생육, 습식 숙성육, 건식 숙성육을 종류별 3종을 구입하여 냉장 상태로 보관하면서 pH, 휘발성 염기질소(VBN), 미생물 정량, 우점균을 분석하였다. 초기 생육, 건식 숙성 육의 중온균은 3.3-3.9 Log CFU/g, 습식 숙성육은 경우 5.4 Log CFU/g 이였으나, 냉장으로 18일 보관 후 생육과 건식 숙성육에 존재하는 중온균은 6.1-6.4 Log CFU/g로 증가하였다. 습식 숙성육의 경우 Lactic acid bacteria (LAB) 는 냉장 보관시 4.5-6.0 Log CFU/g으로 나타났으나, 건식 숙성육에서는 검출되지 않았다. 저장 기간이 길어짐에 따라 중온균, 저온균, LAB, 효모 및 곰팡이 수가 증가하였으나, 식품매개 병원성 미생물은 검출되지 않았다. 식육의 오염 및 부패 판단은 7 Log CFU/g 이상으로 규정하고 있어 본 연구 결과에 의하면 12일 이상 냉장 보관하였을 경우 6-7 Log CFU/g으로 기준을 초과하였다. 이 때 VBN이 평균 15 mg%으로 부패의 초기 단계로 판단 할 수 있었다. 냉장 보관에 따른 우점 미생물은 다양한 양상으로 나타냈 다. 생육에서는 초기 우점균으로 S. saprophyticus가 분석 되었으나, VBN이 증가함에 따라 Carnobacterium divergens 가 우점하는 양상을 나타냈다. 습식 숙성육에서 Carnobacterium divergens가 냉장보관 초기에 우점 미생물로 분석되었으나, 이후 Lactobacillus sakei가 우점균으로 분석되었다. 건식 숙성육의 경우 Dermacoccus nishinomiyaensis 가 냉장보관 초기에 우점하였으나 이후 Pseudomonas fragi 가 우점균으로 변화하였다. 부패의 초기 단계에서 특정 박 테리아의 역할 외에도 부패, 향기 분석 및 숙성 육류의 성분 변화에 대한 연구를 수행하여 숙성 육류의 안전한 유통 및 보관에 활용할 수 있다고 판단된다.

A facile one-pot wet chemical process to prepare pure anatase TiO2 hollow structures using ammonium hexafluorotitanate as a precursor is developed. By defining the formic acid ratio, we fabricate TiO2 hollow structures containing fluorine on the surface. The TiO2 hollow sphere is composed of an anatase phase containing fluorine by various analytical techniques. A possible formation mechanism for the obtained hollow samples by self-transformation and Ostwald ripening is proposed. The TiO2 hollow structures containing fluorine exhibits 1.2 - 2.7 times higher performance than their counterparts in photocatalytic activity. The enhanced photocatalytic activity of the TiO2 hollow structures is attributed to the combined effects of high crystallinity, specific surface area (62 m2g-1), and the advantage of surface fluorine ions (at 8%) having strong electron-withdrawing ability of the surface ≡ Ti-F groups reduces the recombination of photogenerated electrons and holes.

In this study, the quality characteristics and antioxidant activities of wet noodles added with doraji (Platycodon grandiflourm) powder at concentrations of 1%, 2%, 3%, and 4%, respectively, were investigated. The crude protein, crude fat, crude ash, crude fiber, and moisture contents of the dried doraji powder were 11.00%, 0.95%, 4.10%, 29.64%, and 6.21%, respectively. As the added amount of doraji powder increased, weight, volume, and water absorption of the wet noodles after cooking decreased. However, the turbidity of the soup increased. Color L values of wet and cooked noodles decreased, while a and b values increased by the addition of doraji powder. Texture measurement indicated that hardness, cohesiveness, springiness, and chewiness of the cooked noodles decreased by addition of doraji powder. The total polyphenol contents and DPPH radical scavenging activity in wet noodles added with doraji powder increased with increasing amounts of doraji powder. Finally, sensory evaluation of wet noodles added with doraji powder revealed that taste significantly decreased. However, flavor, color, texture, appearance, and overall acceptance scores for the 1% addition group ranked significantly higher than those of the other groups. In conclusion, these findings suggest that doraji powder could be used as functional food ingredients.

The objective of this study was to investigate the effects of dry-aging and wet-aging conditions on the chemical composition, meat quality traits (color, water holding capacity, cooking loss, WBSF and pH) and shelf-life TBARS (2-thiobarbituric acid reactive substances) and VBN (volatile basic nitrogen) of loin (M. longissimus thoracis), sirloin (M. glutaeusmedus) and top-round (M. semimembranosus) cuts of Hanwoo cows. The dry-aging condition (temperature ℃, relative humidity %) was done for 60 d as 2℃, 65％, 20 d＋2℃, 75％, 20 d＋4℃, 85％, 20 d while, the wet-aging was done for 60 d at 1℃, 85%. Results revealed that moisture content was significantly higher in the dry-aged samples than that of the wet-aged samples at 60 d (p<0.05). The a*- and b*-values were significantly higher in 3 cuts as compared with those treated with wet-aging condition. During the dry-aging time, the WHC significantly increased in the loin and sirloin and they were significantly higher than wet-aging condition at 40 d and 60 d (p<0.05). The WBSF values significantly decreased with increased aging time and there was no significant difference between two aging methods. The TBARS and VBN contents significantly increased with increased aging time for all the wet- and dry-aged cuts, and their levels still fell within the acceptable standard limit. Generally, the TBARS and VBN contents were significantly higher in the dry-aged cuts, probably due to the increased levels of protein and fatty acids oxidations. Based on the results obtained in the present study, it can be suggested that application of dry-aging method can improve the quality characteristics of beef.

Surface plasmon resonance is the resonant oscillation of conduction electrons at the interface between negative and positive permittivity material stimulated by incident light. In particular, when light transmits through the metallic microhole structures, it shows an increased intensity of light. Thus, it is used to increase the efficiency of devices such as LEDs, solar cells, and sensors. There are various methods to make micro-hole structures. In this experiment, micro holes are formed using a wet chemical etching method, which is inexpensive and can be mass processed. The shape of the holes depends on crystal facets, temperature, the concentration of the etchant solution, and etching time. We select a GaAs(100) single crystal wafer in this experiment and satisfactory results are obtained under the ratio of etchant solution with H2SO4:H2O2:H2O = 1:5:5. The morphology of micro holes according to the temperature and time is observed using field emission - scanning electron microscopy (FE-SEM). The etching mechanism at the corners and sidewalls is explained through the configuration of atoms.

본 연구에서는 쌀 가공식품에 대한 쌀가루 종류, 유지 종류 및 첨가량의 효과를 제공하고, 쌀빵의 제빵 특성 및 제조방법을 확립하기 위해 습식 및 건식 쌀가루의 물리적 특성을 조사하였으며, 버터 및 식용유를 4.0~5.8% 첨가하였을 때 반죽 및 쌀빵의 특성, 텍스처 특성을 비교 분석하였다. 습식 및 건식 쌀가루의 물리적 특성에서 수분함량은 습식 쌀가루가 건식 쌀가루에 비해 높았고(p<0.001), 전분손상도는 건식 쌀가루가 습식 쌀가루에 비해 높았으며(p<0.001), 쌀가루의 평균 입자크기는 습식 쌀가루가 건식 쌀가루보다 크게 나타났다(p<0.001). 습식 및 건식 쌀가루의 amylogram과 RVA에 의한 pasting 특성에서 습식 쌀가루 A가 결과값들이 크게 조사되었고, 그 다음 건식 쌀가루 C와 B 순으로 나타났다(p<0.001). 습식 및 건식 쌀가루 현탁액의 DSC 측정 결과, 습식 쌀가루 A는 건식 쌀가루 B와 C에 비해 전분호화 개시온도와 전분호화 최고온도가 낮았고, 쌀가루의 호화엔탈피는 습식 쌀가루 A는 10.5 cal/g, 건식 쌀가루 B와 C는 10.1과 2.71cal/g으로 조사되었다(p<0.001). 습식 및 건식 쌀가루의 유지류 첨가 비율에 따른 쌀빵 반죽의 발효 전과 후 비중은 버터 첨가군이 식용유 첨가군보다 높았고, 색도 분석에서는 습식 쌀가루 A가 건식 쌀가루 B와 C에 비해 L값이 높게 나타났다(p<0.001). 쌀가루 종류에 따라 쌀빵의 부피와 비용적은 건식보다 습식 쌀가루가 크게 나타났으며, 버터 첨가군보다 식용유지 첨가군이 크게 나타났다(p<0.001). 쌀빵의 색도 분석에서는 L, a 및 b값이 유의적인 차이를 나타내었다(p<0.001). 쌀빵의 텍스처 특성에서 식용유 첨가군이 버터 첨가군보다 경도가 낮았으며(p<0.001), 습식 쌀가루 A와 건식 쌀가루 B로 만든 쌀빵은 식용유 첨가 수준이 증가할수록 경도가 낮아졌으며, 이러한 경향은 건식 쌀가루 C로 제조한 쌀빵의 경우에서는 보이지 않았다(p<0.001). 쌀빵의 모양은 습식 쌀가루보다 건식 쌀가루에서 빵 중간이 푹 커진 모양을 볼 수 있었으며, 그리고 식용유 첨가군보다 버터 첨가군에서 이러한 현상을 볼 수 있었다. 따라서 쌀빵 제조에 건식 쌀가루보다 습식 쌀가루가, 버터 첨가군보다 식용유 첨가군이, 식용유 첨가군에서는 4.0%보다 5.8% 첨가할 경우, 제빵 효과가 있는 것으로 조사되었다.

This study evaluated the quality characteristics of wet noodles added with sword bean powder(0, 5, 10, 15%) to determine the most preferred noodle recipe for consumer’s desire. The proximate composition of the sword bean powder was as follows: Moisture contents were 13.4±0.08%, protein 30.2±0.12%, fat 0.3±0.09%, protein 1.0±0.11% and carbohydrates 55.1±0.12%, respectively. Total amino acid content of sword bean powder was measured 23,054.266 mg/ 100 g, especially in the order of histidine, glutamic acid and aspartic acid. The flavonoid content of sword bean powder was 17.9750 mg%. Water-binding capacity increased as the level of sword bean powder increased. When viscosity of wheat flours containing sword bean powder was measured by amylograph, the gelatinization point increased significantly as the level of sword bean powder increased, but peak viscosity decreased. As the level of sword bean powder increased, L value decreased, whereas a and b values increased. Weight, water absorption and volume of cooked noodles prepared with wheat flours containing sword bean powder decreased, whereas turbidity of soup increased. For textural properties, addition of sword bean powder increased hardness, springiness, chewiness of cooked noodles, whereas adhesiveness decreased. According to sensory evaluation such as appearance, color, flavor, taste, texture, overall preference, it was revealed noodles with 10% sword bean powder was the most preferred. According to the results, the addition of sword bean powder positively affects the overall sensory evaluation of wet noodle, and 10% is the optimal level for addition.

F-containing TiO2 nanopowders are synthesized using simple wet processes (precipitation-based and hydrothermal) from ammonium hexafluorotitanate (AHFT, (NH4)2TiF6) as a precursor to apply as a photocatalyst for the degradation of rhodamine B (RhB). The surface properties of the prepared samples are evaluated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The results confirm that the synthesized anatase TiO2 has sphere-like shapes, with numerous small nanoparticles containing fluorine on the surface. The photocatalytic activity of F-containing TiO2 compared with F-free TiO2 is characterized by measuring the degradation of RhB using a xenon lamp. The photocatalytic degradation of F-containing TiO2 exhibits improved photocatalytic activity, based on the positive effects of adsorbed F ions on the surface.

Multi-walled carbon nanotube (MWCNT)–copper (Cu) composites are successfully fabricated by a combination of a binder-free wet mixing and spark plasma sintering (SPS) process. The SPS is performed under various conditions to investigate optimized processing conditions for minimizing the structural defects of CNTs and densifying the MWCNT–Cu composites. The electrical conductivities of MWCNT–Cu composites are slightly increased for compositions containing up to 1 vol.% CNT and remain above the value for sintered Cu up to 2 vol.% CNT. Uniformly dispersed CNTs in the Cu matrix with clean interfaces between the treated MWCNT and Cu leading to effective electrical transfer from the treated MWCNT to the Cu is believed to be the origin of the improved electrical conductivity of the treated MWCNT–Cu composites. The results indicate the possibility of exploiting CNTs as a contributing reinforcement phase for improving the electrical conductivity and mechanical properties in the Cu matrix composites.

Phosphorus (P) is a limited, essential, and irreplaceable nutrient for the biological activity of all the living organisms. Sewage sludge ash (SSA) is one of the most important secondary P resources due to its high P content. The SSA has been intensively investigated to recover P by wet chemicals (acid or alkali). Even though H2SO4 was mainly used to extract P because of its low cost and accessibility, the formation of CaSO4 (gypsum) hinders its use. Heavy metals in the SSA also cause a significant problem in P recovery since fertilizer needs to meet government standards for human health. Therefore, P recovery process with selective heavy metal removal needs to be developed. In this paper some of the most advanced P recovery processes have been introduced and discussed their technical characteristics. The results showed that further research is needed to identify the chemical mechanisms of P transformation in the recovery process and to increase P recovery efficiency and the yields.

Alane(aluminum trihydride, AlH3)으로 명명되는 고에너지 물질인 삼수소알루미늄은 수소저장 물질로서 뿐만 아니라 우주항공분야의 고체 추진제나 방위산업의 화약제조용으로도 사용될 수 있다. 본 연구는 습식공정을 통하여 합성하고, 에테르를 세밀하게 분리하는 결정화 공정을 통하여 최종 수소화물을 추출하였다. 결정화 공정에서 삼수소알루미늄-에테레이트(AlH3·(C2H5)2O)가 alane으로 상변이하면서 입자가 성장하고, 85℃에서 2 시간의 결정화 시간이 이루어졌을 때 가장 안정된 결정상이 나타나는 모습을 확인하였다. 최종적으로 추출된 고체상 삼수소알루미늄은 막대모양의 γ-형태가 가장 많은 양을 차지하는 것으로 나타났으며, 크기는 50-100 μm 수준이었다

시중에 유통 중인 물휴지 62 품목을 선정하여 살균보존 제 성분 및 유해물질 함유 여부 등의 안전성을 조사하였다. 일반적으로 화장품 및 식품에 가장 많이 사용하는 살균 보존제인 안식향산나트륨은 46 품목에서 200~3500 ppm 검출되었고 파라벤류는 1품목에서 파라옥시안식향산메칠이 9 ppm 검출되었다. 사용할 수 없는 살균보존제인 메칠클로로이소치아졸리 논과 메칠이소치아졸리논(3:1)혼합물이 1 품목에서 검출되어 부적합 판정되었으며, 메칠클로로이소치아졸리논 5 ppm, 메칠이소치아졸리논 140 ppm 검출되었다. 염화세틸피리디늄은 5 품목에서 7~13 ppm 검출되었으 며, 모두 허용기준 이내로 나타났다. 잔류유해물질인 포름알데히드 검사결과는 0.069~1.796 μg/ g로 허용기준인 20 μg/g 이하였다. 메탄올은 5~51 ppm 검출되었으며, 이 중 4 품목에서 허용기준인 20 ppm보다 2배 이상의 농도가 나타났다. 안전한 제품이 유통될 수 있 도록 메탄올의 잔류경로에 대한 지속적인 조사 및 모니터 링이 필요하다고 판단된다. 물휴지의 pH를 측정한 결과 4.0~8.2로 나타나 유통화장 품의 pH 3.0~9.0 기준에 적합하였으나, 물휴지에는 pH 기 준이 설정되어 있지 않으므로 안전관리를 위해서는 pH 기준을 설정하는 고시개정이 필요할 것이다.

For four times, zooplankton collection were conducted seasonally in October 2015- July 2016 at five sites located in the wet lands of the lower Han River, ie., Si-am, Sung-dong, Gong-reung stream, San-nam and Jang-hang. A total of 46 species of zooplankton were collected, which comprise 25 species of rotifers, seven cladocerans, ten copepods, and one species of nematod, ostracod and decapod, respectively. No brackish and marine species were distributed except for two species of brackish water copepods. Prosperity in the species number of 15 species was observed in October at Sung-dong and Jang-hang. The maximum abundance was recorded in March at Si-am with 8,000 indiv. L-1 with the explosion of Brachionus calyciflorus. Other sites also showed high abundances in March with the abundance higher than 5,000 indiv. L-1. Except in March, the abundance levels were recorded as less than some hundred indiv. L-1 throughout the study. Species diversity varied between 0.4-1.8. The gut contents of the copepodite showed that various diatoms might be their major food items, and lots of unidentified materials were also observed. The environmental conditions of water temperature, pH and dissolved oxygen content showed to vary 10.1-28.2°C, 7.1-8.6 and 4.5-11.0 mg L-1, respectively.

It is necessary to develop a device for the design of wet scrubber with a more efficient deodorization performance in order to enhance the odor reducing effect of the wet scrubber. Therefore in this study, the superiority of the new wet scrubber with the centrifugal separation function different from the conventional wet scrubber was analyzed by the computational fluid dynamics. From CFD analysis, the pressure and velocity distribution, the peak vorticity, the retention time and the flow uniformity were calculated and compared with the performance characteristics of the centrifugal separator. As the results of CFD analysis, the peak vorticity and retention time of the gas flow were increased about 22% and the flow uniformity was improved about 7.2% by the centrifugal separator. Therefore the centrifugal separator in the wet scrubber will improve the deodorizing effect and the cleaning condition of the gas.