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131.
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133.
Jae Mo Yang Byung Seok Ko Chulhwan Park Byungtae Yoo Dongil Shin Jae Wook Ko 《Korean Journal of Chemical Engineering》2014,31(3):393-401
To increase awareness of safety in facilities where hazards may exist, operators, managers, and executive officers on the site should be able to monitor such facilities. However, most compressed natural gas (CNG) service stations in Korea use only local-mode monitoring, with only on-site operators to monitor the facility. To complement this local-mode monitoring, an online safety management system called Ubiquitous-gas safety management system (U-GSMS) was developed. The U-GSMS consists largely of software and hardware. The software consists of systems that can manage safety and operations, while the hardware consists of sensors installed in the gas facility and wireless communication systems using a ubiquitous sensor network (USN) technology that facilitates communication between sensors as well as between sensors and other devices. As these systems are web-based, on-site operators as well as managers and executive officers at the headquarters can more effectively and efficiently perform monitoring and safety management. 相似文献
134.
Sang Hyun Park Younghwan Jin Kyunghan Ahn In Chung Chung-Yul Yoo 《Journal of Electronic Materials》2017,46(2):848-855
The structural and electrical characteristics of Ag/Ni bilayer metallization on polycrystalline thermoelectric SnSe were investigated. Two difficulties with thermoelectric SnSe metallization were identified for Ag and Ni single layers: Sn diffusion into the Ag metallization layer and unexpected cracks in the Ni metallization layer. The proposed Ag/Ni bilayer was prepared by hot-pressing, demonstrating successful metallization on the SnSe surface without interfacial cracks or elemental penetration into the metallization layer. Structural analysis revealed that the Ni layer reacts with SnSe, forming several crystalline phases during metallization that are beneficial for reducing contact resistance. Detailed investigation of the Ni/SnSe interface layer confirms columnar Ni-Sn intermetallic phases [(Ni3Sn and Ni3Sn2) and Ni5.63SnSe2] that suppress Sn diffusion into the Ag layer. Electrical specific-contact resistivity (5.32 × 10?4 Ω cm2) of the Ag/Ni bilayer requires further modification for development of high-efficiency polycrystalline SnSe thermoelectric modules. 相似文献
135.
Ju-An Yoon You-Hyun Kim Nam Ho Kim Seung Il Yoo Sang Youn Lee Fu Rong Zhu Woo Young Kim 《Nanoscale research letters》2014,9(1):191
In this study, the properties of blue organic light-emitting diodes (OLEDs), employing quantum well-like structure (QWS) that includes four different blue emissive materials of 4,4′-bis(2,2′-diphenylyinyl)-1,1′-biphenyl (DPVBi), 9,10-di(naphth-2-yl)anthracene (ADN), 2-(N,N-diphenyl-amino)-6-[4-(N,N-diphenyl amine)styryl]naphthalene (DPASN), and bis(2-methyl-8-quinolinolate)-4-(phenyl phenolato) aluminum (BAlq), were investigated. Conventional QWS blue OLEDs composed of multiple emissive layers and charge blocking layer with lower highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy level, and devices with triple emissive layers for more significant hole-electron recombination and a wider region for exciton generation were designed. The properties of triple emissive layered blue OLEDs with the structure of indium tin oxide (ITO) /N,N′-diphenyl-N,N′-bis(1-naphthyl-phenyl)-(1,1′-biphenyl)-4,4′-diamine (NPB) (700 Ǻ)/X (100 Ǻ)/BAlq (100 Ǻ)/X (100 Ǻ)/4,7-diphenyl-1,10-phenanthroline (Bphen) (300 Ǻ)/lithium quinolate (Liq) (20 Ǻ)/aluminum (Al) (1,200 Ǻ) (X = DPVBi, ADN, DPASN) were examined. HOMO-LUMO energy levels of DPVBi, ADN, DPASN, and BAlq are 2.8 to 5.9, 2.6 to 5.6, 2.3 to 5.2, and 2.9 to 5.9 eV, respectively. The OLEDs with DPASN/BAlq/DPASN QWS with maximum luminous efficiency of 5.32 cd/A was achieved at 3.5 V. 相似文献
136.
Eun Jin Lee Yohannes H. Rezenom David H. RussellBhimanagouda S. Patil Kil Sun Yoo 《Food chemistry》2012,131(3):852-861
The chemical structures of pink-red pigments responsible for ‘pinking’ in macerated onion were tentatively elucidated using HPLC with a diode array detector and tandem mass spectrometry. All pigments were produced in conditions that approximated the natural process as closely as possible, using mixtures of onion thiosulphinates, the enzyme alliinase, and free amino acids. The isotopic distribution of protonated molecules of pink-red pigments produced from individual amino acids indicated the absence of sulphur, with the exception of pigment produced from cystine. The pigments had a basic polymethine framework containing two pyrrole rings (3,4-dimethyl-1H-pyrrole and 3,4-dimethyl-2,5-dihydro-1H-pyrrole) bridged by methines. The side chains attached to the nitrogen of the pyrrole rings were derived from the reacting amino acid. The simplest pink-red pigment, produced from glycine, was identified as 2-(2-(3-(1-(carboxymethyl)-3,4-dimethyl-1H-pyrrol-2(5H)-ylidene)prop-1-en-1-yl)-3,4-dimethyl-1H-pyrrol-1-yl)acetic acid. The pigment from alanine was identified as 2-(2-(3-(1-(carboxymethyl)-3,4-dimethyl-1H-pyrrol-2-yl)allylidene)-3,4-dimethyl-2,5-dihydro-1H-pyrrol-1-yl)propanoic acid. The chemical structures of pink-red pigments from leucine, asparagine, glutamine, tyrosine, and cystine also were determined. 相似文献
137.
Low molecular weight β-glucan stimulates doxorubicin-induced suppression of immune functions in mice
Nak-Yun Sung Eui-Baek Byun Du-Sup Song Young-Choon Yoo Jae-Kyung Kim Jong-Heum Park Beom-Seok Song Sang-Hyun Park Ju-Woon Lee Young-Beob Yu Jae-Hun Kim 《Food science and biotechnology》2012,21(3):645-651
The aim of this study was to evaluate the protective effect of low molecular weight β-glucan (LMG) against doxorubicin (DOX)-induced immune suppression of tumor-bearing mice. The tumor size and spleen cell functions such as spleen cell proliferation, cytokine production (interferon-γ and interleukin-2), and the population of CD4+ and CD8+ T cells were estimated. In the tumorbearing mice, the tumor size was significantly (p<0.05) decreased by DOX treatment. However, there was no significant difference between mice treated with high molecular weight β-glucan (HMG) and mice treated with LMG. Spleen cell proliferation and cytokine production were significantly (p<0.05) decreased in only DOX treated group, but increased in all β-glucan treated groups with DOX. Moreover, the populations of CD4+ and CD8+ T cells were also increased in the LMG-treated group. It appears that LMG effectively reduces the DOX-induced immune toxicity through activation of immune cells such as splenocytes. 相似文献
138.
Chang-Won Kim Wi Sung Yoo Hyunsu Lim Ilhan Yu Hunhee Cho Kyung-In Kang 《International Journal of Project Management》2018,36(5):730-743
An early-warning performance monitoring system (EPMS) is proposed to objectively measure and monitor the performance of a project for early detection of inherent poor performance problems. The EPMS is built based on project progress data and consists of a database of business information, an optimized theoretical model used as a performance measurement baseline, and an index for monitoring and forecasting the performance. By monitoring the performance through an application of the EPMS to the Korean construction project, the quarterly variation of index was found to differ by project type. These results could explain the environmental changes in the project execution. Therefore, the EPMS is expected to be an alternative for objective performance monitoring and forecasting while applying the existing methods is difficult because of the limited available data on performance indicators. The development procedures may also be useful to researchers interested in approaches to quantitatively analyze trends in various industries. 相似文献
139.
Hak-Yoon Kim Insoo Choi Sang Hyun Ahn Seung Jun Hwang Sung Jong Yoo Jonghee Han Jihyun Kim Hansoo Park Jong Hyun Jang Soo-Kil Kim 《International Journal of Hydrogen Energy》2014
Electrochemical reduction of CO2 to HCOOH was performed on a Sn electrode using a proton exchange membrane-embedded electrolysis cell. The effects of reaction conditions such as catholyte and anolyte types, reduction potential, catholyte pH, and reaction temperature on the amount of HCOOH and its faradaic efficiency were investigated. Four different electrolytes (KOH, KHCO3, KCl, KHSO4) were chosen as the candidate catholyte and anolyte; the most suitable electrolyte was chosen by monitoring the amount of HCOOH and faradaic efficiency. The effect of the pH of the selected catholyte on the conversion of CO2 to HCOOH was also investigated. In addition, the reaction temperature was varied and its effect was studied. From the observations made, we determined the optimal reaction conditions for the production of HCOOH via the electrochemical reduction of CO2 by a systematic approach. 相似文献
140.
Kyoungkeun Yoo Shun-Myung Shin Dong-Hyo Yang Jeong-Soo Sohn 《Minerals Engineering》2010,23(3):219-224
Wastewater produced during recycling of spent lithium primary battery was biologically treated with Acidithiobacillus ferrooxidans to decrease the pH and metal concentration. Since the wastewater contains high concentrations of Cr, Ni, and Li, the effects of these metals on the bacterial activity in a 9 K medium were also investigated. Samples of the medium with different metal concentrations were treated, and the oxidation ratio of Fe2+ ions was measured to examine the activity of bacteria. In the treatment of simulated wastewater, the presence of Cr and Ni ions with concentrations of 8000 g m?3 and 13,000 g m?3, respectively, did not inhibit the bacterial activity, whereas the oxidation ratio of Fe2+ ions was observed to be low in the medium when Li ion was present with a concentration at 5000 g m?3. This observation suggested that at this concentration, Li ion suppressed the bacterial activity. In the case of treatment of real wastewater containing Cr, Ni, and Li, the oxidation ratio of Fe2+ to Fe3+ was observed to be low while the Fe concentration and pH decreased to 21,633 g m?3 and 1.8, respectively. Thus, the wastewater produced during the recycling of spent lithium primary batteries can be effectively treated biologically for re-circulating in the recycling process. 相似文献