• Journal of Biosystems Engineering
• /
• 제43권4호
• /
• pp.311-319
• /
• 2018

Purpose: The aim of this study is to develop a small combine for harvesting miscellaneous cereal crops. Methods: A prototype small combine was designed and constructed. Its specifications and basic performance were investigated. Results: The prototype small combine for harvesting miscellaneous cereal crops was designed and constructed to reflect similar specifications as those of the conventional combine. The prototype small combine comprises a diesel engine with the rated power/speed of 22.0 kW/2,600 rpm, three-stage primary and two-stage speed range transmission shifts, and a double acting threshing part. The maximum travel speeds of the prototype combine are approximately 0.72 m/s, 2.50 m/s, 0.30 m/s at the low, high speed range shifts in the forward direction, and while traversing in the reverse direction, respectively. The minimum radius of turning was approximately 1.50 m. In a static lateral overturning test, the prototype combine overturned neither to the right nor to left on a $30^{\circ}$ slope. The results of an oilseed rape harvesting test included the maximum operating speed of 0.32 m/s, the grain loss ratio of approximately 9.0%, and the effective field capacity of approximately 10.3 a/h. Additionally, among the outputs in grain outlet, the whole grains, damage grains, and materials other than grain (MOG) ratios accounted for 97.4%, 0.0%, and 2.6%, respectively. Conclusions: The prototype small combine for harvesting miscellaneous cereal crops indicates good driving ability and stability. The results of the oilseed rape harvesting test reveal that the harvesting performance must be enhanced such that the separating and cleaning parts are more suitable for each type of crop, thus reducing grain loss and foreign substances among the outputs in grain outlet. An improved small prototype combine could be used effectively to mechanize the harvesting of miscellaneous cereal crops in small family farms or semi-mountainous areas.

• 한국세라믹학회지
• /
• 제30권6호
• /
• pp.449-456
• /
• 1993

Sintering behaviour of zirconia powders prepared by different processing treatment was discussed. About >99% densities of theoretical were obtaiend on sintering at 140$0^{\circ}C$ for 2h in case of 300MPa uniaxially cold-pressed compact. But the lower densities were obtained on sintering above this temperature due to abnormal grain growth enabling the tetragonal to monoclinic phase transformation during cooling resulted in microcracks. All kinds of different dried powders exhibited nearly the same shrinkage behaviour with end-point shrinkage between 19 and 20%, and had maximum shrinkage rate (0.99~1.27%/min) around 120$0^{\circ}C$. During whole sintering process densification was mainly governed by grain growth and rearrangement of agglomerates. Heterogeneous abnormal grain growth and abrupt decrease in shrinkage were observed when continuous interagglomerate pore collapsed into isolated pores.

• Fisheries and Aquatic Sciences
• /
• 제18권2호
• /
• pp.159-164
• /
• 2015

A feeding experiment was conducted to determine the effect of dietary distillers dried grain (DDG) on the growth and body composition of juvenile abalone, Haliotis discus hannai. Three diets were formulated to contain 0% (DDG0), 30% DDG (DDG1) replacing wheat flour and 30% DDG (DDG2) replacing fish meal and wheat flour. A commercial feed (CF) was also compared with experimental diets. Three replicate groups of abalone averaging $0.6{\pm}0.01g$ were fed one of the four diets for 14 weeks. The highest survival rate was observed in the abalone fed the DDG2 diet, which was higher than that of abalone fed the DDG0 diet. Weight gain, shell length, shell width and soft body weight of the abalone were not affected by dietary DDG and CF diet (P > 0.05). Proximate and amino acid composition of the soft whole body were not affected by dietary DDG and CF diet (P > 0.05). The result of this experiment suggests that DDG is a good ingredient to replace fish meal and wheat flour in the diet and could be used up to 30% in the diet without negative effects on the growth performance of juvenile abalone Haliotis discus hannai.

• 한국자기학회지
• /
• 제11권1호
• /
• pp.1-7
• /
• 2001

열연판을 모재로 하여 압연 및 열처리 공정을 조합한 공정을 3회 냉간압연법을 사용하여 최종두께 100$\mu\textrm{m}$로 제작한 방향성 규소강대에 대하여, 직류자기 특성 및 결정입자의 열처리 의존성, 결정방위 등을 조사하였다. 그 결과, (110)면이 거의 시료 전체표면에 성장하는 것이 관측되었으며, B$_{8}$은 1.9 T정도, 평균$\alpha$각은 약 4.6$^{\circ}$이었다. 향후 약간의 (001)조직의 집적도 개선이 추가된다면, 염가의 열연판을 모재로 사용하여 기존의 방향성 규소강판의 경우보다 훨씬 제조공정수를 단순화함으로써, 경제성이 우수한 방향성 극박 규소강대를 제작할 수 있는 가능성을 확인하였다.

• 한국작물학회지
• /
• 제35권6호
• /
• pp.487-491
• /
• 1990

미질향상을 위한 재배기술을 구명하고자 재배시기, 수비 및 실비시용량, 출수후 락수시기 등을 달리하여 시험한 결과를 요약하면 다음과 같다. 1. 재배시기는 늦어질수록 완전립 비율이 떨어지고 청미와 사미의 비율이 증가되었으며, 아밀로스함량도 높아지는 경향이었다. 2. 수비 및 실비 시용량간에는 완전미비율에 큰 차이가 없었으나 무시용에서 약간 높았다. 아밀로스 함량과 단백질함량은 시비량이 증가함에 따라 약간씩 높아지는 경향이었다. 3. 출수후 조기낙수함에 따라 완전립비율은 낮아지고 청미와 사미는 증가하는 경향이었다. 단백질 함량은 낙수시기에 따라 큰 변화는 없으나 아밀로스 함량은 후기락수할수록 낮아졌다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
• /
• pp.172-179
• /
• 1999

As the martensite structure cause fracture failure during drawing from 5.5mm rod to 3.05mm dia. wire without additional heat treatment, the optium cooling condition to inhibit the occurrence of martensite was investigated. In order to get SAE9254+V quality, the effects of alloying element, vanadium on the mechanical properties were investigated. Based upon CCT and TTT curves and the results form cooling test in mill, optimun cooling was found in the condition of the laying head temp of 780$^{\circ}C$ and of the conveyor speed at 0.15m/sec with the whole cover closed. The wire rods produced under the condition showed the best mechanical properties of 120kg/$\textrm{mm}^2$ in TS and 50% in RA, having an excellent drawability. In vanadium added steels, tensile strength was improved without degrading elongation and charpy impact value. That means the strengthening by vanadium is mainly due to the grain refinement by the fine precipitates during tempering process.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 1996년도 제6회 학술강연회논문집
• /
• pp.197-205
• /
• 1996

A combined extrusion process studied here consists of forward and backward extrusion, and it is formed in single operation. The metal flow involved in the operation has appeared to be difficult to analyze accurately because of mixed directions of the flow. In this study, conventional two operations of a forward and a backward extrusions is transformed into one operation of mixed extrusion. A process designed by an industry expert is simulated by the rigid-plastic finite element method to investigate the metal flow and defects. In addition to the FEM simulation, experimental analysis has been carried out to confirm the design in industry, which includes material characterization, preliminary expriment, and whole experimental forming operation. The experimental results show that warm forming of extrusion is more desirable than cold working and hot forming in view of grain growth. Also two conditions of lubrication between workpiece and die has been investigated.

• 대한화학회지
• /
• 제8권2호
• /
• pp.78-81
• /
• 1964

In this report, some practical problems that are concerned with the infected barley were examined. Most of the toxic substance is present in the bran. It was almost impossible to remove the toxic substance with water or methanol completly, however, we found it is effectively eliminated by soaking the whole grain with 2%, calcium hydroxide suspension for 24 hours. As a detoxifying agent, kieselguhr was very effective; the grain mixed with little amounts (0.4-0.5%) of kieselguhr may be used as an animal feed.

• 천문학회보
• /
• 제46권1호
• /
• pp.57.1-57.1
• /
• 2021

The icy mantles of interstellar grains are developed by the freeze-out of interstellar molecules and atoms onto grain surfaces. The ice molecules become more complex by surface chemistry induced directly by high energy photons or by the thermal energy diffused over heated grain surface. Therefore, the ice composition is an important tracer of physical conditions where the ices form. Ices have been studied via their absorption features against continuum sources, such as young stellar objects or evolved background stars, in infrared wavelengths. The Spitzer IRS was the most sensitive spectrometer for the observations of infrared ice absorption features. We has been developing an automated analysis tool for the Spitzer IRS spectra, especially for the 15 ㎛ CO₂ bending mode. The 15 ㎛ CO₂ absorption feature is very useful for the study of accretion process in star formation since its spectral shape varies with thermal condition of the dust grains. Eventually, this tool will cover the whole range of the Spitzer IRS spectrum (5~20 ㎛).

• Applied Biological Chemistry
• /
• 제44권1호
• /
• pp.30-34
• /
• 2001

쌀에 혼합취반이 가능한 혼식용 혼합쌀의 제조를 위해 곡물원료인 현미, 보리쌀, 밀, 조, 수수, 콩, 팥에 대한 물리화학적 특성 및 압출성형 특성을 조사하였다. 혼합쌀의 제조에 사용한 곡물은 전분, 단백질, 지방, 희분 및 총 식이섬유함량에서 서로 차이를 보여주었다. 곡분은 명도에 있어 백미, 보리쌀, 콩, 현미, 밀, 수수, 팥, 조의 순으로 낮았으며, 대부분 적황색도를 나타내었으나 곡종에 따라 다소간의 차이를 보여주었다. 곡분의 평균입자크기는 백미, 보리쌀과 같이 도정한 곡물에서 작았으며 현미, 조, 수수 같이 강층을 포함하는 정곡에서 다소 큰 것으로 분석되었다. 곡분의 손상전분 함량은 곡류에서 $5.4{\sim}10.9%$ 범위였으며 콩과 팥에서는 $0.5{\sim}1.4%$로 낮았다. 곡분의 수분흡수지수는 팥, 백미, 수수, 현미, 밀, 조, 보리쌀, 콩의 순으로 낮았으며 수분용해도지수는 두류인 콩과 팥에서 높게 나타났다. 혼합쌀 제조시에 곡종에 따른 이화학적 특성차이가 혼합쌀의 압출성형가공에 크게 영향을 주었으며, 현미 50%, 보리쌀 20%, 밀 10%, 조 5%, 수수 5%, 콩 7%, 팥 3%의 적정 배합비로 압출성형한 혼합쌀은 일반쌀과 혼용이 가능한 형태인 것으로 나타났다.