scholarly journals PROPRIEDADES FÍSICAS E MECÂNICAS DA MADEIRA DE Toona ciliata EM DIFERENTES IDADES

FLORESTA ◽  
2013 ◽  
Vol 43 (4) ◽  
pp. 663 ◽  
Author(s):  
Rafael Leite Braz ◽  
José Tarcísio da Silva Oliveira ◽  
Marina Donária Chaves Arantes ◽  
Brunela Pollastrelli Rodrigues
Keyword(s):  
Specific Gravity ◽  
Dimensional Stability ◽  
Modulus Of Rupture ◽  
High Dimensional ◽  
Forest Plantations ◽  
Mechanical Parameters ◽  
High Mechanical Strength ◽  
Anisotropic Factor ◽  
Toona Ciliata ◽  
Wood Resistance

O presente trabalho teve como objetivo caracterizar a madeira de árvores de Toona ciliata (cedro australiano) aos 6, 12 e 18 anos de idade, provenientes de um plantio florestal na região de Venda Nova do Imigrante, ES. Foram avaliadas as propriedades físicas quanto à densidade básica e à retratibilidade e as propriedades mecânicas quanto à resistência à compressão axial e ao módulo de ruptura e módulo de elasticidade à flexão estática da madeira. Foram utilizadas três árvores para cada idade, das quais foram retiradas toras, que foram desdobradas em pranchas radiais para retirada de corpos de prova, ensaiados de acordo com as normas MB 26/40 (ABNT, 1940) e NBR 7190 (1997). Observou-se o aumento da densidade básica e a redução das contrações tangencial e volumétrica e do fator anisotrópico em função do aumento da idade. O uso da madeira deve ser limitado em situações que exijam elevada resistência mecânica e na fabricação de produtos com elevada estabilidade dimensional. Deve-se optar por árvores com idades superiores, viabilizando a aplicabilidade da madeira com qualidade para diversos fins.Palavras-chave: Cedro australiano; resistência da madeira; estabilidade dimensional. AbstractPhysical and mechanical properties of wood of Toona ciliata at different ages. The objective of the present study was to characterize the wood of trees Toona ciliata at 6, 12 and 18 years old, coming from forest plantations in the region of Venda Nova do Imigrante at Espírito Santo State in Brazil. We evaluated the physical properties as the specific gravity and shrinkage, and the mechanical parameters in relation to the compressive strength and modulus of rupture and elasticity in static bending. We use tree logs that were sawed and prepared the samples for analysis according to standards MB 26/40 (ABNT, 1940) e NBR 7190 (1997). We observed an increase in specific gravity and decrease of tangential and volumetric shrinkages and the anisotropic factor with the increase for the age. The use of this wood should be limited in situations which high mechanical strength is required and manufacture of products with high dimensional stability. We should opt for more aged trees, allowing the applicability of quality wood for various purposes.Keywords: Australian cedar; wood resistance; dimensional stability.

Selected Properties of Parallel Strand Lumber Made from Southern Pine and Yellow-Poplar

Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Y. Liu ◽  
A.W.C. Lee
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Specific Gravity ◽  
Moisture Content ◽  
Dimensional Stability ◽  
Modulus Of Rupture ◽  
Southern Pine ◽  
Yellow Poplar ◽  
Average Modulus ◽  
Parallel Strand Lumber

Summary This study was conducted to explore basic physical and mechanical properties of parallel strand lumber (PSL) made exclusively from southern pine and yellow-poplar, respectively, and to examine their relationships using statistical analysis. Small specimens were prepared from commercial southern pine PSL and yellow-poplar PSL billets and tested for specific gravity, moisture content, dimensional stability, bending properties, shear strength and compressive strength. Results indicate average specific gravity of southern pine PSL is higher than that of yellow-poplar PSL, while their average moisture content and dimensional stability are very similar. Southern pine PSL has higher average modulus of elasticity but lower average modulus of rupture than yellow-poplar PSL. While average longitudinal shear strength does not exhibit differences between southern pine PSL and yellow-poplar PSL, average compressive strength of southern pine PSL is higher than that of yellow-poplar PSL. There are positive correlations among modulus of elasticity, modulus of rupture and specific gravity. PSL improves some properties of solid wood from which PSL is made.

scholarly journals CARACTERIZAÇÕES ANATÔMICA E FÍSICO-MECÂNICA DA MADEIRA DE Liquidambar sp.

FLORESTA ◽  
2015 ◽  
Vol 45 (4) ◽  
pp. 723 ◽  
Author(s):  
Thaís Pereira Freitas ◽  
Lairo David Feuchard ◽  
José Tarcísio Silva Oliveira ◽  
Juarez Benigno Paes ◽  
Marina Donária Chaves Arantes
Keyword(s):  
Specific Gravity ◽  
Dimensional Stability ◽  
Mechanical Characterization ◽  
Great Influence ◽  
Low Frequency ◽  
Ground Level ◽  
Espírito Santo ◽  
Vessel Elements ◽  
Espirito Santo

Este trabalho teve como objetivo a caracterização anatômica e físico-mecânica da madeira de Liquidambar sp. Para tanto, foram utilizadas três árvores com oito anos de idade, provenientes de um arboreto localizado do município de Guaçuí, Espírito Santo. As características anatômicas analisadas foram as dimensões das fibras (comprimento, diâmetro total e do lume e espessura da parede), dos elementos de vasos (diâmetro tangencial e frequência) e dos raios (altura, largura e frequência). Para a caracterização físico-mecânica foram avaliadas a massa específica (básica, aparente a 12% de umidade e anidra), as contrações totais lineares e volumétrica, a resistência à flexão estática, à compressão paralela às fibras, ao cisalhamento e dureza Janka. Constatou-se frequência vascular numerosa com vasos de pequeno diâmetro tangencial, raios heterocelulares ocorrendo em baixa frequência, e fibras libriformes longas de paredes delgadas a espessas. A massa específica básica da madeira proveniente de discos retirados a 1,30 m do nível do solo foi de 0,48 g cm-3, sendo considerada média, a estabilidade dimensional foi considerada baixa, e houve grande influência da umidade nos valores de resistência da madeira. AbstractAnatomical and physical-mechanical characterization of Liquidambar sp. wood. This research aimed to improve anatomical, physical and mechanical characterization of Liquidambar sp.wood. Three trees were obtained, at eight years of age, from an arboretum located in Guaçuí, Espírito Santo State, Brazil. The analyzed variables were dimensions of the fibers (length, total diameter and diameter of the lumen and wall thickness), the vessel elements (tangential diameter and frequency), and ray (height, width and frequency). The specific gravity (basic, at 12% moisture content and dry), and total volumetric and linear shrinkages, resistance to bending, compression parallel to the fibers, shear and Janka hardness. For anatomical description it was found numerous vessels often with small tangential diameter, heterocellular rays occurring at low frequency, and long libriform fibers with thick to thin walls. The specific gravity of wood from disks taken at 1.30 m from ground level was 0.48 g cm-3, wich we considered average, the dimensional stability was low, and there was great influence of moisture in the resistance values in wood.Keywords: Anatomy; specific gravity; dimensional stability; mechanical strength.

Design and modeling of microneedle integrated with microactuator for drug delivery

2014 ◽  
Vol 03 (03) ◽  
pp. 1450016
Author(s):  
K. Girija Sravani ◽  
Y. Srinivas ◽  
Bikash Swain ◽  
K. Sunil Banu ◽  
K. Srinivasa Rao
Keyword(s):  
Drug Delivery ◽  
Piezoelectric Actuator ◽  
Dimensional Stability ◽  
Blood Sampling ◽  
High Dimensional ◽  
Sampling Device ◽  
Metal Electrodes ◽  
New Model ◽  
Space Requirements ◽  
Manufacturing Time

Today's world has very much demand for the development of microscale devices, due to its less cost, space requirements, high-dimensional stability and especially manufacturing time. In this paper, we have design and simulated MEMS based microactuator and microneedle integration which will be very helpful for blood sampling device like e-mosquito. The dimensions of the modeled beam are of 100 mm long, 30 mm width, 10 mm thickness. This new design model consists of piezoceramic material sandwiched between two metal electrodes and the piezoelectric actuator is made with microneedle which will help for blood sampling purposes. The results after the simulation of this new model present that it will be suitable for blood sampling analysis with aluminum as electrodes and silicon as microneedle.

scholarly journals Effect of Moderate Temperature Thermal Modification Combined with Wax Impregnation on Wood Properties

2020 ◽  
Vol 10 (22) ◽  
pp. 8231
Author(s):  
Jing-Wen Zhang ◽  
Hong-Hai Liu ◽  
Lin Yang ◽  
Tian-Qi Han ◽  
Qin Yin
Keyword(s):  
Mechanical Strength ◽  
Dimensional Stability ◽  
Color Change ◽  
Strength Loss ◽  
Wood Properties ◽  
Thermal Modification ◽  
Moderate Temperature ◽  
Modulus Of Rupture ◽  
Internal Surfaces ◽  
Higher Temperature

Thermal modification (TM) improves the hydrophobicity, dimensional stability, and durability of wood, but TM commonly results in severe color change and mechanical strength loss as wood is treated at higher temperature. In this study, Pterocarpus macrocarpus Kurz wood was thermally modified at moderate temperature (150 °C) and higher temperature (200 °C), and subsequently TM wood at 150 °C was subjected to wax impregnation (WI), the effect of a combination of TM and WI on the hygroscopicity, dimensional stability, and mechanical properties, as well as the micro-structure of wood, were investigated and compared. The results showed that the mass loss of wood was slight at 150 °C TM, while it became severe at 200 °C TM conditions. TM conditions affected the amount of the subsequent wax impregnation; the equilibrium moisture content (EMC), water absorption ratio, and adsorption and absorption swelling of the 150 °C TM + WI group were lower than that of 200 °C TM, and presented the lowest value. Moderate temperature TM could improve the hydrophobicity and dimensional stability of wood, but WI played a key role in the improvement. TM decreased the modulus of rupture (MOR) of wood, while WI improved the MOR. TM increased the modulus of elasticity (MOE) of wood, but WI had little effect on MOE; Scanning electron microscope (SEM) observation showed that the wax was successfully impregnated into the wood interior, and presented an even distribution on the internal surfaces of wood cells; Fourier-transform infrared spectroscopy (FTIR) spectra verified the changes of –OH and C=O after TM and TM + WI, which contributed to decreasing hygroscopicity and improving the dimensional stability of the wood. Impregnated wax improved wood mechanical strength, but decreased the lightness, and deepened the color of wood. The combination of thermal modification at moderate temperature with subsequent wax impregnation is a practical approach for improving wood properties.

Properties of Dan Kwian, Sukhothai and Ratchaburi Pottery Clays Fired at 700 and 900 °C

2014 ◽  
Vol 608 ◽  
pp. 47-61
Author(s):  
Nonglak Meethong ◽  
Wanwisa Pattanasiriwisawa ◽  
Weenawan Somphon ◽  
Waraporn Tanthanuch ◽  
Sutham Srilomsak
Keyword(s):  
Specific Gravity ◽  
Comparative Study ◽  
Water Absorption ◽  
Bulk Density ◽  
Firing Temperature ◽  
Reflectance Spectra ◽  
Modulus Of Rupture ◽  
Regression Equations ◽  
Statistical Software

Dan Kwian, Sukhothai and Ratchaburi pottery clays are economically important pottery clays. They are well known in the Thai ceramic society for making Dan Kwian pottery, Sawankhalok pottery and Dragon jars, respectively. There have been several studies of these pottery clays. However, few of them used statistics to analyze their results. This work is a comparative study of the compositions and properties of these three pottery clays using statistical software to analyze the results. Results show that the major components of these pottery clays are SiO2 and Al2O3. The Modulus of Rupture (MOR) of each pottery clay fired at 700°C are not significantly different. Sukhothai pottery clay fired at 900°C has a higher MOR and bulk density while its porosity, water absorption and apparent specific gravity are less than those of the Dan Kwian and Ratchaburi pottery clays fired at the same temperature. Additionally, the current study developed regression equations for estimating the properties of all pottery clays under study. Finally, it was found that the L*, a*, b* and reflectance spectra of all pottery clays increased when firing temperature was increased from 700 to 900°C.

Novel Trisulfonated Poly(phthalazinone ether phosphine oxide)s with High Dimensional Stability for Proton Exchange Membrane

2020 ◽  
Vol 34 (4) ◽  
pp. 4999-5005 ◽  
Author(s):  
Shanshan Zhang ◽  
Huiping Liu ◽  
Yunlong Tan ◽  
Chen Lu ◽  
Songli Mao ◽  
...  
Keyword(s):  
Phosphine Oxide ◽  
Dimensional Stability ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
High Dimensional ◽  
Exchange Membrane

scholarly journals Research on the Properties of High-strength Gypsum Based Tile Adhesive in Interior Decoration

2020 ◽  
Vol 165 ◽  
pp. 05015
Author(s):  
Ji Xiu Zhang ◽  
Ye Zhang ◽  
Ji Kang Liu ◽  
Yuan Chao Miao ◽  
Sai Hong Duan
Keyword(s):  
Bond Strength ◽  
Dimensional Stability ◽  
High Strength ◽  
High Dimensional ◽  
Strength Development ◽  
Interior Decoration ◽  
High Bond ◽  
High Bond Strength ◽  
Early Strength ◽  
Interface Treatment

In this paper, a new early strength tile adhesive is prepared by using α- high strength gypsum and its properties are discussed. The research methods refer to relevant Chinese standards. The results show that the tensile bond strength of the adhesive can reach 0.6 MPa in one day and 1.5 MPa in 7 days, which is close to 80% of 28-day strength. It is indicating that the adhesive has high bond strength, rapid strength development, and high dimensional stability. It effectively solves the problems that the traditional cement-based tile adhesive is prone to hollowing, falling off, and cracking. Additionally, no interface treatment is required during the using process of this gypsum-based adhesive.

Preparation and Dimensional Stability of Organo-Montmorillonite (O-MMT) Treated Unsaturated Polyester Hybrid Composites Filled with Keratin Fiber

2014 ◽  
Vol 980 ◽  
pp. 28-32
Author(s):  
Kiew Kwong Siong ◽  
Soon Kok Heng ◽  
Sinin Hamdan ◽  
Moaz Mohsin ◽  
Akshay Kakar ◽  
...  
Keyword(s):  
Water Absorption ◽  
Dimensional Stability ◽  
Hybrid Composites ◽  
Unsaturated Polyester ◽  
Fiber Content ◽  
High Dimensional ◽  
Thickness Swelling ◽  
Stability Properties ◽  
Chicken Feathers ◽  
Keratin Fiber

O-MMT treated unsaturated polyester based hybrid composites were prepared using keratin fiber obtained from chicken feathers. Fibers of similar dimension were selected to fabricate composites through hand lay-up method. The preparation and dimensional stability properties of keratin fiber as reinforcements in composites is outlined in this paper. Varying O-MMT contents in nancomposites is performed to investigate the effects on the dimensional stability (water absorption and thickness swelling) of the composites. Results indicated that increasing fiber content deteriorates dimensional stability of the composites and composites. However, improvements in dimensional stability of the keratin fibercomposites were observed with O-MMT. O-MMT treatment reduces the water absorption and thickness swelling, especially at 5wt% of O-MMT concentrationat all range of fiber content. At 5wt% concentration of O-MMt, 10wt% keratin fiber content marks the lowest water absorption and thickness swelling with rate of 0.65% and 1.93%, respectively. Adopting 10wt% of keratin fiber at 5wt% of O-MMT can be utilized for application requiring high dimensional stability.

Effect of juvenile wood on strength properties and dimensional stability of black spruce medium-density fiberboard panels

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Jun Li Shi ◽  
Shu Yin Zhang ◽  
Bernard Riedl
Keyword(s):  
Water Absorption ◽  
Dimensional Stability ◽  
Juvenile Wood ◽  
Black Spruce ◽  
Medium Density Fiberboard ◽  
Strength Properties ◽  
Analysis Of Covariance ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Mean Values

Abstract Strength properties and dimensional stability of medium-density fiberboard (MDF) panels made from black spruce (Picea mariana [Mill.] BSP.) 0–20, 21–40, and over 40 year old fiber were studied. An analysis of covariance (ANCOVA) was performed to examine the differences in modulus of rupture (MOR), modulus of elasticity (MOE), and thickness swell (TS) of the three types of panels, while panel density was treated as a covariate in order to adjust the mean values that were partly attributed to panel density. The results indicate that MOR, internal bond (IB), and water absorption of MDF panels made from 0–20 year old fiber, which contained 100% juvenile wood, were significantly superior to those of panels made from 21–40 and over 40 year old fiber; but linear expansion (LE) of MDF panels made from 0–20 year old fiber was significantly larger than that of panels from the other two age classes. The differences in MOR, IB, water absorption, and LE between panels made from 21–40 and over 40 year old fiber were not significant. The comparisons of panel MOE and TS were relatively dependent on panel density due to existence of interactions among the three age groups.

Sign in / Sign up

Export Citation Format

Share Document