scholarly journals Physical and mechanical properties of rubberwood (Hevea brasiliensis) dyed with Lasiodiplodia theobromae

2019 ◽  
Vol 65 (1) ◽  
Author(s):  
Boshi Zhao ◽  
Zhiming Yu ◽  
Yang Zhang ◽  
Chusheng Qi
Keyword(s):  
Mass Loss ◽  
Water Absorption ◽  
Hevea Brasiliensis ◽  
Ph Value ◽  
Energy Dispersive Spectrometer ◽  
Physical And Mechanical Properties ◽  
Blue Staining ◽  
Loss Ratio ◽  
Lasiodiplodia Theobromae ◽  
Infrared Spectrometer

AbstractBlue staining on rubberwood (Hevea brasiliensis) is a common kind of defect. There currently exists much research focused on the prevention and control of blue staining. However, little research has been concentrated on the utilization of blue staining for green dyeing. The research conveyed in this paper primarily used Lasiodiplodia theobromae to dye rubberwood, and used scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR) to analyze the commission internationale eclairage (CIE) L*a*b* value of color, the contact angle, the pH value, 24-h water absorption, mass loss ratio, and compressive strength in increments between 5 and 40 days. The results found that the color of rubberwood became darker and more uniform, and that the surface dyed with fungi can reach a super-hydrophobic state. With the increase of time, the pH value of rubberwood changed from acidic to alkaline. Furthermore, hyphae entered the wood mainly through vessels for their large pore diameter, and reduced water absorption. Mass loss ratio increased gradually between 5 and 40 days. The research in this paper concludes that the microorganism was an effective method of wood dyeing, and lays a foundation for further research.

scholarly journals Effects of Different Types of Fibers on the Physical and Mechanical Properties of MICP-Treated Calcareous Sand

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 268
Author(s):  
Jitong Zhao ◽  
Huawei Tong ◽  
Yi Shan ◽  
Jie Yuan ◽  
Qiuwang Peng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Glass Fiber ◽  
Physical And Mechanical Properties ◽  
Polyester Fiber ◽  
Engineering Properties ◽  
Fiber Types ◽  
Calcite Precipitation ◽  
Calcareous Sand ◽  
Hemp Fiber

Microbial-induced calcite precipitation (MICP) has been a promising method to improve geotechnical engineering properties through the precipitation of calcium carbonate (CaCO3) on the contact and surface of soil particles in recent years. In the present experiment, water absorption and unconfined compressive strength (UCS) tests were carried out to investigate the effects of three different fiber types (glass fiber, polyester fiber, and hemp fiber) on the physical and mechanical properties of MICP-treated calcareous sand. The fibers used were at 0%, 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, 0.35%, and 0.40% relative to the weight of the sand. The results showed that the failure strain and ductility of the samples could be improved by adding fibers. Compared to biocemented sand (BS), the water absorption of these three fiber-reinforced biocemented sands were, respectively, decreased by 11.60%, 21.18%, and 7.29%. UCS was, respectively, increased by 24.20%, 60.76%, and 6.40%. Polyester fiber produced the best effect, followed by glass fiber and hemp fiber. The optimum contents of glass fiber and polyester fiber were 0.20% and 0.25%, respectively. The optimum content of hemp fiber was within the range of 0.20–0.25%. Light-emitting diode (LED) microscope and scanning electron microscope (SEM) images lead to the conclusion that only a little calcite precipitation had occurred around the hemp fiber, leading to a poor bonding effect compared to the glass and polyester fibers. It was therefore suggested that polyester fiber should be used to improve the properties of biocemented sand.

scholarly journals Kaolin-Enhanced Superabsorbent Composites: Synthesis, Characterization and Swelling Behaviors

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1204
Author(s):  
Mengna Chen ◽  
Xuelong Chen ◽  
Caiyan Zhang ◽  
Baozheng Cui ◽  
Zewen Li ◽  
...  
Keyword(s):  
Water Absorption ◽  
Low Cost ◽  
High Water ◽  
Kinetic Mechanism ◽  
Swelling Kinetics ◽  
Synthesis Conditions ◽  
Ph Tolerance ◽  
Monovalent Salt ◽  
Infrared Spectrometer ◽  
Pseudo Second Order

One type of low-cost and eco-friendly organic‒inorganic superabsorbent composite (SAPC) was synthesized by free radical polymerization of acrylic acid (AA), starch (ST), sodium alginate (SA) and kaolin (KL) in aqueous solution. The structure and morphology of the SAPC were characterized by Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The influence of different reaction conditions on water absorption of SAPC, i.e., SA and KL contents, AA neutralization degree (ND), potassium persulfate (KPS) and N, N′-methylenebisacrylamide (MBA) loading were systematically studied. Under the optimal synthesis conditions, very high water absorption of 1200 g/g was achieved. The swelling kinetic mechanism of SAPC was studied by pseudo-second order swelling kinetics model and Ritger‒Peppas model. The performances of SAPC under different environments were tested and results revealed that this new SAPC had excellent swelling capacity, high water retention, good salt tolerance in monovalent salt solution (NaCl solution) and good pH tolerance between 4 and 10.

scholarly journals Microstructure and Properties of Self-Assembly Graphene Microcapsules: Effect of the pH Value

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 587 ◽  
Author(s):  
Yan-Dong Guo ◽  
Jun-Feng Su ◽  
Ru Mu ◽  
Xin-Yu Wang ◽  
Xiao-Long Zhang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Chemical Engineering ◽  
Ph Value ◽  
Liquid Paraffin ◽  
Energy Dispersive Spectrometer ◽  
Core Material ◽  
Microstructure And Properties ◽  
Ph Values

Graphene has attracted attention in the material field of functional microcapsules because of its excellent characteristics. The content and state of graphene in shells are critical for the properties of microcapsules, which are greatly affected by the charge adsorption equilibrium. The aim of this work was to investigate the effect of pH value on the microstructure and properties of self-assembly graphene microcapsules in regard to chemical engineering. Microcapsule samples were prepared containing liquid paraffin by a self-assembly polymerization method with graphene/organic hybrid shells. The morphology, average size and shell thickness parameters were investigated for five microcapsule samples fabricated under pH values of 3, 4, 5, 6 and 7. The existence and state of graphene in dry microcapsule samples were analyzed by using methods of scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). Fourier Transform Infrared Spectoscopy (FT-IR) and Energy Dispersive Spectrometer (EDS) were applied to analyze the graphene content in shells. These results proved that graphene had existed in shells and the pH values greatly influenced the graphene deposition on shells. It was found that the microcapsule sample fabricated under pH = 5 experienced the largest graphene deposited on shells with the help of macromolecules entanglement and electrostatic adherence. This microcapsules sample had enhanced thermal stability and larger thermal conductivity because of additional graphene in shells. Nanoindentation tests showed this sample had the capability of deforming resistance under pressure coming from the composite structure of graphene/polymer structure. Moreover, more graphene decreased the penetrability of core material out of microcapsule shells.

Preparation of ZrO2 Composite Ceramics with High Thermal Shock Resistance

2012 ◽  
Vol 455-456 ◽  
pp. 650-654 ◽  
Author(s):  
He Yi Ge ◽  
Jian Ye Liu ◽  
Xian Qin Hou ◽  
Dong Zhi Wang
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Sintering Temperature ◽  
Fiber Composite ◽  
Physical And Mechanical Properties ◽  
Composite Ceramics ◽  
Shock Resistance ◽  
Absorption Measurements

The physical and mechanical properties of nanometer ZrO2-ZrO2fiber composite ceramics were studied by introduction of ZrO2fiber. ZrO2composite ceramics at different sintering temperature was investigated by porosity and water absorption measurements, flexual strength and thermal shock resistance analysis. Results showed that ZrO2composite ceramics containing 15 wt% ZrO2fiber with sintering temperature of 1650°C exhibited good mechanical properties and thermal shock resistance. The porosity and the water absorption were 8.84% and 1.62%, respectively. The flexual strength was 975 MPa and the thermal shock times reached 31 times. Scanning electron microscope (SEM) was used to analyze the microstructure of ZrO2composite ceramics.

scholarly journals Prediction of Douglas-Fir Lumber Properties: Comparison between a Benchtop Near-Infrared Spectrometer and Hyperspectral Imaging System

2018 ◽  
Vol 8 (12) ◽  
pp. 2602 ◽  
Author(s):  
Laurence Schimleck ◽  
Joseph Dahlen ◽  
Seung-Chul Yoon ◽  
Kurt Lawrence ◽  
Paul Jones
Keyword(s):  
Hyperspectral Imaging ◽  
Near Infrared ◽  
Imaging System ◽  
Nir Spectroscopy ◽  
Physical And Mechanical Properties ◽  
Douglas Fir ◽  
Modulus Of Rupture ◽  
Visual Grade ◽  
Fit Statistics ◽  
Infrared Spectrometer

Near-infrared (NIR) spectroscopy and NIR hyperspectral imaging (NIR-HSI) were compared for the rapid estimation of physical and mechanical properties of No. 2 visual grade 2 × 4 (38.1 mm by 88.9 mm) Douglas-fir structural lumber. In total, 390 lumber samples were acquired from four mills in North America and destructively tested through bending. From each piece of lumber, a 25-mm length block was cut to collect diffuse reflectance NIR spectra and hyperspectral images. Calibrations for the specific gravity (SG) of both the lumber (SGlumber) and 25-mm block (SGblock) and the lumber modulus of elasticity (MOE) and modulus of rupture (MOR) were created using partial least squares (PLS) regression and their performance checked with a prediction set. The strongest calibrations were based on NIR spectra; however, the NIR-HSI data provided stronger predictions for all properties. In terms of fit statistics, SGblock gave the best results, followed by SGlumber, MOE, and MOR. The NIR-HSI SGlumber, MOE, and MOR calibrations were used to predict these properties for each pixel across the transverse surface of the scanned samples, allowing SG, MOE, and MOR variation within and among rings to be observed.

Controlled Synthesis of Different Morphologies of SrWO4 Crystals via a Surfactant-Assisted Hydrothermal Precipitation Method

2013 ◽  
Vol 785-786 ◽  
pp. 449-454
Author(s):  
Yan Zhao ◽  
Chun Yan Wu ◽  
Dan Qin ◽  
Xin Lai ◽  
Si Wu ◽  
...  
Keyword(s):  
Ph Value ◽  
Precipitation Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Parameters ◽  
Infrared Spectrometer ◽  
Luminescent Spectra ◽  
Hydrothermal Precipitation ◽  
Surfactant Assisted

SrWO4 octahedrons, flowers, bundles, ellipsoids and dendrites had been successfully synthesized via surfactant-assisted method. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photo-luminescent spectra techniques (PL) and fourier transrform infrared spectrometer (FTIR). By through various comparison experiments, it can be found that some related experimental parameters including the reagent concentration, [Sr2+]/[WO42-] molar ratio (R), aging temperature and the pH value had great influences on morphology of the products.

scholarly journals Possibility to use waste tire waste in the composition of mixtures for the manufacture of cement blocks

2020 ◽  
Vol 9 (9) ◽  
pp. e69996773
Author(s):  
Maria Gabriela Araujo Ranieri ◽  
Maria Auxiliadora de Barros Martins ◽  
Patrícia Capellato ◽  
Mirian de Lourdes Noronha Motta Melo ◽  
Adilson da Silva Mello
Keyword(s):  
Water Absorption ◽  
Maximum Stress ◽  
Physical And Mechanical Properties ◽  
Laboratory Research ◽  
Structural Function ◽  
Mechanical Resistance ◽  
Fine Aggregate ◽  
Natural Sand ◽  
Waste Tires ◽  
Made In

The modern lifestyle has led to an increase in the amount of solid waste in the world, and waste tires are one of the most generated. Annually billions of tons of waste tires are produced, so in this study, we sought to reuse them to make materials for civil construction. For this, a laboratory research was carried out where samples were made in 50 x 100 mm cylinders with traces of 0, 10, 15 and 20% (by weight) of waste, in addition to cement, natural sand and water. The granulometric distribution of waste tires and sand was also carried out. And, with the samples in cylinders, the physical and mechanical properties were evaluated, such as water absorption and apparent density, in addition to the analysis of the mechanical resistance to compression and the modulus of elasticity. The results showed that the granulometric distribution of the tire residue fits as a fine aggregate, similar to the sand granulometry. The water absorption rate of the waste specimens was less than 10%. However, the mechanical resistance decreases proportionally as the amount of tire waste has increased. However, when analyzing the behavior of the stress x strain curves, the specimens containing residues, became more flexible, as they are capable of supporting loads beyond the maximum stress. In this way, the resistance and the ability to absorb energy were increased. We concluded that it is possible to incorporate certain quantities of waste tires in blocks for civil construction, but without a structural function.

An attempt to use „Tetra Pak” waste material in particleboard technology

2021 ◽  
Vol 114 ◽  
pp. 70-75
Author(s):  
Radosław Auriga ◽  
Piotr Borysiuk ◽  
Alicja Auriga
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
Waste Material ◽  
Thickness Swelling ◽  
The Core ◽  
Tetra Pak ◽  
The Impact

An attempt to use „Tetra Pak” waste material in particleboard technology. The study investigates the effect of addition Tetra Pak waste material in the core layer on physical and mechanical properties of chipboard. Three-layer chipboards with a thickness of 16 mm and a density of 650 kg / m3 were manufactured. The share of Tetra Pak waste material in the boards was varied: 0%, 5%, 10% and 25%. The density profile was measured to determine the impact of Tetra Pak share on the density distribution. In addition, the manufactured boards were tested for strength (MOR, MOE, IB), thickness swelling and water absorption after immersion in water for 2 and 24 hours. The tests revealed that Tetra Pak share does not affect significantly the value of static bending strength and modulus of elasticity of the chipboard, but it significantly decreases IB. Also, it has been found that Tetra Pak insignificantly decreases the value of swelling and water absorption of the chipboards.

Investigation of Physical, Mechanical and Thermal Properties of Building Wall Materials

2017 ◽  
Vol 751 ◽  
pp. 521-526 ◽  
Author(s):  
Jiraphorn Mahawan ◽  
Somchai Maneewan ◽  
Tanapon Patanin ◽  
Atthakorn Thongtha
Keyword(s):  
Compressive Strength ◽  
Thermal Properties ◽  
Water Absorption ◽  
Calcium Silicate Hydrate ◽  
Lightweight Concrete ◽  
Physical And Mechanical Properties ◽  
Mechanical And Thermal Properties ◽  
Thermal Insulating ◽  
Building Wall ◽  
Wall Materials

This research concentrates to the effect of changing sand proportion on the physical, mechanical and thermal properties of building wall materials (Cellular lightweight concrete). The density, water absorption and compressive strength of the 7.0 cm x 7.0 cm x 7.0 cm concrete sample were studied. It was found that there are an increase of density and a reduction of water absorption with an increase of sand content. The higher compressive strength can be confirmed by higher density and lower water absorption. The physical and mechanical properties of lightweight concrete conditions conformed to the Thai Industrial Standard 2601-2013. The phases of CaCO3 and calcium silicate hydrate (C-S-H) in the material indicate an important factor in thermal insulating performance.

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