Open Access Original Research Article

Bio-tower Application for Wastewater Treatment

Klaus Doelle, Yue Qin, Qian Wang

Journal of Engineering Research and Reports, Page 1-7
DOI: 10.9734/jerr/2020/v11i117048

The study tested the performance of a batch-type recirculating laboratory scale bio-tower for the treatment of municipal wastewater. Performance tests were done with a HACH DR-1900 spectrophotometer include chemical oxygen demand, total phosphorus and nitrogen ammonia.

This study showed that the recirculated laboratory type bio-tower containing 0.276 ft3 (0.008 m3) of polypropylene growth media with a surface area of 6.624 ft2 (0.615 m2) can reduce the chemical oxygen demand between 70% to 87%. NH3-N reduction was found to be between 94% to 96%, and total phosphorus reduction was between 69% and 87% for flow rates of 0.6 l/min to 1.5 l/min.

Open Access Original Research Article

A Study of the Effect of Back Grind Wheels on Wafer Edge Chippings and Die Strength

Bryan Christian S. Bacquian

Journal of Engineering Research and Reports, Page 8-14
DOI: 10.9734/jerr/2020/v11i117049

The drive for thinner package architecture is already becoming a necessity. There were a need of thinner Integrated Circuit or IC in order to fit in to thinner applications like mobile phones. One of the major semiconductor process that enables miniaturization was wafer back grinding. The process involves wafer thinning to a required thickness with the use of back grinding wheels that serve as the abrasive material. The paper will discuss the effect of back grind input parameters like step grinding and wheel grit size to its output characteristics like total thickness variation, edge chippings and die strength. Total thickness variation will define if the new wheel will not affect the variation with the wafer. On the other hand, edge chippings and die strength will define the reliability of the die on different conditions of the package. Lastly, these 3 characteristics will establish the manufacturability of the process as it will eliminate the probability of wafer breakage.

Open Access Original Research Article

Design of Sequencing Batch Reactor (SBR) Treatment Plant for Abattoir Wastewater (A Case of Apa Mmini Stream)

Ogbebor Daniel, Ndekwu, Benneth Onyedikachukwu

Journal of Engineering Research and Reports, Page 15-21
DOI: 10.9734/jerr/2020/v11i117050

Aim: The study aimed at designing a wastewater treatment method for removal of (Biological Oxygen Demand) BOD5 using Sequencing batch reactor (SBR).

Study Design: SBR functions as a fill-and-draw type of activated sludge system involving a single complete-mix reactor where all steps of an activated sludge process take place.

Methodology: The intermittent nature of slaughterhouse wastewaters favours batch treatment methods like sequence batch reactor (SBR). Attempts to remediate the impact of this BOD5 on the stream, led to the design of a sequence batch reactor which was designed to treat slaughterhouse effluent of 1000 L.

Results: The oxygen requirement for effective removal of BOD5 to 95% was determined to be 21.10513 kgO2/d, while L:B  of 3:1 was considered for the reactor. Also, air mixing pressure for the design was 0.16835 bar, while settling velocity was .

Conclusion: To ensure proper treatment of BOD5 load of the slaughterhouse, a sequencing Batch reactor of 1000 litre carrying capacity was designed. For effective operation of this design, the pressure exerted by the mixing air was 0.16835 bar which was far greater than the pressure exerted by the reactor content and the nozzle. Settling velocity of 0.0003445 m/s for 0.887 hrs was required for the reactor to be stable and a theoretical air requirement of 1.6884 m³/d was calculated. Hence the power dissipated by the rising air bubbles to ensure efficient mixing of oxygen in the reactor was calculated as 26530003.91 Kilowatts. With these design parameters, the high BOD5 load downstream of the river can be treated to fall below the FMEnv recommended limit of 50 mg/l.

Open Access Original Research Article

Die Attach Process Analysis of Enhanced Stand-off Stopper on Tapeless Leadframe

E. Graycochea Jr., F. Gomez, R. Rodriguez, B. Bacquian

Journal of Engineering Research and Reports, Page 22-26
DOI: 10.9734/jerr/2020/v11i117051

Improvement on the process and design is often a reliable way to resolve a problem especially in semiconductor industry. This paper presents a leadframe or semiconductor carrier merged with a stand-off design structure that will maintain a consistent bond line thickness (BLT) criteria for quad-flat no-leads (QFN) packages. Through package and process conceptualization, the stand-off design located on the leadframe underneath the silicon die corners would result to a steady and consistent BLT during die attach process. With the improved design, die tilt occurrence in die attach process would be mitigated.

Open Access Original Research Article

Effect of Grid Instability on Power Generation System's Reliability

Joseph Benedict Bassey, Isaac F. Odesola

Journal of Engineering Research and Reports, Page 27-37
DOI: 10.9734/jerr/2020/v11i117053

Aims: Reliability assessment of power generation system may be performed with the concept of system adequacy, security or both. Grid being a major component in the power distribution chain is seen to have some influence on the state of the generation system reliability because of the perturbation that may arise from it. In this study, the generation system reliability is evaluated using both the system adequacy and security concept.

Study Design: To capture the system security problems attributed to grid disturbance, the generation system is structured into two component systems (1 - generation component and 2 - transmission component) with a series arrangement.

Methodology: The reliability indices such as, mean time to failure, mean time to repair, failure rate and repair rate are assessed on component bases and with respect to the entire generation system.

Results: The effect of failure rate of the transmission component on the entire generation system failure rate was evaluated as 66.25%, 55.55%, 33.33%, 55.00% and 35.72% in year 2013, 2014, 2017 2018 and 2019 respectively for FIPL Power Plant and 52.94%, 82.35%, 61.38% and 100% effect was evaluated in the year 2016, 2017, 2018 and 2019 respectively for GT5 of Omoku Power Plant.

Conclusion: These results showed that there is a significant influence of grid disturbances on the reliability state of the two gas turbine power plants in Nigeria. Measures on possible reliability state improvement of the power generation systems were suggested to include training and retraining of technical personnel on the management of major equipment in the generation and transmission stations.