• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.103-103
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• 2020

눈개승마 (Aruncus dioicus)는 장미과(Rosaceae) 눈개승마속(Aruncus)에 속하는 다년생 초본식물로 울릉도에서 자생하는 잎줄기 채소이다. 독특한 향기가 특징이며, 인삼맛, 두릅맛, 고기맛이 나는 산채로 세가지 맛이 난다고 하여 예로부터 삼나물로도 불러왔다. 눈개승마에는 caffeic acid, 1-O-Caffeoyl-β-D-glucopyranose 등의 항산화 성분이 다량 함유되어 있으며, 전초는 해독, 편도선염에 효과가 있어 약용으로 쓰이고 어린순은 탄수화물과 무기물 함량이 풍부하다. 비지는 대두를 이용하여 두부를 제조하는 과정에서 발생되는 것으로서 대두로부터 수용성 단백질이 추출되었지만 나머지 약 23%의 단백질, 57%의 식이섬유와 이소플라본 등의 유용한 성분을 다량 포함하고 있다. 또한 비지의 단백질은 다른 식품에는 부족한 황 함유 아미노산과 리신의 함량이 비교적 많고, 두부에 거의 없는 식이섬유가 다량 함유된 고 식이섬유 소재이다. 그리하여, 이러한 콩비지를 고부가가치 식품 소재로 활용하기 위해 건조 미세분말 비지를 제조하고, 이를 산채와의 혼합 가공을 통한 기능증진 효과를 연구하였다. 일반적으로 산채는 쓴맛 제거와 보관성 증진을 위해 데침공정을 주로 하나 산채를 물에 데칠 경우 산채의 유용성분이 대부분 손실된다. 눈개승마의 경우 유용성분이 17.25%, 그 중 폴리페놀 성분이 약 90% 손실된다. 본 연구에서는 기존의 데침공정 대신 찜공정을 이용하여 산채의 유용성분을 보존하고 콩비지를 첨가하여 산채 유용성분의 생이용성 증진 효과를 연구하였다. 눈개승마를 콩비지와 혼합하여 고온고압 가공함으로써 산채의 쓴맛을 줄이고 보관성을 높이는 동시에 눈개승마 폴리페놀의 단량체화를 통해 눈개승마 단독가공에 비하여, 단량체 비율이 약 100~200배 증가하는 것을 확인하였다. 본 연구를 통하여 콩비지의 고부가가치 소재로의 가능성을 확인하였을 뿐만 아니라 산채의 다이어트·건강기능식품 소재로의 산업화에도 기여할 수 있을 것으로 기대된다.

• 대한기계학회논문집B
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• 제39권4호
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• pp.379-384
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• 2015

최근 전기방사를 이용한 프린팅이 미세 패터닝 분야에 응용이 되고 있다. 전기방사를 이용한 패터닝은 연속 프린팅 방식으로 기존의 요구적출형 방식에 비해 패터닝 속도가 빠르다는 장점이 있다. 안정적인 연속 프린팅을 위해서는 고분자의 폴리머를 프린팅하려고 하는 잉크에 혼합하는 것이 필요하다. 본 연구에서는 PEO 를 이러한 첨가 폴리머로 사용하였다. 이러한 폴리머의 첨가에 대한 잉크의 점도 및 Taylor cone 형성에 대해 미치는 영향을 조사하였다. 마지막으로 전기방사 프린팅의 예로서 실버 페이스트 잉크를 유리 기판 위에 패터닝하였다.

• 대한기계학회논문집B
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• 제32권2호
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• pp.133-140
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• 2008

A reduced chemical kinetic mechanism is developed in order to predict the flame phenomena in premixed $CO/H_2/Air$ flames at atmospheric pressure, aimed at studying the coal gas combustion for the IGCC applications. The reduced mechanism is systematically derived from a full chemical kinetic mechanism involving 11 reacting species and 66 elementary reactions. This mechanism consists of four global steps, and is capable of explicitly calculating the concentration of 7 non-steady species and implicitly predicting the concentration of 3 steady state species. The fuel blend contains two fuels with distinct thermochemical properties, whose contribution to the radical pool in the flame is different. The flame speeds predicted by the reduced mechanism are in good agreement with those by the full mechanism and experimental results. In addition, the concentration profiles of species and temperature are also in good agreement with those by the full mechanism.

• 한국연소학회지
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• 제11권4호
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• pp.27-35
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• 2006

The impacts of equivalence ratio on flow structure and flame dynamic in a model gas turbine combustor are investigated using large eddy simulation(LES). Dynamic k-equation model and G-equation flamelet model are employed as LES subgrid model for flow and combustion, respectively. As a result of mean flow field for each equivalence ratio, the increase of equivalence ratio brings about the decrease of swirl intensity through the modification of thermal effect and viscosity, although the same swirl intensity is imposed at inlet. The changes of vortical structure and turbulent intensity etc. near flame surface are occurred consequently. That is, the decrease of equivalence ratio can leads to the increase of heat release fluctuation by the more increased turbulent intensity and fluctuation of recirculation flow. In addition, the effect of inner vortex generated from vortex breakdown on the heat release fluctuation is increased gradually with the decrease of equivalence ratio. Finally, it can be identified that the variations of vortical structure play an important role in combustion instability, even though the small change of equivalence ratio is occurred.

• 한국연소학회지
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• 제10권3호
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• pp.10-16
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• 2005

Detailed flame structures of the counterflow flames of $CH_4/Air$ formed with $CO_2$ and $H_2O$ addition are studied numerically. The detailed chemical reactions are modeled by using the OPPDIF and CHEMKIN-II code. Only the $CO_2$ and $H_2O$ are assumed to participate in radiative heat transfer while all other gases are assumed to be transparent. The discrete ordinates method(DOM) and the narrow band based WSGGM with a gray gas regrouping technique(WSGGM-RG) are applied for modeling the radiative transfer through non-homogeneous and non-isothermal combustion gas mixtures generated by the counter flow flames. The results compared with the SNB model show that the WSGGM-RG is successful in modeling the counterflow flames with non-gray gas mixture. The numerical results show that the addition of $CO_2$ and $H_2O$ to the oxidant nozzle lowers the peak temperature and the NO concentration in flame.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.215-218
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• 2012

In this study, syngas laminar burning velocities with various hydrogen contents were studied using both experimental measurements and kinetic simulations. The laminar burning velocities were measured by the angle method of Bunsen flame configuration and the numerical calculations including burning velocities were made using CHEMKIN Package with USC-Mech II. A large range of syngas mixture compositions such as 10:90%, 25:75%, 50:50%, 75:25% and equivalence ratio from lean condition of 0.5 to rich condition of 5.0 have been conducted. The experimental results of burning velocity were in good agreement with previous other research data and numerical simulation. Also, it was shown that the experimental measurements of laminar burning velocity linearly increased with the increasing of $H_2$ content although the flame speed of hydrogen is faster about ten times than carbon monoxide. This phenomenon is attributed to the rapid production of the hydrogen related radicals such as H and OH at the early stage of combustion, which is confirmed the linear increasing of radical concentrations on kinetic simulation.

• 대한기계학회논문집B
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• 제21권4호
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• pp.518-524
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• 1997

Experimental studies on combustion phenomena within a porous ceramic burner are reported. Main interest of the present work is to investigate fundamental flame behaviors and their effects on the burner operation. Due to high thermal capacity of the porous ceramic materials, the response of flame to burning condition changes is slow and thus to have a stabilized flame is quite difficult and takes much time. It is found that the temperature profile obtained at downstream of the flame zone is not much sensitive to the movement of flame and the speed of flame movement is less than 0.1 mm/sec for the conditions tested. With the premixed LPG/air flame imbedded within the porous ceramic burner, stable combustion regions and unstable combustion regions leading to blowoff or flashback phenomena are observed and mapped on flow velocity versus equivalence ratio diagram. For the development of burner operation technique which is more practical and safe, intermittent burning technique, where the fuel or/and air is supplied to the burner intermittently, is proposed as one of the flame control methods for the porous ceramic burner and tested in this study. Through the experiment, it is realized that the proposed method is acceptable in respect to burner performance and give much flexibility in the operation of porous ceramic burner.

• 대한기계학회논문집B
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• 제25권2호
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• pp.235-243
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• 2001

This paper describes a design study of the cylindrical multi-hole premixed burner to be used for condensing gas boiler which can raise performance and reduce NOx emission. In this study, specifications of the multi-hole burner (hole diameters and arrangement) are investigated using model flat burners in terms of flame stability, and combustion characteristics for stability and NOx emission are examined for cylindrical multi-hole burner. As a result, the equivalence ratio for optimum operation condition of the cylindrical burner is around 0.72(0.7∼0.75). In this condition, turn-down ratio becomes 3 : 1 at least which is suitable for proportional control. The NOx and CO emission is less than 40ppm and 25ppm(0$_2$0% basis), respectively. This burner can be applied LPG as well as NG because there is no difference for stable combustion region.

• 대한기계학회논문집B
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• 제27권7호
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• pp.893-900
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• 2003

Numerical simulations of freely propagating flames burning stoichiometric C $H_4$/CHC1$_3$/ $O_2$/$N_2$ mixtures are performed at atmospheric pressure in order to understand the effect of the $O_2$ enrichment level and the CHC1$_3$/C $H_4$ molar ratio. A chemical kinetic mechanism is developed, which involves 69 gas-phase species and 379 forward and 364 backward reactions. The calculated flame speeds are compared with the experiments for the flames established at several CHC1$_3$/C $H_4$ molar ratio (R<1), the results of which is in excellent agreement. As a results of the increased $O_2$ enrichment level from 0.21 to 1, the flame speed and the temperature in the burned gas are increased. At high CHC1$_3$/C $H_4$ molar ratio two peak values appear on the $O_2$ consumption rate, which are affected by CC1$_2$＋ $O_2$$_{-}$>C1O+CC1O and H＋ $O_2$$_{-}$>O＋OH.＋OH.

• 대한기계학회논문집B
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• 제20권2호
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• pp.659-669
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• 1996

To clarify the effects of equivalence ratio, initial pressure and temperature on the flame propagation and radicals characteristics, a series of the experimental study were conducted in a quiescent methane-air premixture using a constant volume chamber. The development of the flame was visualized following the start of ignition using high speed schlieren photo and radical images by intensified CCD camera. Combustion pressure and ion current were recorded simultaneously according to the experimental conditions which were equivalence ratio with 0.7 to 1.2, initial pressure with 0.08 MPa to 0.40 MPa and initial premixture temperature with 3l3.2K to 403.2K. The results showed that the flame speed by ion current and mass fraction burned by combustion pressure characterized the effects of flame propagation very well. And increased combustion duration due to lean combustion condition that was below equivalence ratio, 0.8 caused cycle variation and decreasing the power of engine.