Hasan Ghafori - Academia.edu (original) (raw)

Papers by Hasan Ghafori

Journal of the Saudi Society of Agricultural Sciences

Metal Science and Heat Treatment, 2020

The effect of heat treatment on the microstructure, hardness, and abrasive wear of the hammer mil... more The effect of heat treatment on the microstructure, hardness, and abrasive wear of the hammer mills knives made of steels EN 1.2080, 1.7225, 1.7131, and 1.1191 used in the grain crop processing into groats has been studied. The wear tests were performed using an "impeller-in-cup" type machine, and metallographic studies were performed using optical and scanning electron microscopy. A comparative analysis of the steel properties was performed. Steel EN 1.2080, which demonstrated the highest wear resistance, was recommended for knife manufacturing. The optimal heat treatment conditions for such steel were proposed.

AFRICAN JOURNAL OF AGRICULTURAL RESEEARCH, 2011

In this research, physical properties of corn and barley seeds were first determined and then, to... more In this research, physical properties of corn and barley seeds were first determined and then, to obtain the change in pressure drop, power consumption and mechanical seed damage as a function of air velocity during suction conveying of corn and barley, a suction-type pneumatic conveying system was designed and constructed and finally the pneumatic conveying characteristics of corn and barley seeds were determined under seven air velocities. The results indicated that the geometric and arithmetic mean diameters and sphericity of corn seeds were 80, 63 and 20%, respectively, more than the barley seeds. Pressure drop increased nonlinearly and linearly with an increase in air velocity for corn and barley seeds, respectively. However, power consumption was nonlinearly increased with air velocity for both seeds. Mechanical damage of both seeds increased linearly as the air velocity was increased. There was a turning point at which the pressure drop increased rapidly with an increase in air velocity. The lowest pressure drop for corn and barley occurred at the air velocity of 20 and 15 m s-1 , respectively. Therefore, for reducing the specific energy consumption and mechanical damage to corn and barley seeds at the conveying capacity of 15 ton h-1 , the air velocity in pneumatic conveying must be decreased below 20 and 15 m s-1 , respectively.

Majlesi Journal of Electrical Engineering, 2017

Engines with variable poppet valve timing systems are among numerous efforts that aim to reduce e... more Engines with variable poppet valve timing systems are among numerous efforts that aim to reduce engine emissions and/or increase efficiency. In the present paper we have investigated the stability of a magnetic valve system in MATLAB. First we designed the magnet and interactive forces inside the electromagnetic valve system, then we produced a mechanical model for the system by using a two degree of freedom mass and spring system and finally designed a PID controller to maintain system stability. The results of the present study indicate that the controller had decreased the maximum valve displacement domain and duration from 2 mm to 0.001 mm and 0.1 seconds to 0.022 seconds, respectively. Poppet valve settling speed was 0.0126 and had a standard deviation of 0.1304 while the armature settling speed was 0.0184, with a standard deviation of 0.1363. Passes for the phases were -37.5 and -169, with gains of 10.3 and -9.35.

Majlesi Journal of Electrical Engineering, 2016

Abstract: Nowadays, compared to the past, the growth of technology in suspension systems have led... more Abstract: Nowadays, compared to the past, the growth of technology in suspension systems have led the magnetic bearings to a more powerful and economical design. Such bearings proved to have lots of benefits such as performance capability in high speeds and the ability to perform action without lubrication in different performances. That cause a decrease in the environmental and system pollution and makes it possible to work in vacant environments. Such bearings which work without friction show to have little attrition. In This paper, investigates the operation of magnetic bearing having 8 and 16 polar at a velocity rate at 30000 rpm and gap tolerance ranging from 2 to 0.5 mm. The magnetic for condition simulates based on finite element by optimizing the best mesh measurement. Normal 0 false false false EN-US X-NONE FA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso...

Dense-phase pneumatic conveying is used in many industries such as chemical, pharmaceutical and f... more Dense-phase pneumatic conveying is used in many industries such as chemical, pharmaceutical and food industries due to its advantages including less dust, minimum product degradation and segregation, low specific energy consumption and low pipe wear. This is in sharp contrast to dilute-phase conveying system. In spite of these advantages, little attention has been paid to the adaptation of the dense-phase conveying system for agricultural uses. Most of the earlier researchers worked on positive pressure for dense-phase conveying in agriculture. The main objective of the research reported here was to design and develop a dense-phase suction pneumatic system for conveying corn and barley. The pneumatic conveyor system consisted of a centrifugal blower, an electric motor, a seed hopper, a rotary airlock, a rotary airlock motor, intake and discharge pipes, a separator cyclone and a discharging cyclone. The choice of power source and vacuum blower was based on the ability of the blower t...

Journal of Stored Products Research