고사리(Pteridium aquilinum)뿌리 전분의 이화학적 특성에 관한 연구 : 제2보 : 전분의 물리적 특성 Ⅱ. Physical Properties

曺哉銑,金成坤,李啓瑚,權泰完 경희대학교 부설 식량자원개발연구소 1981 硏究論文集 Vol.2 No.-

고사리뿌리 전분의 이화학적인 특성연구의 일환으로 실시된 물리적 특성시험 결과는 다음과 같다. 전분입자의 미구조의 결합력을 보기 위한 흡수도, 팽운력, 용해도 시험결과 감자전분이나 타피오카전분보다 강한 결합을 하고 있으며 곡류전분보다는 약하며 팽윤력이 single-stage pattern을 이루고 있었다. 가열에 의한 전분입자의 복굴절성 상실, α-아밀라아제에 의한 소화성 및 X-선 회절둥으로 전분의 호화과정을 살펴본 결과 55-60℃에서 호화가 시작되고 60~70℃에서는 95%이상 호화되었다. 또한 3~6%전분용액의 가열에 따른 점도변화를 amyl-ograph를 사용하여 실험한 결과 pasting temperature 62~68℃, 최고점도 80~840BU, 50℃로 냉각후의 점도는 110~555BU였다. 따라서 다른 전분에 비해서 점도가 낮으나 setback이 현저히 느렸다. 수분함량 50%의 전분겔의 경도는 팥 전분보다는 약하고 감자나 밀전분에 비해서는 현저히 높았다. 전분겔의 저장중 노화속도는 밀 전분보다는 느리고 파지오카 전분보다는 빨랐다. 고사리뿌리 전분은 팥 전분겔특성에 큰 변화를 주지않지만 노화를 억제하였고 밀 전분겔에 첨가시에는 겔의 경도가 저하되어 부드러워지는 경향을 보였다. The gelatinization phenomena of bracken root starch were examined by means of the loss of birefringence, degree of digestibility by amylase and X-ray diffraction. These results indicated that gelatinization temperature of the starch was 55∼60℃ and over 95% of starch were gelatinized at the temperature between 60 and 70℃. The swelling power of the bracken root starch was much less steeper than that of potato or tapioca starch. Amylograph data on the various starch concentrations showed the pasting temperature of 62∼68℃, peak height of 80∼840 Brabender unit (BU) and peak after cooling to 50℃ of 110∼555 BU. According to the information obtained from amylograph data, the bracken root starch showed low set back. The rate of retrogradation of the starch as tested by Texturometer was slower and faster than potato and tapioca starches, respectively.

光質이 채소作物의 種子發芽와 初期生育 및 除草劑의 活性에 미치는 效果

李政明,金侊來,權臣漢,曺哉銑,朴啓仁,金尙根,李承雨 慶熙大學校 1987 論文集 Vol.16 No.-

Studies were conducted to investigate the response of some horticultural plants to various light qualities provided by different kind of materials such as cellophane sheets, EVA, PVC(polyvinyl chloride, and polyethylene (PE) films of different color. Major findings are summarized as follows. White fluorescence light and red light promoted seed germination of lettuce and inhibited that of radish seeds. Blue light inhibited the seed germination of both types of light-sensitive seeds. The light sensitivity varied considerably depending upon the kind of crops, cultivars, and the seed batches of the same cultivar. The blue light was equally or more strongly effective in inhibiting the seed germination as compared to the farred light. The growth of young seedlings developed from seeds was considerably promoted when grown under orange colored plastic film coverings. The growth of larger seedlings was, however, not influenced by the color of plastic films. Mulching pepper field with colored PVC film did not show further advantages over the commonly-used black PE film. Herbicidal activity of oxyfluorfen was very strong under natural light or red light conditions' and weak under blue or green light conditions. The degree of oxyfluorfen-induced phytotoxicity varied considerably depending upon the light quality and the kind of vegetable crops.

光質이 채소作物의 種子發芽와 初期生育 및 除草劑의 活性에 미치는 效果

李政明,金侊來,權臣漢,曺哉銑,朴啓仁,全尙根,李承雨 경희대학교 부설 식량자원개발연구소 1987 硏究論文集 Vol.8 No.-

Studies were conducted to investigate the response of some horticultural plants to various light qualities provided by different kind of materials such as cellophane sheets, EVA, PVC(polyvinyl chloride,. and polyethylene (FE) films of different color. Major findings are summarized as follows. White fluorescence light and red light promoted seed germination of lettuce and inhibited that of radish seeds. Blue light inhibited the seed germination of both types of light-sensitive seeds. The light sensitivity varied considerably depending upon the kind of crops, cultivars, and the seed batches of the same cultivar. The blue light was equally or more strongly effective in inhibiting the seed germination as compared to the farred light. The growth of young seedlings developed from seeds was considerably promoted when grown under orange colored plastic film coverings The growth of larger seedlings was, however. not influenced by the color of plastic films Mulching pepper field with colored PVC film did not show further advantages over the commonly -used black PE film. Herbicidal activity of oxyfluorfen was very strong under natural light or red light conditions, and weak under blue or green light conditions The degree of oxyfluorfen-induced phytotoxicity varied considerably depending upon the light quality and the kind of vegetable crops.

Autonomous evaluation of ambient vibration of underground spaces induced by adjacent subway trains using high-sensitivity wireless smart sensors

Ke Sun,Wei Zhang,Huaping Ding,Robin E. Kim,Billie F. Spencer Jr. 국제구조공학회 2017 Smart Structures and Systems, An International Jou Vol.19 No.1

The operation of subway trains induces secondary structure-borne vibrations in the nearby underground spaces. The vibration, along with the associated noise, can cause annoyance and adverse physical, physiological, and psychological effects on humans in dense urban environments. Traditional tethered instruments restrict the rapid measurement and assessment on such vibration effect. This paper presents a novel approach for Wireless Smart Sensor (WSS)-based autonomous evaluation system for the subway train-induced vibrations. The system was implemented on a MEMSIC\'s Imote2 platform, using a SHM-H high-sensitivity accelerometer board stacked on top. A new embedded application VibrationLevelCalculation, which determines the International Organization for Standardization defined weighted acceleration level, was added into the Illinois Structural Health Monitoring Project Service Toolsuite. The system was verified in a large underground space, where a nearby subway station is a good source of ground excitation caused by the running subway trains. Using an on-board processor, each sensor calculated the distribution of vibration levels within the testing zone, and sent the distribution of vibration level by radio to display it on the central server. Also, the raw time-histories and frequency spectrum were retrieved from the WSS leaf nodes. Subsequently, spectral vibration levels in the one-third octave band, characterizing the vibrating influence of different frequency components on human bodies, was also calculated from each sensor node. Experimental validation demonstrates that the proposed system is efficient for autonomously evaluating the subway train-induced ambient vibration of underground spaces, and the system holds the potential of greatly reducing the laboring of dynamic field testing.

Solution Synthesis of Large-Scale, High-Sensitivity ZnO/Si Hierarchical Nanoheterostructure Photodetectors

Sun, Ke,Jing, Yi,Park, Namseok,Li, Chun,Bando, Yoshio,Wang, Deli American Chemical Society 2010 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.132 No.44

<P>This Communication reports a low-cost solution fabrication of wafer-scale ZnO/Si branched nanowire heterostructures and their high photodetection sensitivity, with an ON/OFF ratio larger than 250 and a peak photoresponsivity of 12.8 mA/W at 900 nm. This reported unique 3D branched nanowire structure offers a generic approach for the integration of new functional materials for photodetection and photovoltaic applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2010/jacsat.2010.132.issue-44/ja1038424/production/images/medium/ja-2010-038424_0003.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja1038424'>ACS Electronic Supporting Info</A></P>

Wet dual clutch launching adaptive control considering service time

Ke Ma,Dongye Sun,Guanlong Sun,Dongyang Wang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

In this study, an adaptive control strategy named, “front-end optimization + back-end compensation,” is proposed to address the wet dual-clutch transmission start-up problem, while considering the effect of service time on the degradation of friction characteristics. First, the effect of service time on friction characteristics is investigated experimentally. Subsequently, the friction coefficient is estimated using a dual extended Kalman filter, and the optimal motion and control trajectory for the launching process are obtained using the pseudospectral method. Finally, a back-end compensator is designed. The effectiveness of the strategy is verified using the MATLAB/Simulink platform and a vehicle test. The results show that compared with the minimum principle method, the pseudo-spectral method shows less jerk and friction loss with a comparable launching time. The control law is adjusted based on the estimated friction coefficient, which ensures a good start-up. Moreover, the back-end compensator can track the reference trajectory well with parameter perturbation.

Characterization and magnetic properties of polyethylene glycol modified NiZn ferrite thin films

Ke Sun,Zhongwen Lan,Zhong Yu,Xiaoliang Nie 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Polyethylene glycol (PEG) modified Ni_0.5Zn_0.5Fe_2.0O_4.0 ferrite thin films were deposited on Si (100)substrate by a sol―gel method. The crystal structure, surface morphology and magnetic properties of PEG-modified NiZn ferrite thin films (NZFs) were investigated by using the X-ray diffractometer (XRD),atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). The FTIR spectrums showed that PEG molecules were on the surface of asprepared particles, which effectively improved their dispersibility. The crystallization of NZFs improved and crystallite size increased with increasing PEG concentration. Optimal PEG concentration could improve the surface morphology and reduce the roughness. Magnetic properties measurement indicated that compared with the sample without PEG, PEG-modified NZFs showed excellent magnetic properties with higher saturation magnetization and lower coercive force. Finally, PEG-modified NZFs showed a high saturation magnetization 312 emu/cm3 and low coercive force 90 Oe when PEG concentration was 40 g/L.

Research on Antenna Arraying Combining Technology for Deep Space Measurement & Control

Ke Sun,Xiaomin Hou 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.7

In this dissertation, the key technology of uplink array for deep space TTC is studied. Based on the concept of power combining, the theoretical analysis is made on the uplink array. The spatial power combining can be achieved in a certain power. The uplink antenna array technology is a power combiner. At first this chapter introduces the principle of power combining and leads to the concept of the uplink antenna arraying. Then analyze the theory of the uplink antenna arraying power combining, including the signal strength and antenna pattern. The influence of the number of element, spacing, phase and time delay on power combining is analyzed by simulation. At last the uplink antenna arraying power combining performance is analyzed and verified by simulation.

A novel prismatic-shaped isolation platform with tunable negative stiffness and enhanced quasi-zero stiffness effect

Ke Ke,Jing Bian,Xu-Hong Zhou,Michael C.H. Yam,Yu-Hang Wang,Zi Gu,Miaojun Sun 국제구조공학회 2023 Smart Structures and Systems, An International Jou Vol.31 No.3

A passive prismatic-shaped isolation platform (PIP) is proposed to realize enhanced quasi-zero stiffness (QZS) effect. The design concept uses a horizontal spring to produce a tunable negative stiffness and installs oblique springs inside the cells of the prismatic structure to provide a tunable positive stiffness. Therefore, the QZS effect can be achieved by combining the negative stiffness and the positive stiffness. To this aim, firstly, the mathematical modeling and the static analysis are conducted to demonstrate this idea and provide the design basis. Further, with the parametric study and the optimal design of the PIP, the enhanced QZS effect is achieved with widened QZS range and stable property. Moreover, the dynamic analysis is conducted to investigate the vibration isolation performance of the proposed PIP. The analysis results show that the widened QZS property can be achieved with the optimal designed structural parameters, and the proposed PIP has an excellent vibration isolation performance in the ultra-low frequency due to the enlarged QZS range. Compared with the traditional QZS isolator, the PIP shows better performance with a broader isolation frequency range and stable property under the large excitation amplitude.

Crystalline ZnO thin film by hydrothermal growth

Sun, Ke,Wei, Wei,Ding, Yong,Jing, Yi,Wang, Zhong Lin,Wang, Deli Royal Society of Chemistry 2011 Chemical communications Vol.47 No.27

<P>In this work, we have successfully synthesised ZnO crystal thin film with a high quality from hydrothermal reaction on sapphire substrate. The growth mechanism is clarified based on an extensive XTEM study. In addition, electrical and optical properties of the crystal thin film, which can be controlled by impurities, are characterized. The synthesis technique provides fairly high quality and cost-effective substrates for optoelectronic and renewable energy applications.</P> <P>Graphic Abstract</P><P>The capability to control the structural/optical/electrical properties is enabled using a high quality ZnO thin film from solution for electronics and optoelectronics applications. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1cc11397f'> </P>