Open Access Original Research Article

Remediation of Crystal Violet Dye Aqueous Solution Using Agro Waste Based Activated Carbon: Equilibrium and Kinetics Studies

Chukwunonso Chukwuzuloke Okoye, Okechukwu Dominic Onukwuli, Chinenye Faith Okey- Onyesolu, Ifeoma Amaoge Obiora- Okafo

Journal of Engineering Research and Reports, Page 1-11
DOI: 10.9734/jerr/2020/v15i417149

Remediation of crystal violet (CV) dye aqueous solution was attempted using acid activated raphia hookeri seeds (AARHS) as adsorbent. Adsorption equilibrium and kinetics of CV dye uptake onto AARHS were examined in series of experimental runs, and effects of contact time and initial CV dye concentrations were investigated at different solution temperatures (303 K, 313 K and 323 K). Equilibrium and kinetic data modeling of the adsorption process was performed using selected theoretical methods. Four different forms of Langmuir (type I, II, III and IV) and Freundlich isotherms were considered for fitting the equilibrium data while zero order, first order, pseudo-first order (PFO), second order, types I, II, III and IV pseudo-second order (PSO) and intra-particle diffusion models were selected to describe the kinetics of the adsorption process. Error functions including coefficient of determination (R2), root mean square error (RMSE), chi square (χ2) and average relative error (ARE) were employed to reveal model of best fit. Results obtained from error value computations show that the equilibrium data best followed Freundlich isotherm, which indicates multilayer adsorption of CV dye onto AARHS. The calculated Freundlich’s adsorption intensity values at different temperatures reveal the favourability of the adsorption process. PSO type I, II and IV best fitted the kinetic data compared to other investigated models. Intra-particle diffusion plots depict that the adsorption process of CV dye onto AARHS is a two-step process and also, intra-particle diffusion is not the only rate-limiting step.

Open Access Original Research Article

Leadframe Design Enhancement for Elimination of Burrs at Singulation Process

Antonio Sumagpang Jr., Frederick Ray Gomez, Edwin Graycochea Jr.

Journal of Engineering Research and Reports, Page 12-16
DOI: 10.9734/jerr/2020/v15i417150

The paper focused on the improvement done in leadframe design to address the copper (Cu) burrs defect in assembly manufacturing.  Newly qualified device struggled to hit the target yield due to the said Cu burrs defect. A holistic approach through why-why analysis was performed by the technical cross-functional team to identify the root-cause and come-up with the robust solution to the issue. The paper discussed how the device in focus was made as point of reference in designing a leadframe carrier. Ultimately, the new and enhanced leadframe design successfully eliminated the occurrence of Cu burrs with 100% improvement in the scrappage rate.

Open Access Original Research Article

Pressure Transient Analysis for Sandstone Reservoir by Using Saphir

Hussein Al- Ali

Journal of Engineering Research and Reports, Page 17-24
DOI: 10.9734/jerr/2020/v15i417151

This work is discussed how to differentiate between two tricky models for sand stone formation by using the pressure transient analysis PTA for three Wells which are distributed in south, middle and north of X field. In the derivative curve these two models have the same sequence of flow regime which are by hump, first radial flow regime, transition hump and then late radial flow regime. The parameter Kappa (K) played the most important key to select the type of reservoir model and differentiate between the two models in PTA. In the middle and south of the field, this parameter has a value close to one at well no. Rt-16 & Rt-18, which means that the system behaves as dual porosity. On the other hand, Kappa has a value of around (0.74) in Rt-17 to represent a double permeability system but without cross flow between two layers due to the small value of Lamda.

Open Access Original Research Article

Economic Analysis of Compressor Inlet Air Precooling Techniques of a Gas Turbine Operational in Nigerian Energy Utility Sector

Victor C. Okafor

Journal of Engineering Research and Reports, Page 25-34
DOI: 10.9734/jerr/2020/v15i417152

Economic analysis of gas turbine compressor inlet air precooling is based on the economical evaluation (maintenance, operations and personnel costs) of the various precooling systems used to improve the performance of gas turbine operational in Nigeria energy utility sector. The precooling techniques studied are evaporative, vapour compression and vapour absorption precooling techniques. This study objectively compared the three precooling techniques taking into consideration the prevailing climatic conditions of Nigeria. The overall yearly cost for evaporative, vapour compression and vapour absorption precooling techniques are evaluated to be USD25501.31/KWh, USD69867.19/KWh and USD1184548.01/KWh respectively and the payback time is three years. The system profitability for evaporative, vapour compression and vapour absorption precooling systems are USD1785376.83/KWh, USD7198182.79/KWh and USD11103747.4/KWh respectively and the payback time is three and a half year. The Net Revenue of the systems is USD8782909.21/KWh, USD15888192.52/KWh and USD84947043.84/KWh respectively. In conclusion, it is recommended that evaporative precooling system should be used in dry and humid weather conditions (Northern region of Nigeria) but it must be ensured that water is in abundance and refrigeration precooling should be employed in the moderate climatic conditions (Southern Region of Nigeria).

Open Access Original Research Article

The Role of Nano-SiC on Microstructure and Tribo-logical Properties of SiC/Cu Nano-Composite

M. A. Metwally, M. M. Sadawy, M. Ghanem, I. G. El- Batanony

Journal of Engineering Research and Reports, Page 35-44
DOI: 10.9734/jerr/2020/v15i417153

The present study has investigated the role of nano-SiC on microstructure and tribological properties of SiC/Cu nano-composite. The nano-composite powders have been cold compacted under a constant pressure of 480 MPa and sintered at 8600 C under argon gas for 2 h. SEM-EDS and XRD diffraction were performed for microstructure examinations. Pin-on-disk experiments were carried out under wet conditions (3.5 wt. % NaCl solution). All samples have been investigated against abrasives of different sizes (from 7, 13, 20 and 26 µm), at different applied loads (10, 15, 20 and 25 N), and sliding speed (0.25, 0.5, 0.75 and 1.0 m/s).  The results revealed   that the grain structure of the copper matrix was reduced with increasing SiC nano-particles. Furthermore, it was found that the wet wear resistance was improved as a function of nano-SiC content.

Open Access Original Research Article

Analysis of Petro-Physico-Mechanical Properties of Coarse Aggregate and Its Implications on the Performance Characteristics of Concrete

Larry Pax Chegbeleh, Lawrence Opanin Nkansah, Frank Siaw Ackah, Richard Adams Mejida

Journal of Engineering Research and Reports, Page 45-60
DOI: 10.9734/jerr/2020/v15i417164

The importance of concrete as one of the major materials in the building and construction industry cannot be over emphasized due to the myriad benefits and versatility to humankind. However, its performance characteristics on the stability of engineered structures have mostly been overlooked. In this paper, petrographic characteristics and physico-mechanical properties of ten (n=10) rock samples and some quantity of coarse aggregate representing one set of samples, each obtained from two quarry sites around Amasaman and Shai Hills in the Greater Accra Region of Ghana, have been investigated. This study aimed to determine the impact of aggregate size, content and type on the compressive strength of concrete. The study was conducted through petrographic and physico-mechanical properties analyses on the samples obtained. Petrographic studies were performed on the ten (n=10) rock samples from each quarry site, while the physico-mechanical property tests were conducted directly on the coarse aggregate. However, compressive strength tests were performed on cast concretes produced from aggregates with varying sizes and type obtained from the two quarry sites. Results of the petrographic analysis reveal two rock types: Quartzo-feldspathic gneiss and Granodiorites from Amasaman quarry and also two rock types: Gneiss and Meta-granite from Shai Hills quarry. Results of the physico-mechical properties tests are consistent with requirement of approved construction standards. Compressive strength tests show increasing compressive strength of concretes with increasing aggregate nominal sizes of classes A, B and C but show reduced compressive strength for aggregate nominal sizes of class D. It can therefore, be inferred that, aggregate size and content have profound impact on compressive strength of concrete. Also, aggregate type has influence on compressive strength of concrete, as observed in higher compressive strength of concretes produced from the quartzo-feldspathic gneiss and granodiorites than concretes produced from the gneiss and meta-granites.