Journal of Engineering and Sustainable Development (JEASD)

Several chemical and biological processes have been investigated and predicted using Response Surface Methodology (RSM) models. Response Surfaces Methodology is a useful instrument for designing laboratory-scale experiments that optimize and support the research outcomes with statistical analysis. It is a powerful statistical technique for complex variable study systems. The standard optimization (one component at a time) strategy is well-studied. However, it has significant drawbacks, such as requiring more experimental runs and time and failing to reveal the synergistic impact of processing parameters. It is a valuable instrument for process improvement. Recent research has shown, for instance, that RSM successfully optimizes biodiesel in fats and oils generated from diverse feedstocks. According to this study, Response Surface Methodology is the best cost-effective technique for maximizing environmentally friendly and sustainable methods applied to different experimental procedures. The current review reported RSM's application, theory, methodology, advantage, and limitations for different processes using different oil sources.

Natural fibres are potential alternatives to synthetic fibres. Sago palm is a new type of natural fibre and has the potential same as other existing natural fibres. In this study, mechanical properties of sago palm / carbon fibre reinforce with epoxy hybrids were studied. Impact tests were conducted to study the impact properties of sago palm-carbon fibre reinforced epoxy hybrid composites. The hybrid composites contain woven sago palm fibre and carbon fibre reinforced with epoxy resin is produced by the vacuum compaction method. Each sample was prepared with different volume fractions such as 40%, 64% and 91% of composition sago palm fibre. After the preparation of composite material, mechanical properties tests were studied on the prepared sample. In addition, by using Scanning Electron Microscope Tests, the failure mode is investigated. It can be concluded that the 40% of sago palm fiber contain have the best impact behavior compared to the 64% and 91% of sago palm fiber loading because it’s high in impact resistance.

This paper introduces the design of a new dual polarization rectangular microstrip patch antenna based on metamaterial structures at X-band. The work focuses on two distinct configurations of a microstrip patch antenna utilizing metamaterials. Pairs of spiral ring resonators are loaded into a rectangular patch antenna system in the first design. The second strategy involves inserting a split ring resonator at the end of microstrip feed lines. The utilization of metamaterial structures in the microstrip antenna system compensates for the patch antenna's asymmetric current distribution flow, resulting in symmetrical current distribution. The simulation results display an important enhancement in cross polarization discrimination (XPD) and good port decoupling. The antenna system has various characteristics, including a basic structure and metamaterial inclusions that take up a small amount of space, making the suggested metamaterial inclusions more beneficial for dual-linear polarized patch antenna construction. These prototypes are suitable to work for polarimetric radars.

As is usual in a multiple-receiver wireless power transfer (WPT) system based on s-s geometry, the power of load obtained and system efficiency are very sensitive to changes in the number of receivers. An improved multi-receivers WPT system is introduced that ensures the power given for each load remains stable while other receivers enter or exit the system. This study proposes a multiple-load WPT system operated by a class E amplifier. The equivalent system circuit model is analyzed of major parameters such as receiver power, transmitter power, transmission efficiency, and each load power allocation. A control circuit is proposed to obtain high transmission efficiency, power control for the transmitter, and arbitrary power distribution ratios of receivers for different loads. The cross-coupling between the receiver coils is prevented by adding compensating capacitors at the receiver side in series. This further increases the power stability obtained by loads. Finally, in order to verify the feasibility of the proposed process, simulation results are presented.

Strengthening concrete structures with Fibre Reinforced Polymer (FRP) is one of the most commonly used tech-nique to repair and rehabilitate concrete members due to the advanced properties of FRP over other conven-tional materials such as steel plates. The required per-formance of FRP-concrete system is linked to achieve proper bond between FRP and concrete substrates that as exposed to different environmental conditions. In the current paper, a review is conducted to highlight the most reported work by other researchers regarding the bond behavior of concrete members that strengthened with FRP in shear-tension and exposed to temperature-based conditions and compared with ambient conditions. The current review focused on the conducted work on FRP/concrete system that strengthened with two differ-ent installation techniques (externally bonding (ES) and near–Surface mounted (NSM)) using two different bond-ing agents (epoxy-based adhesive (EBA) and cement-based adhesive (CBA)) with and without modification. The adoption of two specific bond test procedures (adhesion and single lap shear tests) at ambient conditions and tem-perature-based conditions was also reviewed intensively to clarify the advantages and drawbacks that associated with each test. Some reported findings by others in con-ducting bond test methods for different FRP/concrete systems was highlighted as well to address the gap in knowledge and the need for further research in this re-gard.

During the past decades, environmental noise and its negative effects on humans in its entire social, economic, and health aspects have been addressed. However, the study of the impact of noise in residential buildings on E-learning for university students during the lockdown period due to the Corona pandemic, specifically in Iraq, had not been sufficiently studied, which is the research problem. The research aims to explain the acoustic insulation and the negative impact of noise exposure in residential buildings on E-learning for university students during the quarantine period. A questionnaire was conducted for several Iraqi university students. The questionnaire has detected many indications (noise sources, use of headphones, duration of use, effects of noise exposure, and noise insulation control). The results showed the negative effects of noise that the students may feel, such as hearing difficulty, lack of concentration, raising the voice when speaking, discomfort, tinnitus, headache, and nausea; and determining the student’s knowledge of noise and their opinions. The research recommends the adoption of acoustic insulation in residential buildings to reduce the negative effects of noise exposure on E-learning education.