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55. Recent Advances on Bacterial Cellulose-Based Wound Management: Promises and Challenges

Author

Moradpoor, Hedaiat, Mohammadi, Hossein, Safaei, Mohsen, Mozaffari, Hamid Reza, Sharifi, Roohollah, Gorji, Pourya, Sulong, Abu Bakar, Muhamad, Norhamidi, and Ebadi, Mona

Subjects
integumentary system, Article Subject
Abstract

Wound healing is a therapeutic challenge due to the complexity of the wound. Various wounds could cause severe physiological trauma and bring social and economic burdens to the patient. The conventional wound healing treatments using bandages and gauze are limited particularly due to their susceptibility to infection. Different types of wound dressing have developed in different physical forms such as sponges, hydrocolloids, films, membranes, and hydrogels. Each of these formulations possesses distinct characteristics making them appropriate for the treatment of a specific wound. In this review, the pathology and microbiology of wounds are introduced. Then, the most recent progress on bacterial cellulose- (BC-) based wound dressing discussed and highlighted their antibacterial and reepithelization properties in vitro and in vivo wound closure. Finally, the challenges and future perspectives on the development of BC-based wound dressing biomaterials are outlined.

Published
2022
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64. Re-Evaluating the Wax Flow Assurance Chemical Mitigation Strategy for a Major Deepwater Oil Pipeline in Malaysia Yields Significant Benefits

Author

Craig John Kelly, Istiyarso Istiyarso, Amir Sani Abdul Bak, Maxwell Tommie Lajawai, Muhamad Norhamidi, Nurul Ashikin Marsidi, Karlos Gusting, and M. Shakir M. Nawi

Subjects
Pipeline transport, Wax, 020401 chemical engineering, Petroleum engineering, visual_art, Flow assurance, visual_art.visual_art_medium, Environmental science, 02 engineering and technology, 0204 chemical engineering, 010502 geochemistry & geophysics, 01 natural sciences, 0105 earth and related environmental sciences
Abstract

This paper describes the change of the chemical flow assurance mitigation strategy for a major deep water waxy crude oil pipeline in SE Asia. The case relates to an application of a Pour Point Depressant (PPD)/Wax Inhibitor (WI) chemical that is critical in maintaining subsea flow assurance due to cooling of a waxy crude oil over the length of the 210 km deep water subsea pipeline. The paper further describes how the injection strategy was successfully changed. New chemical key performance indicators (KPIs) were initially determined based on chemical performance and risk mitigation requirements. Results of the laboratory new chemical formulation, qualification and subsequent successful field trial are presented. Other significant benefits yields are also discussed. KPI targets for the PPD/WI application were first determined based on field application performance and requirements. Candidate PPD/WI chemicals were selected based on the KPI requirements and initially screened to evaluate performance in reducing the crude oil pour point. Product development was then further refined once a definitive correlation between chemical structure and performance for the specific waxy crude oil was identified. Subsequently, more detailed laboratory testings were performed, including rheology measurements, coaxial shearing paraffin deposition and dynamic wax flow loop measurements. Field trial was later conducted to gradually obtain the optimum dosage while closely monitoring both onsite and in the lab to confirm the product effectiveness. Key to the success of the change was the identification of the opportunity to switch the PPD injection from subsea to topsides. This decision enabled a much wider portfolio of PPD chemistries to be evaluated. New topside PPD was identified which was able to reduce the pour point of the crude oil from 18°C to 9°C using a low dose rate of ~100 ppm, which is a ~40% reduction in chemical consumption compared to the previous chemical used. The new chemical was piloted without any disruption to the facilities and/or production. Furthermore, the field trial created significant benefits by reducing OPEX through the reduction in waxy pigging debris and chemical logistics, improving HSE and reducing the risk of chemical non-deliverability due to umbilical blockages. This paper demonstrates the re-evaluation of a field’s flow assurance strategy to realize significant benefits by challenging conventional wisdom regarding the need for subsea PPD/WI injection in waxy deep water fields. Understanding the gel strength of the crude through detailed evaluation and monitoring of the shear force needed to break the gel during a shutdown by using an optimized PPD/WI product/dosage is an important parameter to look at to ensure effective field optimization, rather than relying on the standard method of pour point monitoring.

Published
2020

65. Metal Injection Moulding Parameters Optimization and Interaction Study Using Taguchi Method

Author

Tan, Koon Tatt, Muhamad, Norhamidi, Che Haron, Che Hassan, Sulong, Abu Bakar, Tan, Koon Tatt, Muhamad, Norhamidi, Che Haron, Che Hassan, and Sulong, Abu Bakar

Abstract

In this study, the Taguchi method is used to find the optimal moulding parameters for the metal injection moulding (MIM) feedstocks. Parameters optimised are injection temperature (factor A), mould temperature (factor B), injection pressure (factor C) and flow rate (factor D). Feedstocks used were water atomised stainless steel powder with a solid loading of 62 %Vol and the multicomponent binder consisting  PEG, PMMA and strearic acid. Green defects and green density were considered as quality characteristics (response) and optimised by using Taguchi’s L81 (340) orthogonal array. Green defects evaluated using parameter design for discrete data technique while green densities were measured according to the MPIF standard 42. The signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to investigate the quality characteristics. The analysis results show that the mould temperature (factor B) is the most significant factor affecting the quality characteristic. The optimal conditions for the green defects and green density are A1B2C0D1 and A2B2C1D0 respectively. The influences of the two-factor interactions and three-factor interactions cannot be neglected.

Published
2020

77. Erratum to: “Effects of thermal cycling on physical and tensile properties of injection moulded kenaf/carbon nanotubes/polypropylene hybrid composites” [JCOMB 161C (2019) 659–666]

Author

Razak, Zakaria, primary, Sulong, Abu Bakar, additional, Muhamad, Norhamidi, additional, Haron, Che Hassan Che, additional, Radzi, Mohd Khairol Fadzly Md, additional, Ismail, Nur Farhani, additional, Tholibon, Dulina, additional, and Tharazi, Izdihar, additional

Published
2019
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79. Organic structure and organisational learning as the main antecedents of workforce agility.

Author

Alavi, Somaieh, Abd. Wahab, Dzuraidah, Muhamad, Norhamidi, and Arbab Shirani, Behrooz

Subjects
ORGANIZATIONAL learning, JOB skills, DECENTRALIZATION in management, DECISION making, BUSINESS enterprises
Abstract

Studies on agility in the workplace have focused excessively on technical factors, and little attention has been given to the workforce. Most studies on workforce agility are conceptual and have a notable absence of quantitative modelling and analysis. In the study, a theoretical model of the impact of two organisational characteristics, namely organisational learning and an organic structure (with three dimensions, which are decentralisation of decision-making, low formalisation and a flat structure), on workforce agility was developed and empirically tested. Several small- and medium-sized enterprises in Iran were investigated. The structural equation modelling showed that organisational learning and only the decentralisation of decision-making and a flat structure were positively and significantly correlated with workforce agility. The impact of the dimensions of an organic structure on organisational learning was also considered. Based on the results, we proposed a process model on workforce agility. [ABSTRACT FROM PUBLISHER]

Published
2014
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80. The Study of Sintering Behavior of Stainless Steel 17-4PH-Stainless Steel 316L for Two Materials Powders Injection Molding (2C-PIM) Process.

Author

Mas'ood, Najlaa Nazihah, Sulong, Abu Bakar, Muhamad, Norhamidi, Foudzi, Farhana Mohd, and Salleh, Farrahshaida Mohd

Subjects
POWDER injection molding, STAINLESS steel, INJECTION molding of metals, SINTERING, MATERIALS, STEEL
Abstract

Two materials Powder Injection Molding (2C-PIM) is a recently developed method to manufacture functionally graded components. This study is focused on determining the suitability of two materials combined via experimental PIM technique by the sintering and microstructural evaluations. In addition, the shrinkage behavior between the two materials is also observed. The materials in 2C-PIM are said to be compatible with each other in terms of metallurgical bonding and responsive during the sintering process. The materials are stainless steels 17-4PH and 316L with palm stearin and polyethylene as the binders. It has been found that the difference sintering shrinkage for both materials is not significant due to the coefficient thermal expansion (CTE) between the two materials are quite similar. Therefore stainless steels 17-4PH and 316L can be combined successfully via the 2C-PIM technique. [ABSTRACT FROM AUTHOR]

Published
2019
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