Open Access Case study

A Comparative Study on the Developmental Trends in the Contemporary Iranian Architecture; Case Study-Khosrawi Leather Factory of Tabriz

Shayan Mahmoudi, Ali Rezvani, Mehdi Niknam

Journal of Engineering Research and Reports, Page 1-18
DOI: 10.9734/jerr/2020/v10i217032

Architecture and urbanization are representatives of our architectural and cultural histories. Many of the lost historical characteristics can come out of the back door citing such representatives. Reconstruction and restoration are a set of activities that deal with the body and spirit of a subject. The subject can be a city, a natural environment or an architectural structure. There are different approaches to reconstruction and restoration, which differ significantly in terms of the level of intervention in a historical subject. This is a technique that our archaeologists are not sufficiently familiar with. From an archaeological point of view on the historical subjects, any document could not be as consistent as the architectural works with the circumstances of the community. The nature of the art of modern history is to see which cases have not been addressed in historical documents. As the historical subjects’ evidence, we were not so diligent in the preservation of such subjects as a documentary. The aim of this study is to investigate the heritage of contemporary architecture and to determine how to preserve such works, as well as to review the Khosrawi leather factory in Tabriz, which has now maintained its role as the Islamic Art University. The results of this research, which are obtained through a descriptive-analytical method, show that we can preserve the architectural structures by changing the application of traditional structures to the cultural or social ones.

Open Access Original Research Article

Modified Sidewall Design of QFN Package

Frederick Ray I. Gomez, Rennier S. Rodriguez

Journal of Engineering Research and Reports, Page 19-23
DOI: 10.9734/jerr/2020/v10i217033

The paper offers an improvement for leadframe devices to mitigate the occurrence of package chipping rejection during package mechanical singulation. The discussion provides a specialized design of mold chase for mold encapsulation process, and an augmented mechanical cutting technique of package singulation. Furthermore, insights are shared to apprehend the manufacturability of the improved design and process during assembly manufacturing specifically on the critical process steps of mold encapsulation and package singulation.

Open Access Original Research Article

Retracted: Investigation and Implementation of Compressed Air Powered Motorbike Engine

Tamer Nabil

Journal of Engineering Research and Reports, Page 24-38
DOI: 10.9734/jerr/2020/v10i217034

Fossil fuels amount became very limited due to their terrific use. Also, the fossil fuels dependence has brought many environmental complications. Vehicles using compressed air as a fuel are considered like a dream and have involved many considerations. The compressed air engine (CAE) is receiving worldwide attention because it takes advantages of renewable energy and has zero exhaust emissions. The motorbike engine has emission percentage greater than any fuel operated engines. Currently in Egypt, there are more than 3 million motorcycles (motorbikes and covered three wheeled motorbikes called tuktuk) driven by fossil fuel. This paper provides an overview of air power engine for motorcycle, called air bikes. The objective is to modify the four stroke petrol engine into two stroke compressed air engine by replacing the spark plug by solenoid valve and using the Infra-Red (IR) modules for the piston timing. Due to availability, the used air compressor is piston type with maximum 8bar and 100 L capacity. Prototype of air powered motorbike engine is implemented by modification of 150 cm3 Dayun commercial petrol engine. The modified compressed air engine speed is 300 rpm at 8bar air pressure with 7.8 Nm torque and 245 watt power. The efficiency of the compressed air engine reached 9.6%. Yet, due to utilization of low compressed air pressure, the performance of the investigated CAE is so poor that it clearly has minor impact in motive power and hinders its commercialization.

 

Retraction Notice: This paper has been retracted from the journal after receipt of written complains. This journal is determined to promote integrity in research publication. This retraction is in spirit of the same. After formal procedures editor(s) and publisher have retracted this paper. Related policy is available here: http://goo.gl/lI77Nn

Open Access Original Research Article

Warpage Mitigation through Diebond Process Improvement with Enhanced Leadframe Configuration

Edwin M. Graycochea Jr., Frederick Ray I. Gomez, Rennier S. Rodriguez

Journal of Engineering Research and Reports, Page 39-42
DOI: 10.9734/jerr/2020/v10i217035

This paper presents an improvement in the design of quad flat no-leads (QFN) leadframe material to reduce the amount of unit rejection due to excessive leadframe warpage observed after die attach curing (DAC) process. The enhanced leadframe design includes modification through increasing the number of unit panels from 2 maps structure into 4-panel configuration to integrate mechanical relief for coefficient thermal expansion (CTE) mismatch between different material composition present inside the device. The implementation of this design in the assembly of QFN successfully reduced the amount of leadframe warpage into manufacturable level with positive impact in production output and assembly yield.

Open Access Original Research Article

Optimization of Mild Steel Welding Process Parameters Using Multivariate Linear Regression

William E. Odinikuku, David Atadious, Ikechukwu P. Onwuamaeze

Journal of Engineering Research and Reports, Page 43-50
DOI: 10.9734/jerr/2020/v10i217036

Local welders in Nigeria are prone to poor quality weldment because of their lack of welding technical skills. When these local welders carry out their welding operation, the welded joints are considered to be good enough because the metal materials welded together are seen to be good and satisfactory. In most case, when these welded joints have not fully served their service life, these materials fail due to the poor quality of the weldment. Material quality can easily be assessed by inspecting the microstructure of the weldment. In this wok, mild steel welding process parameters were optimized using multivariate linear regression (MLR). The study involves the determination of the suitable set of conditions for the welding process parameters that would give the optimum weld of mild steel (low carbon steel) using Gas Metal Arc welding (GMAW) technique and obtain a relationship between the three welding process parameters and the ultimate tensile strength and Brinell hardness number. For this reason, an experimental study was carried out using nine samples of the specimen of mild steel. The experimental and predicted results show that arc voltage and gas flow rate affect the ultimate tensile strength and the Brinell hardness number of mild steel. The maximum ultimate tensile strength and Brinell hardness number were obtained at 180A, 15V and 20l/min. It was also observed that the ultimate tensile strength decreases with increases in arc voltage and gas flow rate. But these two parameters tend to have a positive effect on the Brinell hardness number.

Open Access Original Research Article

A Comprehensive Study for Specialized Silicon-on-Insulator Wafers

Bryan Christian S. Bacquian, Frederick Ray I. Gomez

Journal of Engineering Research and Reports, Page 51-57
DOI: 10.9734/jerr/2020/v10i217037

The relentless advancement and trends on thinner packages have become the focus in the semiconductor manufacturing industry. The requirement of thinner packages also demands a thinner vertical structure of the semiconductor electronic design. As a major contributor on the vertical structure of the electronic package, die or wafer is also essential to go thinner. As the wafer becomes thinner, various problems may occur during transport and even the backgrinding process itself.

Wafer warpage is one of the main concerns during the wafer backgrinding process. Insufficient vacuum may cause non-planar wafer in contact with the chuck table that may result to poor grinding and broken wafer. Wafer backgrinding stress and backgrinding tape tension also contribute to the effect on wafer warpage. Challenges exist in processing different silicon wafer technology, particularly the silicon-on-insulator (SOI) technology. Evaluating the effect of backgrinding tape selection and vacuum efficiency to eliminate such warpage is presented in this paper.