physical properties of materials and fluids

... fabrication and the physical properties of the multi-component ceramics based on PZT and the relaxor ferroelectric materials The objective of the thesis is: (i) Fabrication and research the effects of ... systematic research of the dielectric, piezoelectric and ferroelectric properties contribute further understanding of the physical properties of the multi-component ceramics based on PZT and the relaxor ... important and main materials of applications often have the perovskite structures, ABO3 That is the Pb(Zr,Ti)O3 (PZT) ceramics, and PZT doped softand hard such as La, Ce, Nd, Nb, Ta, and Mn, Fe,...

Ngày tải lên: 04/12/2014, 02:54

... 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 ... 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 ... bending properties, along longitudinal and radial directions of one, three, and five year old bamboo and determine the correlation between SG and bending properties, and (5) compressive strength of...

Ngày tải lên: 22/02/2014, 09:20

... properties to Program Offices (e.g., Office of Water, Office of Solid Waste and Emergency Response, Office of Prevention, Pesticides and Toxic Substances) and Regional Offices Also, SPARC has been used ... databases The strength of the electrostatic interaction between S and C depends on the magnitude and relative orientation of the local fields of S and C and the dielectric properties and distances through ... Effect 3.4.3.3 Temperature Effect 3.4.4 Results and Discussions 3.4.5 Conclusion PHYSICAL PROPERTIES 4.1 Estimation of Physical Properties 4.2 Physical Properties Computational Approach 4.3 SPARC...

Ngày tải lên: 22/03/2014, 14:20

... Pryor and Jentoft, 1961 Anderson and Prausnitz, 1986 Miller and Hawthorne, 2000 Mathis et al., 2004 Alwani and Schneider, 1969 Pryor and Jentoft, 1961 Pryor and Jentoft, 1961 Pryor and Jentoft, ... Barr-David and Dodge, 1959 Anderson and Prausnitz, 1986 Marshall and Jones, 1974b Marshall and Jones, 1974b Griswold and Wong, 1952 Marshall and Jones, 1974b Wormald and Yerlett, 2002 Griswold and Wong, ... crust, and of major importance in geology, geochemistry, mining, and in industrial practices such as metallurgy and the synthesis and growth of crystals The theoretical understanding of the phase...

Ngày tải lên: 01/04/2014, 11:22

Ngày tải lên: 02/04/2014, 16:04

... image and EDAX (Figure 4) spectrum of Ca10-xAgx(PO4)6(OH)2, with x = and 0.2, are shown The morphology of the nanoparticles of HAp and Ag: HAp was investigated by SEM SEM images provide the Page of ... results of XRD and TEM, the FTIR and FT-Raman spectra of the HAp show the absorption bands characteristic of hydroxyapatite XPS results provide the additional evidence for the successful doping of ... and composition of the samples Figure shows the survey XPS narrow scan spectra of Ag:HAp (x = 0.2) nanopowder obtained at 100°C and XPS narrow scan spectra of Ag element In the XPS spectrum of...

Ngày tải lên: 20/06/2014, 23:20

... effects of crystallinity on the physical properties of the PEAs  Prepare a PEA with an ester to amide ratio of 4:1 in order to model the trend observed in the physical properties versus ester to ... al., Journal of Biomaterials Science-Polymer Edition, 2007 18(6): p 673-685 Guo, K and C.C Chu, Journal of Polymer Science Part a-Polymer Chemistry, 2005 43(17): p 3932-3944 Advantage of Lipid-based ... based materials References: Hojabri, L., X.H Kong, and S.S Narine, Biomacromolecules, 2009 10(4): p 884-891 Williams, C.K and M.A Hillmyer, Polymer Reviews, 2008 48(1): p 1-10 Previous Examples of...

Ngày tải lên: 02/07/2014, 13:01

... 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, (iii) a low value of longitudinal ... 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 ... Wood properties from tropical species 505 Figure Localization of specimen (disk and rods) used for the experiments 2.5 Air dry longitudinal modulus of elasticity The longitudinal modulus of elasticity...

Ngày tải lên: 07/08/2014, 16:21

... 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 ... 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 ... 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 changing the electron or hole...

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 ... Electrode ∆f Resonator Electrode 3.225 © H.L Tuller-2001 23 Choice of Piezoelectric Materials • Temperature limitations of piezoelectric materials Material Max Operating Limitations o Temperature ( ... 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 •...

Ngày tải lên: 11/08/2014, 14:20

... (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) ... stability … 3.225 23 Sensor Materials Chemical Environmental Stimulus Gas Sensor Electrical Signal compatible with Microprocessor System Requirements of Gas Sensor Materials • • • • • • • • 3.225 ... film (150 nm (Massachusetts Institute of Technology) Sputtered SnO2 film (60 nm) (Fraunhofer Institute of Physical Measurement Techniques) • Target gases: Electrical Measurement H2, CO, NH3, NO2...

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, ... Means to Create Internal Potentials: Heterojunctions • Different semiconductor materials have different band gaps and electron affinity/work functions Internal fields from doping p-n must be superimposed...

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 ... 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...

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 • ... induction, “softer” Magentic anisotropy hardness of loop dependent on crystal direction comes from spin interacting with bonding 3.225 © E Fitzgerald-1999 Domains in Ferromagnetic Materials B ... 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...

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

... 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 creating polarization in materials (not ... 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 ... E-M waves travel in insulating materials: What is the response of the material (εr) to these waves? 3.225 © E Fitzgerald-1999 Wave Eqn with Insulating Material and Polarization r r ∂B ∇xE = −...

Ngày tải lên: 11/08/2014, 14:20

... Portland Cement 2.2 Physical properties of MTA 2.3 Biological Properties of MTA 13 2.4 Comparison of White and Gray MTA 20 2.5 Comparison between MTA and ... STUDY OF THE BIOLOGICAL AND PHYSICAL PROPERTIES OF VISCOSITY ENHANCED ROOT REPAIR MATERIAL (VERRM) AND MTA PALLAVI UPPANGALA (BDS RGUHS, India) A THESIS SUBMITTED FOR THE DEGREE OF MASTER OF SCIENCE ... antimicrobial and antifungal properties similar to that of super-EBA and ZOE (Torabinejad et al 1995d, Al-Nazhan & Al-Judai 2003) The cytotoxic properties of MTA were lower than that of IRM and super-EBA...

Ngày tải lên: 15/09/2015, 22:51