physical chemical and mechanical properties of uhmwpe

... [Leithoff and Peek 2001] Since the amount of each chemical composition of bamboo varies with age, height, and layer, the chemical compositions of bamboo are correlated with its physical and mechanical ... on the physical properties of pulp [Tamolong 1967; Zamuco et al 1969] Aging of a bamboo culm influences physical, chemical, and mechanical properties, and consequently its processing and utilization ... and utilization The physical and mechanical properties of bamboo vary with the age of the bamboo and the height of the culm [Chauhan 2000] In general, SG and the properties of bamboo drop from...

Ngày tải lên: 22/02/2014, 09:20

... decided to select 10 trees presenting clear sectors of reaction wood, with the widest possible diversity and to measure the physical and mechanical properties in the tension wood sector as compared ... Aubl for example has a rather high resin content in all parts of the trunk) Figure Size of samples used for mechanical and physical properties CSCP: Crushing strength in compression parallel to ... gymnosperms and physical- mechanical models of wood behaviour, a low value for MFA should result in (i) a high value of specific modulus of elasticity, (ii) a higher value of tangential and radial shrinkage,...

Ngày tải lên: 07/08/2014, 16:21

... increasing height, following the trend of increasing density 3.4 Veneer quality – Density and mechanical properties of plywood Figure gives an overview of the efficiency of the veneer processing as well ... clone Table VI gives an overview of the density, modulus of elasticity and modulus of rupture for each clone Both mechanical properties were tested perpendicular and parallel to the grain as described ... related properties of poplar wood 627 Table VI Density (kg/m3 ), modulus of elasticity and modulus of rupture (N/mm2 ) for a 7-layer plywood for each of the selected clones Beaupré Density of the...

Ngày tải lên: 07/08/2014, 16:21

... uniform 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 ... principles of testing and classification of the natural durability of wood [10] ISO 3131, Wood – Determination of density for physical and mechanical tests [11] ISO 3133, Wood – Determination of ultimate ... projects toward the improvement of the silvicultural management of existent stands and of the knowledge of that wood, in order to find its best end use DISTRIBUTION AND ECOLOGICAL CHARACTERS The...

Ngày tải lên: 08/08/2014, 14:20

... Chemical and Biological Properties of Food Allergens Chemical and Functional Properties of Food Components Series SERIES EDITOR Zdzisław E Sikorski Chemical and Biological Properties of Food ... Tomasik Chemical and Functional Properties of Food Lipids Edited by Zdzisław E Sikorski and Anna Kolakowska Chemical and Functional Properties of Food Proteins Edited by Zdzisław E Sikorski Chemical ... Department of Food and Chemical Risk Analysis TNO Quality of Life Utrecht, Netherlands xv Agata Szymkiewicz Department of Food Enzymes and Allergens Institute of Animal Reproduction and Food Research...

Ngày tải lên: 28/05/2014, 14:08

... process of ENR, which results in the higher 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 ... matrix XRD and TEM results indicated that the organoclay were intercalated and exfoliated at phr of organoclay and partly exfoliated and re-aggregated at 10 phr of organoclay Journal of Physical ... sulphur and amine-groups of the organoclay and of chain opening reaction of epoxy group in ENR 50 that participated in the vulcanisation reaction This leads to a lowering of the scorch time and cure...

Ngày tải lên: 07/08/2014, 14:20

... Conductivity of Metals? • Drude model: Sea of electrons – all electrons are bound to ion atom cores except valence electrons – ignore cores – electron gas Schematic model of a crystal of sodium ... R=V/I; σ=E/j=neµ) Ohms/square ⇒ Note, if L=W, then R= ρ /t independent of magnitude of L and W Useful for working with films of thickness, t R R R 3.225 © H.L Tuller-2001 17 How to Make Resistance ... from electric force on electron! 3.225 © E.A Fitzgerald-1999 Equation of Motion - Impact of Collisions Assume: • probability of collision in time dt = dt/τ • time varying field F(t) v(t+dt) = (1-...

Ngày tải lên: 11/08/2014, 14:20

... 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 in the system ... 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, a method of ... 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...

Ngày tải lên: 11/08/2014, 14:20

... capable of 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 ... Micromachining - Application of microfabrication tools, e.g lithography, thin film deposition, etching (dry, wet), bonding 3.225 © H.L Tuller-2001 12 Gas Sensors and MEMS • Miniaturization • ... temperatures • Oxidation resistant • Chemically inert • Abrasion resistant Wide band gap semiconductor/insulator 3.225 © H.L Tuller-2001 17 Photo Electro -chemical Etching - PEC Features: • materials...

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 ... 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 (1995).) Semiconducting; Electrochemical; ... (Najafi and Hetke, IEEE Trans Biomed Eng 37, 474 (1990).) 3.225 28 14 Measurement of Gas Sensor Performance • Gas sensing materials: Sputtered ZnO film (150 nm (Massachusetts Institute of Technology)...

Ngày tải lên: 11/08/2014, 14:20

... , z )ψ = − i ∂t 2m ψ and ∆ ψ must be finite, continuous and single valued ψψ * real with ψψ *dV = probability of finding particle in volume dV Average or expectation value of 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 = − =ε 2m ψ i φ ... determined by the crystal structure and valence n determines the energy and velocity of the highest occupied electron state at T=0 3.225 © E Fitzgerald-1999 Representation of E,k for 2-D Material E= h...

Ngày tải lên: 11/08/2014, 14:20

... achieved where diffusive flux of the carriers is balanced by the drift flux 3.225 © E Fitzgerald-1999 12 Joining p and n p n Ec EF Ev Carriers flow under driving force of diffusion until EF is flat ... Qualitative Effect of Bias • • • Applying a potential to the ends of a diode does NOT increase current through drift The applied voltage upsets the steady-state balance between drift and diffusion, ... 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...

Ngày tải lên: 11/08/2014, 14:20

... of a 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 ... Fitzgerald-1999 Characteristics of Optical Fiber 3.225 Colors Produced by Chromium Above: alexandrite, emerald, and ruby Center: carbonate, chloride, oxide Below: potassium chromate and ammonium dichromate ... The splitting of the 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...

Ngày tải lên: 11/08/2014, 14:20

... 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 of tracking electrons ... 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: ... Real Band Structures • GaAs: Very close to what we have derived in the nearly free electron model • Conduction band minimum at k=0: Direct Band Gap 3.225 © E Fitzgerald-1999 15 Review of H atom...

Ngày tải lên: 11/08/2014, 14:20

... 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 Microscopic Source of Magnetization • ... Fe, Ni, Co -> J positive! Other elements J is negative Rule of Thumb: interatomic distance r ≡ > 2ra 2(atomic radius) J is a function of distance! 3.225 © E Fitzgerald-1999 Ferromagnetism M M (T ... reversible boundary displacement ‘normal’ paramagnet TC Hc H T Easy induction, “softer” Magentic anisotropy hardness of loop dependent on crystal direction comes from spin interacting with bonding...

Ngày tải lên: 11/08/2014, 14:20

... 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 Fields • Microscopic picture ... 3.225 © E.A 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 ... Response of e- to AC Electric Fields • Momentum represented in the complex plane imaginary p (ω>>1/τ) p p (ω

Ngày tải lên: 11/08/2014, 14:20

... So polarization slows down the velocity of the wave in the material © E Fitzgerald-1999 Compare Optical (index of refraction) and Electrical Measurements of ε Material Optical, n2 Electrical, ε ... is the dielectric or electric susceptibility All detail of material response is in εr and therefore P 3.225 © E Fitzgerald-1999 Origin of Polarization • • • We are interested in the true dipoles ... polarization NaCl 2.25 5.9 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...

Ngày tải lên: 11/08/2014, 14:20

... Bleaching Earth and Waste Cooking Oil: Tribology Properties, International Journal of the Physical Sciences 6(20): 4695-4699 Bauer W.H., Finkeltien A.P., Wiberly S.E., 1960, Flow Properties Of Lithium ... Greases As Function Of Soap Consentration And Temperature, ASLE, 3:215-242 Yeong S.K., Luckman P.F., 2004, Steady Flow And Viscoelastic Properties Of Lubricating Grease, J Colloid and Interface Scie., ... Chromatography and lipids, A Practical Guide The Oily press Ayr., UK ASTM D-566-93, 2000, Standard Test Method Of Dropping Point Of Lubricating Grease, Vol.05.01 ASTM D-217, 2000, Standard Test Method Of...

Ngày tải lên: 10/10/2014, 11:08

... review of the basic concepts and analyses of the mechanical properties of materials, as well as the elements of beam mechanics used in this project Chapter describes the fabrication xiv processes of ... Chapter and present the results and analysis, respectively, of the density changes in Cu-Zr and Zr-Cu-Al systems The measurement of Young’s moduli and coefficients of thermal expansion of amorphous ... elastic moduli of metallic glasses correlate with their thermal and mechanical properties, such as the glass transition temperature, toughness of the glass, and glass-forming ability CTE of metallic...

Ngày tải lên: 11/09/2015, 09:16

... techniques consisting of mechanical consolidation, sintering and extrusion Mechanical testing however often exhibits controversial results and the understanding on deformation behavior of fine grained/nc ... Study of microstructures and mechanical properties of Mg MMCs at different ball milling durations Investigation of the deformation behavior of Mg-5wt%Al-1wt%AlN systems Introduction 1.3 Scope of ... objectives of the present study are: Synthesis of AlN composite powder by mechanochemical milling Synthesis of Mg-5wt%Al reinforced with 1wt% of in-situ formed AlN via mechanical milling and power...

Ngày tải lên: 14/09/2015, 14:10