Open Access Original Research Article

Influence of Elevated Temperature on Concrete Properties Containing Natural Wastes Treated by Pyrolysis

Manal M. Farag, Magdy El- Yamany, A. S. Faried, W. H. Sofi

Journal of Engineering Research and Reports, Page 1-15
DOI: 10.9734/jerr/2020/v19i217225

Concrete is probably the most extensively used construction material in the world. The modern concept of construction is directed at the use of recycled materials, in particular, various waste products. This solves a number of problems -saving the expensive materials; - decreasing CO2 emissions by reducing the production of construction materials, so, these can also be used as refractory materials. Plant fibers are the most abundant fiber among all the natural fibers. Bamboo, palm, sisal, jute, date kernel, flax etc. are the commonly known plant fibers. Plant fibers are also called cellulosic fiber and have quite promising tensile strength. Natural Plant fibers treated by pyrolysis in concrete such as additions; determine the effect of these substances and the effect of temperature on the properties of concrete. The natural fibers in concrete are added accordingly with the percentage of 0.5%, 1%, 1.5% and 2% by weight of cement concrete cubes are tested at the age of 7 and 28 days of curing. Natural waste treated by pyrolysis and different additives on concrete behavior to improve its performance in the future to use in Civil Engineering and Construction World. The optimum result for natural fibers was observed at 1.0% for bamboo and date kernel and 1.5% for palm oil of natural fiber.

Open Access Original Research Article

Elimination of Crumpled Leadframe Defect through Machine Sensor Enhancement

Jonathan C. Pulido, Edwin M. Graycochea Jr., Frederick Ray I. Gomez

Journal of Engineering Research and Reports, Page 16-19
DOI: 10.9734/jerr/2020/v19i217226

The paper focused on the improvement done in quad-flat no-leads (QFN) leadframe package assembly to address the quantity of rejection of crumpled leadframe during handling at wirebond process station. Overload sensor at the output magazine handler was found out to be defective, hence a new sensor was installed. With the improvement done, crumpled leadframe strip occurrence was ultimately eliminated.

Open Access Original Research Article

Design of Solar Blind Photodetectors for Communication with Green Signal (λ= 0.532µm) in Space. Part II

Samson Mil’ shtein, Dhawal Asthana

Journal of Engineering Research and Reports, Page 20-25
DOI: 10.9734/jerr/2020/v19i217227

The areas of Free Space Optical (FSO) communication and high-speed Visible Light Communication (VLC) offer potential for very high-speed data transmission. Favorable attributes including high frequency and wider bandwidths that can enable transmission speeds of the order 100Gb/s, associated with the visible region of the electromagnetic spectrum make it preferable for allowing communication among satellites and ground stations, under-water communication, etc. However, limitations associated with spectral absorption characteristics of the propagating media have stymied further development of such technologies.

Aims: Commercial lasers operating in red, green and blue lights combined with three photodetectors, each sensitive to selected wavelengths (colors) present basics of long-distance optical communication system. The current study (Part II) depicts the design and operation of a solar-blind photodetector capable to work explicitly with green wavelength of 532nm.

Study Design and Results: The structure of the solar-blind photodetector consists of two sections made of InxGa1-xN (Indium Gallium Nitride) heterostructure, (where x denotes the mole fraction)-a filter and a double barrier tunneling diode. The topmost approximately 1µm thick section acts as a filter and as a p-i-n solar cell providing the required voltage bias to the photodiode. The filter with Eg (Energy Band Gap)=2.33eV absorbs all photons having wavelengths shorter than 532nm. The double barrier tunneling photodiode which comprises the lower section operates with Eg=2.28eV. It consists of an n-type lightly doped quantum well having a width of 2.5nm housed between two lightly doped barriers of 10nm thickness. The 0.12µm topmost and bottom regions of the photodiode are doped with p and n (2×105cm-3) type impurities, respectively. The illuminated cross-section area of the device is finalized at 1mm2.

Open Access Original Research Article

Wirebond Process Optimization through Stitch Relocation on QFN Package

A. Moreno, E. Graycochea Jr., F. R. Gomez

Journal of Engineering Research and Reports, Page 26-30
DOI: 10.9734/jerr/2020/v19i217228

One of the most challenging assembly manufacturing process in semiconductor industry is wirebond process using a wire as direct material. With this new technology, some issues were encountered during the first trial of a quad flat no-leads (QFN) package. This paper is focused on the heal crack seen on the stitch formation during second bond. A comprehensive improvement was done by relocating the stitch formation on the second bond. Ultimately, heal crack occurrence was successfully eliminated.

Open Access Original Research Article

Optimal Placement and Sizing of Capacitors in Radial Distribution Systems: A Two-Stage Method

Sunday Adeleke Salimon, Abiodun Aderemi Baruwa, Saheed Oluwasina Amuda, Hafiz Adesupo Adeleke

Journal of Engineering Research and Reports, Page 31-43
DOI: 10.9734/jerr/2020/v19i217229

Optimal allocation of shunt capacitors in the radial distribution networks results in both technical and economic benefits. This paper presents a two-stage method of Loss Sensitivity Factor (LSF) and Cuckoo Search Algorithm (CSA) to find the optimal size and location of shunt capacitors with the objective of minimizing cost due to power loss and reactive power compensation of the distribution networks.

The first stage utilizes the LSF to predict the potential candidate buses for shunt capacitor placement thereby reducing the search space of the second stage and avoiding unnecessary repetitive load flow while the second stage uses the CSA to find the size and actual placement of the shunt capacitors satisfying the operating constraints.

The applicability of the proposed two stage method is tested on the standard IEEE 33-bus and Ayepe 34-bus Nigerian radial distribution networks of the Ibadan Electricity Distribution Company. After running the algorithm, the simulation results gave percentage real and reactive power loss reduction of 34.28% and 28.94% as compared to the base case for the IEEE 33-bus system while the percentage real and reactive power loss reduction of 22.89% and 21.40% was recorded for the Ayepe 34-bus system.

Comparison of the obtained results with other techniques in literatures for the standardized IEEE 33-bus reveals the efficiency of the proposed method as it achieved technical benefits of reduced total power loss, improved voltage profile and bus voltage stability, and the economic benefit of reduced total cost due to electrical power loss and compensation.