scholarly journals Modelling of Impact Falling Ball Test Response on Solid and Engineered Wood Flooring of Two Eucalyptus Species

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 933
Author(s):  
Luis Acuña ◽  
Fernando Sepliarsky ◽  
Eleana Spavento ◽  
Roberto D. Martínez ◽  
José-Antonio Balmori
Keyword(s):  
Eucalyptus Grandis ◽  
Hardness Test ◽  
Eucalyptus Species ◽  
Dynamic Impact ◽  
Fast Growing ◽  
Hardwood Species ◽  
Wood Flooring ◽  
Engineered Wood ◽  
Steel Balls ◽  
The Impact

In this study, dynamic hardness tests on solid and engineered wood flooring specimens of Eucalyptus globulus Labill. and Eucalyptus grandis W. Hill ex Maiden hardwoods were performed because nowadays, these fast-growing hardwoods are still scarcely employed for this use. Furthermore, another two examples of hardwood commonly applied on wood flooring, Quercus robur L. and Hymenaea courbaril L., were also tested. To compare their properties, a dynamic impact hardness test based on the impact of steel balls, with several diameters, and drop heights was developed. Accordingly, 120 solid wood flooring specimens and 120 engineering wood flooring specimens were producing with these four hardwood species. Dynamic impact tests were made with three steel balls of different diameters (30–40–50 mm), and they were carried out from five different drop heights (0.60–0.75–0.90–1.05–1.20 m). The impact of the steel ball drew the size of the footprint on the surface and this mark was measured with a digital caliper for both dimensions, diameter and depth, as footprint diameter (FD) and indentation depth (ID). Data from 3000 samples, corresponding to 120 different individual groups (4 species × 3 ball diameters × 5 drop height × 2 floor type) were analyzed. Results indicated that the variability of ID (CV between 19.25–25.61%) is much greater than the values achieved for FD (CV between 6.72–7.91%). Regarding the fast-growing hardwood species tested, E. globulus showed a similar behavior to traditional hardwood applied on wood flooring in Europe, Q. robur, and it could be a promising growth in the flooring industry. However, E. grandis showed the worst values compared to traditional hardwood in all test configurations.

Behavior of xylans from the Eucalyptus species. Part 2. Characterization of 4-O-methylglucuronoxylans isolated from black liquors of kraft pulping of Eucalyptus grandis and E. urophylla

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 123-128
Author(s):  
Andréia S. Magaton ◽  
Teresa Cristina F. Silva ◽  
Jorge Luiz Colodette ◽  
Dorila Piló-Veloso ◽  
Flaviana Reis Milagres ◽  
...  
Keyword(s):  
Average Molecular Weight ◽  
Eucalyptus Grandis ◽  
Kraft Pulping ◽  
Raw Material ◽  
Size Exclusion ◽  
Eucalyptus Species ◽  
Exclusion Chromatography ◽  
Ft Ir ◽  
Black Liquors

Abstract 4-O-methylglucuronoxylans isolated from Eucalyptus grandis and Eucalyptus urophylla kraft black liquors (KBLs) were chemically characterized by Fourier transform infrared spectroscopy (FT-IR), size exclusion chromatography (SEC), and nuclear magnetic resonance (NMR) spectroscopy. Doses of alkali charge, expressed as active alkali (AA), were 16, 17, and 18% while the sulfidity was kept at 25%. Kappa numbers of 19.1, 17.5, and 16.1 for E. grandis and 20.4, 16.8, and 15.4 for E. urophylla were obtained. At higher alkali charges, the recovery of xylans from the KBLs was lower and the degree of substitution of xylans with uronic acids decreased. The average molecular weight (Mw) of the recovered xylans was greater under conditions of mild pulping, i.e., in the case of pulps with higher kappa numbers. Mw of xylans ranged from 16.1 to 19.1 kDa for E. grandis and from 15.4 to 20.4 kDa for E. urophylla. The xylans from KBL may be useful as pulp modifying agents or as a raw material for advanced applications.

Tribological characteristics of AA8090-WC-ZrC metal matrix composites prepared by stir casting process for Aerospace applications

2021 ◽  
Vol 73 (6) ◽  
pp. 980-985
Author(s):  
Kalaiyarasan A ◽  
Sundaram S ◽  
Gunasekaran K ◽  
Bensam Raj J.
Keyword(s):  
Metal Matrix ◽  
Materials Science ◽  
Scientific Information ◽  
High Hardness ◽  
Hardness Test ◽  
Casting Process ◽  
Stir Casting ◽  
Hybrid Particles ◽  
Content Type ◽  
The Impact

Purpose Aerospace field is demanding a material with superior strength and high resistance against wear, tear and corrosion. The current study aimed to develop a new material with high performance to be applicable in aerospace field Design/methodology/approach A metal matrix composite AA8090-WC-ZrC was fabricated using stir casting method and its tribological behavior was investigated. Totally, five composites viz. AA/Z, AA/W, AA/WZ (1:3), AA/WZ (1:1) & AA/WZ (3:1) were prepared. Micro hardness, tensile and wear study were performed on the fabricated composites and the results were compared with AA8090 alloy Findings Vickers hardness test resulted that the AA/W composite showed the higher hardness value of 160 HB compared to other materials due to the reinforcing effect of WC particles with high hardness. Tensile test reported that the AA/W composite displayed the maximum tensile strength of 502 MPa owing to the creation of more dislocation density. Further, wear study showed that the AA/W composite exhibited the least wear rate of 0.0011 mm3/m because of the more resisting force offered by the WC particles. Furthermore, the AA/W composite showed the slightest mass loss of 0.0028 g and lower COF value of 0.31 due to the hinder effect of WC particle to the movement of atoms in AA8090 alloy Originality/value This work is original in the field of aerospace engineering and materials science which deals with the fabrication of AA8090 alloy with the reinforcement particles such as tungsten carbide and zirconium carbide. The impact of the combination of hybrid particles and their volume fractions on the tribological properties has been investigated in this work. This work would provide new scientific information to society.

scholarly journals Effect of microwave disinfection on physical and mechanical properties of acrylic resins

2008 ◽  
Vol 19 (4) ◽  
pp. 348-353 ◽  
Author(s):  
Rafael Leonardo Xediek Consant ◽  
Erica Brenoe Vieira ◽  
Marcelo Ferraz Mesquita ◽  
Wilson Batista Mendes ◽  
João Neudenir Arioli-Filho
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Hardness Test ◽  
Knoop Hardness ◽  
Microwave Energy ◽  
Bending Test ◽  
Acrylic Resins ◽  
Strength Tests ◽  
The Impact

This study evaluated the effect of microwave energy on the hardness, impact strength and flexural strength of the Clássico, Onda-Cryl and QC-20 acrylic resins. Aluminum die were embedded in metallic or plastic flasks with type III dental stone, in accordance with the traditional packing technique. A mixing powder/liquid ratio was used according to the manufacturer's instructions. After polymerization in water batch at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling at room temperature, and submitted to finishing. Specimens non-disinfected and disinfected by microwave irradiation were submitted to hardness, impact and flexural strength tests. Each specimen was immersed in distilled water and disinfected in a microwave oven calibrated to 650 W for 3 min. Knoop hardness test was performed with 25 g load for 10 s, impact test was carried out using the Charpy system with 40 kpcm, and 3-point bending test with a crosshead speed of 0.5 mm/min until fracture. Data were submitted to statistical analysis by ANOVA and Tukey's test (?=0.05). Disinfection by microwave energy decreased the hardness of Clássico and Onda-Cryl acrylic resins, but no effect was observed on the impact and flexural strength of all tested resins.

scholarly journals Topology Optimization of Deformable Bodies with Linear Dynamic Impact and Frictionless Contact Condition

2021 ◽  
Vol 11 (22) ◽  
pp. 10518
Author(s):  
Gil-Eon Jeong
Keyword(s):  
Topology Optimization ◽  
Optimization Approach ◽  
Dynamic Impact ◽  
Frictionless Contact ◽  
Linear Dynamic ◽  
Highly Nonlinear ◽  
Simple Part ◽  
Deformable Bodies ◽  
Increasing Demand ◽  
The Impact

There has been an increasing demand for the design of an optimum topological layout in several engineering fields for a simple part, along with a system that considers the relative behaviors between adjacent parts. This paper presents a method of designing an optimum topological layout to achieve a linear dynamic impact and frictionless contact conditions in which relative behaviors can be observed between adjacent deformable parts. The solid isotropic method with penalization (SIMP) method is used with an appropriate filtering scheme to obtain an optimum topological layout. The condensed mortar method is used to handle the non-matching interface, which inevitably occurs in the impact and contact regions, since it can easily apply the existing well-known topology optimization approach even in the presence of a non-matching interface. The validity of the proposed method is verified through a numerical example. In the future, the proposed optimization approach will be applied to more general and highly nonlinear non-matching interface problems, such as friction contact and multi-physics problems.

scholarly journals Effect of Different Levels of I.B.A Concentration on Clonal Propagation of Eucalyptus Species in Ghana West Africa.

2020 ◽  
Author(s):  
Nana Yaw Sarpong ◽  
Frank Ofori Agyemang ◽  
Daniel E.K.A Siaw ◽  
Essakku Menason
Keyword(s):  
Butyric Acid ◽  
Survival Rates ◽  
Maximum Yield ◽  
Eucalyptus Grandis ◽  
Field Performance ◽  
Cost Effective ◽  
P Value ◽  
Eucalyptus Species ◽  
Eucalyptus Urophylla ◽  
Four Levels

Abstract BackgroundIncreasing global wood demands have necessitated an overall push for cost-effective methods of vegetative propagation using cuttings. Vegetative plant propagation through cuttings although a breakthrough is mostly hampered with the inability of cuttings to root effectively to achieve maximum yield. Ten clones each of Eucalyptus grandis x Eucalyptus urophylla (E. grandis x E. urophylla) and Eucalyptus pellita (E. pellita) were treated with Indole-3-butyric acid (IBA) concentrations of 0 ppm (control), 2000 ppm, 3000 ppm and 4000 ppm respectively.ResultsOverall mean survival of cuttings was low (< 50%) for all concentrations of IBA used in this research. Survival rates of individual clones however varied from clone to clone. E. grandis x E. urophylla cuttings had the highest mean survival (43.39%) when treated with 2000 ppm of IBA and lowest mean survival (37.86%) when treated with 0 ppm. Results from the survival rates of E. grandis × E. Urophylla and Eucalyptus pellita cuttings were subjected to an Analysis of Variance test to identify any significant differences between hormone concentration and cutting survival. ANOVA results indicated that differences between cutting–IBA concentrations for E. grandis × E. Urophylla were significant (p=1.85x10-08) which is lower than standard p value (p=0.05) used in the test.For E. pellita (P) cuttings the highest mean survival (27.14%) was achieved when treated with 2000 ppm of Indole-3-butyric acid (IBA). Individual clones however showed significant differences in survival. E. pellita clone P2 achieved the highest survival (52.68%) in the control experiment (0 ppm). Some clones i.e P51 and P82 achieved survivals of less than 10% in all four levels of IBAConclusionThe best surviving Eucalyptus grandis x Eucalyptus urophylla clone (GH11) achieved a mean survival rate of 75% when the GH11 basal cutting was treated with 2000 ppm IBA. The results indicated that the production of clones with survival rates of less than 20% should be discarded since it makes no economic sense clones with survival rates of more than 40% should be planted out in the field to compare field performance with greenhouse survival.

scholarly journals KARAKTERISTIK SIFAT MEKANIS ANTARA TIGA PRODUK MANUFAKTUR ELEKTRODA E6013

2019 ◽  
Vol 3 (1) ◽  
pp. 40-45
Author(s):  
Basori Basori ◽  
Ferry Budhi Susetyo
Keyword(s):  
Impact Strength ◽  
Test Specimen ◽  
Impact Test ◽  
Surface Hardness ◽  
Welding Process ◽  
Hardness Test ◽  
Bottom Plate ◽  
Weld Deposit ◽  
Welding Electrode ◽  
The Impact

The type of electrode used in the SMAW process has many types, such as E 6010, E 6011, E 6012, E 6013, E 6020, E6027. In this case the type E 6013 is the most widely used. Certainly the type E 6013 is produced by different manufacturers as well. From penelurusan researchers of this type have different prices in accordance with companies that sell it. For that reason researchers are interested to compare the three manufacturing outputs for the type E 6013 in terms of its mechanical properties. Making a specimen welding electrode cut material to be used. then sandpaper the material that has been cut so that no remaining pieces are still attached. The next step to do the welding process with three types of E6013 elekroda. The welding is carried out until it reaches the layer layer 10 mm thickness, then the bottom plate is discarded and the weld deposit deposits only The impact strength and surface hardness value are inversely proportional. For the impact test, the E1 electrode sample specimen has the highest impact strength value and the E3 electrode sample specimen has the lowest impact strength value. While on the hardness test specimen E3 electrode sample has the highest hardness value and sample specimen E1 electrode has the lowest hardness value. This can prove that the harder the object is the more brittle the object.

The Impact of the Conical Indenter on a Plate Laying on a Winkler Foundation

2018 ◽  
Vol 931 ◽  
pp. 84-90 ◽  
Author(s):  
Aleksey N. Beskopylny ◽  
Andrey A. Veremeenko ◽  
Elena E. Kadomtseva ◽  
Natalia I. Beskopylnaia
Keyword(s):  
Contact Time ◽  
Mechanical Characteristics ◽  
Strength Characteristics ◽  
Winkler Foundation ◽  
Building Structures ◽  
Dynamic Impact ◽  
Conical Indenter ◽  
Elastic Plastic ◽  
Plastic Indentation ◽  
The Impact

In the practice of civil engineering, the methods of impact diagnostics of materials find their application, allowing quickly and accurately measure the required strength characteristics at any point in the structure. Impact methods offer many advantages, for example, at smaller dimensions can be developed big the contact force, it can be recorded more information about the response of the material to dynamic impact and others. This approach is widely used in determining the hardness of materials and makes it possible to determine the complex mechanical characteristics: yield strength, ultimate strength, and elongation. In the paper we consider the axisymmetric problem of the impact of the conical indenter on the plate, laying on Winkler Foundation under elastic-plastic deformation. The solution is based on the phenomenological model of elastic-plastic indentation in a quasistatic formulation. The general deformations of the plate are considered elastic, and the local, in the contact zone, are elastoplastic. The main characteristics of the impact are determined: the force of the contact interaction, the local indentation, the contact time. The device and methods of determining the strength characteristics of plates under specified conditions of impact were developed on the basis of obtained solutions. The proposed method has been tested on many building structures: bridges, trusses, structural structures of artificial structures, reinforcement bars, welded joints.

scholarly journals Impact of Structural Defects on the Surface Quality of Hardwood Species Sliced Veneers

2020 ◽  
Vol 10 (18) ◽  
pp. 6265
Author(s):  
Vasiliki Kamperidou ◽  
Efstratios Aidinidis ◽  
Ioannis Barboutis
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Wood Species ◽  
Research Work ◽  
Structural Defects ◽  
Material Surface ◽  
Typical Structure ◽  
Hardwood Species ◽  
The Impact

The surface roughness constitutes one of the most critical properties of wood and wood veneers for their extended utilization, affecting the bonding ability of the veneers with one another in the manufacturing of wood composites, the finishing, coating and preservation processes, and the appearance and texture of the material surface. In this research work, logs of five significant European hardwood species (oak, chestnut, ash, poplar, cherry) of Balkan origin were sliced into decorative veneers. Their surface roughness was examined by applying a stylus tracing method, on typical wood structure areas of each wood species, as well as around the areas of wood defects (knots, decay, annual rings irregularities, etc.), to compare them and assess the impact of the defects on the surface quality of veneers. The chestnut veneers presented the smoothest surfaces, while ash veneers, despite the higher density, recorded the highest roughness. In most of the cases, the roughness was found to be significantly lower around the defects, compared to the typical structure surfaces, probably due to lower porosity, higher density and the presence of tensile wood. The results reveal that the presence of defects does not affect the roughness of the veneers and increases neither the processing requirements of the veneer sheets before finishing, nor the respective production cost of veneers and the veneer-based wood panels. The high utilization prospects of the examined wood species in veneer production, even those bearing various defects, is highlighted.

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