4—physical and mechanical properties of structural lightweight aggregate concrete p 213r 12

... method applied to poplar trees, Ann For Sci 60 (2003) 371–378 [17] Coutand C., Jeronimidis G., Chanson B., Loup C., Comparison of mechanical properties of tension and opposite wood in Populus, ... Specimens from these positions were used for calculation of mean values of opposite wood properties 3.2 Radial growth rate We were unable to measure this property on Carapa procera A DC Radial ... for the trees from Eperua falcata and Laetia procera, species with G layer patterns In the case of Virola and Cecropia trees the specific MOE is very high in the opposite wood and a little lower...

Ngày tải lên: 07/08/2014, 16:21

... commercial species of Populus, J For Prod Res Soc (1952) 62–67 [7] Coutand C., Jeronimidis G., Chanson B., Loup C., Comparison of mechanical properties of tension and opposite wood in Populus, Wood ... properties of poplar clones, Drevàrsky Výskum 43 (1998) 1–17 [9] Dix B., Roffael E., Becker G., Gruss K., Properties of pulps prepared from poplar wood of different clones, sites and ages, Papier 46 ... heartwood proportion and distribution For all clones, the board properties reported in Table VI are well within range to produce plywood for structural applications Variations in plywood properties...

Ngày tải lên: 07/08/2014, 16:21

... brown, leached, typical of the inner, hilly regions of Sicily The stand is mixed, with a percent variation of European Black Pine (Pinus nigra Arnold) and Aleppo Pine (Pinus halepensis Mill.) at ... 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 same species ... different purposes the sample were obtained from those boards, according to the scheme on table I Each sample was placed side by side with a control sample of sapwood of Scots Pine (Pinus sylvestris...

Ngày tải lên: 08/08/2014, 14:20

... industrially produced type fiberboard and often has excellent physical mechanical properties, and perfect surface properties As an ideal board for furniture production and other interior applications, ... influences physical, chemical, and mechanical properties, and consequently its processing and utilization The physical and mechanical properties of bamboo vary with the age of the bamboo and the ... (epidermis, outer, middle, and inner layer), and height location (bottom, middle, and top portion) of Phyllostachys pubescens in detail Physical and mechanical properties of several bamboo species...

Ngày tải lên: 22/02/2014, 09:20

... 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 in valence band, more ... Note that in both photon stimulated promotion as well as thermal promotion, an equal number of holes and electrons are produced, i.e n =p 3.225 © E Fitzgerald-1999 Thermal Promotion of Carriers We ... Conductivity of Semiconductors • Need to include both electrons and holes in the conductivity expression σ = neµ e + peµ h = ne 2τ e pe 2τ h + * * me mh p is analogous to n for holes, and so are τ and...

Ngày tải lên: 11/08/2014, 14:20

... [16] C p , sample  msapphire ysample  reference msample ysapphire  reference C p , sapphire (4.2) where Cp,sample and Cp,sapphire, msample and msapphire are the specific heat capacities and ... the tip of pile-up and the grain size When grain size becomes smaller the number of dislocation at the tip of pile-up is also 98 Processing, physical and tensile properties reduced and the applied ... of composite sample after 40h-MM Compared to YS of 122 MPa for 0h-MMed sample, initial milling of 10 and 20 MM produced 311 MPa and 156 MPa respectively showing significant increase of 155% and...

Ngày tải lên: 14/09/2015, 14:10

... High-Strain-Rate Properties (Chapter 4) 1.1.4 Impact Properties (Chapter 5) 1.1.5 Elevated-Temperature Properties (Chapter 6) 1.2 Description of the Major Building Components ... rates up to 400 s-1 Measured properties were consistent with literature reports on other structural steels Impact properties were evaluated with Charpy testing Properties for perimeter and core ... 3–5 Summary of mechanical properties and chemical compositions for steels from low-strength perimeter columns 40 Table 3–6 Summary of mechanical properties and chemical compositions...

Ngày tải lên: 01/04/2014, 00:20

... Structure–property relationships in nanoparticle/semicrystalline thermoplastic composites In G H Michler and F J Baltá-Calleja (Eds.) Mechanical properties of polymers based on nanostructure and morphology ... array of polymer compounds to find the desired processing and vulcanisate properties, as well as high performance Epoxidised natural rubber (ENR) is one interesting example ENR rubber has properties ... nanocomposites was made because of the anticipation of marked improvements in properties of organoclay-filled ENR nanocomposites compared to organoclay-filled NR nanocomposites The comparison...

Ngày tải lên: 07/08/2014, 14:20

... 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 • Processing/Annealing ... = F(t)/m Note: Term proportional to velocity corresponds to frictional damping term 3.225 © H.L Tuller-2001 Hydrodynamic Representation of e- Motion p= momentum=mv dp( t ) p( t ) =− + F1 ( t ) ... Schematic model of a crystal of sodium metal From: C Kittel, Introduction to Solid State Physics, 3rd Ed., Wiley (1967) p 198 3.225 © E.A Fitzgerald-1999 Does this Microscopic Picture of Metals Give...

Ngày tải lên: 11/08/2014, 14:20

... Thermal Promotion • Because electron-hole pairs 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, ... Impurities at the ppm level drastically change the conductivity (5-6 orders of magnitude) 3.225 © E Fitzgerald-1999 18 Expected Temperature Behavior of Doped Material (Example:n-type) • temperature ... np(t) – np(0) = np0 + G τ Αfter turning off illumination: – np(0) = np0 + G τ e -t/τ 3.225 np(0) gτ np0 τ t © H.L Tuller, 2001 Key Processes: Drift and Diffusion Electric Field: Drift I h = epvd...

Ngày tải lên: 11/08/2014, 14:20

... 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 • Reduced power ... 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 ... 23 Choice of Piezoelectric Materials • Temperature limitations of piezoelectric materials Material Max Operating Limitations o Temperature ( C) Quartz 450 High loss LiNbO3 300 Decomposition Li2B4O7...

Ngày tải lên: 11/08/2014, 14:20

... stability Small size Low cost 24 12 3-Way Catalyst Conversion Efficiency 3.225 25 Potentiometric Gas Sensor Nernst Potential PO2(Exhaust) PO2(Ref) E E = (kT/4q) ln {PO2/ PO2(Ref)} 3.225 26 13 Auto ... dissipation •Rapid response •Cost Neural recording/stimulation microprobe Probes 15µm thick 2-4mm long (Najafi and Hetke, IEEE Trans Biomed Eng 37, 474 (1990).) 3.225 28 14 Measurement of Gas ... Measurement of Gas Sensor Performance • Gas sensing materials: Sputtered ZnO film (150 nm (Massachusetts Institute of Technology) Sputtered SnO2 film (60 nm) (Fraunhofer Institute of Physical Measurement...

Ngày tải lên: 11/08/2014, 14:20

... 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: ... 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 ... energy: responsible for properties Fermi-Dirac distribution NOT Bolltzmann distribution, in which any number of particles can occupy each energy state/level Originates from: EF N possible configurations...

Ngày tải lên: 11/08/2014, 14:20

... injection: pn = p p e − eVbi k bT n p = nn e − eVbi k bT © E Fitzgerald-1999 Qualitative Effect of Bias • • • Applying a potential to the ends of a diode does NOT increase current through drift The applied ... What is the built-in voltage Vbi? p n np eVbi nn pp Ec EF eVbi Ev pn eVbi=EFn-EFp  p E Fp = − k b T ln N  V N   = − k b T ln a N   V  ∴Vbi =      p E Fn = − kbT ln n N  V k bT ... 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 p~ Na n~Nd n~ni2/Na p~ ni2/Nd N E F = −kbT ln a N ...

Ngày tải lên: 11/08/2014, 14:20

... From L.L Hench and J.K West, Principles of Electronic Ceramics, Wiley, 1990, p 243 3.225 © H.L Tuller, 2001 Ferroelectrics • Each unit cell a dipole! • Large PR (remnant polarization, P( E=0) • Coercive ... field required to bring P back to zero E Two equivalent-energy atom positions Can flip cell polarization by applying large enough reverse E-field to get over barrier P PR Ps ∆E ‘normal’ dielectric ... metastable relative positions of positive and negative ions 3.225 © E Fitzgerald-1999 © H.L Tuller, 2001 Ferroelectrics Applications • Capacitors • Non-volatile memories • Photorefractive materials...

Ngày tải lên: 11/08/2014, 14:20

... boundary displacement 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 ... Type χ Paramagnetic +10-5-10-4 Diamagnetic -10-8-10-5 Ferromagnetic +105 3.225 © E Fitzgerald-1999 Microscopic Source of Magnetization • No monopoles • magnetic dipole comes from moving or spinning ... = = 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 field B = H + 4πχH = H + 4πM ∂M =...

Ngày tải lên: 11/08/2014, 14:20

... iωt − i p = − p0 = p0 − eE τ ω>>1/τ, p out of phase with E eE0 p0 = iω − τ eE0 iω ω → ∞, p → ω1/τ) p p (ω

Ngày tải lên: 11/08/2014, 14:20

... representation) will now have a restoring force • Review of dipole physics: -q - Dipole moment: r d r r p = qd + +q r p Applied E-field rotates dipole to align with field: Torque r r r τ = pxE ... r r r Potential Energy U = − p ⋅ E = p E cosθ 3.225 © E Fitzgerald-1999 Microscopic Frequency Response of Materials • For a material with many dipoles: r r r r r P = Np = NαE ( p = αE ) (polarization=(#/vol)*dipole ... 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 creating polarization...

Ngày tải lên: 11/08/2014, 14:20

... Investigation of the material properties and physical parameters of Co/Pd based spinvalves and MTJs with perpendicular anisotropy a Understand the effects of perpendicular anisotropy on the GMR, ... coupling and coercivity b Control of perpendicular anisotropy and coercivity of Co/Pd multilayers and spinvalves c Optimization of the spin-valve and MTJ structure based on the understanding of ... a [Pd/Co]m/Cu/[Co/Pd]n pseudo spin-valve nanopillar with perpendicular anisotropy” J Appl Phys., (In-press) (2011) N Thiyagarajah, H W Joo, L Lin, and S Bae, “Physical nature of anomalous peaks...

Ngày tải lên: 10/09/2015, 15:53

... fortune to work with Prof Li Yi and Prof Carl V Thompson during the past years of my PhD endeavor Both professors are distinguished scientists in their respective fields of expertise and I have learnt ... subsequent chapters Chapter is a 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 ... reviewing the properties, structures and applications of metallic glasses and phase-change materials, respectively The current difficulties in understanding the physics of these two classes of materials,...

Ngày tải lên: 11/09/2015, 09:16