scholarly journals Influence of Chrysoporthe deuterocubensis Canker Disease on the Physical and Mechanical Properties of Eucalyptus urograndis

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 639
Author(s):  
Rasdianah Dahali ◽  
Paridah Md. Tahir ◽  
Adlin Sabrina Muhammad Roseley ◽  
Lee Seng Hua ◽  
Edi Suhaimi Bakar ◽  
...  

Eucalyptus hybrid has been planted rigorously in wet tropical regions including Malaysia. Recently, there was a report on the occurrence of stem canker on these trees. However, the extent of the infections by this stem canker is unknown. The aim of this study was to evaluate the influence of stem canker disease, Chrysoporthe deuterocubensis, on the physical and mechanical properties of 11-year-old E. urophylla × E. grandis or also known as E. urograndis. The samples were taken from infected and healthy trees that were segregated into different classes based on the severity of the attack, i.e., healthy (class 1), moderately infected (class 2), severely infected (class 3) and very severely infected (class 4). A total of 1440 samples from four infection classes were used in this study. The physical and mechanical properties were determined according to the standard test procedures specified by the International Organization for Standardization (ISO) 13061:2014 (Parts 1 to 4, 13, 14 and 17) and British Standard (BS 373: 1957). From the result, a significant effect by the infection classes was observed on physical and mechanical properties of E. urograndis. All infected wood experienced less shrinkage compared to that of a healthy one, particularly the volumetric (Volsh) and radial shrinkage (Rsh). Wood from class 2 and class 3 was less affected by the infection while the majority of wood from class 4 had significantly lower density and poorer strength. Based on the strength data, wood from infection class 2 can be considered to be used for non-structural applications such as furniture, interior finishing, window frames and doors since reduction in mechanical properties was observed. Wood from class 3 would need further investigation to examine its suitability for structural applications.

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lijuan Ping ◽  
Yubo Chai ◽  
Fangwen Zhang ◽  
Bailing Sun ◽  
Junliang Liu

In the study, we report that a safe and simple way for upgrading inferior rubber wood through the combined modification of environment-friendly MUG resin was synthesized from glyoxal, melamine, urea, and other additives. MUG-treated wood samples were prepared with six different MUG resin concentrations (5, 15, 25, 35, 45, and 55 wt %) into the wood matrix and then heated and polymerized to form a solid and hydrophobic MUG resin in the wood scaffold, and the physico-mechanical properties were evaluated. As the MUG resin concentration increased, the weight percent gain and density increased, water uptake and leachability decreased, and the antiswelling efficiency increased at first and then decreased. MUG-treated wood sample can be prepared when the MUG resin concentration was set as 25%, and the physical properties of treated wood was optimum. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy analysis showed that the MUG resin is widely distributed in the cell lumens and cell walls. With enhanced physico-mechanical properties, MUG-treated wood sample can be well used as a promising alternative to existing engineered wood products for structural applications.


2006 ◽  
Vol 114 ◽  
pp. 183-188 ◽  
Author(s):  
G.H. Salimgareeva ◽  
Irina P. Semenova ◽  
V.V. Latysh ◽  
I.V. Kandarov ◽  
Ruslan Valiev

The paper investigates an innovative technological processing method for fabricating nanostructured materials for structural applications. Severe plastic deformation (SPD) and subsequent thermomechanical treatment, was used to produce high physical and mechanical properties in bulk billets.


2020 ◽  
Vol 4 (394) ◽  
pp. 89-98
Author(s):  
Sergei I. Emelyanov ◽  
Nikolay L. Kuchin ◽  
Boris A. Yartsev ◽  
Vladimir L. Lebedev

Object and purpose of research. This paper discusses polymeric composites of various structural applications that may be exposed to extreme temperature and/or radiation, with possible implications for their physical and mechanical properties. Materials and methods. We used static and dynamic methods for determining the constants characterizing the mechanical properties of polymer composites. The analysis of numerous nuclear reactions occurring during neutron irradiation of a polymer composite with a certain chemical composition was carried out by the method of computational prediction. The results of this analysis confirm the change in the composition of the composite and the possibility of changing its internal structure. Main results. Suitability of the investigated composites for the applications accompanied by high-temperature and radiation effects, like foundations of marine nuclear reactors, has been confirmed. Conclusion. For the considered range of temperature and radiation effects, the effect of temperature on structural performance of a composite determined, in its turn, by the mechanical properties of its matrix, is the most significant, while radiation exposure turned out to be less important. Developing polymer composites for more intense radiation environments, like neutron fluxes or gamma rays, it is advisable to optimize their chemistry so as to reduce or totally eliminate the elements capable of generating long-lived radionuclides.


2016 ◽  
Vol 81 (2) ◽  
pp. 62-67 ◽  
Author(s):  
G. Golański ◽  
C. Kolan ◽  
A. Zieliński ◽  
K. Klimaszewska ◽  
A. Merda ◽  
...  

Purpose: The purpose of the investigations was to determine changes in the microstructureand mechanical properties of HR3C creep resisting austenitic steel after service.Design/methodology/approach: The investigations were performed on test specimens takenfrom a part of the steam superheater tube. The range of the investigations included: microstructuralinvestigations - light and SEM microscope; analysis of precipitates - carbide isolates; investigationsof mechanical properties - hardness measurement, static tensile test, impact test.Findings: The precipitation processes at the grain boundaries lead to increase inintergranular corrosion of the HR3C steel resulting in loss of grains in the structure. Theimpact strength testing on test specimens with reduced width may result in overestimationof crack resistance of the material after service.Research limitations/implications: The comprehensive analysis of precipitationprocesses requires TEM examinations. Finding the correlation between the impact strengthdetermined on standard vs. non-standard test specimens with reduced width.Practical implications: The obtained results of investigations are used in industrialpractice for diagnosis of pressure parts of power boilers. Test procedures developed based oncomprehensive materials testing conducted under laboratory conditions are used in upgradingand design of pressure parts of steam boilers. The results of investigations are also the elementof database of the materials characteristics of steels and alloys as well as welded joints made ofthem working under creep conditions developed by the Institute for Ferrous Metallurgy.Originality/value: The results and analysis of the investigations of microstructure andmechanical properties of HR3C steel after service under actual boiler conditions are presented.


1984 ◽  
Vol 39 ◽  
Author(s):  
Norman S. Stoloff

ABSTRACTThis paper will provide an overview of the current status of the development of ordered alloys for high temperature structural applications. The physical and mechanical properties of ordered alloys will be reviewed with particular emphasis on aluminides and (FeNiCo)3V alloys. Alloy theory, slip systems, yielding, strain hardening, fatigue, wear resistance and processing are among the subjects to be covered. Current research programs in the U.S. and abroad will be outlined, and the kinds of scientific and application-oriented research needed in the future will be discussed.


1988 ◽  
Vol 125 ◽  
Author(s):  
Richard C. Dickinson

ABSTRACTCarbon/Carbon is a highly desirable material for use at elevated temperatures in structural applications due to its high strength-to-weight ratio and increasing strength with increasing temperatures.This presentation will survey the general methods used to fabricate and apply oxidation protection systems to these composites. This will be followed by an overview of typical physical and mechanical properties and selected results from oxidation rate studies.


2012 ◽  
Vol 1373 ◽  
Author(s):  
Jorge López-Cuevas ◽  
David Long-González ◽  
Carlos A. Gutiérrez-Chavarría

ABSTRACTFour Celsian (Ba0.75Sr0.25Al2Si2O8)/Mullite (Al6Si2O13) composites, with potential structural applications at high temperatures, are synthesized from coal fly ash (byproduct of a Mexican coal-burning power plant, constituted mainly by SiO2 and Al2O3). Nominal Celsian/Mullite weight ratios studied are 80/20, 60/40, 40/60 and 20/80. Mullite is synthesized separately at 1600ºC/2h and then mixed with a Celsian precursor mixture previously calcined at 900°C/5h. During this process the Celsian phase is formed by a solid state reaction at 1100-1400ºC/5h. Prior to this, the reacting mixture is milled in a planetary mill during 1 or 2h and then compacted by uniaxial and cold isostatic pressing. The microstructure and phase composition of the synthesized composites are characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM/EDS). Their dynamic Young’s modulus is measured by an ultrasonic technique, and their mechanical strength is evaluated from flexural tests carried out at room temperature. The expected phases are obtained in all cases, although with some differences with respect to their expected relative proportions, according to the studied nominal compositions. In general, the longest milling time employed produced samples with the largest degree of crystallinity and density, as well as with the best microstructural characteristics and mechanical properties.


2020 ◽  
Vol 28 (1) ◽  
pp. 1-13
Author(s):  
Marta C.J.A. Nogueira ◽  
Victor A. de Araujo ◽  
Juliano S. Vasconcelos ◽  
André L. Christoforo ◽  
Francisco A.R. Lahr

Eucalypt wood is an important raw material with multiple uses applied for furniture, pulp and paper, charcoal, biomass, and construction. Sixteen tests were performed to evaluate physical and mechanical properties of Eucalyptus triantha, which could estimate the possibility of utilization of this woody material in construction. In all, about 267 repeats were realized. Two moisture contents were regarded according to the Brazilian and American standard documents: fiber saturation point (30%) and standard dried point (12%). Results were statistically treated with t-test and demonstrated increases in six mechanical properties from Eucalyptus triantha wood species: rupture moduli in perpendicular and parallel compressions and static bending; elasticity moduli in parallel tensile, perpendicular compression, and static bending. Volumetric mass and bulk densities were practically stable. Physical and mechanical properties estimation evinced that Eucalyptus triantha wood can be used in structural elements.


Sign in / Sign up

Export Citation Format

Share Document