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Thermal characterization of bio-based phase changing materials in decorative wood-based panels for thermal energy storage

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Green Energy & Environment 2019年第1期4卷 56-65页

作者： Damien Mathis Pierre Blanchet Véronic Landry Philippe Lagière NSERC Industrial Research Chair on Ecoresponsible wood construction(CIRCERB) Laval University Engineering and Mechanics Institute University of Bordeaux Avenue D'Aquitaine

Decorative wood panels containing pouches of bio-based phase changing materials(PCMs) were prepared. Three different PCM mixtures were used: a blend of capric and lauric acids as well as two commercial products, Puretemp?20 and Puretemp?23(Puretemp). The panels consist of engraved Medium Density Fiberboard(MDF) filled with a plastic pouch filled with PCM. High density fiberboard(HDF) was used on top of the panels to enclose the PCM pouches. PCM mixtures were first tested by differential scanning calorimetry(DSC). Phase change temperature and total heat storage of the panels were measured for both fusion and solidification with a Dynamic Heat-Flow Meter Apparatus(DHFMA). DSC and DHFMA results were compared, allowing a better understanding of results gathered from these two techniques. DSC calibration has been revealed important when assessing PCMs. The panels present a phase change temperature and a latent heat storage suitable for buildings applications. The panel made with Puretemp?23 presented the highest energy, with 57.1 J g^(-1). Thermal cycling was conducted on the panels to investigate thermal reliability, which revealed small modifications of thermal properties for two products. For all cases, latent heat was found stable. Hygro-mechanical behavior of the panels was also evaluated as these where designed to be esthetic decorative panels. This study exposes the potential of a new type of wood-based panels loaded with PCM for thermal energy storage and brings overall knowledge about PCM products thermal characterization.

关键词： PCM wood Biosourced Fatty acids DHFMA

Novel Methodologies for Preventing Crack Propagation in Steel Gas Pipelines Considering the Temperature Effect

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Structural Durability & Health Monitoring 2025年第1期19卷 1-23页

作者： Nurlan Zhangabay Ulzhan Ibraimova Marco Bonopera Ulanbator Suleimenov Konstantin Avramov Maryna Chernobryvko Aigerim Yessengali department of Architecture and Urban Planning Mukhtar Auezov South Kazakhstan UniversityShymkent160012Kazakhstan department of Industrial Civil and Road construction Mukhtar Auezov South Kazakhstan UniversityShymkent160012Kazakhstan Mechanics Sound&Vibration LaboratoryDepartment of Civil EngineeringCollege of EngineeringNational Taiwan UniversityTaipei10617Taiwan department of Reability&Dynamic Strength A.Pidhornyi Institute of Mechanical Engineering Problems of National Academy of Sciences of UkraineKharkiv61046Ukraine

Using the software ANSYS-19.2/Explicit Dynamics,this study performedﬁnite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire *** effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also *** results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum *** analysis of the inﬂuence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire *** increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the inﬂuence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline *** analysis of the temperature effect on the pipeline material,within a range from-40℃ to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length *** such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃ and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline signiﬁcantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of *** work integrated the existing methods for crack localization along steel gas pipelines.

关键词： Crack propagation ﬁnite-element internal pressure prestressing steel gas pipeline temperature effect

Electrochemical study of sulfadiazine on a novel phthalocyanine-containing chemically modified electrode

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Chinese Chemical Letters 2013年第4期24卷 329-331页

作者： Xiao-Ping Hong Jing-Ying Ma department of Chemistry Zhejiang Sci-Tech University department of construction.Zhejiang College of construction

In this paper, cobalt tetraaminophthalocyanine （CoPc） was successfully deposited onto a carbon nanotubes modified electrode by consecutive cyclic scanning in supporting electrolyte containing CoPc to form phthalocyanine-containing chemically modified electrode. The electrochemistry of sulfadiazine was studied by voltammetric method and flow injection analysis at the new modified electrode. Compared with glassy carbon electrode, the new modified electrode exhibited exciting performance including low oxidation potential, high current response and promising flow injection response.

关键词： SulfadiazineCarbon nanotubePhthalocyanineElectrochemical detectionFlow injection analysis

Endo-β-1,4-glucanases impact plant cell wall development by influencing cellulose crystallization

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Journal of Integrative Plant Biology 2015年第4期57卷 396-410页

作者： Magdalena Glass Sarah Barkwill Faride Unda Shawn D.Mansfield department of wood Science University of British Columbia

Cell walls are vital to the normal growth and development of plants as they protect the protoplast and provide rigidity to the stem. Here, two poplar and Arabidopsis orthologous endoglucanases, which have been proposed to play a role in secondary cell wall development, were examined. The class B endoglucanases, Pt GH9B5 and At GH9B5, are secreted enzymes that have a predicted glycosylphosphatidylinositol anchor, while the class C endoglucanases, Pt GH9C2 and At GH9C2, are also predicted to be secreted but instead contain a carbohydrate-binding *** poplar endoglucanases were expressed in Arabidopsis using both a 35 S promoter and the Arabidopsis secondary cell wall-specific Ces A8 promoter. Additionally, Arabidopsis t-DNA insertion lines and an RNAiconstruct was created to downregulate At GH9C2 in Arabidopsis. All of the plant lines were examined for changes in cell morphology and patterning, growth and development, cell wall crystallinity, micro fibril angle, and proportion of cell wall carbohydrates. Misregulation of Pt GH9B5/At GH9B5 resulted in changes in xylose content, while misregulation of Pt GH9C2/At GH9C2 resulted in changes in crystallinity, which was inversely correlated with changes in plant height and rosette diameter. Together, these results suggest that these endoglucanases affect secondary cell wall development by contributing to the cell wall crystallization process.

关键词： Cellulose cell walls crystallinity endoglucanase expansion glucose xylose

Experimental Study on Stability of Breakwaters with Penetrating Box Foundations

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海洋工程：英文版 2003年第1期17卷 71-82页

作者：别社安李伟李增志任增金及春宁 department of Port and Coastal Engineering Planning and construction department

The breakwater with top sealed, shallow and wide penetrating box foundations is a new type of structure, applicable to deep water and soft seabed. The relations of horizontal and vertical bearing capacities of the box foundation structure as well as the instability induced failure modes to its dimensions and external loads are discussed through static model tests and wave tests. The mechanical properties of the stability of the box foundation are similar to those of embedded rigid foundations, i.e. the vertical stresses at the bottom of the box are distributed in a linear pattern under the action of vertical loads, and passive and active soil pressures are developed at the front and back sides of the box under the action of horizontal loads; there are two instability induced failure modes of the foundation structure-horizontal slide along the box base and tilting due to insufficient local vertical bearing capacity of the soil beneath the box base. The stability of box foundations can be analyzed by use of the methods applied to analysis of the embedded rigid foundations. To increase the width of the box is the most effective way to improve the stability of box foundations.

关键词： penetrating box foundation breakwater stability bearing capacity model test

Effect of silica forms in rice husk ash on the properties of concrete

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 252-258页

作者： Le Anh-tuan Bui Chun-tsun Chen Chao-lung Hwang department of construction Engineering Taiwan University of Science and Technology

The strength and durability properties of concrete with or without three types of rice husk ash （RHA）, namely, amorphous, partial crystalline, and crystalline RHA, were investigates. The three types of RHA were added into concrete at a 20% replacement level. Consequently, the pozzolanic reactivity of amorphous RHA was higher than that of partial crystalline and crystalline RHA. Concrete added with amorphous RHA showed excellent characteristics in its mechanical and durability properties. The results showed that the higher the amount of crystalline silica in RHA, the lower the concrete resistivity value became. When compared with each other, concretes with 20% of the ce- ment replaced with these types of RHA achieved similar ultrasonic pulse velocity values, but all were lower than that of the control concrete. The incorporation of these kinds of RHA significantly reduced chloride penetration. The results not only encourage the use of amorphous materials, they also support the application of crystalline or partial crystalline RHA as mineral and pozzolanic admixtures for cement.

关键词： rice husk ash silica concrete compressive strength durability waste management

Characterization of Curing and Bonding of wood with Adhesive Mixtures of Liquefied wood and Hexamethylenediamine

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Journal of Renewable Materials 2023年第2期11卷 991-1001页

作者： JureŽigon VitŠeda PetrČermák MilanŠernek department of wood Science and Technology Biotechnical FacultyUniversity of LjubljanaLjubljana1000Slovenia department of wood Science and Technology Faculty of Forestry and Wood TechnologyMendel University in BrnoBrno61300Czech Republic

Various crosslinking agents can be added to the formulations of natural-based adhesives for wood bonding in order to achieve better durability and higher strength of the formed *** the present study,the effect of hexamethylenediamine(HMDA)addition on the performance of liquefied wood(LW)adhesive for wood bonding is *** scanning calorimetry showed the improved thermal stability and crosslinking of the LW adhesive with *** intensified presence of amide linkages(C–N bonds)was found in LW+HMDA with attenuated total reflection Fourier transform infrared *** of the bonded joints using an automated bonding evaluation system showed that a higher press temperature resulted in stronger bonds for both types of ***,the addition of HMDA to LW adhesive improved the bond strength of the joints and accelerated the crosslinking of the ***,with a tensile shear strength of(6.76±2.16)N×mm^(−2)(for LW)and(6.89±2.10)N×mm^(−2)(for LW+HMDA),both adhesives were found to be unsuitable for interior non-structural *** addition,the acidity of LW resulted in relatively high wood failure(70%)in the adhesive joints *** crosslinking of LW with HMDA was reflected in improved resistance of LW+HMDA adhesive joints to water *** conclusion,HMDA is a promising additive for improving the adhesive performance of LW adhesives.

关键词： Adhesive bonding hexamethylenediamine liquefied wood

Statistical determination of significant curved I-girder bridge seismic response parameters

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Earthquake Engineering and Engineering Vibration 2013年第2期12卷 251-260页

作者： Junwon Seo department of Civil Construction & Environmental EngineeringIowa State University

Curved steel bridges are commonly used at interchanges in transportation networks and more of these structures continue to be designed and built in the United States. Though the use of these bridges continues to increase in locations that experience high seismicity, the effects of curvature and other parameters on their seismic behaviors have been neglected in current risk assessment tools. These tools can evaluate the seismic vulnerability of a transportation network using fragility curves. One critical component of fragility curve development for curved steel bridges is the completion of sensitivity analyses that help identify influential parameters related to their seismic response. In this study, an accessible inventory of existing curved steel girder bridges located primarily in the Mid-Atlantic United States （MAUS） was used to establish statistical characteristics used as inputs for a seismic sensitivity study. Critical seismic response quantities were captured using 3D nonlinear finite element models. Influential parameters from these quantities were identified using statistical tools that incorporate experimental Plackett-Burman Design （PBD）, which included Pareto optimal plots and prediction profiler techniques. The findings revealed that the potential variation in the influential parameters included number of spans, radius of curvature, maximum span length, girder spacing, and cross-frame spacing. These parameters showed varying levels of influence on the critical bridge response.

关键词： Plackett-Burman design pareto plot prediction profiler statistical characteristics steel bridge seismic response

Cement-bonded particleboard with a mixture of wheat straw and poplar wood

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Journal of Forestry Research 2013年第2期24卷 381-390页

作者： Morteza Nazerian Vajiihe Sadeghiipanah department of wood and Paper Science and Technology University of Zabol

We investigated the hydration behavior and some physical/mechanical properties of cement-bonded particleboard （CBPB） containing particles of wheat straw and poplar wood at various usage ratios and bonded with Portland cement mixed with different levels of inorganic additives. We determined the setting time and compression strength of cement pastes containing different additives and particles, and studied the effects of these additives and particles on thickness swelling, internal bond strength and modulus of rupture of CBPB by using RSM （Response Surface Methodology）. The mathematical model equations （second-order response functions） were derived to optimize properties of CBPB by computer simulation programming. Predicted values were in agreement with experimental values （R2 values of 0.93, 0.96 and 0.96 for TS, IB and MOR, respectively）. RSM can be efficiently applied to model panel properties. The variables can affect the properties of panels. The cement composites with bending strength 〉 12.5 MPa and internal bond strength 〉 0.28 MPa can be made by using wheat straw as a reinforcing material. Straw particle usage up to 11.5% in the mixture satisfies the minimum requirements of International Standard, EN 312 （2003） for IB and MOR. The dose of 4.95% calcium chloride, by weight of cement, can improve mechanical properties of the panels at the minimum requirement of EN 312. By increasing straw content from 0 to 30%, TS was reduced by increasing straw particle usage up to 1.5% and with 5.54% calcium chloride in the mixture, TS satisfied the EN 312 standard.

关键词： cement-bonded particleboard wheat straw poplar additives setting time physical and mechanical properties