检索结果-内蒙古大学图书馆

MgAl2O4 foams obtained by combustion synthesis

Chemical engineering Transactions 2015年 43卷 1801-1806页

作者： Moraes, Graziela G. Pozzobom, Ida E.F. Fernandes, Celso P. Novaes De Oliveira, Antonio P. Graduate Program in Materials Science and Engineering - PGMAT Laboratory of Glass-Ceramic Materials - VITROCER Federal University of Santa Catarina - UFSC Florianópolis - SC88040 900 Brazil

ISBN: (纸本)9788895608341

This work aims to study magnesium aluminate (MgAl2O4) ceramic foams obtained by combustion synthesis in solution without the need of surfactants to stabilize *** ceramic suspension containing acetone (75 wt%), calcined powder (25 wt%) and a mixture of glycerine (80 % blonde glycerine and 20 % crude glycerine) in the fraction of 100 % with respect to solids was prepared in an alumina ball mill, for 60 min. Subsequently, the suspension was heated at 40 °C, for 30 min, until it became rigid. In order to promote foaming, the suspension was heated to 70 °C and then the following substances were added to it: 2.5 wt% distilled water, 25 wt% Al(NO3)3.9H2O), 12.5 wt% (Mg(NO3)2.6H2O) and 0.625 wt% of a glycerine mixture (80 % blonde glycerine and 20% crude glycerine). After additions the suspension was stirred for 5 min at 950 rpm in a mixer. The resulting foams were dried at 40 °C, for 24 h, in a muffle and fired in two steps, i.e., heating at 0.5 °C/min up to 600 °C/120 min and at 5 °C/min up to 1600 °C/120 *** obtained materials were characterized by SEM,TEM and from tomographic images. The results showed that the obtained magnesium aluminate foams have a high porosity (97 %), a high connectivity and pore sizes (diameters) between 30 and 1200 μm. Copyright © 2015, AIDIC ServiziS.r.l.

关键词： Pore size

来源：评论

学校读者我要写书评

暂无评论

Production and characterisation of glass foams for thermal insulation

引用

Chemical engineering Transactions 2015年 43卷 1777-1782页

作者： Dias, Gabriella M.V. Arcaro, Sabrina Cesconeto, Francielly R. De Oliveira Maia, Bianca G. Pereira, Fabiano R. Novaes De Oliveira, Antonio P. Graduate Program in Materials Science and Engineering - PGMAT Laboratory of Glass-Ceramic Materials - VITROCER Federal University of Santa Catarina - UFSC Florianópolis-SC88040-900 Brazil

ISBN: (纸本)9788895608341

In this work, glass compositions from glass bottles with different colours and graphite (2 - 12 vol%) as the pore-forming agent were prepared for the production of materials with controlled porosity for applications where thermal and acoustic insulations are main technical requirements. The formulated compositions were, in a later stage, uniaxially pressed (40 MPa) and fired at different temperatures (800 - 950 °C) and cycles with holding times between 15 and 120 minutes. The results showed that it is possible to produce glass foams for thermal insulation from optimized compositions containing 90 vol% glass and 10 vol% graphite, fired between 800 and 950 °C for 30 minutes, which showed porosities between 53 and 76 %, with thermal conductivities between 0.16 and 0.08 W/mK and compressive strength between 20 and 4.6 MPa. The obtained glass foams are strong candidates for applications requiring thermal insulation with suitable combination of thermal conductivity, porosity and mechanical strength. Copyright © 2015, AIDIC Servizi S.r.l.

关键词： Thermal insulation

来源：评论

学校读者我要写书评

暂无评论

A case study on statistical characterization and optimization of coercivity in cobalt ferrite nanoparticles

A case study on statistical characterization and optimizatio...

引用

作者： Cedeño-Mattei, Y. Sánchez-Peña, M.L. Lara-Rodríguez, Y. Perales-Pérez, Ó. Cabrera-Ríos, M. Engineering Science and Materials Department University of Puerto Rico at Mayagüez Mayagüez Puerto Rico Industrial Engineering Department University of Puerto Rico Mayagüez Mayagüez 00681-9000 Puerto Rico Graduate Program in Systems Engineering University of Nuevo León Nuevo León Mexico

Characterization and optimization of material properties during synthesis and processing are frequent problems in materials science and engineering. In the present paper, the use of design of experiments (DOE) to characterize and improve coercivity in cobalt ferrite nanoparticles is described. The sequence of experiments was planned to capitalize on previous experimental runs available. Emphasis is placed on the rationale for choosing the additional runs. The results reveal that the choice of an adequate initial experimental design can save effort and resources in arriving at useful conclusions upon which subsequent experimental runs can be planned, capitalizing on the initial experimental structure. A region with attractive solutions in terms of coercivity, including a local maximum, was identified through the experimental sequences described in this case study. © 2011 Authors.

关键词： Design of experiments

来源：评论

学校读者我要写书评

暂无评论

Developing an atomic-level understanding of the mechanisms that govern CO2 sequestration mineral carbonation reaction processes

Developing an atomic-level understanding of the mechanisms t...

引用

2005 TMS Annual Meeting

作者： McKelvy, Michael J. Chizmeshya, Andrew V. G. Diefenbacher, Jason Béarat, Hamdallah Carpenter, R.W. Wolf, George Gormley, Deirdre Center for Solid State Science Arizona State University Tempe AZ 85287 United States Science and Engineering of Materials Graduate Program Arizona State University Tempe AZ 85287 United States Department of Chemistry and Biochemistry Arizona State University Tempe AZ 85287 United States

Mineral carbonation is an emerging CO2 sequestration candidate technology, which produces environmentally benign and geologically stable materials. The primary challenge is economically viable process development. Serpentine and olivine minerals are candidate feedstock materials of interest, due to their wide availability, low-cost, and rapid mineral carbonation potential. Cost-effectively enhancing their carbonation reactivity is critical to reducing mineral sequestration process cost. We will discuss our recent research into the mechanisms that govern serpentine and olivine mineral carbonation reaction processes, including in situ observations of the mineral carbonation process and a novel mechanistic approach to enhance carbonation reactivity that avoids the cost of mineral activation. Our goal is to develop the necessary atomic-level understanding to engineer improved carbonation materials and processes to reduce process cost.

关键词： Chemical reactions

来源：评论

学校读者我要写书评

暂无评论

Assessment of the Morphology and Interaction of PHBV/Clay Bionanocomposites: Uses as Food Packaging

引用

Macromolecular Symposia 2016年第1期367卷 113-118页

作者： da Costa Reis, Dilson Cristino Lemos Morais, Ana Carolina de Carvalho, Laura Hecker Alves, Tatianny Soares Barbosa, Renata Federal University of Piauí Graduate Program in Materials Science Polymers and Conjugated Materials Research Group Av. Ininga S/N Ininga Teresina PiauíCEP 64049-550 Brazil Department of Materials Engineering Federal University of Piauí Technology Center TeresinaPiauí Brazil Federal University of Campina Grande Center Science and Technology Graduate Program in Materials Science and Engineering Campina GrandeParaíba Brazil

The production of plastic waste has caused serious environmental impacts. Since the conventional polymers represent one of the largest percentages of waste, a possible solution for this environmental problem is the use of nanoclay-biopolymers for the preparation of food packaging. The objective of this study was to evaluate the morphological structure of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) bionanocomposites and vermiculite through scanning electronic microscopy (SEM) and to verify their packaging/food interaction through the total migration test. The systems were prepared with natural clay and organophilic clay by melt intercalation technique. The migration test was carried out according to the Resolution 105/99 by ANVISA. The SEM micrographs showed a small number of agglomerates for the natural systems and a more uniform structure for the organophilic systems. The migration results of all systems were within the maximum allowable limit for food packages, indicating a possible use of these materials without causing damage to food security. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

关键词： Biopolymers

来源：评论

学校读者我要写书评

暂无评论

Biomass-Based Discrete Furan Oligomers as materials for Electrochromic Devices

引用

ACS Sustainable Chemistry and engineering 2024年第1期12卷 459-469页

作者： Atayde, Eduardo C. Fong, Guan-Lun Yeh, Jyun-Yi Matsagar, Babasaheb M. Wang, Yu-Cheng Chen, De-Chian Peng, Chi-How Li, Yi-Pei Yamauchi, Yusuke Ho, Kuo-Chuan Wu, Kevin C.-W. Molecular Science and Technology Program Taiwan International Graduate Program (TIGP-MST) Academia Sinica No. 128 Sec. 2 Academia Road Taipei 11529 Taiwan Department of Chemistry National Tsing Hua University No. 101 Sec. 2 Kuang-Fu Road Hsinchu 30013 Taiwan Department of Chemical Engineering National Taiwan University No. 1 Sec. 4 Roosevelt Road Taipei 10617 Taiwan Sustainable Chemical Science and Technology Program Taiwan International Graduate Program (TIGP-SCST) Academia Sinica No. 128 Sec. 2 Academia Road Taipei 11529 Taiwan School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensl Brisbane 4072 QLD Australia Department of Materials Process Engineering Graduate School of Engineering Nagoya University Nagoya 464-8603 Japan Institute of Polymer Science and Engineering National Taiwan University No.1 Sec. 4 Roosevelt Rd. Taipei 10617 Taiwan Department of Chemical Engineering and Materials Science Yuan Ze University No. 135 Yuandong Rd. Taoyuan 320 Taiwan

Electrochromic devices (ECDs) are materials that can undergo reversible changes in transmittance when exposed to different applied potentials. While many conjugated heterocyclic oligomers, such as oligothiophenes, have been developed for this purpose, there is no reported study on the use of discrete oligomeric furans as ECD materials. In this work, we introduce a furan trimer that can be utilized as a discrete electrochromic material, which transitions from light yellow to red and has a very high coloration efficiency of 1940 cm²/C at 507 nm. We propose that the reversible π-stack formation of the oligomer radical cations is behind this phenomenon, as evidenced by both experimental and computational results. The derivability of this oligomer from biomass and its facile synthesis make it an interesting alternative for other existing organic electrochromic materials. © 2023 American Chemical Society

关键词： electrochromism furan oligomer hydroxyalkylation−alkylation reaction solvatochromism π-stacks

来源：评论

学校读者我要写书评

暂无评论

Atmospheric Pressure Plasma Jet Treatment of Human Hair Fibers

引用

Journal of Bio- and Tribo-Corrosion 2015年第1期1卷 1-10页

作者： Öngel, Cansu Keleş, Merve Acar, Erhan Birer, Özgür Department of Chemistry Koç University Rumeli Feneri Yolu Sariyer Istanbul34450 Turkey Department of Molecular Biology and Genetics Koç University Rumeli Feneri Yolu Sariyer Istanbul34450 Turkey Materials Science and Engineering Graduate Program Koç University Rumeli Feneri Yolu Sariyer Istanbul34450 Turkey KUYTAM Surface Science and Technology Center Koç University Rumeli Feneri Yolu Sariyer Istanbul34450 Turkey

Human hair fibers in virgin and dyed forms were treated with atmospheric pressure helium, helium/oxygen, argon, and argon/oxygen plasma jets at 20 W of power. The effects of 10-min plasma treatment on surface morphology and chemistry were studied by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. The plasma treatment was quite effective for removing the organic residues from the surface and creating oxidized functional groups. Helium plasma had a mild cleaning effect on the surfaces while argon/oxygen plasma had the strongest corrosive effect. Mild hydrogen peroxide treatment for the same duration had neither the cleaning nor the oxidizing power of the plasma jets. These types of plasma jets have the potential to replace peroxide treatment. The corrosive jets can be used to restore dyed hair fibers. In addition, the jets can be used to clean the surfaces of hair fibers to prepare samples for analytical investigations where the organic residues may induce problems. © 2015, Springer International Publishing AG.

关键词： Plasma jets

来源：评论

学校读者我要写书评

暂无评论

Assessment of sound transmission characteristics of traditional timber-framed dwellings in Ankara, Turkey 10

Assessment of sound transmission characteristics of traditio...

引用

10th European Congress and Exposition on Noise Control engineering, Euronoise 2015

作者： Erdil, Meltem Tavukçuoğlu, Ayşe Çalışkan, Mehmet Department of Architecture Graduate Program in Building Science Middle East Technical University Ankara Turkey Department of Architecture Materials Conservation Laboratory Middle East Technical University Ankara Turkey Department of Mechanical Engineering Middle East Technical University Ankara Turkey

The impact and airborne sound transmission characteristics of interior wall and floor components in traditional timber-framed dwellings (Ankara, Turkey) were examined by in-situ acoustical measurements and simulation analyses. Presence of voids for the running of pipework or door/ window openings existed in the composition of timber framed wall and floor components was found to reduce their sound insulation performances in the range of 12-22dB. Air/sound leakages through the openings should be sealed properly in order to provide the required Rw and Lnw values for dwellings. In case that the dwelling units/spaces are used as exhibition, meeting, office or hotel rooms, some acoustical improvements in existing wall and floor components can be provided by demountable attachments with sound insulation infill and sound breaks. Copyright ©(2015) by EAA-NAG-ABAV, ISSN2226-5147 All rights reserved

关键词： Timber

来源：评论

学校读者我要写书评

暂无评论

Deformation of porous, nanostructured silver at room temperature and 150C°

Deformation of porous, nanostructured silver at room tempera...

引用

2012 MRS Fall Meeting

作者： Noiseau, Guillaume Becker, Michael F. Keto, John W. Kovar, Desiderio Materials Science and Engineering Graduate Program University of Texas at Austin Austin TX 78712-1591 United States Department of Electrical and Computer Engineering University of Texas Austin TX United States Department of Physics University of Texas Austin TX United States Department of Mechanical Engineering University of Texas Austin TX United States

ISBN: (纸本)9781632661067

Porous, nanostructured silver samples were produced using a direct-write method where a nanoparticle aerosol consisting of particles with a mean size of approximately 5 nm were accelerated to speeds of approximately 1000 m/sec and impacted onto a translating substrate [1]. The impacting particles have sufficient energy to stick to the substrate, allowing patterned thick films to be directly written from the aerosol without a mask. Unlike other low temperature processing routes for achieving patterned films, no organics are added that can interfere with post-deposition processing. Typical films are 5-100 μm thick, up to several centimeters long, and have an as-deposited relative densities as high as 70% of bulk Ag. Compression tests were carried out in steps at room temperature and at 150°C under constant displacement rates. Local strain and densification were measured by optical profilometry between each compression step. The results can be used as a starting point to better understand the mechanisms that govern plasticity, creep, and sintering in nanostructured, porous silver at low processing temperatures. © 2013 materials Research Society.

关键词： Room temperature

来源：评论

学校读者我要写书评

暂无评论

Techno-economic and life-cycle assessment of electrochemical captured CO2 conversion process in monoethanolamine

Techno-economic and life-cycle assessment of electrochemical...

引用

2022 AIChE Annual Meeting

作者： Lee, Suhyun Choi, Woong Kim, Jae Hyung Hwang, Yun Jeong Na, Jonggeol Ewha Womans University School of Chemical Engineering and Materials Science Korea Republic of Ewha Womans University Graduate program in System Health Science and Engineering Korea Republic of Clean Energy Research Center Korea Institute of Science and Technology Korea Republic of Seoul National University School of Chemistry Korea Republic of Korea Republic of Ewha Womans University Dept. of Chemical Engineering & Material science Advanced Manufacturing Systems Laboratory Korea Republic of

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：