An-Najah Blogs :: Ahmad Ramahi http://blogs.najah.edu/author/ahmad-ramahi An-Najah Blogs :: Ahmad Ramahi en-us Thu, 21 Nov 2019 18:04:01 IST Thu, 21 Nov 2019 18:04:01 IST webmaster@najah.edu webmaster@najah.edu Sample of Achieved Graduation Projectshttp://blogs.najah.edu/staff/ahmad-ramahi/article/Sample-of-Achieved-Graduation-ProjectsPublished Articles - Design and Fabrication of a CNC Flame Cutting Machine - Design and Fabrication of a Model for a Pneu-Automatic Soap Cutting and Stamping Line - Design and Fabrication of a Hydraulic Deep Drawing Machine - Materials Selection in Mechanical Design - Computer Aided Production Planning in Garment Industry - Computer Aided Process Planning in Sand Casting - Infra Structure Requirements for SW Collection Systems in the Palestinian Housing - Computer Aided Process Planning in Turning Operations - Experimental Study on Conventional Spinning Process - Experimental Study on Pack Carburizing Process - Designing a proper HVAC system for Nablus Hospital - Cost Reduction Options for the Solid Waste System of Nablus Municipality - Comprehensive feasibility study for the establishment of a Lime Factory in the West BankDesign and Construction of a pseudo Continuous Single Station Automated Cellhttp://blogs.najah.edu/staff/ahmad-ramahi/article/Design-and-Construction-of-a-pseudo-Continuous-Single-Station-Automated-CellPublished ArticlesThis paper presents the work implemented in designing constructing and operating a pseudo continuous automatic drilling machine in which the drilling head acts as two degrees of freedom manipulator The manipulator carries out a complex planer movement to drill parts being transported by a continuously moving conveyor belt The produced machine works as single station automated cell that drills single-model wooden parts The cell is currently utilized in the Production Processes Lab of the Industrial Engineering Department at An-Najah National University The experience gained in designing and constructing such a Mechatronics system was found to be successful in terms of obtaining a properly working automated cell as well as enhancing the students abilities to understand the concepts of design and construction of an automatic machine in particular and Mechatronics systems in general On the Kinematics of Spatial Gearinghttp://blogs.najah.edu/staff/ahmad-ramahi/article/On-the-Kinematics-of-Spatial-GearingPublished ArticlesIn this paper using screw theory complete descriptions for the relative motion of a pair of spatial gears whose axes shafts may simultaneously rotate and translate are given These descriptions are then used to derive the point coordinates of the pitch surfaces corresponding to some practical shafts layouts andor shafts input-output relations are also generated and given in the example sectionThe Effect of Efficient Lighting On the Environment Pilot Project in Palestinehttp://blogs.najah.edu/staff/ahmad-ramahi/article/The-Effect-of-Efficient-Lighting-On-the-Environment-Pilot-Project-in-PalestinePublished ArticlesThis paper presents the resultsgained through the Energy Conservation pilot Project in the Town of SalfeetPalestine The project was funded by the UNDP and executed in a framework of the cooperation between An najah national university the UNDP and Salfeet Municipality The project aims mainly to draw the public attention towards the importance of energy conservation in reducing pollution as well as running cost In fact a major component in the project was the replacement of the incandescent lambs for about 40 of the resident of Salfeet 626 families the 40-100 Watt Lambs were replaced by 18 Watt Compact Florescent Lambs CFL each benefited family was given 3 to 5 CFL free of charge depending on number of persons per family It is found that the total energy saved because of lamp-replacement in Salfeet is about 5000kWhmonth and the total emission saved of CO2 is about 5792 kg as coal is burned to generate electricity Furthermore the project has improved public awareness about energy conservation concepts and their positive impact on local and global climate changesDesign and Construction of a Deep Drawing Machine: Experimental Investigation of Limiting Drawing Ratiohttp://blogs.najah.edu/staff/ahmad-ramahi/article/Design-and-Construction-of-a-Deep-Drawing-Machine-Experimental-Investigation-of-Limiting-Drawing-RatioPublished ArticlesThis paper presents the work implemented in designing constructing and operating a model of a cheep hydraulic deep during machine DDM which is currently utilized in the manufacturing process lab in the Industrial engineering Department IED at An Najah National University The machine is being used in conducting different experiments related to the deep drawing process in general and in investigating the limiting drawing ratioLDR in particular As known deep drawing can be defined as a sheet- metal working process in which a punch draws a blank sheet into a die cavity to form cup-shaped or box-like parts One of the feasibility measures of deep drawing process is the LDR which is defined as the ratio of the maximum starting blank sheet diameter to punch diameter This work was carried out in three stages; the first was the design stage in which all design calculations of the DDM elements were based on the specifications of the product cup to be drawn The second was construction stage in which the DDM elements were fabricated and assembled at the engineering workshops of the university The last was operation and experimentation stage in which the DDM was tested by conducting different experiments As a conclusion our experience in designing and constructing a mechanical lab equipment was found to be successful in terms of obtaining practical results that agree with those available in literature saving money relative to the cost of a similar purchased equipment as well as enhancing the students abilities in understanding the deep drawing process in particular and machine design concepts in general Design of a Proper Solid Waste Collection System for Salfeet Municipalityhttp://blogs.najah.edu/staff/ahmad-ramahi/article/Design-of-a-Proper-Solid-Waste-Collection-System-for-Salfeet-MunicipalityPublished ArticlesThis paper presents the result and experience gained through a case study of designing a proper solid waste collection system for the town of Salfeet in Palestine The study aims mainly to develop a sustainable solid waste collection system that improves the general health condition and quality of life in Salfeet In this study a proper solid waste collection system based on actual solid waste characteristics was designed the required collection technology was first specified a clear plan of collection route frequency and schedule was then developed based on computer analysis using Geographic Information System GIS It is expected that the implementation of the designed solid waste collection system will certainly insure a cost-effective improvement in the quality of life in Salfeet Moreover the study especially the field survey part has drawn the public attention towards correct solid waste disposal practice and its positive impact on human health and environmentOn the Generation of Contact Surfaces of Spatial Indexing cam Mechanisms Via screw theoryhttp://blogs.najah.edu/staff/ahmad-ramahi/article/On-the-Generation-of-Contact-Surfaces-of-Spatial-Indexing-cam-Mechanisms-Via-screw-theoryPublished ArticlesIn this paper based on screw theory a general expression for the point coordinates of the contact surfaces of three-link spatial indexing cam mechanisms are derived These contact surfaces are rolled surfaces generated by the motion of the relative instantaneous screw axis onto each of the cam and the follower Note that cam mechanisms generated in this way have the property of minimum power losses at the higher pair ie with minimum sliding velocity along the contact line Few examples are also given to illustrate the approachDesign of Gating and Risering Systems in Sand Castinghttp://blogs.najah.edu/staff/ahmad-ramahi/article/Design-of-Gating-and-Risering-Systems-in-Sand-CastingPublished ArticlesThe success of a sand casting process depends mainly on the design of efficient mold rigging systems; namely the gating and Risering systems However it is observed that the mold preparation in most of local foundries in Palestine depends totally on the experience of the foundry man who does not pay much attention to the engineering mold-design procedure In fact almost all of the foundry men in local market have gained their experiences by trial and error which usually leads to higher production cost and less production quality This paper is a review paper It reviews in a simplified and comprehensive way the most important practical and scientific rules and procedures related to Gating and Risering systems design Detailed examples are also given to explain the implementation of these rules and procedures One main objective of the paper is to contribute to the improvement of local-foundry efficiency Therefore the paper is available in Arabic for researchers engineers and other interested people On the other hand the paper presents a useful summery of a list of the most important references related to the design of Gating and Risering systems in sand casting Furthermore the material of the paper can support in developing modern Computer Aided Mold Design SystemsUsing a Geometry Based Classification and coding Approach in the Design of Mold Rigging System in Sand Castinghttp://blogs.najah.edu/staff/ahmad-ramahi/article/Using-a-Geometry-Based-Classification-and-coding-Approach-in-the-Design-of-Mold-Rigging-System-in-Sand-CastingPublished ArticlesThe quality of cast metal parts is very dependent upon the design of the rigging system sprue runners gates and risers Traditionally designing a rigging system is implemented manually given a set of drawings or model to visualize the casting dimensions and geometric features The design procedure of mold rigging system can be made quite simple through the use of computers However this requires a method of describing the geometry which plays a central rule in rigging design of casting part in an easy and non-expensive way; the basic group technology classification is such a method making use of a digital coding system This paper presents the development of such a system to be mainly implemented for the mold rigging design in sand casting