let s be a monoid and x a class of s-acts which is closed under coproducts. the object of this article is to find conditions under which all s-acts have x-precovering. we have shown that the existence of torsion-free precovering implies the existence of torsion-free covering. this work is an attempt to further facilitate the study of the conjecture that all s-acts have flat cover.

Background: The aim of the present study was to evaluate how left ventricular twist and torsion are associated with sex between sex groups of the same age.Materials and Methods: In this analytical study, twenty one healthy subjects were scanned in left ventricle basal and apical short axis views to run the block matching algorithm; instantaneous changes in the base and apex rotation angel...

Torsion of elastic and poroelastic circular shaft of radially inhomogeneous, cylindrically orthotropic materials is studied with emphasis on the end effects example for extruder. To examine the conjecture of Saint-Venant’s torsion, we consider torsion of circular shaft with one end fixed and the other end free on which tractions that results in a pure torque are prescribed arbitrarily over the fr...

PURPOSE Femoral artery stents are prone to fracture, and studying their deformations could lead to a better understanding of the cause of breakage. The present study sought to develop a method of imaging and analyzing stent deformation in vitro with use of a calibrated test device. MATERIALS AND METHODS High-resolution (approximately 200 μm) volumetric data were obtained with a flat-panel det...

2 We discuss the theoretical basis for the search of the possible experimental manifestations of the torsion field at low energies. First, the quantum field theory in an external gravitational field with torsion is reviewed. The renormalizability requires the nonminimal interaction of tor-sion with spinor and scalar (Higgs) fields. The Pauli-like equation contains new torsion-dependent terms wh...

Aim The aim of the present study was to assess the protective effects of magnesium sulfate (MgSO4) on ischemia/reperfusion (I/R) induced ovarian damage in a rat ovarian torsion model. Methods Forty-two female Sprague Dawley rats were included in the study. They were divided into six groups as Group 1, sham; Group 2, bilateral ovarian torsion; Group 3, bilateral ovarian torsion-detorsion; Grou...

BACKGROUND The usefulness of T2*-weighted (T2*W) imaging for the detection of adnexal torsion has yet to be determined. PURPOSE To assess the usefulness of T2*W imaging for detecting and differentiating adnexal torsion. MATERIAL AND METHODS Eight patients with eight ovaries with torsion and 44 patients with 72 ovaries without torsion were included in this study. All patients underwent 1.5-T...