composition microstructure and mechanical properties

... chemical, and mechanical properties of the bamboo species Phyllostachys pubescens The effects of plant age, horizontal layer, and vertical height location on physical, chemical, and mechanical properties ... fiberboard and evaluate water soaking, modulus of elasticity (MOE), modulus of rupture (MOR), and internal bond (IB) properties of the panels and compare the age effect on the physical and mechanical properties ... alpha cellulose, and Klason lignin contents and the lowest extractive and ash contents The epidermis had the highest extractive and ash contents and the lowest holocellulose and alpha-cellulose...

Ngày tải lên: 22/02/2014, 09:20

... crystallisation NR also had shown excellent improvements in mechanical properties, thermal properties, barrier properties and flame-retardant properties when compounded with organoclays.7–11 In this ... min–1 RESULTS AND DISCUSSION 3.1 Cure Characteristics Figures and and Table show the results for the scorch time, t2, and cure time, t90, for both organoclay-filled NR nanocomposites and organoclayfilled ... values of the minimum and maximum torques 3.2 Mechanical Properties Figure and Table show the effect of organoclay loading on the tensile strength of organoclay-filled NR and ENR nanocomposites...

Ngày tải lên: 07/08/2014, 14:20

... diversity and to measure the physical and mechanical properties in the tension wood sector as compared to the opposite wood sector, on specimen corresponding to the standard methods MATERIAL AND METHODS ... bending and in compression (MPa), Tangential, radial and longitudinal shrinkage (%), tangential/radial shrinkage ratio (TS/RS) and transversal + radial shrinkage for opposite wood (OW) and tension ... angles and chemical composition: Implication for functional properties, J Mater Sci lett 22 (2003) 963–966 [27] Jourez B., Riboux A., Leclercq A., Anatomical characteristics of tension wood and...

Ngày tải lên: 07/08/2014, 16:21

... between wood density or mechanical properties and growth rate in P deltoides × nigra The objective of this study is to evaluate the variability in selected physical and mechanical properties of new ... characteristics for selected trees and total stand; mean radial increment and radial increment of last 10 years (cm), circumference at BH (cm) and total tree height (m) with standard deviations Clone Beaupré ... proportion and the slower decrease of heartwood proportion with height in ’Hoogvorst’, the increase in density is less pronounced The relation between density and mechanical properties (MOE and MOR)...

Ngày tải lên: 07/08/2014, 16:21

... vary according to the soil and climate conditions and to other factors such as composition, structure, age and cutting system Increments vary indeed between 1–1.5 and 6–7 m3 ha–1 per year in ... The results of physical and mechanical characterisation of Atlas cedar wood from Southern Italy are summarised on table IV Table V refers about physical and mechanical properties found on the ... Molise, Calabria, Sardinia and Sicily Table I Performed tests, dimensions of utilised samples and standard followed for the tests Test type Sample dimension (cm) Standard reference long × transerve...

Ngày tải lên: 08/08/2014, 14:20

... How Do We Arrive at Properties That We Want? • Crystal Structure: • diamond vs graphite • Composition • silicon vs germanium • Doping • n-Si:P vs p-Si:B • Microstructure • single vs polycrystalline ... drag term, i.e the electrons have many collisions during drift 1/τ represents a ‘viscosity’ in mechanical terms 3.225 © E.A Fitzgerald-1999 10 Mean-free Time Between Collisions, Electron Mobility ... electrons crossing plane in time dt = n(dxA) = n(vddtA) • # charges crossing plane per unit time and area = j ( ) j = n v d dtA (− e ) dtA = − nevd = (ne 2τ m )E • Ohm’s Law: j = σ E ⇒ σ = (ne...

Ngày tải lên: 11/08/2014, 14:20

... E F =  m*   * + kbT ln h   me  Eg Since me* and mh* are close and in the ln term, the Fermi level sits about in the center of the band gap ( ) − Eg  k T 2 * * p or n = ni = 2 b  me ... are generated, the Fermi level is approximately in the middle of the band gap • The law of mass action describes the electron and hole populations, since the total number of electron states is fixed ... similar to a chemical reaction, where Eg is the barrier NCNV is the density of the reactants, and n and p are the products N C NV  → e′ + h • Eg − Eg n np =ekT = i N C NV N C NV b • • • Thus,...

Ngày tải lên: 11/08/2014, 14:20

... Temp:360C, H2, CO, NH3 (10, 50 and 100 ppm), NO2 (0.2, 0.4, and ppm) [ Pfad: \ alpha missy Messungen messplatz_1 ] 3.225 M Jägle / 27.02.2001 © H.L Tuller-2001 11 MicroElectroMechanical Systems - MEMS ... sensing a change in environment and responding without need for a microprocessor A device has both gas sensing and actuating function by integration of semiconducting oxide and piezoelectric thin films ... 21 Smart Gas Sensor Semiconducting oxide thin films for high gas sensitivity : Microstructure (Nano-Structure) and Composition Piezoelectric thin films for providing actuating function Thin film...

Ngày tải lên: 11/08/2014, 14:20

... Traditionally admired for their stability • Mechanical • Chemical • Thermal • Exhibit other key functional properties • Electrical, Electrochemical, Electromechanical • Optical • Magnetic 3.225 20 ... (Pb0.98La0.02(Zr0.7Hf0.3)1-xTixO3 AFE­ FE System (C Heremans and H.L Tuller, J Euro Ceram Soc., 19, 1139 (1999).) Atmosphere dependent conductivity (I Kosacki and H.L Tuller, Sensors & Actuators B 24-25, 370 ... • Conservation • ♦ Emissions • Smoke stack • Automotive Needed: advances in sensors, actuators and energy conversion devices 3.225 18 Harsh Environments Ceramic Sensors Automotive Emissions Factory...

Ngày tải lên: 11/08/2014, 14:20

... absorb energy and contribute to properties TF~104K (Troom~102K), EF~100Eclass, vF2~100vclass2 3.225 © E Fitzgerald-1999 Effect of Temperature (T>0): Coupled electronic-thermal properties in conductors ... variable α = ∫ ψ *α op ψ dV v 3.225 © H.L Tuller-2001 19 Time and Spatial Dependence of ψ Assume ψ (x,y,z,t) separable into ψ(x,y,z) and φ(t) Applying separation of variables: − h ∇ 2ψ h ∂φ +V ... Model Traveling wave picture L Standing wave picture Ψ ( x) = Ψ ( x + L) L e ikx = e ik ( x + L ) e ikx = 2πn k= L Just having a boundary condition means that k and E are quasi-continuous, i.e...

Ngày tải lên: 11/08/2014, 14:20

... Note that dopants move the fermi energy from mid-gap towards either the valence band edge (p-type) or the conduction band edge (n-type) n-type material in equilibrium p-type material in equilibrium ... Joining p and n p n Ec EF Ev Carriers flow under driving force of diffusion until EF is flat - - + + + + Holes diffuse Electrons diffuse 3.225 © E Fitzgerald-1999 13 Space Charge, Electric Field and ... increases depletion region, and no current flows ideally Forward Bias Reverse Bias np np eVbi-e|Va| nn nn eVbi-e|Va| pp Solve minority carrier diffusion equations on each side and determine J at depletion...

Ngày tải lên: 11/08/2014, 14:20

... Fiber 3.225 Colors Produced by Chromium Above: alexandrite, emerald, and ruby Center: carbonate, chloride, oxide Below: potassium chromate and ammonium dichromate 3.225 © H.L Tuller, 2001 Chromium ... five 3d orbitals in a tetrahedral and an octahedral ligand field Note: When the element is a mid-gap dopant, transitions within this element lead to absorption and/ or emission via luminescence ... chromium atom (A) and a trivalent chromium ion (B) 3.225 © H.L Tuller, 2001 10 Octahedral Environment of Transition Metal Ion Interaction of the d orbitals of a central ion with six ligands in an octahedral...

Ngày tải lên: 11/08/2014, 14:20

... promoted from the valence band to the conduction band E Ec near band gap E=hν k Creates a ‘hole’ in the valence band Ev near band gap 3.225 © E Fitzgerald-1999 Holes and Electrons • • Instead ... 1,000,000 Remember that: 3.225 µ= eτ m* and 1 ∂2E = m * h ∂k 2 Metals and Insulators • EF in mid-band area: free e-, metallic • EF near band edge – EF in or near kT of band edge: semimetal – EF in gap: ... ionic, MP and Eg increase while ao tends to decrease 3.225 © H.L Tuller-2001 Trends in III-V and II-VI Compounds Larger atoms, weaker bonds, smaller U, smaller Eg, higher µ, more costly! Band Gap...

Ngày tải lên: 11/08/2014, 14:20

... I A L e- What is µ? For θ=0, E = − µH ≈ −Φ B I since energy ~ LI and for loop L = ΦB I Φ B = ∫ ∫ H ⋅ dS ~ HA ∴ µH = Φ B I = HAI and ∴ µ = IA e ω A = πr c 2π e µ = − ωr 2c I =− 3.225 © E Fitzgerald-1999 ... magnetization MKS: B = µ0(H+M) = µ0nI + µ0M µr = B/ µ0H = + (M/H) = + χm 3.225 © E Fitzgerald-1999 Maxwell and Magnetic Materials • Ampere’s law ∫ H ⋅ dl = I = • For a permanent magnet, there is no real ... length = nl Nφ B N ( BA) 4π L= n lA = = I I c B= 3.225 © E Fitzgerald-1999 Magnetic Permeability and Susceptibility Insert magnetic material Magnetic dipoles in material can line-up in magnetic...

Ngày tải lên: 11/08/2014, 14:20

... Hall Results on Metals • Valence=1 metals look like free-electron Drude metals • Valence=2 and 3, magnitude and sign suggest problems 3.225 © E.A Fitzgerald-1999 25 13 Response of Free e- to AC Electric ... Fitzgerald-1999 Complex Representation of Waves sin(kx-ωt), cos(kx-ωt), and e-i(kx-ωt) are all waves e -i(kx-ωt) is the complex one and is the most general imaginary A θ Acosθ iAsinθ real e iθ=cosθ+isinθ ... (ω>>1/τ) p p (ω

Ngày tải lên: 11/08/2014, 14:20

... polarization (E-field may distort ion positions and temporarily create dipoles) – electronic polarization (bound electrons around ion cores could distort and lead to polarization) • • Except for the ... Optical (index of refraction) and Electrical Measurements of ε Material Optical, n2 Electrical, ε diamond 5.66 5.68 Only electronic polarization NaCl 2.25 5.9 Electronic and ionic polarisation H2O ... Electronic and ionic polarisation H2O 1.77 80.4 Electronic, ionic, and molecular polarisation Polarization that is active depends on material and frequency 3.225 © E Fitzgerald-1999 Microscopic Frequency...

Ngày tải lên: 11/08/2014, 14:20

... MIT Master’s degree and spend one and half years at MIT to conduct research In particular, I would like to thank the program chairs, Prof Choi Wee Kiong and Prof Carl Thompson, and the administrative ... materials and metallic glasses 52 1.3.3.1 Glass-forming abilities and the corresponding density changes upon crystallization - 52 1.3.3.2 Mechanical properties ... 1.3.4 Summary of Chapter and motivation of this research project 54 Chapter Background: mechanical properties of materials and beam mechanics for...

Ngày tải lên: 11/09/2015, 09:16

... microscope (FESEM) and transmission electron microscope (TEM) Physical properties such as thermal properties, electrical resistivity, coefficient of thermal expansion and mechanical properties such ... Mg-5wt%Al reinforced with 1wt% of in-situ formed AlN via mechanical milling and power metallurgy techniques Study of microstructures and mechanical properties of Mg MMCs at different ball milling durations ... stress, duration of its application and temperature, and crystal defects To minimize and control the level of defects and contaminants without sacrificing material properties is the major challenge...

Ngày tải lên: 14/09/2015, 14:10

... [147] Environmental regulations and quality demands require clean and efficient processes for recovery of materials from scraps and wastes With an increase in demand and due to magnesiums excellent ... resolved shear stress (CRSS) between basal and non-basal slip gives rise to the severe anisotropic mechanical properties [94] As a result, their mechanical properties are significantly influenced ... nanometer range) and texture (for micrometer range) dependence of mechanical properties in Mg can be found in literature However, the influence of texture on the mechanical properties of nanograined...

Ngày tải lên: 14/09/2015, 14:10

... operating at 40 kV and 30 mA was carried out for structural examination of MMed powders and MMed powders after annealing at 500°C and 1250°C (designated hereafter as xxh-MMed, xxh-MMed-500 and xxhMMed-1250 ... melting point and asymmetric structure of pyrazine, it is unstable under thermal treatment and/ or mechanical activation [23] Pyrazine therefore decomposed to some extent after 40h of milling and a certain ... in 20h and 30h-MMed-500 samples After annealing at 1250°C, AlN was found to form in both 20h and 30h-MMed powders In addition to AlN formation, oxide and carbide were detected from Al2O3 and Al4C3...

Ngày tải lên: 14/09/2015, 14:10