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81.
Recent increases in the demand for mobile devices have stimulated the development of nonvolatile memory devices with high performance. In this Communication, we describe the fabrication of low‐cost, high‐performance, digital nonvolatile memory devices based on semiconducting polymers, poly(o‐anthranilic acid) and poly(o‐anthranilic acid‐co‐aniline). These memory devices have ground‐breaking and novel current–voltage switching characteristics. The devices are switchable in a very low voltage range (which is much less than those of all other devices reported so far) with a very high ON/OFF current ratio (which is on the order of 105). The low critical voltages have the advantage for nonvolatile memory device applications of low operation voltages and hence low power consumption. With this very low power consumption, the devices demonstrate in air ambient to have very stable ON‐ and OFF‐states without any degradation for a very long time (which has been confirmed up to one year so far) and to be repeatedly written, read and erased. Our study proposes that the ON/OFF switching of the devices is mainly governed by a filament mechanism. The high ON/OFF switching ratio and stability of these devices, as well as their repeatable writing, reading and erasing capability with low power consumption, opens up the possibility of the mass production of high performance digital nonvolatile polymer memory devices with low cost. Further, these devices promise to revolutionize microelectronics by providing extremely inexpensive, lightweight, and versatile components that can be printed onto plastics, glasses or metal foils. 相似文献
82.
Do-Sik Shim Jong-Youn Son Eun-Mi Lee Gyeong-Yun Baek 《International Journal of Material Forming》2017,10(4):581-596
This paper focuses on the corrugated thin-walled sheet metal in the roll bending process. The main defect that appears in corrugated panels subjected to high amounts of bending deformation is a wavy edge. Edge defects are caused by excessive longitudinal stress and strain near the edge of the plate, and local edge buckling may occur when some critical value of the bending radius is exceeded. This paper proposes two different approaches to avoid a wavy edge for a formed panel: excessive stress on the edge region is restrained by controlling the length of the cross-sectional end of the corrugated panel while considering the stress distribution, and the bending radius in each forming step is determined by considering the strain limit at which the initial edge waviness occurs to avoid excessive compression at particular steps. The experimental and numerical results indicated that the two proposed design strategies can minimize wavy edges in the formed shape. 相似文献
83.
Seong-Joon Baek Aaron Park Jinyoung Kim Aigou Shen Jiming Hu 《Chemometrics and Intelligent Laboratory Systems》2009,98(1):24-30
In this paper, we consider a new background elimination method for Raman spectra. The proposed method is based on peak detection, smoothing, and interpolation. Since the background is usually slowly varying with respect to wavelength, we could estimate the background by eliminating significant peaks. For this purpose, we seek the peaks by inspecting the smoothed derivative of a given spectrum. After clipping out the corresponding peak regions, we estimate the background by applying a modified linear interpolation. Then the background is eliminated from the measured Raman spectrum by simple subtraction. The experimental results showed that the proposed method gave satisfactory results for real Raman spectra as well as synthetic data. As the proposed method requires no prior knowledge of spectrum, we expect that the method could be applied to other spectral data as well. 相似文献
84.
Muhammad Iman Utama Abdul Aziz Ammar Nokeun Park Eung Ryul Baek 《Metals and Materials International》2018,24(2):291-299
We studied the origin of different characteristics and properties of a Ti–10V–2Fe–3Al beta (β) titanium alloy with surface height irregularities that occurred during machining. The height differences were observed in two different regions, labeled as “soft region” and “hard region.” The present study showed a higher Fe and a lower Al content in the hard region, which resulted in higher β-phase stability to resist primary alpha (αp) phase precipitation caused by a failure of the solution treatment process. In contrast, the soft region contained a higher volume fraction of αp phase and a lower volume fraction of the matrix, which consisted of a combination of β and secondary alpha (αs) phase. A high number of αs/β interface in the matrix with a predicted hardness of 520 HV generated an improvement of hardness in the hard region. Therefore, the hard and the soft regions had different abilities to resist wear during machining process, resulting in surface height irregularities. 相似文献
85.
Changho Lee Daeseok Han Byoungmok Kim Namin Baek Byung‐Kee Baik 《International Journal of Food Science & Technology》2013,48(5):984-991
Anthocyanin‐rich acetone extracts of barley grain of four hulless pigmented genotypes were investigated to determine their potential as functional food ingredients. The purple barley cultivar contained 11 anthocyanins, whereas only one anthocyanin, peonidin derivative, was observed in blue, black and yellow barley. The total anthocyanin content of pigmented barley genotypes ranged from 3.2 to 678.5 mg kg?1 in whole grain and from 4.5 to 1654.6 mg kg?1 in bran. The purple barley bran extract gave the highest DPPH radical scavenging capacity, superoxide radical scavenging capacity and total antioxidant activity. The half maximal inhibitory concentration (IC50) of angiotensin I‐converting enzyme (ACE) of anthocyanin‐rich extract of purple barley grain and bran was 8.77 and 4.54 mg mL?1, respectively. Purple barley appears to have great potential uses for the promotion of human health and development of nutraceuticals and functional foods. 相似文献
86.
Vivek K. Bajpai Ajay Sharma Kwang‐Hyun Baek 《International Journal of Food Science & Technology》2013,48(11):2300-2305
This study investigated the antibacterial mechanism of action of the seed essential oil of Eleutherococcus senticosus (ESEO) against foodborne pathogenic bacteria. Preliminarily, the ESEO (1000 μg disc?1) showed potential antibacterial effect as diameter of inhibition zones (12.0 ± 0.2–37.0 ± 2.0 mm) against the tested foodborne pathogens. The MIC and MBC values of ESEO against the tested bacteria were found in the range of 125–500 and 500–1000 μg mL?1, respectively. At MIC concentration, the ESEO had potential inhibitory effect on the cell viability of the tested pathogens. In addition, SEM analysis showed the inhibitory effect of ESEO as confirmed by considerable morphological alterations on the cell wall of B. cereus ATCC 13061 and E. coli O157:H7 ATCC 43889. Moreover, the ESEO revealed its mode of action against foodborne pathogens on membrane integrity as confirmed by release of extracellular ATP, 260‐nm absorbing materials and leakage of potassium ions. These findings confirm that the ESEO can be used as a potential antibacterial agent in food industry to inhibit the growth of various foodborne pathogens. 相似文献
87.
Nanogap Array Fabrication Using Doubly Clamped Freestanding Silicon Nanowires and Angle Evaporations
Han Young Yu Chil Seong Ah In‐Bok Baek Ansoon Kim Jong‐Heon Yang Chang‐Guen Ahn Chan Woo Park Byung Hoon Kim 《ETRI Journal》2009,31(4):351-356
We present a simple semiconductor process to fabricate nanogap arrays for application in molecular electronics and nano‐bio electronics using a combination of freestanding silicon nanowires and angle evaporation. The gap distance is modulated using the height of the silicon dioxide, the width of the Si nanowires, and the evaporation angle. In addition, we fabricate and apply the nanogap arrays in single‐electron transistors using DNA‐linked Au nanoparticles for the detection of DNA hybridization. 相似文献
88.
Kitae?Baek Hyun-Jae?Shin Hyun-Ho?Lee Young-Sun?Jun Ji-Won?YangEmail author 《Korean Journal of Chemical Engineering》2002,19(4):627-631
Electrochemical removal of sodium ion from fermented food composts was analyzed and statistically modeled by response surface
methodology (RSM). Empirical models were developed to describe relationships between the operating variables (operation time,
current density and water contents) and three responses (removal efficiency, energy expenditure and energy efficiency). Statistical
analysis indicated that operation time and current density have significant effect on all responses. Good agreement between
predicted and measured values confirmed the usefulness of the model. The models were verified by additional experimental at
optimum conditions. 相似文献
89.
Cesari V Colautti P Magrin G De Nardo L Baek WY Grosswendt B Alkaa A Khamphan C Ségur P Tornielli G 《Radiation protection dosimetry》2002,99(1-4):337-342
This paper illustrates a tissue-equivalent proportional counter designed to have high gas gain and good energy resolution at nanometric simulated site sizes. Microdosimetric neutron and gamma spectra were measured in dimethyl ether and in propane-based tissue-equivalent gas mixture down to 35 nm. The comparison of experimental data with the results of Monte Carlo calculations shows a satisfactory agreement. 相似文献
90.
Proposed is an all-fibre retro-reflector realised via shaping a fibre end into a right-angled cone for a pump reflector in cladding-pumped fibre lasers. The conical-shaped fibre-optic retro-reflector allows folded, total internal reflections for pump beams that propagate in the inner cladding of a double-clad fibre. The proposed scheme was applied to a cladding-pumped ytterbium-doped fibre laser and readily achieved over 55% of reflection for the unabsorbed pump throughput, thereby generating 29% more signal output power than without the pump retro-reflector 相似文献