Mechanical behavior of materials 2879

... measure of a material’s mechanical properties, and all students of Mechanics of Materials will encounter them often However, they are not without some subtlety, especially in the case of ductile materials ... along with the value of 10,000 lb for Pf , and the problem is solved A number of materials properties are listed in the Materials Properties2 module, where we fi...

Ngày tải lên: 24/03/2014, 05:20

... The influence of a weight-bearing platform on the mechanical behavior of two Ilizarov ring fixators: tensioned wires vs halfpins Jan Gessmanna*, Mustafa Citaka, Birger Jettkantb, Thomas A Schildhauera, ... unknown The aim of this study was to analyze the mechanical effects of a weight-bearing platform on the traditional all-wire, four -r...

Ngày tải lên: 20/06/2014, 07:20

... Fitzgerald -1 9 99 14 Extracting Typical τ for Metals • τ ~1 0 -1 4 sec for metals in Drude model 3.225 © E.A Fitzgerald -1 9 99 15 Thermal Velocity • So far we have discussed drift velocity vD and scattering ... independent of magnitude of L and W Useful for working with films of thickness, t R R R 3.225 © H.L Tuller-20 01 17 How to Make Resistance Measurements Rc2 I Rc1 Rs V...

Ngày tải lên: 11/08/2014, 14:20

... For Si, Eg=1.1eV, and let µe and µh be approximately equal at 1000cm2/V-sec (very good Si!) σ~1010cm-3*1.602x1 0-1 9*1000cm2/V-sec=1.6x1 0-6 S/m, or a resistivity ρ of about 106 ohm-m max • • One important ... atoms per cm-3 – n~10 15, p~1020/10 15~ 1 05 σ/σi~(p+n)/2ni~n/2ni~1 05! Impurities at the ppm level drastically change the conductivity ( 5- 6 orders of magnitude) 3.2 25...

Ngày tải lên: 11/08/2014, 14:20

... conductivity: σ = 4.4 10 -1 8 S cm-1 T [°C] 900 -4 800 700 600 500 10 Y-cut -5 -1 σ [S cm ] 10 -1 σ0 = 2.1 S cm EA = 105 kJ mol -6 10 -1 -7 10 3.225 10 11 10 /T [1/K] 12 13 © H.L Tuller-2001 26 13  ... Substrate: Si wafer 20 40 60 80 110 100 90 80 70 60 50 40 30 20 10 -1 0 110 100 90 80 70 60 50 40 30 20 10 -1 0 20 MFC2 Feuchte Temp CO 40 NO2...

Ngày tải lên: 11/08/2014, 14:20

... Tuller-2001 Influence of Dopants on Electrical Conductivity of SrTiO3 log(σ / (Ωcm )-1 ) λ 0 .99 5 1,005 T = 800 °C no -1 ac -2 ce pto -3 rd op rd op ed ed -4 Sr2+ Ti4+ O 2-3 -5 acceptor donor -2 0 -1 6 ... Versatility High Strain (Pb0 .98 La0.02(Zr0.7Hf0.3)1-xTixO3 AFE­ FE System (C Heremans and H.L Tuller, J Euro Ceram Soc., 19, 11 39 ( 199 9).) Atmosphere de...

Ngày tải lên: 11/08/2014, 14:20

... are discrete 3. 225 © E Fitzgerald-1999 24 12 Representation of E,k for 1-D Material E= states electrons h 2k p = 2m 2m E EF All e- in box accounted for m=+1/2 ,-1 /2 En+1 En En-1 Quasi-continuous ... k y ) E(kx,ky) 2m ky kx 3. 225 © E Fitzgerald-1999 Representation of E,k for 3- D Material kz Ε(kx,ky,kz) ky kF E= m π2 2mE h3 Fermi Surface or Fermi Sphere k F = (3 n )3 vF = 2m kx 2π...

Ngày tải lên: 11/08/2014, 14:20

... when you join these together? 3.225 © E Fitzgerald-1999 11 Drift and Diffusion - - - - - + + + + + + + + Holes diffuse Electrons diffuse - - - - - - + + + + E + + + + An electric field forms due ... force of diffusion until EF is flat - - + + + + Holes diffuse Electrons diffuse 3.225 © E Fitzgerald-1999 13 Space Charge, Electric Field and Potentia...

Ngày tải lên: 11/08/2014, 14:20

... of positive and negative ions 3.225 © E Fitzgerald-1999 © H.L Tuller, 2001 Ferroelectrics Applications • Capacitors • Non-volatile memories • Photorefractive materials 3.225 Characteristics of ... τ=9.5x1 0-1 1 sec, ω~1010 microwave oven, transmission of E-M waves 3.225 © E Fitzgerald-1999 19 Dielectric Constant vs Frequency • Completely general ε due to the localized charge in m...

Ngày tải lên: 11/08/2014, 14:20

... =0,1,2,…,n-1 ml =- l, - l+1,…,0,…, l , -1 (ms=+ or - 1/2) U(r) -1 3.6eV 3.225 © E Fitzgerald-1999 16 Relationship between Quantum Numbers s s p s p d Origin of the periodic table © E Fitzgerald-1999 ... © E Fitzgerald-1999 © H.L Tuller-2001 Energy Gap and Mobility Trends Material Eg(eV)°K µn(cm2/V·s) GaN 3.39 150 AlAs 2.3 180 GaP 2 .4 2,100 GaAs 1.53 16,000 InP 1 .41 44...

Ngày tải lên: 11/08/2014, 14:20

... magnetic material Material Type χ Paramagnetic +1 0-5 -1 0-4 Diamagnetic -1 0-8 -1 0-5 Ferromagnetic +105 3.225 © E Fitzgerald-1999 Microscopic Source of Magnetization • No monopoles • magnetic dipole ... E~-S1S2 > Energy if 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...

Ngày tải lên: 11/08/2014, 14:20

... 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 3 .22 5 © E.A Fitzgerald-1999 ... metals • Valence =2 and 3, magnitude and sign suggest problems 3 .22 5 © E.A Fitzgerald-1999 25 13 Response of Free e- to AC Electric Fields • Microscopic picture EZ =...

Ngày tải lên: 11/08/2014, 14:20

... 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 Microscopic ... 3.225 © E Fitzgerald-1999 15 Ionic Polarizability Eloc •2 coupled differential eqn’s •1 for + ions •1 for - ions - + - + M= p u- u+ Ionic materials always have ioni...

Ngày tải lên: 11/08/2014, 14:20