introduction: due to sensitiveness of flow to roughness coefficient (rc), selection of this coefficient is important in earth canals designing purposes. precision selection of this coefficient is necessary for design and operation of earthen canals purposes. overestimation of the actual amount of this coefficient will cause an underestimation for flow velocity. accordingly, sedimentation in the...

Honing is an abrasive procedure that removes material and creates grooves by employing three simultaneous motions of stones. Because honing operation, predicting the process outcome analytically challenging. The steep peaks a surface are eliminated during plateau process, producing reasonably finish along with cross hatch pattern for retaining oil increased bearing area. A cylinder liner instal...

X-ray and electron di!raction have been used to determine the surface roughness parameters of thin "lms and thus evaluate roughness e!ects on magnetic properties. For self-a$ne roughness, the demagnetizing factor is in#uenced by the roughness exponent H, and is proportional to w/m2 with w being the RMS roughness amplitude and m being the lateral correlation length. Roughness anisotropy can ampl...

The one dimension computational model of a sequential injection engine, which runs on compressed natural gas (CNG) with spark ignition, is developed for this study, to simulate the performance of gas flow pressure profile, under various speed conditions. The computational model is used to simulate and study of the steady state and transient processes of the intake manifold. The sequential injec...

   In this study, the change of porosity and roughness of carbon nanostructures, including fullerenes, carbon nanotubes and graphene was investigated according to oxidation process. The effect of oxidation was more sensible on smoother surface of nanostructures. Oxidation increases surface roughness of graphene up to 5.2% and porosity up to 35.2%. While, roughness of hummers graphene is 13....

Small end bearings are a critical component of reciprocating engines, and the performance their lubrication directly affects engines’ reliability mechanical efficiency. There many factors that influence lubrication. A new type small-end bearing test rig was developed to reveal key influencing on characteristics, multi-body dynamic model coupled with elastohydrodynamic (EHD) characteristics buil...

Hydrodynamic river models are applied to design and evaluate measures for purposes such as safety against flooding. The modeling of river processes involves numerous uncertainties, resulting in uncertain model results. Knowledge of the type and magnitude of these uncertainties is crucial for a meaningful interpretation of the model results. The aim of this study is to quantify the uncertainty d...

This paper outlines the authors’ experimental research in rough-wall-bounded turbulent flows that has spanned the past 15 years. The results show that, in general, roughness effects are confined to the inner layer. In accordance with Townsend’s Reynolds number similarity hypothesis, the outer layer is insensitive to surface condition except in the role it plays in setting the length and velocit...

objectives: scaling and root planing (srp) is one of the most commonly used procedures during periodontal treatment. the aim of this study was to evaluate the root surface roughness after srp with erbium: yttrium aluminum garnet (er:yag) laser compared to ultrasonic and hand instruments.   materials and methods: in this experimental study, 56 extracted sound single-rooted teeth with moderate le...