检索结果-内蒙古大学图书馆

Comparative photocatalytic performances towards acid yellow 17 (AY17) and direct blue 71 (DB71) degradation using Sn3O4 flower-like structure

引用

Journal of Physics: Conference Series 2019年第1期1282卷

作者： A Huda R Ichwani C T Handoko M D Bustan B Yudono F Gulo Program Studi Ilmu Lingkungan Program Pascasarjana Universitas Sriwijaya Jalan Padang Selasa No. 524 Palembang 30121 Sumatera Selatan Indonesia Department of Material Science and Engineering Worcester Polytechnic Institute Worcester-MA 01609 United State of America Program Studi Teknik Kimia Fakultas Teknik Universitas Sriwijaya Jalan Palembang Prabumulih Km. 32 Indralaya Ogan Ilir 30862 Sumatera Selatan Indonesia

Microsphere Sn3O4 flower-like structure has been successfully synthesized using a novel microwave-assisted hydrothermal method and comprehensively characterized by X-ray diffraction (XRD), field emission gun scanning electron microscope (FEG-SEM) and UV Vis spectrophotometer equipped with diffuse reflectance spectroscopy (UV-Vis DRS). In order to examine its photocatalytic performance, two synthetic azo-based dyes, acid yellow 17 (AY17) and direct blue 71 (DB71), have been used as organic pollutant models degraded under visible-light illumination. The results show that the negative charges of Sn3O4 produce higher efficiency photocatalytic activity on DB71 degradation compared to that on AY17 degradation. Further investigation has confirmed that the adsorption capacities played the main role in determining photocatalytic performance and differentiated the quantum yield of dye degradation. Moreover, the different adsorption capacities are generated by the formation of electrostatic interaction and repulsion between surface charge of Sn3O4 and dyes functional groups.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Effects of alkali-cosolvent pre-treatment on properties of SwBKP handsheets

引用

Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry 2017年第5期49卷 42-48页

作者： Choi, Kyoung-Hwa Seo, Ji-Hye Cho, Byoung-Uk Program of Paper Science and Engineering Division of Forest Material Science and Engineering College of Forest and Environmental Sciences Kangwon National University Chuncheon Korea Republic of Changgang Institute of Paper Science and Technology Kangwon National University Chuncheon Korea Republic of

Effects of the alkali-cosolvent (dimethyl sulfoxide, DMSO) pre-treatment of softwood bleached kraft pulp (SwBKP) on the handsheet properties were investigated. In order to evaluate the effect of DMSO addition ratio in the DMSO-water solvent system, the DMSO ratio was varied from 0% to 70% and NaOH solution concentration was adjusted to 13% (w/w). In addition, the concentration of NaOH solution was varied from 0% to 13% at DMSO-water solvent (50:50) in order to evaluate the effect of NaOH soultion concentration. It was found that bulk of handsheet was increased with increasing the addition ratio of DMSO. Also, the addition of DMSO reduced the minimal concentration of NaOH solution to obtain the maximum handsheet bulk. On the other hand, paper strength was decreased with increasing the addition ratio of DMSO during the alkali swelling while no distinct effect of optical properties on handsheets was found.

关键词： Optical properties

来源：评论

学校读者我要写书评

暂无评论

Spin mediated enhanced negative magnetoresistance in Ni80Fe20 and p-silicon bilayer

arXiv

引用

arXiv 2017年

作者： Lou, Paul C. Kumar, Sandeep Department of Mechanical Engineering University of California RiversideCA United States Material Science and Engineering Program University of California RiversideCA United States

In this work, we present an experimental study of spin mediated enhanced negative magnetoresistance in Ni80Fe20 (50 nm)/p-Si (350 nm) bilayer. The resistance measurement shows a reduction of ~2.5% for the bilayer specimen as compared to 1.3% for Ni80Fe20 (50 nm) on oxide specimen for an out-of-plane applied magnetic field of 3T. In the Ni80Fe20-only film, the negative magnetoresistance behavior is attributed to anisotropic magnetoresistance. We propose that spin polarization due to spin-Hall effect is the underlying cause of the enhanced negative magnetoresistance observed in the bilayer. Silicon has weak spin orbit coupling so spin Hall magnetoresistance measurement is not feasible. We use V2ω and V3ω measurement as a function of magnetic field and angular rotation of magnetic field in direction normal to electric current to elucidate the spin-Hall effect. The angular rotation of magnetic field shows a sinusoidal behavior for both V2ω and V3ω, which is attributed to the spin phonon interactions resulting from the spin-Hall effect mediated spin polarization. We propose that the spin polarization leads to a decrease in hole-phonon scattering resulting in enhanced negative magnetoresistance. Copyright © 2017, The Authors. All rights reserved.

关键词： Spin Hall effect

来源：评论

学校读者我要写书评

暂无评论

Effects of pre-treatment with low concentration alkali-urea on beating properties of SwBKP

引用

Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry 2017年第5期49卷 71-77页

作者： Park, Jae-Jun Choi, Kyoung-Hwa Cho, Byoung-Uk Program of Paper Science and Engineering Division of Forest Material Science and Engineering College of Forest and Environmental Sciences Kangwon National University Chuncheon Korea Republic of Changgang Institute of Paper Science and Technology Kangwon National University Chuncheon Korea Republic of

Effects of low concentration alkali-cosolvent swelling pre-treatment on beating characteristics of softwood bleached kraft pulp (SwBKP) fibers was investigated. Urea was applied as a cosolvent. When the pulp was swollen at a low concentration below 2% (based on the oven-dried pulp), the weight loss was below 1%. NaOH treatment below 2% concentration could improve the swelling of SwBKP. Addition of urea with NaOH solution promoted the swelling. In addition, low concentration NaOH-urea pre-treatment reduced the beating time to reach a certain level of beating degree. Lowest freeness level was obtained when SwBKP was treated with 1% NaOH while highest fibrillation level was obtained at 2% NaOH and 1% urea. It could be concluded that grinding efficiency could be improved by the low concentration alkali-cosolvent swelling while optimization for the pre-treatment is necessary.

关键词： Urea

来源：评论

学校读者我要写书评

暂无评论

Changes in grinding characteristics of pulp fiber with CMC addition - Effect of molecular weight and degree of substitution of CMC-

引用

Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry 2017年第3期49卷 64-70页

作者： Cho, Kyoung-Hwa Lee, Jae-Hun Cho, Byoung-Uk Program of Paper Science and Engineering Division of Forest Material Science and Engineering College of Forest and Environmental Sciences Kangwon National University Chuncheon Korea Republic of Changgang Institute of Paper Science and Technology Kangwon National University Chuncheon Korea Republic of

This study was conducted to investigate the effect of molecular weight and degree of substitution of carboxymethyl cellulose (CMC) on the grinding characteristics of hardwood bleached kraft pulp (HwBKP) during MFC production. CMCs having different molecular weights and degree of substitution were added into the pulp stock before grinding, and then the fibrillation and morphological properties of HwBKP during grinding were analyzed. The result showed that CMC contributed to improvement in grinding of HwB-KP. Fibrillation factors including fibril area, water retention value, and pulp slurry viscosity were increased with CMC addition. It is speculated that CMC improved fibrillation of HwBKP during grinding because CMC acted as a lubricant and/or a thickener. The CMC with a high molecular weight showed improved grinding characteristics while a distinct effect of degree of substitution of CMC was not observed.

关键词： Grinding (machining)

来源：评论

学校读者我要写书评

暂无评论

Cure monitoring and characterization of epoxy/amine networks, modified with 1-butyl-3-bethylimidazolium tetrafluoroborate ionic liquid 32

Cure monitoring and characterization of epoxy/amine networks...

引用

32nd Technical Conference of the American Society for Composites 2017

作者： Prozorovska, Liudmyla Muralidharan, Nitin Westover, Andrew Pint, Cary Adams, Douglas Department of Civil and Environmental Engineering Vanderbilt University NashvilleTN37235 United States Interdisciplinary Materials Science Program Vanderbilt University NashvilleTN37225 United States Department of Mechanical Engineering Vanderbilt University NashvilleTN37235 United States Material Science and Technology Division Oak Ridge National Laboratory Oak RidgeTN37831 United States

ISBN: (纸本)9781510853065

In the present work, electrochemical impedance spectroscopy (EIS) was employed for cure monitoring of bisphenol A/F based epoxy resin-polyoxypropylenediamine hardener systems modified with various concentrations of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) ionic liquid (IL). These systems exhibited phase separation induced by an increase in the molar mass through the curing of the resin. The progress of the curing process was accompanied by a steady increase of impedance for all types of samples, as expected, due to the increasing viscosity of the medium for increased degree of cure. The results were compared to those of unmodified resin-hardener systems. The sensitivity of EIS as a cure monitoring technique increased dramatically with the addition of the IL. The cure kinetics of the epoxy resin was characterized by differential scanning calorimetry and the data were used to create a model for comparison with the EIS results. The change of the ionic conductivity during curing as a function of IL concentration and the effect of IL loading on mechanical properties of the resin were also studied. We demonstrate that [BMIM]BF4 loading of 5wt.% increased the room temperature ionic conductivity of the fully cured product by an order of magnitude with only a 2.5% reduction in compression strength from that of pure epoxy. Copyright © (2017) by DEStech Publications, Inc. All rights reserved.

关键词： Epoxy resins

来源：评论

学校读者我要写书评

暂无评论

Evaluation of low-temperature cooking of paper mulberry bast fiber with potassium based cooking chemicals

引用

Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry 2017年第3期49卷 35-40页

This study was conducted to investigate the efficiency of low-temperature cooking of paper mulberry using KOH, which is one of main components of the Korean traditional pulping chemicals. Cooking of paper mulberry bast was performed at various KOH or NaOH concentrations at low temperature (100°C and 120°C). Then, changes in pulping characteristics were evaluated in terms of Kappa number, pulping yield, viscosity of pulp and the degree of polymerization (DP) of cellulose. It was found that the paper mulberry bast fiber having a high molecular weight cellulose can be produced by a low-temperature cooking with KOH. Delignification and screening yield of paper mulberry bast fibers with the low-temperature KOH cooking were similar with that with the low-temperature NaOH cooking. However, cooking with KOH could produce the bast fibers with higher DP of cellulose than that with NaOH.

关键词： Cellulose

来源：评论

学校读者我要写书评

暂无评论

Studies on production of antibacterial wet-tissue saturated with hypochlorous acid water - Changes in HOCL absorption rate in different tissue fabric and its effects on antibacterial activity

引用

Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry 2017年第3期49卷 5-11页

作者： Choi, Kyoung-Hwa Seo, Jin Ho Lee, Myoung-Ku Changgang Institute of Paper Science and Technology Kangwon National University Chuncheon24341 Korea Republic of Program of Paper Science and Engineering Division of Forest Material Science and Engineering College of Forest and Environmental Sciences Kangwon National University Chuncheon Korea Republic of

This study was conducted to investigate the changes in the HOCl absorption rate in the different tissue fabric and its effects on antibacterial rate against Klebsiella pneumoniae. HOCl solution was made by electrolysis of NaCl solution. As results, the absorption rate of HOCl solution into the basic tissue fabric increased with increasing cotton or rayon contents. Antibacterial activity against Klebsiella pneumoniae increased as HOCl concentration increased. Especially, the antibacterial activity of wet-tissue was 100% under the conditions of more than approximately 15 ppm of HOCl. However, it was found that antibacterial activity decreased with increasing the elapsed time after HOCl solution treatment.

关键词： Bacteria

来源：评论

学校读者我要写书评

暂无评论

Changes in handsheet properties by addition of the fibrillated cellulose ground with CMC

引用

Palpu Chongi Gisul/Journal of Korea Technical Association of the Pulp and Paper Industry 2017年第6期49卷 111-117页

作者： Lee, Jae-Hun Choi, Kyoung-Hwa Cho, Byoung-Uk Program of Paper Science and Engineering Division of Forest Material Science and Engineering College of Forest and Environmental Sciences Kangwon National University Chuncheon24341 Korea Republic of Changgang Institute of Paper Science and Technology Kangwon National University Chuncheon24341 Korea Republic of

This study was conducted to investigate the effect of fibrillated cellulose (FC) on hand-sheet properties and to evaluate the possibility of using FC as a dry strength agent for papermaking. The FC or low grade MFC (microfibrillated cellulose) was produced by grinding hardwood bleached kraft pulp slurry with/without carboxymethyl cellulose (CMC). The grinding pass number for the production of FC was adjusted to three. It was found that paper strength was significantly increased with addition of FC. The FC produced with CMC showed much higher strength properties than that without CMC. With addition of 5% FC produced with CMC, tensile energy absorption (TEA) was increased 215% and folding strength was improved 670%. The results showed that fibrillated cellulose (FC) produced with CMC can be used as a good dry strength agent for papermaking.

关键词： Cellulose

来源：评论

学校读者我要写书评

暂无评论

Elucidating the atomistic mechanisms underpinning plasticity in Li-Si nanostructures

引用

Physical Review materials 2017年第5期1卷 055401-055401页

作者： Xin Yan Afif Gouissem Pradeep R. Guduru Pradeep Sharma Department of Mechanical Engineering University of Houston Texas 77004 USA School of Engineering Brown University Providence Rhode Island 02912 USA Department of Physics University of Houston Texas 77004 USA Material Science and Engineering Program University of Houston Texas 77004 USA

Amorphous lithium-silicon (a-Li-Si), especially in nanostructure form, is an attractive high-capacity anode material for next-generation Li-ion batteries. During cycles of charging and discharging, a-Li-Si undergoes substantive inelastic deformation and exhibits microcracking. The mechanical response to repeated lithiation-delithiation eventually results in the loss of electrical contact and consequent decrease of capacity, thus underscoring the importance of studying the plasticity of a-Li-Si nanostructures. In recent years, a variety of phenomenological continuum theories have been introduced that purport to model plasticity and the electro-chemo-mechanical behavior of a-Li-Si. Unfortunately, the micromechanisms and atomistic considerations underlying plasticity in Li-Si material are not yet fully understood and this impedes the development of physics-based constitutive models. Conventional molecular dynamics, although extensively used to study this material, is grossly inadequate to resolve this matter. As is well known, conventional molecular dynamics simulations can only address phenomena with characteristic time scales of (at most) a microsecond. Accordingly, in such simulations, the mechanical behavior is deduced under conditions of very high strain rates (usually, 108s−1 or even higher). This limitation severely impacts a realistic assessment of rate-dependent effects. In this work, we attempt to circumvent the time-scale bottleneck of conventional molecular dynamics and provide novel insights into the mechanisms underpinning plastic deformation of Li-Si nanostructures. We utilize an approach that allows imposition of slow strain rates and involves the employment of a new and recently developed potential energy surface sampling method—the so-called autonomous basin climbing—to identify the local minima in the potential energy surface. Combined with other techniques, such as nudged elastic band, kinetic Monte Carlo and transition state theory, we assess the b

关键词： Mechanical deformation Plasticity Energy materials Nanostructures Multiscale modeling

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：