We study the problem of detecting planted solutions in a random satisfiability formula. Adopting the formalism of hypothesis testing in statistical analysis, we describe the minimax optimal rates. We also address algorithmic issues, and describe the performance of a new computationally efficient test. This result is compared to a related hypothesis on the hardness of detecting satisfiability of...

CrNx, MoNx, CrOx, MoOx and CrN/Mo2N multilayer films were deposited by reactive sputtering. Characterization of the coatings was carried out using XRD, XPS, optical profilometer, and nano-indentation. The oxidation of the thin films was studied as a function of annealing temperature. Tribological characterization of the Cr2O3 and the Mo-oxides was carried out as a function of annealing temperat...

SiC reinforced Aluminum samples were produced by stir casting of liquid AA1200 aluminum alloy at 600-650oC casting temperature. 83μm SiC particles were rinsed in 10g/l, 20g/l and 30g/l molar concentration of Sncl2 through cleaning times of 0, 60, 120, and 180 minutes. Some cast samples were tested for mechanical properties and some were subjected to heat treatment before testing. The SnCl2 rins...

Measurement of the strength of brittle materials, such as resin composites, is extremely difficult. Micro-indentation hardness testing is a convenient way of investigating the mechanical properties of a small volume of material. In this study, the mechanical properties of five commercially available flowable resin composites were investigated by the dynamic micro-indentation method. Additionall...

An investigation was carried out in order to study the fretting fatigue behavior of an AlSi9Cu2Mg aluminum alloy. The fretting fatigue tests of AlSi9Cu2Mg were performed using a specially designed testing machine. The failure mechanism of fretting fatigue was explored by studying the fracture surfaces, fretting scars, fretting debris, and micro-hardness of fretting fatigue specimens using scann...

Impact testing methodology is findings the applications for determining the impact strength of the different materials. Oneof the most important characteristics of structural steels, toughness is assessed by the Charpy V-notch impact test. The objective of the research was to maximize the impact toughness by selecting various combinations of Charpy Impact test parameters. In this paper, experim...

This study investigated the effects of a diamond-like carbon (DLC) coating on frictional and mechanical properties of orthodontic brackets. DLC films were deposited on stainless steel brackets using the plasma-based ion implantation/deposition (PBIID) method under two different atmospheric conditions. As-received metal brackets served as the control. Two sizes of stainless steel archwires, 0.01...

Brake pads are generally made of asbestos, which is less environmentally friendly and widely available in nature, therefore motorcycle brake that utilize palm frond fibers filled with alumina powder bonded to a polyurethane matrix. This research was conducted at the Laboratory Material Testing Industrial Chemical Technology Polytechnic (PTKI) Medan. Research carried out from February-July 2020,...

Burnt bricks lined with mortar were among the materials used in the construction of historical load-bearing structures. The need to know the strength characteristics of masonry material arises during repairs of historical structures and their subsequent static securing. These can be investigated either by sampling a masonry specimen, or the employment of non-destructive testing methods. With de...

The purpose of this study was to determine how the mechanical properties and microstructure formed on low alloy steel (tooth bucket) heated at temperatures 850 ⁰C then held for 15 minutes after that it cooled with oil. material hardening process carried out by testing Vickers hardness, impact, observing using an optical microscope 200x magnification. Hardness values obtained from heat treatment...