• 벤처혁신연구
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• 제5권2호
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• pp.85-99
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• 2022

시판되고 있는 실험용 및 산업용 건조기는 일반 드라이오븐, 열풍 순환 건조기, 진공건조기, 동결건조기 등으로 구분되고 기능, 크기 및 용량 등에 따라 그 종류도 다양하다. 그러나 제품의 품질 제어 및 성능 개선을 위해 중요한 요소인 수분측정이 적용되지 않아 현재는 건조 종료 후 임의로 중량을 칭량하기 때문에 매우 수동적이다. 일반적으로 수분을 측정하기 위한 방법은 직접적인 측정법과 간접적인 측정법으로 구분되고 수분 분리 전.후의 질량 또는 부피 변화와 같은 직접적인 측정법이 주로 이용된다. 상대적으로 열전도도, 마이크로파 등과 같은 간접적인 측정법은 측정 장비를 활용하기 때문에 적용이 제한적이다. 본 연구에서는 오픈소스 기반의 아두이노를 이용하여 비교적 손쉽게 수분측정 시스템을 설계하여 외부 환경요인에 영향 받지 않고 수분 변화량 및 무게 변화를 실시간으로 모니터링 하였다. 구체적으로 수분 민감도 물질 및 식품 건조에 적합한 60℃와 80℃에서 작동할 수 있는 온.습도 및 로드셀 측정 센서를 건조기 내부에 패키징하여 각종 변화량을 측정하였다. 또한 바나나, 배, 톱밥의 유기 시료를 이용한 반복적인 실험을 통해서도 건조시간 및 온도에 따른 증발율 변화와 로드셀 측정값에 있어 안정적인 응답특성을 나타냄으로써 성능 안전성을 확보할 수 있었다. 향후 온.습도 범위의 확대와 CFD(Computational Fluid Dynamics) 프로그램과의 비교 분석을 통해 신뢰도를 더욱 향상시킬 수 있을 것으로 판단된다.

• 한국축산식품학회지
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• 제36권1호
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• pp.51-60
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• 2016

This study was performed to evaluate the antioxidant activity of oven-dried tomato powder (OTP) as affected by drying temperature and the effect of OTP on the product quality of pork patties. Three OTP products were obtained by drying of fresh tomato at 60, 80 and 100℃ oven until constant weight was obtained. Total phenolic content of three kinds of OTPs ranged from 1.95 to 5.94 g/100 g. The highest amount of total phenolic compound was observed in OTP dried at 100℃. Antioxidant activity of three kinds of OTPs was measured by 1,1-diphenyl-2-pycrylhydrazyl (DPPH)-radical scavenging activity, iron chelating ability, reducing power and measurement of lipid peroxide in linoleic acid emulsion system. In all parameters, OTP at 100℃ showed the higher antioxidant activity than other temperatures (p<0.05). Based on the model study, the physicochemical properties, and antioxidant and antimicrobial activities of pork patties containing 1% OTP were measured. Redness of pork patties were increased with the addition of OTPs (p<0.05). Thiobarbituric acid reactive substances (TBARS) values of raw pork patties containing OTPs were lower than those of control (CTL) until 7 d of storage, regardless of drying temperatures (p<0.05). Peroxide values of pork patties made with OTP (1%) were lower than those of CTL until the end of storage time (p<0.05). However, no antimicrobial activities were observed among the treatments (p>0.05). Therefore, OTPs could be used as a natural antioxidant in meat products.

• Journal of the Korean Wood Science and Technology
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• 제40권1호
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• pp.44-52
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• 2012

낙엽송 원통형 원주목에 대하여 수증기댐처리와 코팅처리를 실시하여 오-븐건조 하면서 건조속도, 재내의 수증기압 및 재온분포 및 건조할렬 등을 조사한 결과는 다음과 같다. 생재에서 난방된 실내의 이용함수율 수준인 함수율 약 8%까지 건조하는데 72~144시간 소요되었다. 무처리재와 코팅처리재는 전 건조기간에 걸쳐 통공층의 온도가 통피층의 온도보다 항상 높은 분포모형을 보인 반면, 수증기댐처리재의 경우 통피층의 온도가 통공층보다 높거나 같은 분포를 보였다. 수증기댐처리재와 코팅처리재의 경우는 거의 전 건조기간에 걸쳐 통피층의 수증기압이 통공층 보다 큰 분포를 보였다. 총체적으로 할렬발생 정도는 미약하였으며 할렬개수는 코팅처리재, 수증기댐처리재, 무처리재의 순으로 양호한 것으로 나타났다.

• 한국가구학회지
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• 제14권2호
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• pp.13-20
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• 2003

This research is to develop kiln-drying schedules for 2.7 mm thick boards of Neolitsea sericea and Dendropanax morbifera, which grow in the southern region of Korean Peninsula. These two species are lesser-known to woodcraft industry in this country. The proper USDA drying schedules for Neolitsea sericea and Dendropanax morbifera were found to be T10-C6 and T10-E6, respectively, by using the Quick Oven-drying Method. The boards dried in a kiln with the newly-developed schedules were revealed to be free from warping and checking.

• 한국환경과학회지
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• 제25권3호
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• pp.417-424
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• 2016

The objective of this study was to evaluate the microwave drying characteristics of mixtures of chemical wastewater sludge (70~90%) and anthracite coal (10~30%) with respect to physical and economic factors such as mass, volume reduction, moisture content, drying rate and heating value when the wastes were dried at different weight mixing ratio and for different microwave irradiation time. The drying process were carried out in a microwave oven, the combined drying process with a 2,450 MHz frequency and 1 kW of power. Maximum dry rates per unit area on the microwave drying of mixtures with chemical wastewater sludge and anthracite coal were $35.5kg\;H_2O/m^2{\cdot}hr$ for Cs90-Ac10; $40.1kg\;H_2O/m^2{\cdot}hr$ for Cs80-Ac20 and $35.0kg\;H_2O/m^2{\cdot}hr$ for Cs70-Ac30. The result clearly indicated that moisture can be effectively and inexpensively removed from the wastes through use of the microwave drying process.

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.39-45
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• 1995

The plywoods commonly used as decorative interior materials for the construction are inflammable and so it is a causative factor for making fire accidents, resulting in the destruction of human life and personal properties. Indeed, it is, therefore, required to produce fire-retardant plywoods. In this study, a special grade of defect-free, Kapur plywood was used. Specimens were cut into 3- by 20cm dimensions from 120- by 240- by 0.33-cm panels(thin panel) or 120- by 240- by 0.5-cm panels(thick panel). Some specimens were treated with diammonium phosphate(DAP), but some were not treated with diammonium phosphate to use as control panels. Chemical absorption, drying curves, drying rates and dynamic Young's modulus were investigated. The results were summaries as follows; 1. The specimens were soaked into 19% diammonium phosphate solution by a full cell pressure process and the diammonium phosphate retained in the thin and thick plywoods was 1.409kg/$(30cm)^3$, 1.487kg/$(30cm)^3$, respectively. 2. Diammonium phosphate-treated plywoods were redried with press-drying process at one of either condition dried on the platen($115^{\circ}C$) for a period of time or dried on the platen($50^{\circ}C$) for 3 hrs plus in a dry-oven($30^{\circ}C$) for 24 hrs. or dried on the platen($60^{\circ}C$) for 2 hrs plus in a dry-oven($30^{\circ}C$) for 24 hrs. The drying rate of treated thin specimens dried at $60^{\circ}C$ plus $30^{\circ}C$ and $115^{\circ}C$ only was found to be 0.04 %/min. and 8.53 %/min. Similarly, the drying rate of treated thick specimens were 0.03 %/min. and 6.77 %/min. respectively. 3. It was evident that highly-significantly different drying rate of treated plywoods was observed between plywood thicknesses and platen temperatures and the rate was increased by elevating the platen temperature up to $115^{\circ}C$. Based on the two-way variance analysis, highly significant drying rate was observed from the interaction between plywood thicknesses and platen temperatures. 4. After redrying, the specimens were weighed and reconditioned to a constant weight in a facility maintained temperature ($20^{\circ}C$) and relative humidity(65%) prior to test dynamic Young's modulus. The test revealed that the thin specimens dried at the platen temperature of $50^{\circ}C$, $60^{\circ}C$, $115^{\circ}C$ and untreated specimens showed 1.070E+09 dyne/$cm^2$, 1.156E+09 dyne/$cm^2$, 1.243E+09 dyne/$cm^2$, and 1.052E+09 dyne/$cm^2$, respectively. Likewise, the thick specimens revealed 5.647E+09 dyne/$cm^2$ 5.670E+09 dyne/$cm^2$, 6.395E+09 dyne/$cm^2$ and 5.415E+09 dyne/$cm^2$, respectively. 5. It was evident that significantly different dynamic Young's modulus was observed between the plywood thickness and the platen temperature, but not in the two-way interaction between the plywood thickness${\times}$the platen temperature.

• 한국세라믹학회지
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• 제26권5호
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• pp.682-690
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• 1989

Fine mullite powder was prepared by colloidal sol-gel route. Boehmite as a starting material of Al2O3 and silica sol or fumed silica as a starting material of SiO2 were used. $\alpha$-Al2O3, TiO2 and ZrO2 were used as seeding materials. The combination of boehmite and silica was found to be the stoichiometric mullite powder. Techniques for drying used were spray drying, freeze drying, reduced pressure evaporation and drying in a oven. The gelled powder was heated at 130$0^{\circ}C$ for 100min and was attrition-milled for 1~3hrs. The mullite powder obtained was composed of submicrometer, uniform and spherical particles with a narrow size distribution. The mullite powder was characterized by BET, SEM, XRD and IR spectroscopy.

• 한국축산식품학회지
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• 제41권4호
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• pp.715-730
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• 2021

The objective of this study was to evaluate antioxidant activities of eggplant (EP) powder with different drying methods and addition levels to pork sausages to improve product quality. Antioxidant activities of EP with different drying methods, particle sizes, and solvents of extraction were determined. Freeze dried (FD) EP extracted with 100% ethanol had higher 2,2-diphenyl-1picrylhydrazyl radical-scavenging activities (DPPH-RSA) and total phenolic content (TPC) values than other drying methods. FD500 had the highest iron chelating ability (ICA) value. Oven-dried (OD) EP at 60℃ had the highest reducing power. Dried EP was added to sausages of six groups: control without EP, reference added with ascorbic acid, O1 and O2 added with 0.25% and 0.5% OD EP, respectively, and F1 and F2 added with 0.25% and 0.5% FD EP, respectively. Pork sausages added with O2 had the lowest TBARS and TPC values. These values increased during storage. Purge loss (%), lightness (L^*), and redness (a^*) values of F2 were lower than those of other groups, whereas sausages containing F2 had the highest yellowness (b^*). pH values of sausages added with EP were increased regardless of the level of EP added. Hardness values of F2 were higher. However, there were no significant differences in other textural characteristics. Sausages added with EP had higher moisture and protein contents (%), but lower fat contents (%). These results indicate that EP powder could be used to retard lipid oxidation and inhibit microbial counts during storage time.

• 한국도로학회:학술대회논문집
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• 한국도로학회 2008년도 추계학술대회 논문집
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• pp.87-92
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• 2008

• Journal of the Korean Wood Science and Technology
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• 제35권1호
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• pp.17-26
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• 2007

본 연구에서는 수증기댐처리 또는 횡단면 코팅처리 등이 오동나무 장고용 초갈이재의 송풍오븐건조 특성에 미치는 영향을 구명코저하였다. 건조개시 직후의 중량감소량은 무처리(C-NC treatment), 엔드코팅처리(C-CO treatment), 수증기댐처리(V-NC treatment), 수증기댐-엔드코팅처리(V-CO treatment)재의 순으로 크게 나타났다. V-CO처리재는 V-NC처리재와 비교하여 전(全)건조기간에 걸쳐 더 완만한 온도경사를 보였으며 내층과 외층간에 온도경사가 거의 존재하지 않았다. C-CO처리재의 경우 C-NC처리재와 비교하여 건조중기까지는 외층과 내층의 수증기압 모두가, 그리고 건조중기 이후에는 내층의 수증기압이 더 높게 나타났다. V-CO처리재의 경우 건조초기에는 V-NC처리재와 유사한 분포를 보였으나, 건조초기 이후 통공, 외층, 내층의 순으로 절대수증기압이 큰 분포를 보이면서 V-NC처리재와는 전혀 다른 분포모형이 관찰되었다. 재면할렬과 윤할은 모든 처리재에서 전혀 발생하지 않았으나 엔드코팅을 실시하지 않은 C-NC와 V-NC에서는 횡단면할렬이 심하게 발생하였다.