• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.32-32
• /
• 2017

2012년부터 도입된 "신재생에너지 의무할당제(RPS)"로 인하여 500MW이상의 설비 용량을 갖춘 발전소의 경우 총발전량에서 일정 비율을 신재생에너지로 공급하여야 한다. 이러한 신재생에너지 중 농업부산물은 목질계 바이오매스의 한 종류로 '탄소중립(Carbon Neutral)' 연료이며 기존 화석연료와 혼소로 활용 할 수 있는 장점을 지니고 있다. 그러나 낮은 발열량, 운송 및 저장비용, 일정하지 않은 연소특성의 문제로 인하여 대부분 노지에 방치되거나 버려지고 있다. 이러한 버려지는 농업부산물을 효율적으로 활용하기 위한 방법 중 하나로 반탄화(Torrefacation) 처리가 대두되고 있다. 반탄화 처리 시, 발열량이 증대되며, 저장과 이송에서의 이점을 갖게 된다. 그러나, 반탄화는 공정 과정중 질량손실에 따른 에너지 총량의 감소한다는 단점을 가지고 있다. 이에 본 연구에서는 효율적인 반탄화공정을 위한 질량감소모델을 제시 하고자한다. 승온 속도(heating rate)를 $7.5^{\circ}C/min$, $15^{\circ}C/min$, $22.5^{\circ}C/min$의 조건에서의 열중량분석 결과를 토대로 속도모델식(Arrhenius method, Ingraham & Marrier method 등)을 적용하여, 반응속도상수를 도출하였다. 이 반응속도상수를 이용하여 질량감소 모델을 정립하였고, 이를 실험결과와 비교, 검증하였다.

• Textile Coloration and Finishing
• /
• v.6 no.4
• /
• pp.9-16
• /
• 1994

알칼리 수용액 중에서의 Vinylsulfone(VS)계 반응성염료의 혼합상태의 가수분해 반응을 정량적으로 조사하였다. 혼합이량체의 생성 및 분해반응 속도상수를 각각의 염료의 가수분해반응에서 구한 속도상수를 이용하여 계산하였다. 단독이량체를 생성하는 염료들을 조합하였을 경우에는 혼합이량체가 생성되었다. C.I.Reactive Blue 19가 다른 VS계 염료들과 혼합되었을 경우에는 일반적으로 혼합이량체가 생성되었다. Blue 19와 Orange 16의 조합의 경우에는 낮은 염료농도에서만 혼합이량체가 생성되었으며, Red 22의 경우에는 단독 및 혼합이량체가 생성되지 않았다. 단독이량체가 생성되지않는 Orange 7는 다른 VS계 염료들과의 조합에서 혼합이량체를 생성함을 확인하였다. Yellow 17의 혼합이량체의 분해속도 상수값이 가장 큼을 알 수 있었다.

• Food Industry And Nutrition
• /
• v.10 no.1
• /
• pp.11-16
• /
• 2005

식물성 단백질의 주요 공급원이며 우리나라 전통식품 중의 하나인 두부의 유통기한을 정량적으로 예측할 수 있는 수학적 모델을 개발하고자 온도와 초기균수에 따른 두부 부패세균의 성장 실험 결과를 데이터베이스화하여 이를 바탕으로 균의 성장을 정량적으로 평가할 수 있는 수학적 모델을 개발하였다. 근의 증식 지표인 최대증식속도상수(k), 유도기(LT), 세대시간(GT)은 온도에 지배적인 영향을 받았으며, 초기균수에 따른 유의 적 인 차이 는 없었다(p<0.05). 최대증식속도상수와 온도 및 초기균수의 상관관계를 나타내는 수학적 정량평가모델인 square root model을 이 용하여 두부 부패 세균의 성장을 정량적으로 예측할 수 있는 모델$({\surd}{\kappa}=0.016861(T+6.87095))$을 개발하였으며 실험치와 예측치의 상관계수는0.969이었다. 이 예측 정량평가모델로부터 예측한 최대증식속도상수와 두부의 관능적 부패시 점을 반영 한 Gompertz 변형 모델을 이용하여 두부의 유통기한을 예측할 수 있는 모델$(Spoilage-critrion(hr)=\frac{2{\times}Ln2+Ln[(Nmax/No)-1])}{k}$을 개발하였다

• Applied Biological Chemistry
• /
• v.33 no.1
• /
• pp.24-33
• /
• 1990

The changes in water uptake rate, cooking properties, color of rice grains and gelatinization properties of brown and milled rices during storage were studied. The brown and milled rices were stored at $4^{\circ}$ and $25^{\circ}C$ for 5 and 3 months, respectively. The water uptake rate constants of rices during hydration at $30^{\circ}$ were linearly decreased during storage. The volume increase rate also showed similar trend to the water uptake rate. The terminal point of cooking of milled rice at $100^{\circ}$ in a sealed brass vessel was about a half of that of brown rice. The cooking rate of milled rice was 1.8 times faster than that of brown rice. The cooking rate constant of both brown and milled rices linearly decreased with the increase of storage time. The L(lightness) value increased for brown rice grain and remained unchanged for milled rice grain during storage. The peak viscosity of rice flours by amylograph increased during storage, but enthalpy for gelatinization decreased, as measured by differential scanning calorimetry.

• Journal of the Korean Chemical Society
• /
• v.44 no.5
• /
• pp.429-434
• /
• 2000

The rate constants for the hydrolysis of styryldiphossphine oxide(SDPO) were deter-mined by ultraviolet visible spectrophotometric method and rate equation which can be applied over wide pH ranges was obtained. On the basis of pH-rate profile, hydrolysis product analysis, general base catalysis and substituent effect, a plausible hydrolysis mechanism is proposed : Below pH 4.5, the hydrolysis reaction is pro-ceeded by the attack of water to carbocation after protonaticentration of hydroxide ion.

• Journal of the Korean Chemical Society
• /
• v.16 no.6
• /
• pp.369-372
• /
• 1972

The dissociation constants of dibasic carboxylic acids $(HOOC(CH_2)_nCOOH$, n = 0~4] in methanol, N, N-dimethylformamide and acetonitrile have been determined by the potentiometric method with a glass electrode. The difference between over-all dissociation constants in each other solvent is found to be of the same order of magnitude, and the $K_1/K_2$ ratios in aprotic dimethylformamide and acetonitrile are much greater than those in protic methanol and water.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.5
• /
• pp.555-561
• /
• 2005

A new graphical method was developed to separate two distinctive decay rate coefficients($k_1$ and $k_2$) at their respective degradable substrate fractions($S_1 and $S_2$). The mesophilic batch reactor showed $k_1$ of $0.151\;day^{-1}$ for wasted activated sludge(WAS), $0.123\;day^{-1}$ for thickened sludge(T-S), $0.248{\sim}0.358\;day^{-1}$ at S/I ratio of $1{\sim}3$ for sorghum and $0.155{\sim}0.209\;day^{-1}$ at S/I ratio $0.2{\sim}1.0$ for swine waste, whereas their long term batch decay rate coefficients($k_2$) were $0.021\;day^{-1}$, $0.001\;day^{-1}$, $0.03\;day^{-1}$ and $0.04\;day^{-1}$ respectively. At least an order of magnitude difference between $k_1$ and $k_2$ was routinely observed in the batch tests. The portion of $S_1$, which degrades with each $k_1$ appeared 71% for WAS, 39% for T-S, 90% for sorghum, and $84{\sim}91%$ at S/I ratio of $0.2{\sim}1.0$ for swine waste. Ultimate biodegradabilities of 50% for WAS, 40% of T-S, $82{\sim}92%$ for sorghum, and $81{\sim}89%$ for swine waste were observed.

• The Journal of Korean Philosophical History
• /
• no.35
• /
• pp.385-413
• /
• 2012

This thesis is a study on the relation of between Xiangshu Zhouyi Theory and mathematics, Zhouyi Theory as the one of the study of Chinese classics, was formed by Zhouyi' Eight Diagrams, the theory of Yinyangwuxing and the knowledge of natural science in Han dynasty. 'Xiangshu' had been regarded as the important concept and theory in the history of Zhouyi Theory From the beginning of Han dynasty to the end of Qing dynasty. At this developing of this Periodical Change, 'Xiangshu' had been endoded in the expression system of mathematics. This thesis considers binary system and surplus nembers, multiple and progression, magic square and circular constant, a proportional expression from Zhouyi Theory point of view. Xiangshu Zhouyi theory got the answer of these questions like the origin of Zhouyi, interpreting Guayao-word and Cosmology by using those expression systems of mathematics. Besides mathematics, Xiangshu Zhouyi theory was also related to astronomy, medicine, etc. Xiangshu Zhouyi theory had kept the pace with the general development of natural science. This thesis from the premise that Xiangshu Zhouyi theory kept the pace with natural science, summing up the mathematical expression system in the history of Zhouyi theory, proves that Xiangshu Zhouyi theory had developed according as the conditions of natural science.

• Journal of the Korean GEO-environmental Society
• /
• v.9 no.1
• /
• pp.17-25
• /
• 2008

In this study, external and internal pit growth rate model and external non-linear regression corrosion model were proposed by measuring pit depths and evaluating various soil factors known to contribute to the corrosion for metallic water pipes. Average pit depths of external and internal for metallic water pipes were measured 1.38 mm and 2.13 mm, and internal pit growth rate also fasted twice than external pit growth rate. This means the corrosion potential of water quality was higher than soil. The corelation between external corrosion rate and each soil corrosion factor was low. However, proposed external non-linear regression corrosion model considering all soil corrosion factors showed a little higher correlation ($R^2=0.46$) than conventional model.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.12 no.2
• /
• pp.123-130
• /
• 1992

We check up on whether the one-dimensional station precipitation model of Geogakakos and Bras is suitable to the storm model for Chonju station or not. The fundamental variables of the physically based model consists of the pressure at the cloud top, the hight-averaged updraft velocity(HAUV), and the inverse of the average diameter of the hydrometeors(ADH) at cloud base. And they are parameterized by input variables. The parameters are eastimated by the direct search algorithm of Hooke and Jeeves in this paper. The results show that HAUV and ADH are dominant factors to minimize root mean square error between the calculated and the observed rainfall. In this numerical analysis, the deviation between the calculated and the total observed rainfall is small, otherwise the gap for the time distribution is quite big.