scholarly journals MACRO- FEATURES AND DENSITY OF VARIOUS TIMBER SPECIES FROM PAPUA

2020 ◽  
Vol 6 (2) ◽  
pp. 141-148
Author(s):  
MULIYANA ARIFUDIN ◽  
WAHYUDI
Keyword(s):  
Tropical Forest ◽  
Sample Size ◽  
Grain Orientation ◽  
Density Measurement ◽  
Pulp And Paper ◽  
Timber Species ◽  
Low Density ◽  
Dominant Color ◽  
Alstonia Scholaris ◽  
Grain Orientations

This research highlights diversity of macro-features and density of major timber species from Papua. Thirty-one species of air-dried timber with sample size of 13 cm × 6 cm × 4 cm gathered across Papua were used for density measurement and macro-features observation, cover of colors, grain orientation, and wood texture. The results showed that whitish and straw to yellow brown are dominant color of timber mostly harvested from Papua tropical forest. Their grain orientations are mostly straight, while their textures are medium. With regard to their density, Xantostemum spp is the heaviest timber having density of 1,25 g/cm3 while Alstonia scholaris is the lightest species of timber with density of 0.29 g/cm3. Therefore, majority Papua`s timber species studied are classified into light class species or low density timbers. Pulp and paper, veneer, plywood, flooring, meubels, indoor urnitures and handles or woody utensils are the potential uses of these timber species.

scholarly journals Reliability of multigrain indexing for orthorhombic polycrystals above 1 Mbar: application to MgSiO3 post-perovskite

2017 ◽  
Vol 50 (1) ◽  
pp. 120-130 ◽  
Author(s):  
Christopher Langrand ◽  
Nadège Hilairet ◽  
Carole Nisr ◽  
Mathieu Roskosz ◽  
Gábor Ribárik ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Grain Orientation ◽  
Diamond Anvil Cell ◽  
Polycrystalline Material ◽  
Data Set ◽  
Grain Orientations ◽  
Diamond Anvil ◽  
Diffraction Peaks

This paper describes a methodology for characterizing the orientation and position of grains of an orthorhombic polycrystalline material at high pressure in a diamond anvil cell. The applicability and resolution of the method are validated by simulations and tested on an experimental data set collected on MgSiO3 post-perovskite at 135 GPa. In the simulations, ∼95% of the grains can be indexed successfully with ∼80% of the peaks assigned. The best theoretical average resolutions in grain orientation and position are 0.02° and 1.4 µm, respectively. The indexing of experimental data leads to 159 grains of post-perovskite with 30% of the diffraction peaks assigned with a 0.2–0.4° resolution in grain orientation. The resolution in grain location is not sufficient for in situ analysis of spatial relationships at high pressure. The grain orientations are well resolved and sufficient for following processes such as plastic deformation or phase transformation. The paper also explores the effect of the indexing parameters and of experimental constraints such as rotation range and step on the validity of the results, setting a basis for optimized experiments.

Grrain Orientations and their Influence on Precipitation in Hot Compressed Columnar Grains in Electrical Steel

2011 ◽  
Vol 702-703 ◽  
pp. 738-741
Author(s):  
H. Qian ◽  
Ping Yang ◽  
G.H. Zheng ◽  
Wei Min Mao
Keyword(s):  
Hot Deformation ◽  
Grain Orientation ◽  
Electrical Steel ◽  
Compression Axis ◽  
Electrical Steels ◽  
Grain Orientations ◽  
Columnar Grains ◽  
Columnar Grain ◽  
The Relationship ◽  
Sample Axis

To identify the relationship between grain orientation and precipitation of MnS/AlN particles during hot deformation, cylinder samples containing columnar grains in electrical steels were prepared with different angles between columnar grain axis and sample axis. They were heated at 1360°C and compressed at 1100°C for 50%. Grain orientations and the precipitation states are determined using XRD, EBSD, EDS and SEM. Results indicate a general behavior of less precipitates in <100> and more precipitates in <111> grains. In addition, more precipitates were observed in samples with grain boundaries perpendicular to compression axis.

scholarly journals Microstructural differences between naturally-deposited and laboratory beach sands

2021 ◽  
Vol 24 (1) ◽  
Author(s):  
Amy Ferrick ◽  
Vanshan Wright ◽  
Michael Manga ◽  
Nicholas Sitar
Keyword(s):  
Mechanical Properties ◽  
Coordination Number ◽  
Grain Orientation ◽  
Flowing Water ◽  
X Ray ◽  
Depositional Processes ◽  
Grain Orientations ◽  
Computed Microtomography ◽  
X Ray Computed ◽  
Beach Sands

AbstractThe orientation of, and contacts between, grains of sand reflect the processes that deposit the sands. Grain orientation and contact geometry also influence mechanical properties. Quantifying and understanding sand microstructure thus provide an opportunity to understand depositional processes better and connect microstructure and macroscopic properties. Using x-ray computed microtomography, we compare the microstructure of naturally-deposited beach sands and laboratory sands created by air pluviation in which samples are formed by raining sand grains into a container. We find that naturally-deposited sands have a narrower distribution of coordination number (i.e., the number of grains in contact) and a broader distribution of grain orientations than pluviated sands. The naturally-deposited sand grains orient inclined to the horizontal, and the pluviated sand grains orient horizontally. We explain the microstructural differences between the two different depositional methods by flowing water at beaches that re-positions and reorients grains initially deposited in unstable grain configurations.

scholarly journals Nanoscale investigation of deformation characteristics in a polycrystalline silicon carbide

2019 ◽  
Vol 56 (3) ◽  
pp. 951-967 ◽  
Author(s):  
D. Zhang ◽  
L. G. Zhao ◽  
A. Roy ◽  
Y.-L. Chiu
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
Grain Orientation ◽  
Indentation Depth ◽  
Mechanical Response ◽  
Electron Backscatter Diffraction ◽  
High Dose ◽  
Grain Orientations ◽  
Dislocation Movement

AbstractIn this paper, we study the mechanical behaviour of silicon carbide at the nanoscale, with a focus on the effects of grain orientation and high-dose irradiation. Grain orientation effect was studied through nanoindentation with the aid of scanning electron microscopy (SEM) and EBSD (electron backscatter diffraction) analyses. Mechanical properties such as hardness, elastic modulus and fracture toughness were assessed for different grain orientations. Increased plasticity and fracture toughness were observed during indentations on crystallographic planes which favour dislocation movement. In addition, for SiC subjected to irradiation, increases in hardness and embrittlement were observed in nanoindentations at lower imposed loads, whereas a decrease in hardness and an increase in toughness were obtained in nanoindentations at higher loads. Transmission electron microscopy (TEM) analyses revealed that the mechanical response observed at a shallow indentation depth was due to Ga ion implantation, which hardened and embrittled the surface layer of the material. With an increased indentation depth, irradiation-induced amorphization led to a decrease in hardness and an increase in fracture toughness of the material.

Automated Crystal Orientation Mapping (ACOM) of Thin Metallization Layers and Interconnects

1997 ◽  
Vol 472 ◽  
Author(s):  
R.A. Schwarzer
Keyword(s):  
Electron Microscope ◽  
Grain Orientation ◽  
Crystal Orientation ◽  
Silicon Substrates ◽  
Orientation Measurement ◽  
Orientation Mapping ◽  
Grain Orientations ◽  
Aluminum Metallization ◽  
Crystal Orientation Mapping

ABSTRACTA system for acquisition and interpretation of Kikuchi patterns with computer-controlled electron microscopes is presented. It enables interactive as well as fully automated determination of individual grain orientations. Special features for automated crystal orientation mapping (ACOM) with the scanning electron microscope (SEM) are digital beam scan, autocalibration and dynamic focus controlled by the computer. With the present setup about three orientations per second can be measured unattendedly. In the transmission electron microscope (TEM) the on-line determination of Burgers vectors and identification of deformation systems are based on crystal orientation measurement. The characterization of dislocations is facilitated by the simulation of diffraction patterns on the computer as a function of specimen tilt.Crystal orientation maps are obtained by assigning to the raster points in the image a color specific for the grain orientation, the misorientation or character of the grain boundary. The dala set of grain orientations is used to calculate the Schmid factors grain by grain, the orientation distribution function (ODF) and the correlated as well as the uncorrelated misorientation distribution functions (MODF) which characterize crystallographic texture in a statistical sense.Applications of individual grain orientation measurement are:. Thermomechanical hillocks in aluminum metallization layers on silicon substrates. Stress-induced grain growth in aluminum metallization layers on silicon substrates. Electromigration voids and hillocks in aluminum interconnectsA working hypothesis for electromigration failure, based on experimental findings, is discussed

The Influence of Sampling Method, Sample Size, and Frequency of Observations on Plant Phenological Patterns and Interpretation in Tropical Forest Trees

2009 ◽  
pp. 99-121 ◽  
Author(s):  
L. Patricia C. Morellato ◽  
Maria Gabriela G. Camargo ◽  
Fernanda F. D’Eça Neves ◽  
Bruno G. Luize ◽  
Adelar Mantovani ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Sample Size ◽  
Sampling Method ◽  
Forest Trees

Wood Anatomy and Fibre Quality of the Least Known Timbers Belong to Actinidiaceae from Indonesia

2020 ◽  
Vol 10 (2) ◽  
pp. 33-38
Author(s):  
Ratih Damayanti ◽  
Listya Mustika Dewi
Keyword(s):  
Wood Anatomy ◽  
Pulp And Paper ◽  
Timber Species ◽  
Fibre Quality ◽  
Anatomical Features ◽  
Light Yellow ◽  
Quality Classification ◽  
Microscopic Features ◽  
Bright Color

Wood anatomy of 417 genera and 86 families belong to the major, minor, and the lesser  known timbers of South- East Asia have been studied and described in 3 volumes of PROSEA books. This paper deals with timber species  of the least known timbers, which have  not been  treated in the above  mentioned  PROSEA books, i.e.:  Saurauia bracteosa, S. capitulata., and S. nudiflora from family Actinidiaceae.  The  objective  of this study was  to acquire  descriptions of their anatomical  features and evaluate  the quality of their fibres for pulp and paper manufacture. Samples were provided by Xylarium Bogoriense,   which were collected  from various  forest  areas   in  Indonesia.   Microscopic features  observed comprise all features those listed by IAWA Committee in 1989. Fibre quality was determined based  on their dimension and evaluated  according to quality classification developed  by FPRDC  Bogor. The results indicate  that identification of timber up to genera level is possible. Fibres of Saurauia spp.  fall into quality class  I, which  means   good  for pulp and paper. The descriptions of anatomical features were presented. Sauraria have  bright color, light yellow to light brown, fine texture, light, smooth to rather rough surface,  and make it suitable to substitute ramin (Gonystylus  spp.)

scholarly journals Evolution of Microstructures on Stainless Steel induced by Ultra-Short Laser Ablation

2019 ◽  
Author(s):  
Norbert Ackerl ◽  
Gabriela Fisch ◽  
Janko Auerswald ◽  
Konrad Wegener
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Laser Ablation ◽  
Grain Orientation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Surface Structures ◽  
Periodic Surface ◽  
Processing Window ◽  
Grain Orientations

Ultra-short pulsed laser ablation of stainless steel is accompanied by the evolution of different microstructures. Depending on the fuence, accumulated energy and number of laser passes cones from impurities, laser induced periodic surface structures and conelike protrusion (CLP) evolve at the surface. These often unwanted morphologies can be inhibited by carefully choosing the strategy and laser parameters. Here, the identifed region shows a small processing window fordesigned 515nm sub 1 ps ablation leading to low surface roughness. CLP are still not well understood and here a pre-cursor structure is reported. Subsequently, the CLP growth is grain orientation and polarization dependent and studied in more depth. Preferentially, CLP start to evolve at the (101) grain orientations with linear polarized laser radiation. Moreover, a nanoindentation study reveals robust mechanical properties, which could be beneficial for tribology applications in the hydrodynamic regime.

Effects of Grain Boundaries in Columnar Grained Electrical Steels during Deformation and Recrystallization

2013 ◽  
Vol 753 ◽  
pp. 173-176
Author(s):  
Ping Yang ◽  
Yuan Yuan Shao ◽  
Ning Zhang ◽  
Ling Cheng ◽  
Wei Min Mao
Keyword(s):  
Grain Boundaries ◽  
Grain Orientation ◽  
Rolling Direction ◽  
Single Type ◽  
Electrical Steels ◽  
Grain Orientations ◽  
Columnar Grains ◽  
Cold Rolled ◽  
Ebsd Technique ◽  
Hot Rolled

The crystallographic and topographic anisotropies of columnar grains can exert strong influence on the subsequently hot rolled, cold rolled and annealed microstructures, textures and properties. The single type tilting grain boundaries among columnar grains will behave differently depending on grain orientations, rolling direction and stress state due to hot rolling and thus affect in return the microstructure and texture to some extents. This work aims to reveal the effects of grain boundaries and their neighboring grain orientation gradients in three types of Fe-3Si in differently processed samples using EBSD technique.

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