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Void-free electrospun SPEEK/Cloisite15A® densed (SP/e-spunCL) membranes are prepared. Different loadings of Cloisite15A® (0.10, 0.15, 0.20, 0.25 and 0.30 wt %) are incorporated into electrospun fibers. The physico-chemical characteristics (methanol permeability, water uptake and proton conductivity) of the membranes are observed. Thermal stability of all membranes is observed using Thermal Gravimetry Analysis (TGA). The thrree stages of degradation range between 163.1 and 613.1 °C. Differential Scanning Calorimetry (DSC) is used to study the wettability of the membranes. SP/e-spunCL15 shows the lowest freezing bound water of 15.27%, which contributed to the lowest methanol permeability. The non-freezing bound water that proportionally increased with proton conductivity of SP/e-spunCL15 membrane is the highest, 10.60%. It is suggested that the electrospinning as the fabricating method has successfully exfoliated the Cloisite in the membrane surface structure, contributing to the decrease of methanol permeability, while the retained water has led to the enhancement of proton conductivity. This new fabrication method of SP/e-spunCL membrane is said to be a desirable polymer electrolyte membrane for future application in direct methanol fuel cell field.

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This paper outlines on the preliminary outcomes of pilot project aimed at exploring the issue related to managing of maintenance activity in the Malaysian Small and Medium Enterprises (SMEs). SMEs have been accepted as vital components of domestic industry development in many countries. However, the literature portrays that many of Malaysian SMEs particularly the companies involved in manufacturing, fabrication and machining services are struggling to manage the maintenance of their manufacturing equipment. Dependable manufacturing equipment is important factor towards organizational profitability. Managing the maintenance activity of those manufacturing equipment nowadays, is becoming more challenging due to automation and computerization. Due to such issues, SMEs companies are under stiff pressure to minimize lost time for their survival. Thus, this study seeks to explore the related issues towards further improvements. Qualitative research methodology was adopted in the study. Data were collected at eight (8) SMEs located in three (3) different areas, namely southern, central and eastern region of peninsular Malaysia. Information was gathered from semi-structured interviews with SMEs management and observations focuses on different areas of maintenance management at the respective SMEs. The main concern is to validate the critical success factors (CSFs) in managing the maintenance activity at selected SMEs. This study discovered that nine (9) CSFs are having the most significant impact towards improving the maintenance management practice for SMEs. These include: understanding the MM philosophy; management commitment and leadership; maintenance strategy; maintenance planning; maintenance training; monitoring and assessment; appropriate number of maintenance staff; integration of tools, techniques and technology, and; record of maintenance data. All those CSFs construct are integrated in a simple yet self-explanatory MM Framework to convey the conceptual idea of MM implementation program to the management and technical people within SMEs. It is believed that the MM Framework developed would serve as an indicator of company’s MM focus level. Through the identification of the CSFs constructs, the SMEs can utilize the information to improve their approach in systematic MM program. The discovered CSFs are vital for all stakeholders that directly or indirectly involve in managing the maintenance activity in SMEs. Doi: 10.28991/esj-2021-01283 Full Text: PDF

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Epoxy resin is commonly used in the oil and gas industry due to its excellent toughness, low shrinkage, good adhesive strength, and relatively good thermal resistance. It is used for water shutoff, zonal isolation, cementing, enhanced oil recovery, and preventing leakage in wells. This paper reviews the chemistry aspect of using an epoxy resin system as a sealant to prevent well leakage and it offers insights into the chemistry of the epoxy resin system, as applied in previous studies. The paper also unveils the reasons for the application of this system from the chemistry perspective, allowing this aspect to be better understood. Success in the investigated cases depended on the formulation design. The epoxide and hydroxyl functional groups have been found to contribute substantially to the excellent performance of the sealant system. Furthermore, the amine curing agent triggers the abrupt reaction of the oxirane ring to stabilise when the cured sealant is perfectly applied. Based on the findings, it is suggested that other types of epoxies, namely epoxidised oils, require further study. Finally, in terms of safety and sustainable energy, it is suggested that more curing agent and diluent studies are undertaken.