The purpose of this study was to evaluate the effect of spreader penetration depth on apical microleakage using the lateral compaction method. A total of 96 extracted maxillary central incisors were instrumented using the step-back method, and randomly divided into the following four experimental groups: A) with tug-back and spreader penetration 1 mm short of the working length; B) without tug-...

A post-tensioning tendon duct filled with grout can effectively prevent corrosion of the reinforcement, maintain bonding behavior between the reinforcement and concrete, and enhance the load bearing capacity of concrete structures. In practice, grouting of the post-tensioning tendon ducts always causes quality problems, which may reduce structural integrity and service life, and even cause acci...

To make the bearing capacity tests safer and more affordable for prestressed high-strength concrete (PHC) piles, this paper proposes a reaction device anchor piles filled with core grout based on geometric mechanical characteristics of PHC piles. The proposed has advantages convenient construction, strong controllability connection quality low cost. In addition, pile will not experience prestre...

The greatest stability of in vitro plant materials with practical storage periods measured in decades can be achieved by cryogenic storage at ultra low temperatures. Liquid Nitrogen (LN) is the most common medium for cryostorage as it is relatively inexpensive and readily available (Withers, 1987; Panis and Lambardi, 2005). This process puts the cells in suspended animation where they can retai...

Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride we...

Compensation grouting has been attracting attention in recent years to control ground settlement caused by underground construction. A successful and effective application of compensation grouting depends not only on the use of a good monitoring system in the field but also on a fundamental understanding of grout behavior in soils. For compensation grouting in clay, there is a need to consider ...

The diffusion progress of grout is hindered by groundwater, which means the distance cannot reach designed values required in engineering for water plugging or reinforcement. In this study, based on generalized Darcy’s law and continuity equation steady column penetration, a mechanism Bingham fluid, considering displacement effect proposed. This then validated penetration grouting experiments t...

in this paper, the grouting ability of sandy soils is investigated by artificial neural networks based on the results of chemical grout injection tests. in order to evaluate the soil grouting potential, experimental samples were prepared and then injected. the sand samples with three different particle sizes (medium, fine, and silty) and three relative densities (%30, %50, and %90) were injecte...

specific structure of ewe's cervix is one of artificial insemination limitation in sheep. successful insemination in ewes has a close relation with morphology of their cervix. the objective of this experiment was to compare anatomical structure of cervix in makui, kurdish and afshari ewes. in this study, reproductive tract of 300 ewes of aforesaid sheep (100 ewes of each strain) were colle...