We conducted nanoindentation to explore the hardness and elastic properties of silica stishovite, synthesized at high pressure and quenched to ambient conditions. A total of 10 crystallographic orientations were examined on selected grains with a maximum load of 4 or 20mN. We observed discontinuity in the load–displacement curve (pop-in) for the 1⁄22 5 1̄ and 1⁄26 2 1̄ grains subjected to a maxim...

AIM This study aimed to verify the influence of oral environment and denture cleansers on the surface roughness and hardness of two different denture base materials. METHODS A total of sixteen identical removable disc specimens (RDS) were processed. Eight RDS were made from heat-cured acrylic resin (AR) and the other eight were fabricated from thermoplastic injection moulded resin (TR). Surfa...

background: in recent times, the decreasing groundwater reserves due to over-consumption of water resources and the unprecedented reduction of precipitation, during the past 1 decades, have resulted in a change in the volume and quality of water with time. the aim of this study was to determine the spatial and temporal variations of hardness and total dissolved solids in drinking water resource...

OBJECTIVE The purpose of this study was to evaluate the hardness of the adhesive interface between resin and Er:YAG laser-irradiated bovine dentin by nano-indentation. BACKGROUND DATA It has been reported that laser output energy and pulse repetition rate affect the tensile bond strength in Er:YAG laser-irradiated dentin. MATERIALS AND METHODS Three laser settings were evaluated at the same...

BACKGROUND Clinical features of thyroid dysfunction vary with age, and an oligosymptomatic presentation of hyperthyroidism is frequently observed in the elderly. This suggests age modulation of thyroid hormone (TH) action, which may occur, for example, by alterations in TH production, metabolism and/or TH action in target organs. OBJECTIVES In this paper, we address possible changes in TH tra...

The total Steiner k-distance and the k-th total path length are the sum of the size of Steiner trees and ancestor-trees over sets of k nodes of a given tree, respectively. They are useful statistics with many applications. Consequently, they have been analyzed for many different random trees, including increasing tree, binary search tree, generalized m-ary search tree and simply generated trees...

Groundwater is one of the most important water resources especially for irrigation in the east of Iran. So, it is important to note its water quality variation for deciding to manage it. To this end, the study were done to zone Birjand plain located at latitude between 32˚ 30’-33˚ 00’ N and longitude between 58˚ 45’-59˚ 41’ E. In order to achieve this goal, the required layers, Sodium adsorptio...

Regulation of tyrosine hydroxylase (TH) by intermittent hypoxia (IH) was investigated in rat pheochromocytoma 12 (PC-12) cells by exposing them to alternating cycles of hypoxia (1% O2, 15 s) and normoxia (21% O2, 3 min) for up to 60 cycles; controls were exposed to normoxia for a similar duration. IH exposure increased dopamine content and TH activity by approximately 42 and approximately 56%, ...