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291.
Soon Yong Kweon Seung Jin Yeom Sahang Kyoo Lee Yong Sik Yu Deuk Soo Pyun Cheong Tae Kim 《Integrated ferroelectrics》2013,141(1-4):251-259
Abstract The capacitor contact barrier (CCB) structure was introduced to prevent both the Pt/Al reaction and the Ti effect to a SBT capacitor. TiN CCB layer could not perfectly block the Pt/Al reaction. And ferroelectric properties of SBT capacitor were degraded during back-end processes. So, we applied a new Ir/IrOx layer to the CCB layer. The SBT capacitor with the Ir/IrOx CCB layer exhibited higher delta polarization (dP~15 μC/cm2) after the metal-2 etching process, compared with the value in the case of the TiN CCB layer (dP~12μC/ cm2). Moreover, the dP uniformity was improved to 4% when we used the Ir/IrOx CCB layer, from the ~20% of the TiN CCB layer. And the defect formed by the Pt/Al reaction was not found in the Ir/IrOx CCB layer structure. 相似文献
292.
Amorphous ZnO-SnO2-In2O3 films were grown by direct current magnetron sputtering from vacuum hot pressed ceramic oxide targets of Zn:In:Sn cation ratios 1:2:1 and 1:2:1.5 onto glass substrates. X-ray diffraction analysis showed that the microstructure remained amorphous during annealing at 200 °C for up to 5 hours. By monitoring the electrical resistivity, oxygen content and substrate temperature were optimized during deposition. The optimal films were characterized by Hall Effect, work function and optical spectroscopy measurements. Films of 1:2:1 composition showed the lowest resistivity (7.6 × 10− 4 Ω-cm), when deposited onto substrates preheated to 300 °C. Transmissivity of all films exceeded 80% in the visible spectral region. The energy gap was 3.52-3.74 eV, and the work function ranged 5.08-5.22 eV, suitable for cathode applications in organic light emitting diodes. Overall, the film characteristics were comparable or superior to those of amorphous tin-doped indium oxide and zinc-doped indium oxide films and may serve as viable, lower-cost alternatives. 相似文献
293.
Effects of commercial‐scale pulsed electric field (PEF) processing on the microbial stability, ascorbic acid, flavor compounds, color, Brix, pH, and sensory properties of orange juice were studied and compared with those of thermal processing. Freshly squeezed orange juice was thermally processed at 90 °C for 90 s or processed by PEF at 40 kV/cm for 97 ms. Both thermally processed and PEF‐processed juices showed microbial shelf life at 4 °C for 196 d. PEF‐processed juice retained more ascorbic acid, flavor, and color than thermally processed juice (P<0.05). Sensory evaluation of texture, flavor, and overall acceptability were ranked highest for control juice, followed by PEF‐processed juice and then by thermally processed juice (P<0.01). 相似文献
294.
Sung Min Kang Nathaniel S. Hwang Jihyeon Yeom Sung Young Park Phillip B. Messersmith Insung S. Choi Robert Langer Daniel G. Anderson Haeshin Lee 《Advanced functional materials》2012,22(14):2949-2955
Surface modification is one of the most important techniques in modern science and engineering. The facile introduction of a wide variety of desired properties onto virtually any material surface is an ultimate goal in surface chemistry. To achieve this goal, the incorporation of structurally diverse molecules onto any material surface is an essential capability for ideal surface modification. Here, a general strategy for surface modification is presented in which many diverse surfaces can be functionalized by immobilizing a wide variety of molecules. This strategy functionalizes surfaces by a one‐step immersion of substrates in a one‐pot mixture of a molecule and a catecholamine surface modification agent. This one‐step procedure for surface modification represents a standard protocol to control interfacial properties. 相似文献
295.
Myung-Jun Lee Jung-Kuk Yeom Jong-Yul Ha Sung-Sik Chung 《Journal of Mechanical Science and Technology》2001,15(9):1311-1318
It is necessary to diagnose accurately the characteristics of soot formation and oxidation in a diesel engine. Whereas past measurement techniques for soot concentration give limited information for soot, laser-based two-dimensional imaging diagnostics have a potential to provide temporally and spatially superior resolved measurements of the soot distribution. The technique using laser sheet beam has been applied to an optically accessible diesel engine for the quantitative measurement of soot. The results provided the information for reduction of soot from the diesel engine. Both LIS (Laser Induced Scattering) and LII (Laser Induced Incandescence) techniques were used simultaneously in this study. The images of LIS and LII showed the quantitative distribution of the soot concentration in the diesel engine. In this study, several results were obtained by the simultaneous measurements of LIS and LII technique. The diameter and number density of soot in combustion chamber of the test engine were obtained from ATDC 20 degree to 110 degree. The soot diameter increased about 37% between ATDC 20 degree and 110 degree. The number density of soot, however, decreased significantly between ATDC 40 degree and 70 degree. 相似文献
296.
Hyeongsik ParkKyungsoo Jang Krishna KumarShihyun Ahn Jaehyun ChoJuyeon Jang Kyungjun AhnJeonghoon Yeom Dongseok KimJunsin Yi 《Thin solid films》2011,519(20):6910-6915
Cost efficient and large area deposition of superior quality Al2O3 doped zinc oxide (AZO) films is instrumental in many of its applications, including solar cell fabrication due to its numerous advantages over indium tin oxide (ITO) films. In this study, AZO films were prepared by a highly efficient rotating cylindrical direct current (DC) magnetron sputtering system using an AZO target, which has a target material utilization above 80%, on glass substrates in argon (Ar) ambient. A detailed analysis on the electrical, optical, and structural characteristics of AZO thin films was performed for the solar cell, as well as display applications. The properties of films were found to critically depend on deposition parameters, such as sputtering power, substrate temperature, working pressure, and film thickness. A low resistivity of ~ 5.5 × 10− 4 Ω cm was obtained for films deposited at 2 kW, keeping the pressure, substrate temperature and thickness constant at 3 mTorr, 230 °C and ~ 1000 nm respectively. This was due to an increase in carrier mobility and large grain size. Mobility is found to be controlled by ionized impurity scattering within the grains, since the mean free path of carriers is much smaller than the grain size of the films. The AZO films showed a high transparency of ~ 90% in the long wavelength region. Our results offer a cost-efficient AZO film deposition method that can fabricate films with significant low resistivity and high transmittance that can be applied in thin-film solar cells, as well as thin film transistor (TFT) and non-volatile memory (NVM). 相似文献
297.
Kang Cholmin Yeom Inhwa Ashtari Amirsaman Woo Woontack Noh Junyong 《Virtual Reality》2023,27(3):1919-1936
Virtual Reality - Engaging in outdoor daily activities such as shopping is an essential, yet challenging activity for older wheelchair users (OWU). However, little is investigated on how to augment... 相似文献
298.
Hyo Lee Sojeong Lee Chaewon Park Minjoo Yeom Jong-Woo Lim Thi Thu Hang Vu Eunjung Kim Daesub Song Seungjoo Haam 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(26):2207117
African swine fever virus (ASFV) is a severe and persistent threat to the global swine industry. As there are no vaccines against ASFV, there is an immense need to develop easy-to-use, cost-effective, and rapid point-of-care (POC) diagnostic platforms to detect and prevent ASFV outbreaks. Here, a novel POC diagnostic system based on affinity column chromatography for the optical detection of ASFV is presented. This system employs an on-particle hairpin chain reaction to sensitize magnetic nanoclusters with long DNA strands in a target-selective manner, which is subsequently fed into a column chromatography device to produce quantitatively readable and colorimetric signals. The detection approach does not require expensive analytical apparatus or immobile instrumentation. The system can detect five genes constituting the ASFV whole genome with a detection limit of ≈19.8 pm in swine serum within 30 min at laboratory room temperature. With an additional pre-amplification step using polymerase chain reaction (PCR), the assay is successfully applied to detect the presence of ASFV in 30 suspected swine samples with 100% sensitivity and specificity, similar to quantitative PCR. Thus, this simple, inexpensive, portable, robust, and customizable platform for the early detection of ASFV can facilitate the timely surveillance and implementation of control measures. 相似文献
299.
Chaewon Park Eunjung Kim Geunseon Park Byoung Choul Kim Srivithya Vellampatti Jong-Woo Lim Sojeong Lee Soohyun Chung Sung-Hoon Jun Sangyoon Lee Sajid Ali Minjoo Yeom Daesub Song Seungjoo Haam 《Advanced functional materials》2023,33(31):2214603
The emergence of fatal viruses that pose continuous threats to global health has fueled the intense effort to develop direct, accurate, and high-throughput virus detection platforms. Current diagnostic methods, including qPCR and rapid antigen tests, indicate how much of the virus is present, whether small fragments or whole viruses. However, these methods do not indicate the probability of the virus to be active, capable of interacting with host cells and initiating the infection cycle. Herein, a sialic acid-presenting fusogenic liposome (sLipo–Chol) nanosensor with purposefully modulated membrane rigidity to rapidly detect the fusion-competent influenza A virus (IAV) is developed. This nanosensor possesses virus-specific features, including hemagglutinin (HA) binding and HA-mediated membrane fusion. It is explored how the fusogenic capability of sLipo–Chol with different membrane rigidities impacts their sensing performance by integrating Förster resonance energy transfer (FRET) pairs into the bilayers. The addition of an intact virus led to instant FRET signal changes, thus enabling the direct detection of diverse IAV subtypes—even in avian fecal samples—within an hour at room temperature. Therefore, the sensing approach, with an understanding of the cellular pathogenesis of influenza viruses, will aid in developing bioinspired nanomaterials for evolution into nanosystems to detect infection-competent viruses. 相似文献
300.
Dr. Min-Ju Seo Tae-Eui Lee Prof. Soo-Jin Yeom Prof. Deok-Kun Oh Prof. Kyung-Chul Shin 《Chembiochem : a European journal of chemical biology》2023,24(23):e202300556
A lipoxygenase from Pleurotus sajor-caju (PsLOX) was cloned, expressed in Escherichia coli, and purified as a soluble protein with a specific activity of 629 μmol/min/mg for arachidonic acid (AA). The native PsLOX exhibited a molecular mass of 146 kDa, including a 73-kDa homodimer, as estimated by gel-filtration chromatography. The major products converted from polyunsaturated fatty acids (PUFAs), including AA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), were identified as trioxilins (TrXs), namely 13,14,15-TrXB3, 13,14,15-TrXB4, and 15,16,17-TrXB5, respectively, through high-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses. The enzyme displayed its maximum activity at pH 8.0 and 20 °C. Under these conditions, the specific activity and catalytic efficiency of PsLOX for PUFAs exhibited the following order: AA>EPA>DHA. Based on HPLC analysis and substrate specificity, PsLOX was identified as an arachidonate 15-LOX. PsLOX efficiently converted 10 mM of AA, EPA, and DHA to 8.7 mM of 13,14,15-TrXB3 (conversion rate: 87 %), 7.9 mM of 13,14,15-TrXB4 (79 %), and 7.2 mM of 15,16,17-TrXB5 (72 %) in 15, 20, and 20 min, respectively, marking the highest conversion rates reported to date. Collectively, our results demonstrate that PsLOX is an efficient TrXs-producing enzyme. 相似文献