Saeid Naser Vafaei

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We present data products from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). CFHTLenS is based on the Wide component of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). It encompasses 154 deg of deep, optical, high-quality, sub-arcsecond imaging data in the five optical filters u∗g′r′i′z′. The scientific aims of the CFHTLenS team(More)
This paper investigates the change in contact angle of droplets of fluid containing dispersed nanoparticles (nanofluid) functionalized with thioglycolic acid molecules as a function of the concentration and size of nanoparticles, and the quality and composition of the substrate material. Bismuth telluride nanoparticles with an average size ranging from 2.5(More)
The purpose of this paper is to present a consistent theoretical concept that can explain the various physical phenomena associated with the effect of droplet size on contact angle for droplets on solid surfaces, and with the geometry of the liquid/gas/solid contact line in general. Two droplet geometries have been considered: uniformly elongated droplets(More)
The effect of gold nanoparticles on the formation of gas bubbles on top of a stainless steel tube is investigated in this work. Unlike other observations of bubble dynamics under evaporation or boiling conditions, which are caused by the surface modification due to particle sedimentation, this work reveals a unique phenomenon of enhanced pinning of the(More)
A likelihood-based method for measuring weak gravitational lensing shear in deep galaxy surveys is described and applied to the Canada–France–Hawaii Telescope (CFHT) Lensing Survey (CFHTLenS). CFHTLenS comprises 154 deg2 of multi-colour optical data from the CFHT Legacy Survey, with lensing measurements being made in the i′ band to a depth i ′ AB < 24.7,(More)
This work investigates the effect of size and concentration of nanoparticles on the effective gas-liquid surface tension of aqueous solutions of bismuth telluride nanoparticles functionalized with thioglycolic acid. The gas-liquid surface tension is obtained by solving the Laplace-Young equation under experimentally measured boundary conditions and droplet(More)
This work investigates the feasibility of engineering surface wettability by using different nanoparticles. As an illustration, detailed formation of gas bubbles on top of a stainless steel substrate plate in a quiescent pool of aqueous gold and alumina nanofluids is studied. The presence of nanoparticles is shown to be able to modify the dynamics of triple(More)
This investigation introduces the asymptotic contact angle as a criterion to quantify the surface wettability of nanofluids and determines the variation of solid surface tensions with nanofluid concentration and nanoparticle size. The asymptotic contact angle, which is only a function of gas-liquid-solid physical properties, is independent of droplet size(More)
This work investigates detailed formation of air bubbles on a submerged micrometer-sized nozzle. The experimental study is conducted on a submerged nozzle of radius of 55 microm under low gas flow rate conditions (0.015-0.83 ml/min). The bubble formation is recorded by a high-speed optical camera and detailed characteristics of bubble formation such as the(More)
This paper begins with an extensive review of the formation of gas bubbles, with a particular focus on the dynamics of triple lines, in a pure liquid and progresses into an experimental study of bubble formation on a micrometer-sized nozzle immersed in a quiescent pool of aqueous gold nanofluid. Unlike previous studies of triple line dynamics in a nanofluid(More)