.05). The AV of MD/SC/WPI varied from 4.74 to 4.61 (p>0.05). The pH and AV were not significantly different. The POV of MD/SC/WPI increased with storage day (p<0.05). It was concluded that MD/SC/WPI could delay lipid oxidation and high yield (82.55%) of salmon oil powder.

Colostrum Management and Use in Domestic Dairy Farms (국내 낙농가의 초유관리와 이용)

  • Jeong, Seok-Geun;Ham, Jun-Sang;Kim, Dong-Hun;Chae, Hyun-Seok;You, Young-Mo;Jang, Ae-Ra;Kwon, Il-Kyung;Lee, Seung-Gyu
    • Journal of Animal Science and Technology
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    • v.51 no.2
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    • pp.163-170
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    • 2009
  • Colostrum provide a complete diet for the newborn calves. In ruminants, colostrum is also the sole source of initial acquired immunity for the offspring. Colostrum, therefore, plays an important role in ruminants host defense. Bovine colostrum imparts passive immunity to newborn calves during the first 24h of life and generally has been fed for the first 3 days after birth. Colostrum can be preserved conveniently for future use by brief refrigeration, freezing, or storage at ambient temperatures (fermentation or chemical treatment). Colostrum management were surveyed via data collection from 67 dairy farms in Gyeonggi and Chungnam provinces. After parturition for five days the total amount of produced colostrum was 80.4 kg on average, and the average amount of lactation fed to a calf was 20.9 kg. According to the survey results, identified treatment methods for surplus colostrum are as follows; disposal 17.9%, other calf feeding 37.3%, storage 22.4%, other livestock feeding 20.9% and other treatment 1.5%. For improvement in the quality of colostrum, there must be controlled usage of medicines (such as antibiotics) before and after parturition, proper choices of milk-drying agents, and increased milking yields during the early stage of the milking period.

Proximate Compositions of Green Garlic Powder and Microbiological Properties of Bread with Green Garlic (풋마늘 분말의 일반성분 및 풋마늘 첨가 식빵의 미생물학적 특성)

  • Lee Mi Kyung;Park Jung Suk;Na Hwan Sik
    • Food Science and Preservation
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    • v.12 no.1
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    • pp.95-100
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    • 2005
  • To enhance the utilization of green garlic as food materials, the nutritional and microbiological properties of green garlic powder and bread were investigated. Proximate compositions of green garlic powder were as follows; moisture $6.99\%$, crude protein $7.62\%$, crude lipid $1.84\%$, crude ash $6.60\%$, crude fiber $9.88\%$ and carbohydrate $76.95\%$. Free sugars were composed of glucose, glucose and sucrose. The major minerals of green garlic powder were k(1,140 mg/100 g), Ca(679.05 mg/100 g), P(342.09 mg/100 g) and Na(130.42 mg/100 g). In the total and free amino acid analysis, the major amino acids were methionine, cystine, proline and glutamic acid. When various amount of freeze dried green garlic powder were added in bread, bread with $0.5\%$ green garlic powder had lower level of total bacterial count compared with the control group at ambient temperature$(30{\pm}1^{\circ}C)$. Result of sensory evaluation showed that the preference scores decreased as the green garlic powder content increased. Through the result of these experiment we can conclude that the highest quality of green garlic powder content is no more than $0.5\%$ in making bread added with green garlic powder.

CuO Nanograss as a Substrate for Surface Enhanced Raman Spectroscopy

  • Lee, Jun-Young;Park, Jiyun;Kim, Jeong-Hyun;Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.249-249
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    • 2013
  • Surface-enhanced Raman spectroscopy (SERS) is a sensitive approach to detect and to identify a variety of molecules. To enhance the Raman signal, optimization of the gap between nanostructures is quite important. One-dimensional materials such as nanowires, nanotubes, and nanograsses have great potential to be used in SERS due to their unique sizes and shape dependent characteristics. In this study we investigate a simple way to fabricate SERS substrates based on randomly grown copper oxide (CuO) nanowires. CuO nanograss is fabricated on pre-cleaned Cu foils. Cu oxidized in an ammonium ambient solution of 2.5 M NaOH and 0.1 M $(NH_4)_2S_2O_8$ at $4^{\circ}C$ for 10, 30, and 60 minutes. Then, Cu(OH)2 nanostructures are formed and dried at $180^{\circ}C$ for 2 h. With the drying process, the Cu(OH)2 nanostructure is transformed to CuO nanograss by dehydration reaction. CuO nanograss are grown randomly on Cu foil with the average length of 10 ${\mu}m$ and the average diameter of a 100 nm. CuO nanograsses are covered by Ag with various thicknesses from 10 to 30 nm using a thermal evaporator. Then, we immerse uncoated and Ag coated CuO nanowire samples of various oxidation times in a 0.001M methanol-based 4-mercaptopyridine (4-Mpy) in order to evaluate SERS enhancement. Raman shift and SERS enhancement are measured using a Raman spectrometer (Horiba, LabRAM ARAMIS Spectrometer) with the laser wavelength of 532 nm. Raman scattering is believed to be enhanced by the interaction between CuO nanograss and Ag island film. The gaps between Ag covered CuO nanograsses are diverse from <10 nm at the bottom to ~200 nm at the top of nanograsses. SERS signal are improved where the gaps are minimized to near 10s of nanometers. There are many spots that provide sufficiently narrow gap between the structures on randomly grown CuO nanograss surface. Then we may find optimal enhancement of Raman signal using the mapping data of average results. Fabrication of CuO nanograss based on a solution method is relatively simple and fast so this result can potentially provide a path toward cost effective fabrication of SERS substrate for sensing applications.

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Evaluation of Pretreatment Moisture Content and Fixation Characteristics of Treated Wood for Pressure Treatment of Japanese Red Pine and Japanese Larch Skin Timber with ACQ, CUAZ and CuHDO (소나무와 낙엽송 스킨팀버의 ACQ, CUAZ, CuHDO 가압처리를 위한 처리용 목재의 적정 함수율 및 처리목재의 정착 특성 평가)

  • Choi, Yong-Seok;Oh, Se-Min;Kim, Gyu-Hyeok
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.6
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    • pp.481-489
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    • 2011
  • This study was conducted to evaluate the pressure treatment characteristics of Japanese red pine and Japanese larch skin timber with ACQ-2, CUAZ-2 and CuHDO-1. The effect of moisture content (MC) on preservative treatability was investigated for Japanese red pine sapwood and Japanese larch heartwood, and fixation characteristics of CCA alternatives was also evaluated. Japanese red pine sapwood, which was dried below 30 percent MC, was fully penetrated with preservatives, and minimum requirement of preservative retention for the hazard class H3 was achieved. Through measuring preservative retention gradient in Japanese red pine sapwood, it was confirmed that the retention gradient of CuHDO-1 was steeper than that of both ACQ-2 and CUAZ-2. In particular, it was intensified at a higher MCs of wood samples (25∼30%). Japanese larch heartwood did not meet the minimum requirement of penetration and retention for the hazard class H3 over the range of pretreatment MCs tested. With presteaming under $121^{\circ}C$ for 12 hours, the treatability of Japanese larch heartwood was enhanced to meet the minimum requirement for the hazard class H3. The fixation rate of copper was much more faster under drying condition compared with nondrying condition; more than 95% of copper were fixed in 3~6 days and 1 day under drying conditions in Japanese red pine sapwood and Japanese larch heartwood, respectively. After 3-week fixation period at ambient temperature, the amount of mobile copper in treated wood sample that remains available for leaching from treated wood was the highest in the wood samples treated with ACQ-2, followed by CuHDO-1 and CUAZ-2. It was proportional to the amount of copper in treating solution.