OBJECTIVE To determine whether the human Achilles tendon has higher material properties than other tendons and to test for strain rate sensitivity of the tendon. DESIGN Mechanical testing of excised tendons. BACKGROUND While the human Achilles tendon appears to experience higher in vivo stresses than other tendons, it is not known how the Achilles tendon's material properties compare with t...

String theory requires two kinds of loop expansion: classical (α ′) world-sheet loops with expansion parameter < T > where T is a modulus field, and quantum (¯ h) spacetime loops with expansion parameter < S > where S is the dilaton field. Four-dimensional string/string duality (a corollary of ten-dimensional string/fivebrane duality) interchanges the roles of S and T and hence interchanges cla...

The collagenous dura mater isolates the brain from the external environment and requires a secure closure following invasive neurosurgery. This is typically accomplished by approximation of the dura mater via sutures and adhesives. In selected cases, however, large portions of dura mater require excision, necessitating a tissue replacement patch. The mild reaction conditions and long-term bioco...

Polyvinyl ester green composites were synthesized with walnut shell powder (WSP) by in-situ polymerization technique. The green composites have been evaluated for mechanical properties such as tensile strength, tensile modulus and hardness. Sliding wear loss, specific wear rate and coefficient of friction were investigated by using computerized pin-on–disc machine at normal applied loads of 20,...

The change of the ultrasound (US) speed in articular cartilage (artC) under applied strain conditions may induce significant measurement errors of the mechanical properties of the artC during both indentation and compression tests using US. In this paper, the strain dependence of the US speed in bovine artC (n = 20) under compression in vitro was investigated by virtue of using a custom-made US...

We are interested in the approximation of functions f ~ Lp(I), 0 < p < 1, I = [ 1 , 1], by algebraic polynomials. Such approximation has previously been studied by other authors, most notably, Storozhenko, Krotov, and Oswald [-S-K-O] and Khodak [K]. Our main departure from these previous works is that we shall prove direct estimates for the error of polynomial approximation in terms of the Ditz...

We announce some new results about systems of residue sets. A residue set R C Z is an arithmetic progression R = {a,a±n,a± 2n,...}. The positive integer n is referred to as the modulus of R. Following Znam [21] we denote this set by a(n). We need several number-theoretic functions. p(ra)-the least prime divisor of a natural number ra, P(m)-the greatest prime divisor of ra, A(m)-the greatest div...

Objectives: Nowadays, Snap-fits are used in the automotive industry as a proper alternative for mechanical joints, cabling joints, and car interior lining joints. Due to the special form of these joints, which are assembled manually, the contact area between Snap-fits and the worker&rsquo;s fingertips can be too small. This can cause skin pain on the worker&rsquo;s&nbsp; fingertips. Therefore, ...

Introduction: Articular cartilage is typically subjected to physiological loading at high strain rates. The mechanical response to this type of load is mainly governed by interactions among three material phases: collagen fibrils, proteoglycan matrix and water containing diffusible ions. Previous model studies, which have adopted the same constitutive laws for the fibrils and the proteoglycans,...

BACKGROUND The mechanical properties of 1-2-year-old pediatric cranial bones and sutures and their influential factors were studied to better understand how the pediatric calvarium reacts to loading. MATERIAL AND METHODS Cranial bone and suture specimens were extracted from seven fresh-frozen human infant cadavers (1.5±0.5 years old). Eight specimens were obtained from each subject: two front...