Abstract Contact geometry allows us to describe some thermodynamic and dissipative systems. In this paper we introduce a new geometric structure in order time-dependent contact systems: cocontact manifolds. Within setting develop the Hamiltonian Lagrangian formalisms, both regular singular cases. case, present constraint algorithm aiming find submanifold where solutions exist. As particular cas...

We present a complete theory of higher-order autonomous contact mechanics, which allows us to describe dynamical systems with dissipation. The essential tools for the are extended tangent bundles, TkQ×R, whose geometric structures previously introduced in order state Lagrangian and Hamiltonian formalisms these kinds systems, including their variational formulation. principle, forms, equations o...

Spontaneous Generations 2:1 (2008). ISSN 1913‐0465. University of Toronto 139 Models and Theories at the Nanoscale Eric Winsberg∗ One of the most interesting things about science and engineering at the nanoscale, from the point of view of the philosophy of science, is the frequent use they make of models constructed out of theories belonging to different levels of description. We usually take ...

Recently, the mechanical behavior of micro-/nano-structures has sparked an ongoing debate, which leads to a fundamental question: what steps can be taken investigate characteristics these structures, and characterize their performance? From standpoint non-classical materials, size-dependent theories considered analyze behavior. The application classical in investigation small-scale structures l...

BACKGROUND A contributory factor to hip osteoarthritis (OA) is abnormal cartilage mechanics. Acetabular retroversion, a version deformity of the acetabulum, has been postulated to cause OA via decreased posterior contact area and increased posterior contact stress. Although cartilage mechanics cannot be measured directly in vivo to evaluate the causes of OA, they can be predicted using finite e...

in the current investigation a novel nano hybrid adsorbent mcm-41/n-(3-trimethoxysilyl)-propyl)diethylenetriamine (mcm-41/tmspdeta) was prepared and was characterized using dls (dynamic light scattering), fourier transform infrared (ftir), x-ray diffraction (xrd), brunauer–emmett–teller (bet) analytical techniques and transmission electron microscopy (tem). the synthesized mcm-41/tmspdeta adsor...

The polyvinylidene fluoride (PVDF)/Fe 3+ -TiO2 catalytic membrane was prepared by sol-gel method. It was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR spectrum (FT-IR), mechanics capability, water flux, pepsin retention, porosity and contact angle etc. The catalytic activity of PVDF/Fe 3+ -TiO2 catalytic membrane was evaluated by the degradation of refracto...

in the present study, removal of dibenzothiophene (dbt) from model oil (n-hexane) was investigated using magnetic activated carbon (mac) nano-composite adsorbent. the synthesized nano-composite was characterized by ft-ir, fe-sem, bet and vsm techniques. the mac nano-composite exhibited a nearly superparamagnetic property with a saturation magnetization (ms) of 29.2 emu g-1, which made it desira...