Sharif Digital Repository

corrosion of steel reinforcements in concrete is one of the most important reasons for durability reduction of offshore structures. To reduce the diffusion rate of ion reactivity in concrete and its reinforcement surface, different methods such as chemical change and coating of reinforcement and concrete are used. In this research for increase corrosion resistance, effect of Pozzolanic additive materials such as fly ash and micro silica , in optimized percentages, 25% and 10% by weight of cement respectively, the percentage of polypropylene fibers improved 2.5% volume of concrete and Ferrogard-901 industrial inhibitor with 3% by weight of cement in concrete mixing plan, were investigated.... 

In recent years, using the nanoparticles has caused a great revolution and development into the materials structure and the polymer science developed corresponding to important role of it in consumer goods. So Carbon Nano Tubes (CNTs) belonging to the precious physical, Mechanical and thermal properties has been studied. The CNT is mixed by mechanical and solution methods with elastomeric matrix. In this research the mechanical method used, because of industrial applications. Although, there are many challenges against dispersion owing to weak cohesion between CNTs and matrix in the mechanical method. The progress in rubber composites reinforced by CNTs and other reinforcement and as well as... 

Nanotechnology inrecent yearshas attractedthe attention of manyscientists and industrialists. Having atiny structure with extraordinary properties of nanoparticlesin the fields of electrical, mechanical and thermal, leading to their use isgrowing and newer application sarebeing found forth eseparticles. One of them Nanodiamond powderiswidely usedin the industryhas found wideapplication. Among these can be used in electrochemistry, chemical coatings, pastesand suspensions, add thepolymer, ceramic and industrial rubber and adhesives,adsorbentsand catalysts, filters and membranes, and finally cancer treat mentnoted. One of these applicationsisinPolymers and Rubber Industry. According to earlier... 

The growing use of the Internet has led to the creation of new businesses around it. Traditional businesses have to use the Internet in order to maintain their competitive conditions. One of the most important strategies for developing sales on the Internet is the proper use of recommendation systems.With the advent of businesses in cyberspace, the way has been paved for the use of recommendation systems in this space.Recommendation systems should exploit their knowledge about users’ preferences and explore their new preferences simultaneously. Establish a balance between exploring users’ new interests and exploiting known interests is key to build a good recommendation system. Existing data... 

Time-varying electromagnetic structures have provided the possibility of realizing new phenomena and, as a result, new applications, which include non-reciprocity, frequency conversion, amplification, and frequency comb. Among the researches that have been done on time-varying electromagnetic structures, less has been done on the rotating time-varying structure. Rotating time variations have great advantages over other time-varying structures. One of the advantages of rotating time changes is the lack of production of many additional harmonics, which originates from the principle of rotating Doppler shift in frequency. Among its other advantages, it is possible to define a time...