• 제목/요약/키워드: solid

검색결과 17,871건 처리시간 0.046초

Solid형 맥류의 줄기의 특성과 Solidness 변이 (Characteristics of Solid Culm and Solidness Variation in Winter Wheat and Triticale)

  • 강양순;하용웅;박광근;허화영
    • 한국작물학회지
    • /
    • 제36권6호
    • /
    • pp.501-505
    • /
    • 1991
  • Solid형 맥류의 사이레지 적성 판단을 위한 기초 연구로서 환경적 및 품종간 간의 특성과 solidness를 검토코자 포장과 온실에 추파하여 출수기에 각 절간중간부위 단면의 solidness 정도와 각 정간중의 공기 체적을 조사한 결과 1. Solid 맥류는 간벽이 두껍고 pith가 간의 내부로 차게 되어 절간중 공기 함유량이 줄어들어 Solidness가 증가되었다. 2. Solid 정도는 hollow 품종인 보통밀 원광이 14.6%, 트리티케일의 신기호밀이 15.0%인데 비하여 Solid 품종인 듀럼밀은 77.0-100%, 빵밀은 61.0-95.8%, 트리티케일은 18.7-37.0%로 맥종간 품종간 변이가 컸다. 3. 듀럼밀인 Golden ball의 solidness 정도는 포장 재배 조건에서보다 온실재배 조건에서 높았고 절위별로는 상위절 일수록 그리고 주간에서보다는 분벽지에서 각각 높았다. 4. 줄기당 함유 공기용량은 hollow품종인 신기호밀이 4.85ml인데 비하여 solid 품종들은 1.01-2.3ml로서 매우 낮아 사이레지 가공시 암착효율이나 유산 발효면에서 유리할 것으로 나타났다.

  • PDF

알루미늄합금의 반용융 단조 및 주조공정에 관한 수치해석 (Numerical Analysis on Semi-Solid Forging and Casting Process of Aluminum Alloys)

  • 강충길;임미동
    • 소성∙가공
    • /
    • 제6권3호
    • /
    • pp.239-249
    • /
    • 1997
  • The behaviour of alloys in the semi-solid state strongly depends on the imposed stress state and on the morphology of the phase which can vary from dendritic to globular. To optimal net shape forging of semi-solid materials, it is important to investigate for filling phenomena in forging process of arbitrarily shaped dies. To produce a automotive part which has good mechanical property, the filling pattern according to die velocity and solid fraction distribution has to be estimated for arbitrarily shaped dies. Therefore, the estimation of filling characteristic in the forging simulation with arbitrarily shaped dies of semi-solid materials are calculated by finite element method with proposed algorithm. The proposed theoretical model and a various boundary conditions for arbitrarily shaped dies is investigated with the coupling calculation between the liquid phase flow and the solid phase deformation. The simulation process with arbitrarily shaped dies is performed to the isothermal conditions of two dimensional problems. To analysis of forging process by using semi-solid materials, a new stress-strain relationship is described, and forging analysis is performed by viscoelastic model for the solid phase and the Darcy's law for the liquid flow. The calculated results for forging force and filling limitations will be compared to experimental data. The filling simulation of simple products performed with the uniform billet temperature(584$^{\circ}C$) from the induction heating by the commercial package MAGMAsoft. The initial step of computation is the touching of semi-solid material with the end of die gate and the initial concept of proposed system just fit with the capability of MAGMAsoft.

  • PDF

Biopharmaceutical Evaluation of a Solid Dispersion System Containing Sibutramine Freebase

  • Lee, Min-Suk;Chang, Hee-Chul;Kim, Taewan;Park, Jung-Hwa;Lee, Bong-Sang;Kim, Sung-Hee;Kim, Do-Hwan;Kim, Bo-Gyun;Oh, Seong-Tae;Kang, Myung-Joo;Park, Jong-Hyeok;Lee, Jaehwi;Choi, Young-Wook
    • Bulletin of the Korean Chemical Society
    • /
    • 제29권4호
    • /
    • pp.749-754
    • /
    • 2008
  • To increase the solubility of sibutramine freebase, the solid dispersion was prepared using a fluid-bed granulator. The solid dispersion containing sibutramine freebase was characterized by differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). After filling the sibutramine solid dispersion in the gelatin hard capsule, we performed in vitro dissolution test, the stability test under accelerated conditions and pharmacokinetic study in beagle dogs. The DSC and XRD data showed that sibutramine solid dispersion would be amorphous state. The dissolution rate of sibutramine solid dispersion was significantly increased about 70% than sibutramine freebase. The stability of sibutramine solid dispersion capsules was equivalent or above to commercial product of sibutramine. In beagle dogs, the sibutramine solid dispersion showed equivalent pharmacokinetic behavior with commercial product of sibutramine hydrochloride. In conclusion, the solid dispersion system provided a possible way to overcome the low solubility of sibutramine freebase, and the sibutramine solid dispersion can be a bioequivalent with the commercial product in humans.

기체-고체 유동층에서 루프실의 형상이 고체순환에 미치는 영향 (Effect of Loop Seal Geometry on Solid Circulation in a Gas-Solid Fluidized Bed)

  • 류호정;조성호;이승용;이도연;남형석;황병욱;김하나;원유섭;김정환;백점인
    • 한국수소및신에너지학회논문집
    • /
    • 제30권4호
    • /
    • pp.312-319
    • /
    • 2019
  • Effect of loop seal geometry on solid circulation characteristics was investigated with two different types of upper loop seals and lower loop seals in a gas-solid fluidized bed system. Upper loop seal which has a wide gap between solid intake and outlet parts requires more fluidization gas to maintain smooth solid circulation. Moreover, the lower loop seal which has a wide gap requires more fluidization gas to achieve the same solid circulation rate. These results can be explained by results of minimum fluidization velocity in the lower loop seals. Consequently, if a loop seal has a wide gap between solid intake and outlet parts, more fluidization gases should be fed to ensure enough solid circulation rate and smooth solid circulation.

Degradation of All-Solid-State Lithium-Sulfur Batteries with PEO-Based Composite Electrolyte

  • Lee, Jongkwan;Heo, Kookjin;Song, Young-Woong;Hwang, Dahee;Kim, Min-Young;Jeong, Hyejeong;Shin, Dong-Chan;Lim, Jinsub
    • Journal of Electrochemical Science and Technology
    • /
    • 제13권2호
    • /
    • pp.199-207
    • /
    • 2022
  • Lithium-sulfur batteries (LSBs) have emerged as a promising alternative to lithium-ion batteries (LIBs) owing to their high energy density and economic viability. In addition, all-solid-state LSBs, which use solid-state electrolytes, have been proposed to overcome the polysulfide shuttle effect while improving safety. However, the high interfacial resistance and poor ionic conductivity exhibited by the electrode and solid-state electrolytes, respectively, are significant challenges in the development of these LSBs. Herein, we apply a poly (ethylene oxide) (PEO)-based composite solid-state electrolyte with oxide Li7La3Zr2O12 (LLZO) solid-state electrolyte in an all-solid-state LSB to overcome these challenges. We use an electrochemical method to evaluate the degradation of the all-solid-state LSB in accordance with the carbon content and loading weight within the cathode. The all-solid-state LSB, with sulfur-carbon content in a ratio of 3:3, exhibited a high initial discharge capacity (1386 mAh g-1), poor C-rate performance, and capacity retention of less than 50%. The all-solid-state LSB with a high loading weight exhibited a poor overall electrochemical performance. The factors influencing the electrochemical performance degradation were revealed through systematic analysis.

레오로지 소재의 고상입자 변형거동 해석 (Solid Particle Behavior Analysis in Rheology Material by Fortran 90)

  • 권기영;강충길
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2008년도 추계학술대회 논문집
    • /
    • pp.234-237
    • /
    • 2008
  • It was reported that the semi-solid forming process has many advantages over the conventional forming process, such as a long die life, good mechanical properties and energy savings. It is very important, however, to control liquid segregation to gain mechanical property improvement of materials. During forming process, Rheology material has complex characteristics, thixotropic behavior. Also, difference of velocity between solid and liquid in the semi-solid state material makes a liquid segregation and specific stress variation. Therefore, it is difficult for a numerical simulation of the rheology Process to be Performed. General Plastic or fluid dynamic analysis is not suitable for the behavior of rheology material. The behavior and stress of solid particle in the rheology material during forging process is affected by viscosity, temperature and solid fraction. In this study, compression experiments of aluminum alloy were performed under each other tool shape. In addition, the dynamics behavior compare with Okano equation to Power law model which is viscosity equation.

  • PDF

다중 고체상을 고려한 고체 연료층 연소 모델링 (Combustion Modeling of a Solid Fuel Bed with Consideration of the Multiple Solid Phases)

  • 양원;류창국;최상민
    • 한국연소학회:학술대회논문집
    • /
    • 한국연소학회 제26회 KOSCO SYMPOSIUM 논문집
    • /
    • pp.119-127
    • /
    • 2003
  • In this study we propose an unsteady I-dimensional model of bed combustion with multiple solid phases, which confers a phase on each solid material. This model can be applied to a variety of bed combustion cases of various configurations and ignition methods. It contains fuel combustion, gaseous reaction, heat transfers between each phase, and geometric changes of the solid particles. An iron ore sintering pot is selected for verifying the model validity and simulation results are compared with the limited experimental data set of various coke contents and air supply rates. They predict the experimental results well and show applicabilities to the various system of the fuel bed with various solid materials.

  • PDF

대형 압출 빌렛트의 재가열 공정 (Reheating Process of Extrusion Billet with Large Dimension)

  • 배정운;서판기;강충길
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2003년도 추계학술대회논문집
    • /
    • pp.261-264
    • /
    • 2003
  • Semi-solid processing is now becoming of great interest for the production of various parts by pressure die casting. Many advantages are associated with this forming process at the condition that the forming operation is performed under appropriate conditions. The thixoforming process, which needs a suspension of a globular, non-dendritic solid phase in the liquid phase, is characterized by three major steps. The first step is casting of billets with a microstructure suited for thixoforming. The second step is reheating of slugs cut from these billets. The third step is injection of the semi-solid slugs into a die. In this paper, the horizontal reheating machine to obtain the optimal conditions suitable for semiu-solid die casting process was used and applied to extrusion material. It is estimated the possibility of application on semi-solid die casting with extrusion material through various results.

  • PDF

마이크로 고체 추진제 추력기 요소의 성능 평가 (Performance Evaluation of Components of Micro Solid Propellant Thruster)

  • 이종광;이대훈;최성한;권세진
    • 대한기계학회논문집B
    • /
    • 제28권10호
    • /
    • pp.1264-1270
    • /
    • 2004
  • In this paper research on micro solid propellant thruster is reported. Micro solid propellant thruster has four basic components; micro combustion chamber, micro nozzle, solid propellant and micro igniter. In this research igniter, solid propellant and combustion chamber are focused. Micro igniter was fabricated through typical micromachining and the effect of geometry was evaluated. The characteristic of solid propellant was investigated to observe burning characteristic and to obtain burning velocity. Change of thrust force and the amount of energy loss following scale down at micro combustion chamber were estimated by numerical simulation based on empirical data and through the calculation normalized specific impulses were compared to figure out the efficiency of combustion chamber.

표고버섯의 고체배양에 의한 단백 다당류 생산 (Production of Protein-bound Polysaccharides by Solid-substrate Fementation of Lentinus edodes)

  • 박경숙
    • 한국식품영양학회지
    • /
    • 제11권6호
    • /
    • pp.667-672
    • /
    • 1998
  • The possibility of solid-substrate fermentation of Lentinus edoes for the productin of protein-boud polysaccharides (PBP) was studied. Zeolite and orchid-pot soil were used as solid materials for the culture because of the desirable physical properties. Sucrose and starch were good carbon sources for the production of PBP by the solid-substrate fermentatin of L. edodes. Among the nitrogen source, bactosoyton was very effective for the PBP production. The optimum pH for solid-substrate fementation for the production of PBP was at pH of 5.5. The PBP production reached to 5∼5.5mg per 100g solid-substrate.

  • PDF