this study aimed to evaluate persian search engines based on the criteria obtained from alexa databank using correspondence analysis. through searching the web, 23 search engines were found, which due to their cease and no coverage by alexa, this number was reduced to 16. data analysis revealed that ghatreh search engine occupied a high rank in most of attributes like traffic rank, time spent o...

nowadays, due to increasing the complexity of ic engines, calibration task becomes more severe and the need to use surrogate models for investigating of the engine behavior arises. accordingly, many black box modeling approaches have been used in this context among which network based models are of the most powerful approaches thanks to their flexible structures. in this paper four network base...

in this research work, the impact of user’s behavior on search engine results is discussed. it aims to improvement of search results which leads to the higher satisfaction of users. in other words, we are trying to present a personalized search engine for each user, based on his/her activity and search history. we base our hypothesis that the search history of each user in a specific time frame...

investigations are carried out to evaluate the performance of a low heat rejection (lhr) diesel engine consisting of air gap insulated piston with 3-mm air gap, with superni (an alloy of nickel) crown and air gap insulated liner with superni insert with different operating conditions of crude jatropha oil with varied injection timing and injection pressure.  performance parameters of brake ther...

the aim of this manuscript is to study the implication of aluminium-oxide nanofluid for an amphibious vehicle engine (viable on land and under water) cooling system both analytically and experimentally. to achieve this, a one-dimensional model of the engine cooling system (radiator) is considered through a computational fluid code in which the mass flow rate for a range of the coolant temperatu...

gas motion within the cylinder is one of the major factors that control the combustion process in spark ignition engine. it also has significant impact on heat transfer. both the bulk gas motion and the turbulence characteristics of the flow are important and governing the overall behavior of the flow. an arrangement for obtaining a stratified charge, using port injection, is proposed for a cur...

in this research, nano materials with tubular structures are added to sae 20w50 engine oil to study the rate of their effects on the properties of engine oil. multi-walled carbon nanotubes (mwcnts) and vanadium oxide nanotubes (vonts) has been used as two different additive materials, one of them is carbonic and the other is metallic oxides and their effect on  different parameters containing v...

Piston scuffing is one of the destructive faults in internal combustion (IC) engines. There are different causes to make this fault that lack of lubricant is the most important one among them. The purpose of this paper is the quantitative study of the piston scuffing effects on the engine performance parameters which is a new research direction in the IC engine filed. For this reason, several e...

In this paper, numerical solution of beta-type Stirling engine was presented considering its non-ideal regenerator. To this end, the second-order model including heat and power losses was used. Then, a numerical code was applied for calculating geometrical and physical optimum values of the engine. To confirm the obtained results, the physical and geometrical parameters of the GPU-3 engine were...

Engines equipped with camless valve trains will have greater space for performance optimization. In this paper, based on the electromagnetic actuated valve train system, one-dimensional and three-dimensional simulation models on engine thermodynamic cycle and in-cylinder charge motion are established, respectively. With the application of early-intake-valve closing (EIVC) strategy，unthrottled l...