• Journal of Biosystems Engineering
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• 제18권4호
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• pp.371-381
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• 1993

Threshing operation is performed by impact, compression and friction forces inside the thresher. These values should be appropriate to the crop condition to enhance the threshing and separating efficiency and to decrease the grain damage. To analyze the threshing process inside the rasp-bar type thresher, impact, friction and compression forces were measured using transducers with strain gage circuits. To measure the impact forces and friction forces between the rasp-bar and crop, full bridge strain gage circuit was built on the rasp-bar holder. To measure the compression forces and circumferential friction forces between the concave and crop, two sets of full bridge strain gage circuits were built on the T-type concave transducer. Threshing work of wheat crop with 12% of moisture content was performed at 3 levels of compression ratio and with 3 replications. Each transducer could not measure the exact forces continuously because the transducer oscillates with the forces. However they could measure maximum forces and force distribution according to the time. Average friction coefficients between crop and concave was 0.61 not showing any significant difference according to the compression ratio. Average acceleration of the crop in the cylinder appeared from $70.6m/s^2$ to $140.8m/s^2$ according to the compression ratio. The velocity of the crop at the exit of the cylinder appeared from 10.7m/s to 15.0m/s according to the compression ratio.

• 열처리공학회지
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• 제30권6호
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• pp.258-263
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• 2017

The effect of cooling rate on the damping capacity of pure Mg was studied. Two Mg samples with different cooling rates were prepared by heat treatment at 873 K for 24 h, followed by water quenching and by furnace cooling to room temperature, respectively. The average grain sizes of the Mg samples were almost identical regardless of the cooling rate, but more twins were observed in the sample with faster cooling rate. The calculated vacancy fraction was higher in the fast cooling sample than the slow cooling one. It is noted that the fast cooling sample exhibited lower damping capacity both in the strain-amplitude independent and strain-amplitude dependent regions. Higher values of vacancy concentration and number density of twins in the fast cooling sample are considered to be responsible for the deteriorated damping capacity in the strain-amplitude independent and strain-amplitude dependent regions, respectively.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.63-68
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• 1999

Because misaligned shafts have caused noise, vibration, bearing failures, and stress concentration of coupling part, which decrease the efficiency and life of a shaft system, the proper alignment of shaft system should be monitored continuously in dynamic condition. To solve these problems under dynamic condition, a telemetry system is this study is used to find the condition of the least bending moment, which is known by analyzing the structure and stress induced by misalignment is investigated. The moment derived from two shaft strain at the nearby coupling is measured. The bending strain is measured 5 times for average in static state as well as dynamic state with 100~700 rpm.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.115-123
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• 2003

Simultaneous measurements of velocity and OH distribution were made using particle image velocimetry(PIV) and planar laser-induced fluorescence(PLIF) of OH radical in turbulent hydrogen nonpremixed flames with coaxial air. The OH radical was used as an approximate indicator of chemical reaction zone. The OH layer was correlated well with the stoichiometric velocity, $U_s$, instantaneously and on average. In addition, high strain-rate regions almost coincide with the OH distribution. The residence time in flame surface, calculated from the root-mean-square value of the radial velocity, is proportional to $(x/d_F)^{0.7}$. It is found that the mean value of principal strain rate on the OH layer can be scaled with $(x/d_F)^{-0.7}$ and therefore, the product of the residence time and the mean strain rate remains constant over all axial positions.

• 한국미생물·생명공학회지
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• 제22권4호
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• pp.373-381
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• 1994

An actinomycete strain, HSL-613 was isolated -from soil and identified by International Streptomyces Project (ISP) and chemotaxonomic methods. The spore chain of the strain HSL-613 appears in a spiral shape, and its spores are spherical shape with smooth surface. The cell wall contains LL-diaminopimelic acid (DAP). Menaquinone MK-9 (H$_{6}$, H$_{8}$) and iso- and anteiso-branched fatty acids were detected from whole cell extract. Sugars identified from whole cell extract include galactose, glucose, mannose and ribose, which are distinct from general sugar patterns of Streptomyces. Average G+C content in the chromosome is 59%. 5S rRNA of HSL-613 consists of 120 nucleotides as determined by comparing with that of a type strain Streptomyces griseus subsp. KCTC 9080. Through morphological, physiological, and chemical characterization, HSL-613 was identified and named as Streptomyces sp. HSL-613.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.96-99
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• 2007

The microstructure with fine and uniform AGS(austenite grain size) along thickness direction over no recrystallization temperature is strongly required for production of the high strength steels. The previous AGS prediction only based on the average strain improves to find the rolling conditions for accomplishment of the fine grain, but cannot find those for uniform grain. In this paper, an integrated mathematical model for prediction of the strain distribution along thickness direction is developed by carrying out finite element simulation for a series of rolling conditions. Also, the AGS distribution after rough rolling is predicted by applying the proposed model with AGS prediction model.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.666-670
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• 2021

Paenibacillus konkukensis sp. nov., SK3146 is a novel strain isolated from a pig feed. Here, we present complete genome sequence of SK3146. The genome consists of a single circular genome measuring 7,968,964 bp in size with an average guanine + cytosine (G+C) content of 53.4%. Genomic annotation revealed that the strain encodes 151 proteins related to hydrolases (EC3), which was higher than those in Bacillus subtilis and Escherichia coli. Diverse kinds of hydrolases including galactosidase, glucosidase, cellulase, lipase, xylanase, and protease were found in the genome of SK3146, coupled with one bacteriocin encoding gene. The complete genome sequence of P. konkukensis SK3146 indicates the immense probiotic potential of the strain with nutrient digestibility and antimicrobial activity functions.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.167-172
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• 2002

Nonlinear analysis of the reinforced concrete beam subjected to torsion is presented. Seventeen equations involving seventeen variables are derived from the equilibrium equation, compatibility equation, and the material constitutive laws to solve the torsion problem. Newton method was used to solve the nonlinear simultaneous equations and efficient algorithms are proposed. Present model covers the behavior of reinforced concrete beam under pure torsion from service load range to ultimate stage. Tensile resistance of concrete after cracking is appropriately considered. The softened concrete truss model and the average stress-strain relations of concrete and steel are used. To verify the validity of Present model, the nominal torsional moment strengths according to ACI-99 code and the ultimate torsional moment by present model are compared to experimental torsional strengths of 55 test specimens found in literature. The ultimate torsional moment strengths by the present model show good results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.399-400
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• 2010

본 연구에서는 순환재료를 사용한 그린 변형 경화형 시멘트 복합체의 압축, 휨 및 직접 인장거동 특성에 대하여 평가한다. 순환재료로 재생 PET 섬유, 플라이애쉬 및 폐콘크리트로부터 생산된 순환잔골재 등이 사용되었다. 실험결과, 5개의 덤벨형 인장 시험편의 직접 인장강도는 4.76MPa, 휨 및 압축강도는 7.40MPa 및 38MPa로 각각 평가되었다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.211-215
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• 2000

A new methodology is presented to evaluate material properties at high strain rates and high temperatures based on orthogonal metal cutting experiments and FEM simulations. Average strain rate and average temperature found in the deformation zone are computed and flow stress data at these conditions are modified until cutting forces calculated in simulations match those determined in experiments. Material properties obtained from this method were verified by additional metal cutting simulations. Derivation from cutting forces measured in experiments was less than 10%. The feasibility of tool design using FEM simulations is also demonstrated.