scholarly journals Acoustic Properties of Resonant Spruce Wood Modified Using Oil-Heat Treatment (OHT)

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1962
Author(s):  
Przemysław Mania ◽  
Mateusz Gąsiorek
Keyword(s):  
Heat Treatment ◽  
Modulus Of Elasticity ◽  
Acoustic Properties ◽  
Bending Test ◽  
Acoustic Parameters ◽  
Static Modulus ◽  
Spruce Wood ◽  
Before And After ◽  
Different Temperatures ◽  
The Mean

Wedge-shaped boards of spruce wood (Picea abies Karst.) are used to make violin fronts, also known as soundboards. Oil-heat treatment (OHT) can influence the acoustic properties of resonant wood, such as spruce. In this study, the effect of OHT on spruce wood was evaluated, using palm oil as a heating medium, at four different temperatures: 140, 160, 180 and 200 °C. Physical, mechanical and acoustic properties of spruce wood were evaluated before and after OHT and included the following: density, modulus of elasticity in the static bending test, and wood sound velocity. The acoustic parameters after OHT improved; however, the samples bent after modification had a higher modulus of elasticity, with a simultaneous deterioration of the acoustic parameters. The dynamic modulus of elasticity increased by 11%, and the musical constant by 5%. The static modulus increased by more than 3.5%, but the acoustic parameters calculated on the basis of these results indicated a deterioration of the acoustic properties of completely oven-dried wood. The increase in moisture content to air-dried condition contributed to a slight increase in the mean musical constant at the highest modification temperature.

Microstructural and Fractographic Analysis of CuAlNi Shape Memory Alloy before and after Heat Treatment

2020 ◽  
Vol 405 ◽  
pp. 100-106
Author(s):  
Ivana Ivanić ◽  
Mirko Gojić ◽  
Stjepan Kožuh ◽  
Borut Kosec
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Fracture Surface ◽  
Shape Memory ◽  
Fractographic Analysis ◽  
Before And After ◽  
Different Temperatures ◽  
The Difference ◽  
Type Of Fracture ◽  
Scanning Electron

The paper presents comparison of microstructure and fracture surface morphology of the CuAlNi shape memory alloy (SMA) after different heat treatment procedures. The investigation was performed on samples in as-cast state and heat treated states (solution annealing at temperatures of 850 °C / 60’ / H2O and 920 °C / 60’ / H2O along with tempering at two different temperature 150 °C / 60’ / H2O and 300 °C / 60’ / H2O). The microstructure of the samples was examined by optical (OM) and scanning electron microscope (SEM) equipped with device for EDS analysis. The obtained fracture surfaces were examined by SEM. Optical and scanning electron microscopy showed martensitic microstructure in all investigated samples. However, the fractographic analysis of samples after tensile testing reveals significant changes in fracture mechanism. In both solution annealed states the results shows transgranular type of fracture, but after tempering at two different temperatures the difference is obvious. After tempering at 150 °C, along with transgranular type of fracture appear some areas with intergranular type of fracture. After tempering at 300 °C, fracture surface reveals completely intergranular type of fracture.

Influence of roasting temperature on physicochemical properties of different coffees

1998 ◽  
Vol 4 (1) ◽  
pp. 59-66 ◽  
Author(s):  
M.D. Ortolá ◽  
L. Londoño ◽  
C.L. Gutiérrez ◽  
A. Chiralt
Keyword(s):  
Quality Parameters ◽  
Soluble Solids ◽  
Volume Increase ◽  
Weight Losses ◽  
Before And After ◽  
Different Temperatures ◽  
Roasting Temperature ◽  
The Mean ◽  
Colour Development ◽  
Different Origins

Arabica and robusta coffees from different origins were characterized before and after roasting at different temperatures (between 220 and 295°C). Samples were roasted (dark roast) until they attained the same colour. Colour development of the ground samples was measured throughout using CIE L*a*b* co-ordinates. The roasting temperature did not affect final weight loss and moisture content of the different coffees significantly, but slight differences were detected in the mean weight losses for the different coffees. Roasting temperature affected bulk and bean densities, grain volume increase, and soluble solids and acidity of coffee extracts. Robusta coffees were less sensitive to the bean volume increase, but showed a stronger temperature effect on the content of soluble solids and in the acidity of the aqueous extract, which can benefit its quality parameters.

scholarly journals Dynamic and static comparison of beech wood dovetail, tongue and groove, halving, and dowel joints

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3787-3798
Author(s):  
Amir Mollahassani ◽  
AmirHooman Hemmasi ◽  
Habibollah Khademi Eslam ◽  
Amir Lashgari ◽  
Behzad Bazyar
Keyword(s):  
Modulus Of Elasticity ◽  
Pearson Correlation ◽  
Dynamic Assessment ◽  
Beech Wood ◽  
Static Tests ◽  
Static Modulus ◽  
Fagus Orientalis Lipsky ◽  
Significant Difference ◽  
The Mean ◽  
Static Modulus Of Elasticity

Dynamic and static elastic properties beech wood joints were assessed. Conventional joints, namely dovetail, tongue and groove, dowel, and halving joints were prepared with beech wood (Fagus orientalis Lipsky) using polyvinyl acetate and cyanoacrylate adhesives. The results of the dynamic and static modulus of elasticity of the joints in this research indicated the highest reduction trends in halving, dowel, tongue and groove, and dovetail joints, respectively. The modulus of dovetail joint elasticity, its homogeneous joint texture, and lack of an extended adhesive line, corresponded to that of the jointed samples. The average static modulus of elasticity was approximately 10.5% lower than that of the dynamic modulus of elasticity. The results of the Student’s t-test indicated a significant difference between the mean of dynamic and the mean of static modulus of elasticity, significance at 5% level and the Pearson correlation test indicated that the dynamic and static modulus of elasticity of the samples were significant at the 5% level and indicated a positive correlation. Based on the observed correlation in the dynamic and static tests’ results, using these methods, dynamic assessment of NDTs may be regarded as an appropriate alternative in standardizing destructive static testing for wood assessment and categorization.

Analysis of the Effect of Cyclic Fatigue on the Flexural Strength of a Ceramoceramic System Used in Dental Prostheses

2018 ◽  
Vol 930 ◽  
pp. 43-47
Author(s):  
Cristiane Fonseca de Carvalho ◽  
Cláudio Luis de Melo-Silva ◽  
Tereza Cristina Favieri de Melo-Silva ◽  
Fábio Amaral de Araújo ◽  
Jefferson Fabricio Cardoso Lins
Keyword(s):  
Flexural Strength ◽  
Ceramic Coating ◽  
Cyclic Fatigue ◽  
Bending Test ◽  
Mean Values ◽  
Three Point Bending ◽  
Cyclic Stresses ◽  
Dental Prostheses ◽  
Before And After ◽  
The Mean

The aim of this study was to analyze the flexural strength of ceramics based on yttria-stabilized zirconia (YTZP) , used in the manufacture of dental prostheses infrastructure before and after aging with cyclic fatigue in moisture. The samples were made by pre-sintered blocks of ZirkonTransluzent (Zirkonzahn GMHB) from YTZP ceramics with and without feldspathic ceramic coating, divided into groups: G1 = YTZP control; G2 = YTZP aged; G3 = YTZP + feldspathic; G4 = YTZP + aged feldspathic. The samples were submitted to a three-point bending test with a speed of 0.5 mm / min. The mean values of the flexural strength values were G1 = 645 MPa (DP ± 124), G2 = 681 MPa (DP ± 129), G3 = 904Mpa (DP ± 157) and G4 = 954Mpa (DP ± 243). The values of groups G1 and G2; G3 and G4 were statistically similar, depending on the presence or absence of coating. Cyclic stresses did not affect the flexural strength of the material

scholarly journals Influence of Heat Treatment on the Mechanical Properties of Ni Films on 430 Stainless Steel Substrate

2017 ◽  
Vol 36 (8) ◽  
pp. 855-861
Author(s):  
Yong Pan ◽  
Junwei Cui ◽  
Weixin Lei ◽  
Jie Zhou ◽  
Zengsheng Ma
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
X Ray Diffraction ◽  
Before And After ◽  
430 Stainless Steel ◽  
Different Temperatures ◽  
Texture Orientation

AbstractEffects of heat treatment on the mechanical properties of Ni films on 430 stainless steel substrate were investigated. The Ni films were annealed at heat treatment temperatures ranging from 0 °C to 800 °C for 2 h. The surface morphology, composition, and texture orientation of Ni films were studied by scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction. The load–indentation depth curves of Ni films before and after heat treatment were measured by using nanoindentation method. In conjunction with finite element modeling and dimensional analysis, the stress–strain relationships of Ni films on 430 stainless steel substrate at different temperatures are successfully obtained by using a power-law hardening model.

Enhancement of the Gray Cast Iron Properties by Adding Chromium Element

2017 ◽  
Vol 753 ◽  
pp. 218-221
Author(s):  
Awad Eisa Gaib Alla Mohamed ◽  
Khairi Abdulsalam
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
Chromium Content ◽  
Gray Cast ◽  
Three Samples ◽  
Before And After ◽  
Different Temperatures

In this paper the effect of chromium element on some mechanical properties of gray cast iron is studied .The work was divided in to four categories, each category has three samples; each sample has three different chromium content 0.0%, 1.7%, 3.7%. The mechanical properties were investigated (hardness and impact) before and after the heat treatment. The heat treatment was carried out for period of 12 minutes at two different temperatures. The results confirmed that durability, toughness, and hardness are proportional to the chromium content. The ultimate aim of this research is to enhance the mechanical properties of gray cast iron by adding chromium element.

scholarly journals Prediction of Mechanical Properties of Hardwood Species Using the Longitudinal Vibration Acoustic Method

2021 ◽  
Vol 71 (4) ◽  
pp. 391-400
Author(s):  
Kayode Olaoye ◽  
Lawrence Aguda ◽  
Bolade Ogunleye
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Longitudinal Vibration ◽  
Modulus Of Rupture ◽  
Damping Factor ◽  
Acoustic Parameters ◽  
Static Modulus ◽  
Hardwood Species ◽  
Static Modulus Of Elasticity

Abstract Acoustic test methods such as longitudinal vibration have been developed to predict the elastic properties of wood. However, attention has not been shifted to using this method to predict other mechanical properties, especially on Nigeria's preferred, and lesser-used wood species. Thus, we further investigate relationships among mechanical and acoustic properties of selected hardwood species with a view of predicting the mechanical properties of wood from acoustic parameters. Clear wood samples (324) of 20 by 20 by 20 mm3 were collected axially from Albizia adianthifolia, Gmelina arborea, Delonix regia, and Boscia anguistifolia trees, and conditioned before testing. The longitudinal vibration method was adopted to test for the dynamic (acoustic) parameters and properties (fundamental frequency, damping factor, dynamic modulus of elasticity, sound velocity, specific elastic modulus, radiation coefficient, acoustic conversion efficiency, acoustic impedance) while the universal testing machine was used to test for the mechanical properties (static modulus of elasticity, modulus of rupture, maximum compression strength parallel to grain). The damping factor, dynamic modulus of elasticity, and acoustic impedance were the best acoustic parameters that significantly correlated with the static modulus of elasticity (−0.57, 0.81, 0.76), modulus of rupture −0.64, 0.82, 0.85) and maximum compression strength parallel to grain (−0.52, 0.78, 0.84), respectively. There was a significant difference in the mechanical properties with respect to species, thus A. adianthifolia and G. arborea were mechanically better than D. regia and B. anguistifolia for construction or structural purposes. This study revealed that additional new acoustic measures are suitable for inferring mechanical wood properties.

Relativity Analysis between Dynamic and Static Modulus of Elasticity on Different Thickness Wood-Plastic Structural Plates

2011 ◽  
Vol 121-126 ◽  
pp. 4254-4258 ◽  
Author(s):  
Gui Wen Yu ◽  
Ying Cheng Hu ◽  
Ji You Gu
Keyword(s):  
Mechanical Properties ◽  
Nondestructive Testing ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Bending Test ◽  
Three Point Bending ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Static Modulus Of Elasticity ◽  
Different Thickness

The relativity was evaluated between dynamic modulus of elasticity (MOE) and static MOE, in order to assess the potential of using nondestructive testing (NDT) method as a checking tool for mechanical properties of wood-plastic structural plates. The dynamic MOE was evaluated on a FFT system, and the static MOE was determined by three point bending test. All of specimens were made of polyethylene（PE）and poplar flour. A significant correlation between the dynamic MOE and the static MOE was obtained from relativity analysis. These results suggest that the NDT method could be appropriate to estimate the dynamic MOE of specimens with different thickness.

Amorphous Calcium Phosphates (ACP): Formation and Stability

2005 ◽  
Vol 284-286 ◽  
pp. 7-10 ◽  
Author(s):  
Racquel Z. LeGeros ◽  
Dindo Q. Mijares ◽  
J. Park ◽  
X.-F. Chang ◽  
I. Khairoun ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Synergistic Effects ◽  
Calcium Phosphates ◽  
X Ray Diffraction ◽  
Solution Composition ◽  
X Ray ◽  
Dissolution Properties ◽  
Before And After ◽  
Different Temperatures

Our earlier studies showed that several ions inhibit the crystal growth of apatite and promote the formation of amorphous calcium phosphates (ACP). These ions include: magnesium (Mg), zinc (Zn), stannous (Sn), ferrous (Fe), carbonate (CO3), pyrophosphate (P2O7). The purpose of this study was to investigate the effect of combination of these ions (e.g., Mg & CO3, Mg & P2O7, Mg & Zn, etc) on the formation and stability of ACP. ACP compounds containing the different ions were prepared at 25 and 37oC according to the method we previously described. Chemical stability was investigated by suspending the different ACP preparations in solutions with or without inhibitory ions. Thermal stability was determined by sintering the ACP at different temperatures. Dissolution properties were determined in acidic buffer. The ACP before and after chemical or thermal treatment were analyzed using X-ray diffraction, infrared spectroscopy, and thermogravimetry. Results showed synergistic effects of inhibitory ions on the formation of ACP. ACP materials, regardless of their composition, remained amorphous even after heat treatment at 400oC. Transformation of ACP to other calcium phosphate phases depended on the pH and on the solution composition.

Comparative Study on Four Different Methods for Measuring the Dynamic Modulus of Elasticity of Acer Mono Wood

2010 ◽  
Vol 160-162 ◽  
pp. 384-388
Author(s):  
Hua Dong Xu ◽  
Li Hai Wang
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Bending Test ◽  
Linear Regression Method ◽  
Clear Wood ◽  
Vibration Method ◽  
Dynamic Modulus Of Elasticity ◽  
The Mean ◽  
The Difference ◽  
Acer Mono

The dynamic modulus of elasticity (MOE) of forty one small Acer mono clear wood specimens was tested via stress wave, ultrasonic wave, edgewise vibration and flatwise vibration method respectively in laboratory. Then the static MOE of these specimens was measured with static bending test. The correlations between dynamic and static MOE were analyzed using linear regression method, and the difference of various methods was discussed using paired t test. The results show that the dynamic MOE of wood measured by four methods described above are higher than the static MOE, but their linear correlation is significantly strong. Thus, it is feasible to estimate static MOE using these four methods. Additionally, the mean of paired difference between static MOE and dynamic MOE tested by flatwise vibration method is least, and the correlation highest. Therefore, it is better to use flatwise vibration method to estimate static MOE of wood.

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