When dealing with complex mechanical systems that include sliding contact, it is necessary to account for the coupling between the dynamic behavior of the system and the local behavior at the contact. A particular consequence of interaction between system dynamics and contact behavior is the occurring of vibrational instabilities of the mechanical system, induced by the frictional contact. The ...

this study compared tear function tests and cytologic changes on the conjunctival surface in asymptomatic patients wearing contact lens of different materials. included in this study were 40 eyes wearing daily wear 4 week replacement hydrogel (h) lenses, 32 eyes wearing silicone hydrogel (sih) lenses, 18 eyes wearing rigid gas-permeable (rgp) lenses, and 21 healthy eyes (no lenses) as the contr...

background: the salvage proximal femoral osteotomy is performed in mild or moderate osteoarthritis when the articulating surfaces are normal and relieves the subject’s pain. because the importance of angular mal-alignment of the femur bone at the hip junction accurate pre-op planning based on patient specific anatomy is required to prevent any lower limb misalignment and joint problem pre-opera...

State–of–the–art approaches to optimal control of contact–rich robot dynamics use smooth approximations of value and policy functions and gradient–based algorithms for improving approximator parameters. Unfortunately, the dynamics of mechanical systems subject to unilateral constraints—i.e. robot locomotion and manipulation—are generally nonsmooth. We show that value and policy functions genera...

Porous polymeric materials, such as textile fabrics, are elastic and widely used in our daily life for garment and household products. The mechanical and dynamic heat transfer properties of porous polymeric materials, which describe the sensations during the contact process between porous polymeric materials and parts of the human body, such as the hand, primarily influence comfort sensations a...

We present theoretical results for the backaction force noise and damping of a mechanical oscillator whose position is measured by a mesoscopic conductor. Our scattering approach is applicable to a wide class of systems; in particular, it may be used to describe point contact position detectors far from the weak tunneling limit. We find that the backaction depends not only on the mechanical mod...

The changes of molecular conformation, contact geometry, and metal-molecule bonding are revealed by inelastic-electron-tunneling spectroscopy measurements characterizing the molecular vibrational modes and the metal-phonon modes in alkanedithiol molecular junctions at low temperature. Combining inelastic-electron-tunneling spectroscopy with mechanical control and electrode material variation (A...

Size-evolutionary patterns of mechanical and electronic transport properties in junctions are discussed, showing formation of nanowires upon narrowing, regardless of the initial dimensions of the junctions. Mechanical and conductance reversibility of such nanowires in elongation and compression cycles is studied. Ab-initio localspin-density functional based molecular dynamics simulations show f...

Microstructures responsible for temporary arresting of contacting surfaces are widely distributed on surfaces in different organisms. Recent morphological studies show that these structures have different density of outgrowths and not ideal distribution pattern on both complementary parts of the contact. One can suggest that this difference is optimized by natural selection to get stronger mech...