Aim The aim of this study is to compare and to evaluate effect of curing light and curing modes on the nanohybrid composite resins with conventional Bis-GMA and novel tricyclodecane (TCD) monomers. Methodology Two nanohybrid composites, IPS empress direct and charisma diamond were used in this study. Light-emitting diode (LED)-curing unit and quartz-tungsten-halogen (QTH)-curing unit which we...

Algorithmic research strives to develop fast algorithms for fundamental problems. Despite its many successes, however, many problems still do not have very e cient algorithms. For years researchers have explained the hardness for key problems by proving NP-hardness, utilizing polynomial time reductions to base the hardness of key problems on the famous conjecture P ”= NP. For problems that alre...

OBJECTIVE THE AIM WAS TO EVALUATE THE EFFECT OF ER, CR: YSGG laser and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on surface micro-hardness of primary tooth enamel. MATERIALS AND METHODS A total of 30 freshly extracted caries free primary anterior teeth were cleaned and stored in 1% thymol. Teeth were embedded in acrylic resin such that only their buccal surfaces were exposed...

Hardness homogeneity of the commonly used structural ferrous and nonferrous engineering materials is of vital importance in the design stage, therefore, reliable information regarding material properties homogeneity should be validated and any deviation should be addressed. In the current study the hardness variation, over wide spectrum radial locations of some ferrous and nonferrous structural...

Hardness of the widely used structural steel is of vital importance since it may help in the determination of many mechanical properties of a material under loading situations. In order to obtain reliable information for design, properties homogeneity should be validated. In the current study the hardness variation over the different diameters of the same AISI 4140 bar is investigated. Measurem...

In this study, the effects of cutting edge geometry, workpiece hardness, feed rate and cutting speed on surface roughness and resultant forces in the finish hard turning of AISI H13 steel were experimentally investigated. Cubic boron nitrite inserts with two distinct edge preparations and throughhardened AISI H13 steel bars were used. Four-factor (hardness, edge geometry, feed rate and cutting ...

Austenitic stainless steels (ASSs) have an excellent corrosion resistance but relatively-low hardness and yield strength [1,2], leading to limited usage in applications that high values of hardness and wear resistance is necessary for material surface. Therefore, surface properties such as hardness must be improved using appropriate techniques. Mechanical surface treatments such as ultrasonic s...

Impagliazzo and Levin showed a reduction from average-case hardness of any NP-search problem under any polynomialtime samplable distribution to that of another NP-search problem under the uniform distribution in [12]. Their target was the hardness of positive instances occurring with probability 1/poly(n) under the distributions. In this paper, we focus on hardness of a larger fraction of insta...

INTRODUCTION For the construction of any dental prosthesis, accurate impressions are necessary. Hence, we undertook the present study to evaluate and compare the surface hardness of gypsum casts poured from impressions made using conventional alginate and self-disinfecting alginate. MATERIALS AND METHODS A total of 30 impressions of stainless steel die were made, out of which 15 impressions w...

Empirical hardness models predict a solver’s runtime for a given instance of an NP-hard problem based on efficiently computable features. Previous research in the SAT domain has shown that better prediction accuracy and simpler models can be obtained when models are trained separately on satisfiable and unsatisfiable instances. We extend this work by training separate hardness models for each c...