OBJECTIVES The goal of this study was to compare the density of gutta-percha root fillings obturated with the following techniques: cold lateral (CL) compaction, ultrasonic lateral (UL) compaction, and warm vertical (WV) compaction. MATERIALS AND METHODS Thirty-three extracted mandibular first molars, with two separate mesial canals in each, were selected. After instrumentation, the canals we...

INTRODUCTION Root canal obturation seals the root canal system to prevent re-entry and/or growth of microorganisms. The provision of an appropriate restoration to coronally seal the access cavity affects the success of endodontic treatment. The purpose of this study was to evaluate the coronal microbial leakage in root canals that were either filled by lateral compaction, GuttaFlow or warm vert...

Intergranular pressure solution creep is an important deformation mechanism in the Earth's crust. The phenomenon has been frequently studied and several analytical models have been proposed that describe its constitutive behavior. These models require assumptions regarding the geometry of the aggregate and the grain size distribution in order to solve for the contact stresses and often neglect ...

We present an experimental study of the compaction dynamics for two-dimensional anisotropic granular systems. The compaction dynamics of rods is measured at three different scales: (i) the macroscopic scale through the packing fraction rho, (ii) the mesoscopic scale through both fractions of aligned grains phi(a) and ideally ordered grains phi(io), and (iii) the microscopic scale through both r...

The Mollisols from the Pampas Region of Argentina have been described as presenting different compactability behaviors under agricultural systems. The purpose of this study was to provide information on the inherent soil factors related to the susceptibility to compaction. Total organic carbon (TOC), texture (CLAY, SILT, SAND), water retention at 0.33 kPa (WR), Proctor maximum bulk density (BDM...

We study, formally and experimentally, the trade-off in temporal and spatial performance when managing contiguous pieces of memory using the explicit, dynamic memory management system Compact-fit (CF). The key property of CF is that temporal and spatial performance can be bounded, related, and predicted in constant time through the notion of partial and incremental compaction. Partial compactio...

BACKGROUND Compaction of human ocular lens fiber cells as a function of both aging and cataractogenesis has been demonstrated previously using scanning electron microscopy. The purpose of this investigation is to quantify morphological differences in the inner nuclear regions of cataractous and non-cataractous human lenses from individuals with diabetes. The hypothesis is that, even in the pres...

Cardiomyopathies classification is based on morphological and functional phenotypes and subcategories of familial/genetic and non-familial/non-genetic disease. The non-compaction cardiomyopathy is a rare disorder which is considered to be an unclassified cardiomyopathy according to the ESC Working Group on Myocardial and Pericardial Diseases and the World Health Organization or a primary geneti...

assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. this study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. 309 in gorazbon district in kheyrud educational and research forest. the objective of this stu...

Let P be a set of n objects on a square grid. A push is a transformation of P that involves sweeping a horizontal or vertical line by one unit, starting from the hull of P , displacing objects in the direction of the sweep. For example, when pushing to the right, all the leftmost objects are displaced one unit to the right. This in turn displaces other objects further right. Given P , we want t...