检索结果-南通市图书馆

Comparative Analysis of Reaction to Fire and Flammability of Hemp Shives Insulation Boards with Incorporated Microencapsulated Phase Change Materials

引用

Journal of Renewable Materials 2024年第3期12卷 603-613页

作者： Inga Zotova Edgars Kirilovs Laura Ziemele Institute of Architecture and Design Riga Technical UniversityRigaLV-1048Latvia Forest and Wood Products Research and Development Institute JelgavaLV-3001Latvia

Nowadays buildings contain innovative materials,materials from local resources,production surpluses and rapidly renewable natural *** Change Materials(PCM)are one such group of novel materials which reduce building energy *** the wider availability of microencapsulated PCM,there is an opportunity to develop a new type of insulating materials,combinate PCM with traditional insulation materials for latent heat energy *** materials are typically flammable and are located on the interior wall finishing yet there has been no detailed assessment of their fire *** this research work prototypes of low-density insulating boards for indoor spaces from hemp shives using carbamide resin binder and cold pressing were ***-scale cone calorimeter tests were conducted to evaluate fire risk,with a focus on assessing material flammability properties and the influence of PCM on the *** this research,the amount of smoke,heat release rate,effective heat of combustion,specific extinction coefficient,mass loss,carbon dioxide yield,specific loss factor,ignition time of hemp straws samples and samples of hemp straws with 10%and without PCM admixture were *** is a risk of flammability for PCM and their fire reaction has not been evaluated when incorporating PCM into interior wall finishing *** obtained results can be used by designers to balance the potential energy savings of using PCM with a more complete understanding and predictability of the associated fire risk when using the proposed *** also allows for appropriate risk mitigation strategies.

关键词： Encapsuled phase change material renewable resources reaction to fire flammability

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Synthesis of Photoactive Compounds from Tall Oil Fatty Acids

引用

Journal of Renewable Materials 2020年第9期8卷 1077-1089页

作者： Beatrise Sture Mikelis Kirpluks Sergejs Gaidukovs Edgars Vanags latvian State Institute of Wood Chemistry Polymer LaboratoryRigaLV-1006Latvia Riga Technical University Faculty of Applied Chemistry and Material ScienceInstitute of Polymer MaterialsRigaLV-1048Latvia

Photocurable systems are more effective,faster and require less energy than conventional thermal curing *** facilitate the ongoing transition toward a biobased economy,photoactive compounds were synthesized from tall oil fatty acids(TOFA)which is a by-product from wood *** this study,photoactive monomers were synthesized by two different chemical pathways using oleic acid and TOFA as raw ***,double bonds present in TOFA were epoxidized,followed by epoxy ring-opening with acrylic acid which introduced photoactive functional groups into the fatty acid *** and final products were analysed using titration methods(acidic value,epoxy value,iodine value)and *** preferred final product(3-acryloyloxy-2-hydroxypropyl)-9-hydroxy-10-acryoyloxystearate(Acr-St)was synthesized by both *** the case of oleic acid,a compound of Acr-St was yielded,while in case of TOFA,the Acr-St was present in mixture along with TOFA acryloyloxy derivates(***.).The final products were photopolymerized using UV irradiation(396 nm)and as a photoinitiator 3 wt%solution of TPO(2,4,6–trimethylbenzoyl diphenylphosphine oxide)was ***,only the synthesis using oleic acid yielded a photocurable compound.

关键词： Photopolymerization TOFA acrylic acid renewable materials

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

On new chaotic mappings in symbol space

引用

Acta Mechanica Sinica 2011年第1期27卷 114-118页

作者： Inese Bula Jnis Buls Irita Rumbeniece University of latvia Department of Mathematics Zellu 8R1gaLV 1586Latvia Institute of Mathematics and Computer Science of University of latvia Raina bulv.29RgaLV 1048Latvia University of latvia Department of Mathematics

A well known chaotic mapping in symbol space is a shift ***,other chaotic mappings in symbol space exist *** basic change is to consider the process not only at a set of times which are equally spaced,say at unit time apart（a shift mapping）,but at a set of times which are not equally spaced,say if the unit time can not be *** increasing mapping as a generalization of the shift mapping and the k-switch mapping are *** increasing and k-switch mappings are chaotic.

关键词： Symbol space Chaotic mapping Increasing mapping k-switch mapping

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Viscoelastic and Thermal Properties of Polyurethane Foams Obtained from Renewable and Recyclable Components

引用

Journal of Renewable Materials 2018年第7期6卷 755-763页

作者： S.Gaidukovs G.Gaidukova A.Ivdre U.Cabulis Faculty of Material Science and Applied Chemistry Institute of Polymer MaterialsRiga Technical University3/7 Paula Valdena St.LV 1048RigaLatvia Faculty of Material Science and Applied Chemistry Institute of Applied ChemistryRiga Technical University3/7 Paula Valdena St.LV 1048RigaLatvia latvian State Institute of Wood Chemistry 27 Dzerbenes St.LV-1006RigaLatvia

This article deals with the study of the viscoelastic and thermal properties of polyurethane (PU) rigid foamsfrom biobased and recycled components. Rapeseed oil (RO) and recycled poly(ethylene terephthalate)(PET) were used to synthesize PU polyols. Addition of adipic acid (ADA) to polyol resulted in improvedthermal and viscoelastic properties of foam materials. ADA content was varied from 1 to 6 wt%. Results ofthe dynamic mechanical spectra indicate an increase of the storage modulus E′ and the loss modulus E″ inthe whole temperature range for specimens with higher loading of ADA. In addition, damping factor shiftedto higher temperatures, but damping intensity remained almost unaffected by the compositions. Scanningelectron microscopy of the foams’ cross sections testified that the average cells’ size of 110 mm was unaffectedby the ADA content in polyol.

关键词： Polyurethane rigid foam rapeseed oil recycled poly(ethylene terephthalate) viscoelastic properties thermalproperties

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Wood pulp industry by-product valorization for acrylate synthesis and bio-based polymer development via Michael addition reaction

引用

Journal of Bioresources and Bioproducts 2023年第3期8卷 265-279页

作者： Ralfs Pomilovskis Eliza Kaulina Inese Mierina Arnis Abolins Olga Kockova Anda Fridrihsone Mikelis Kirpluks Polymer Laboratory Latvian State Institute of Wood ChemistryRiga LV-1006Latvia Institute of Technology of Organic Chemistry Faculty of Materials Science and Applied ChemistryRiga Technical UniversityRiga LV-1048Latvia Institute of Macromolecular Chemistry CAS Prague 16200Czech Republic

It is crucial to adapt the processing of forest bio-resources into biochemicals and bio-based ad-vanced materials in order to transform the current economic climate into a greener *** oil,as a by-product of the Kraft process of wood pulp manufacture,is a promising resource for the extraction of various value-added *** oil fatty acids-based multifunctional Michael acceptor acrylates were *** suitability of developed acrylates for polymerization with tall oil fatty acids-based Michael donor acetoacetates to form a highly cross-linked polymer ma-terial via the Michael addition was *** this novel strategy,valuable chemicals and innovative polymer materials can be produced from tall oil in an entirely new way,making a significant contribution to the development of a forest-based *** different tall oil-based acrylates were successfully synthesized and *** acrylates were successfully used in the synthesis of bio-based thermoset *** polymers had a wide variety of mechanical and thermal properties(glass transition temperature from-12.1 to 29.6°C by dynamic mechanical analysis,Young’s modulus from 15 to 1760 MPa,and stress at break from 0.9 to 16.1 MPa).Gel permeation chromatography,Fourier-transform infrared(FT-IR)spectroscopy,matrix-assisted laser desorption/ionization-time of flight mass spectrometry,and nuclear magnetic resonance were used to analyse the chemical structure of synthesized *** addition,various titration methods and rheology tests were applied to characterize *** chemical composition and thermal and mechanical properties of the developed polymers were studied by using FT-IR,solid-state nuclear magnetic resonance,thermal gravimetric analy-sis,differential scanning calorimetry,dynamic mechanical analysis,and universal strength testing apparatus.

关键词： Tall oil fatty acid Fatty acids-based michael acceptor Bio-based acrylate Michael addition Bio-based polymer

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Sol-gel auto-combustion synthesis of spinel-type ferrite nanomaterials

引用

Frontiers of Materials Science 2012年第2期6卷 128-141页

作者： Andris SUTKA Gundars MEZINSKIS Department of Silicate High Temperature and Inorganic Nanomaterials Technology Institute of Silicate Materials Riga Technical University 14/24 Azenes Str. Riga LV-1048 Latvia

Recent developments and trends spinel ferrite nanomaterial synthesis are briefly of sol-gel auto-combustion method for discussed and critically analyzed. The analysis of various parameters of reaction which could be used for better understanding of synthesis process and control of microstructure and property of spinel ferrite nanopowder products was the main objective of this review article. Special attention was paid to variety of particle size and phase purity. For these purposes the correlation between complexant, oxygen balance and combustion process chemical additives, as well as heating mechanism and atmosphere, was established. These results are relevant from standpoints of both application and processing of ferrites.

关键词： ferrite synthesis sol gel auto-combustion nanomaterial

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基于硫酸为电解液的超级电容器木基活性炭电极材料的制备（英文）

引用

新型炭材料 2017年第4期32卷 319-326页

作者： Aleksandrs Volperts Galina Dobele Aivars Zhurinsh Darya Vervikishko Evgeny Shkolnikov Jurijs Ozolinsh latvianStateInstituteofWoodChemistry 27DzerbenesSt.LV-1006RigaLatvia ScientificAssociationforHighTemperatures RussianAcademyofSciences13/2IzhorskayaSt.125412MoscowRussia RigaTechnicalUniversity FacultyofMaterialScienceandAppliedChemistry14/24AzenesStreetLV-1048RigaLatvia

以NaOH为活化剂,采用两步热化学过程制备出木基活性炭。将所制活性炭用作以硫酸为电解液的超级电容器电极材料。探讨了合成条件对活性炭孔结构和电化学性能。结果表明,在微孔中形成双电层电容,介孔和大孔则实现离子运输。在高的活化温... 详细信息

以NaOH为活化剂,采用两步热化学过程制备出木基活性炭。将所制活性炭用作以硫酸为电解液的超级电容器电极材料。探讨了合成条件对活性炭孔结构和电化学性能。结果表明,在微孔中形成双电层电容,介孔和大孔则实现离子运输。在高的活化温度或高碱炭比下,材料被过度活化,导致高的介孔、大孔孔容,这增加了电解液的吸收,从而降低质量比电容。最佳的活性炭合成条件为,活化温度:600℃,碱炭比:1.25。

关键词：活性炭孔结构热化学活化碱活化超级电容器

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advanced Control System Development on the Basis of Festo Training Laboratory ＂Compact Workstation＂

引用

Journal of Energy and Power Engineering 2014年第5期8卷 966-972页

作者： Vladimir Skopis Igors Uteshevs Aivars Pumpurs Faculty of Power and Electrical Engineering Riga Technical University Riga LV-1048 Latvia

This article describes the development of automatic control system on the basis of Festo ＂Compact Workstation＂ training stand. Such control systems are used in different branches of industry and infrastructure including oil industry, chemical industry, water treatment, canalization and others. The stand allows realizing level, flow, pressure and temperature control systems, using pump, valves, discrete and analog sensors. Level control system is described in this work. PID （proportional integral derivative） controllers are used in these systems. Control is switched on and off and the parameters of control systems are changed by means of SCADA （supervisory control and data acquisition） system. During real technological processes, these actions are performed by the operator. The algorithm of the control system is realized using PLC （programmable logic controller）. At the end of the article conclusions about the research are drawn.

关键词： PLC SCADA PID controller liquid level control.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Investigation of Differently Modulated Optical Signals Transmission in HDWDM Systems

引用

Computer Technology and Application 2011年第10期2卷 801-812页

作者： Aleksejs Udalcovs Vjaceslavs Bobrovs Girts Ivanovs Institute of Telecommunications Faculty of Electronics and Telecommunications Riga Technical University Riga LV-1048 Latvia

The authors＇ developed combined system model can be considered under the concept of next generation optical network （NGON） as a model for the future design of backbone networks. Such solution can be topical in the result of different telecom operators＇ optical networks convergence. In this case a necessity to transmit differently modulated signals over a single optical fiber even with different bit rates may occur. This research is performed with OptSim 5.2 simulation software that numerically solves nonlinear SchrOdinger equation. The authors have revealed the optimal parameter configuration for developed combined transmission systems and obtained in system＇s channels detected signals bit-error-rate （BER） correlation diagrams. They represent BER as a function from different system＇s parameters such as channel output power level, optical amplifier fixed output power level and system＇s channels allotment in C-band of ITU-T （Telecommunication Standardization Sector of the International Telecommunications Union） recommended spectral grid. As well as these obtained BER values were compared with the results for similar system, where instead of standard single mode fiber （according ITU-T Rec. G.652 D） optical signals are transmitted over non-zero dispersion shifted fiber （ITU-T Rec. G. 655）.

关键词： Wavelength division multiplexing (WDM) modulation formats bit-error-rate

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Development of Biomass Utilization in latvia

引用

Journal of Energy and Power Engineering 2013年第1期7卷 96-101页

作者： Peteris Shipkovs Galina Kashkarova Kristina Lebedeva Lana Migla Energy Resources Laboratory Institute of Physical Energetics Riga L V-1006 Latvia Riga Technical University Riga LV-1048 Latvia

This paper describes an efficient and appropriate use of biomass in latvian conditions as well as analyzing the current situation, leading to recommendations for rational use of biomass and the full implementation of the latvian energy sector. In recent year＇s, latvian energy sector development analysis shows, that there is a positive tendency--an increase of local and renewable energy share of energy balance. The paper will be identified for future development opporttmities, and will undertake an analysis of renewable energy consumption forecasting in accordance with the renewable energy potential assessment, taking into account the effective use of innovative technologies and ecological aspects of the energy sector. Increasing use of biomass for district heating （and cogeneration）, also increase the efficient use ofbiomass in cost efficiency and reducing of GHG emissions. Efficient use of biomass analyzed in the paper, taking into account technical, legislative, institutional/organizational, economic, information and financial aspects. Promoting of the efficient use of biomass will increase national energy independence.

关键词： Biomass energy balance cogeneration district heating biomass utilization.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：