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31.
Eun-Sil Kang Da Won Chae Baekjin Kim Young Gyu Kim 《Journal of Industrial and Engineering Chemistry》2012,18(1):174-177
2,5-Dihydroxymethylfuran (DHMF) and 5-hydroxymethylfuranoic acid (HMFA) are the versatile intermediate chemicals of high industrial potential. An efficient preparation of both DHMF and HMFA is reported from biomass-derived HMF via a Cannizzaro reaction using ionic liquids as a reusable reaction solvent under the water-free conditions. The operationally simple and environment-friendly process produces both DHMF and HMFA from HMF consistently in good to high yields up to five runs with the recycled ionic liquid. 相似文献
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Wonghil Chang GeumHee Chae So Ra Jang Jihye Shin Byoung Joon Ahn 《Journal of Industrial and Engineering Chemistry》2012,18(2):581-585
Palladium catalysts, Pd/MCM-41 and Pd/SBA-15 were prepared by impregnation of an aqueous solution of [Pd(NH3)4]Cl2 on MCM-41 and SBA-15. Palladium contents of Pd/MCM-41 and Pd/SBA-15 are 8.4% and 8.7%, respectively. It has been shown that these catalysts are very suitable to microwave-assisted Suzuki reactions under solvent-free condition. It is also found that the base additives for this reaction are K2CO3, Cs2CO3 or CsF. Thus, phenylboronic acid and phenyl iodide with Pd/MCM-41 produce biphenyl by microwave irradiation for 10 min in 97.4% yield. Phenyl bromide, instead of phenyl iodide, also proceeds the reaction with phenylboronic acid using Pd/MCM-41 or Pd/SBA-15 yielding biphenyl by microwave irradiation for 10 min in excellent yield. Whereas the reaction of phenyl chloride with phenylboronic acid gives poor yield in same condition. Various aryl iodides and aryl bromides are tested. In this paper our recent results of microwave-assisted Suzuki reaction using Pd/MCM-41 and Pd/SBA-15 under solvent-free condition are described. 相似文献
34.
Effects of Color,Scouring Method,and Age on the Visual Sensibility of Naturally Colored Organic Cotton (NaCOC) 下载免费PDF全文
Jangwoon Park Yoon Chang Wongi Hong Myungeun Lee Ahreum Han Youngjoo Chae Gilsoo Cho Heecheon You 《人机工程学与制造业中的人性因素》2014,24(3):318-327
In parallel to the social trend of green consumerism and well‐being, the demand for naturally colored organic cotton (NaCOC) continually increases in the textile and clothing industry. The present study examined the effects of NaCOC color, scouring method, and age on the visual sensibility of NaCOC. Two age groups (20s and 30s; 40s and 50s) of women rated three color sets of NaCOC specimens (ivory, green, and coyote brown) treated by two chemical scouring methods (Na2CO3 and NaOH) and two bioscouring methods (enzyme and boiling water) using 7‐point scales of nine visual sensibilities (bright‐dark; clear‐murky; heavy‐light; vivid‐subdued; warm‐cool; fresh‐stale; strong‐weak; showy‐plain; and luxurious‐cheap). Preferred scouring methods by NaCOC color and/or age group were recommended for each visual sensibility (e.g., preferred scouring methods for fresh sensibility are Na2CO3 for ivory NaCOC, Na2CO3 and NaOH for green NaCOC, and boiling water for coyote brown NaCOC). In addition, the representative visual sensibilities of each NaCOC color (e.g., those of coyote brown NaCOC are dark, murky, heavy, vivid, warm, stale, strong, plain, and luxurious sensibilities) were identified for the women participants. Last, it was demonstrated that a bioscouring method can replace the traditional chemical methods for selected visual sensibilities (e.g., boiling water for luxurious sensibility). © 2012 Wiley Periodicals, Inc. 相似文献
35.
Puneet Negi H. M. Agrawal Jitendra Pal Singh Hemaunt Kumar R. C. Srivastava K. Asokan Keun Hwa Chae 《Journal of Superconductivity and Novel Magnetism》2017,30(6):1419-1425
The present study deals with the investigation of magnetic properties along with morphological and microstructure analyses of a multiferroic GdMnO3 film fabricated on Si(100) substrate by the pulsed laser deposition technique. Rutherford backscattering spectroscopic analysis suggests that the film is fabricated in the form of diffused layers having different stoichiometric proportions. Raman spectroscopy signifies that few modes present in the film are associated with MnO6 octahedra and some extra peaks indicating the mixed phase formation in tuning with the Rutherford backscattering spectroscopy. Atomic force microscopy confirms the granular nature of the film. Field-cooled and zero-field-cooled thermal magnetization curves show irreversible behaviour extending well above room temperature, which is associated with spin disorder. The presence of Gd+3 state and Mn+3/Mn+4 mixed states in the uppermost layers of the film was confirmed by near-edge X-ray absorption fine structure. Subsequently, in association with these observations, the film is a weak ferromagnetic at 5 K and even at room temperature. 相似文献
36.
Seonil Kwon Yong Ha Hwang Minwoo Nam Hyeonwook Chae Ho Seung Lee Yongmin Jeon Somin Lee Chan Young Kim Seungyeop Choi Eun Gyo Jeong Kyung Cheol Choi 《Advanced materials (Deerfield Beach, Fla.)》2020,32(5):1903488
Advances in material science and nanotechnology have fostered the miniaturization of devices. Over the past two decades, the form-factor of these devices has evolved from 3D rigid, volumetric devices through 2D film-based flexible electronics, finally to 1D fiber electronics (fibertronics). In this regard, fibertronic strategies toward wearable applications (e.g., electronic textiles (e-textiles)) have attracted considerable attention thanks to their capability to impart various functions into textiles with retaining textiles' intrinsic properties as well as imperceptible irritation by foreign matters. In recent years, extensive research has been carried out to develop various functional devices in the fiber form. Among various features, lighting and display features are the highly desirable functions in wearable electronics. This article discusses the recent progress of materials, architectural designs, and new fabrication technologies of fiber-shaped lighting devices and the current challenges corresponding to each device's operating mechanism. Moreover, opportunities and applications that the revolutionary convergence between the state-of-the-art fibertronic technology and age-long textile industry will bring in the future are also discussed. 相似文献
37.
Jiyoung Lim Inshil Doh Kijoon Chae 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2016,20(5):1829-1840
As an efficient and intelligent system for managing and monitoring electricity usage, the “smart grid” has many useful applications. It supports energy producers and energy consumers efficiently by supporting the estimation and provision of the proper amount of electricity at the proper time. The most serious threat to a smart grid system may be when information is altered or forged by attackers; the system could malfunction and could collapse. In some cases, the attackers could waste system resources on purpose and this could lead to disastrous results. In this paper, we propose security system architecture to provide the secure and reliable smart grid service. It includes a data authentication process to verify the aggregated data and virtual network management to detect a compromised area or node. It detects a false data injection attack and further prevents a denial of service attack efficiently with less overhead for the individual devices comprising the smart grid system. 相似文献
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Hoon Chae Park Hang Seok Choi Ji Eun Lee 《Korean Journal of Chemical Engineering》2016,33(4):1159-1169
Rapid quenching of volatiles in fast pyrolysis is important for achieving high yield and quality of the bio-oil product, but few studies have examined the condensation of volatiles and their related heat exchangers. Accordingly, we have studied the condensation characteristics of volatiles by varying heat transfer conditions in a direct contact heat exchanger. As the mass flow rate ratio of quenching oil to pyrolysis gas increased, the heat transfer rate and yield of bio-oil increased. The heat transfer rate and yield of bio-oil reached a maximum value at an intermediate air-to-quenching oil mass flow rate ratio. Additionally, the heat transfer rate and yield of bio-oil decreased as the temperature of the quenching oil increased. Experiments were also conducted to derive an empirical relationship for the volumetric heat transfer coefficient for direct contact heat exchangers. 相似文献
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