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  1. Wei LK, Abd Rahim SZ, Al Bakri Abdullah MM, Yin ATM, Ghazali MF, Omar MF, et al.
    Materials (Basel), 2023 Jun 27;16(13).
    PMID: 37444950 DOI: 10.3390/ma16134635
    In the pursuit of achieving zero emissions, exploring the concept of recycling metal waste from industries and workshops (i.e., waste-free) is essential. This is because metal recycling not only helps conserve natural resources but also requires less energy as compared to the production of new products from virgin raw materials. The use of metal scrap in rapid tooling (RT) for injection molding is an interesting and viable approach. Recycling methods enable the recovery of valuable metal powders from various sources, such as electronic, industrial, and automobile scrap. Mechanical alloying is a potential opportunity for sustainable powder production as it has the capability to convert various starting materials with different initial sizes into powder particles through the ball milling process. Nevertheless, parameter factors, such as the type of ball milling, ball-to-powder ratio (BPR), rotation speed, grinding period, size and shape of the milling media, and process control agent (PCA), can influence the quality and characteristics of the metal powders produced. Despite potential drawbacks and environmental impacts, this process can still be a valuable method for recycling metals into powders. Further research is required to optimize the process. Furthermore, ball milling has been widely used in various industries, including recycling and metal mold production, to improve product properties in an environmentally friendly way. This review found that ball milling is the best tool for reducing the particle size of recycled metal chips and creating new metal powders to enhance mechanical properties and novelty for mold additive manufacturing (MAM) applications. Therefore, it is necessary to conduct further research on various parameters associated with ball milling to optimize the process of converting recycled copper chips into powder. This research will assist in attaining the highest level of efficiency and effectiveness in particle size reduction and powder quality. Lastly, this review also presents potential avenues for future research by exploring the application of RT in the ball milling technique.
  2. Idris SN, Amelia TSM, Bhubalan K, Lazim AMM, Zakwan NAMA, Jamaluddin MI, et al.
    Environ Res, 2023 Aug 15;231(Pt 1):115988.
    PMID: 37105296 DOI: 10.1016/j.envres.2023.115988
    Plastics have become an integral part of human life. Single-use plastics (SUPs) are disposable plastics designed to be used once then promptly discarded or recycled. This SUPs range from packaging and takeaway containers to disposable razors and hotel toiletries. Synthetic plastics, which are made of non-renewable petroleum and natural gas resources, require decades to perpetually disintegrate in nature thus contribute to plastic pollution worldwide, especially in marine environments. In response to these problems, bioplastics or bio-based and biodegradable polymers from renewable sources has been considered as an alternative. Understanding the mechanisms behind the degradation of conventional SUPs and biodegradability of their greener counterpart, bioplastics, is crucial for appropriate material selection in the future. This review aims to provide insights into the degradation or disintegration of conventional single-use plastics and the biodegradability of the different types of greener-counterparts, bioplastics, their mechanisms, and conditions. This review highlights on the biodegradation in the environments including composting systems. Here, the various types of alternative biodegradable polymers, such as bacterially biosynthesised bioplastics, natural fibre-reinforced plastics, starch-, cellulose-, lignin-, and soy-based polymers were explored. Review of past literature revealed that although bioplastics are relatively eco-friendly, their natural compositions and properties are inconsistent. Furthermore, the global plastic market for biodegradable plastics remains relatively small and require further research and commercialization efforts, especially considering the urgency of plastic and microplastic pollution as currently critical global issue. Biodegradable plastics have potential to replace conventional plastics as they show biodegradation ability under real environments, and thus intensive research on the various biodegradable plastics is needed to inform stakeholders and policy makers on the appropriate response to the gradually emerging biodegradable plastics.
  3. Saaid FI, Kasim MF, Winie T, Elong KA, Azahidi A, Basri ND, et al.
    Heliyon, 2024 Jan 15;10(1):e23968.
    PMID: 38249110 DOI: 10.1016/j.heliyon.2023.e23968
    The demand for lithium-ion batteries (LIBs) has skyrocketed due to the fast-growing global electric vehicle (EV) market. The Ni-rich cathode materials are considered the most relevant next-generation positive-electrode materials for LIBs as they offer low cost and high energy density materials. However, by increasing Ni content in the cathode materials, the materials suffer from poor cycle ability, rate capability and thermal stability. Therefore, this review article focuses on recent advances in the controlled synthesis of lithium nickel manganese cobalt oxide (NMC). This work highlights the advantages and challenges associated with each synthesis method that has been used to produce Ni-rich materials. The crystallography and morphology obtained are discussed, as the performance of LIBs is highly dependent on these properties. To address the drawbacks of Ni-rich cathode materials, certain modifications such as ion doping, and surface coating have been pursued. The correlation between the synthesized and modified NMC materials with their electrochemical performances is summarized. Several gaps, challenges and guidelines are elucidated here in order to provide insights for facilitating research in high-performance cathode for lithium-ion batteries. Factors that govern the formation of nickel-rich layered cathode such as pH, reaction and calcination temperatures have been outlined and discussed.
  4. Sreedharan DK, Alias H, Makhtar MMZ, Shun TJ, Mokhtar AMA, Shukor H, et al.
    Open Life Sci, 2024;19(1):20220809.
    PMID: 38283116 DOI: 10.1515/biol-2022-0809
    Bacteriocins produced by Bacillus subtilis have gained recognition for their safe use in humans. In this study, we aimed to assess the inhibitory activity of an antimicrobial peptide synthesized by the wild-type strain of B. subtilis against the notorious pathogen Pseudomonas aeruginosa. Our investigation employed the broth microdilution method to evaluate the inhibitory potential of this peptide. Among the four different pathogen strains tested, P. aeruginosa exhibited the highest susceptibility, with an inhibition rate of 29.62%. In parallel, we explored the cultivation conditions of B. subtilis, recognizing the potential of this versatile bacterium for applications beyond antimicrobial production. The highest inhibitory activity was achieved at pH 8, with an inhibition rate of 20.18%, indicating the potential for optimizing pH conditions for enhanced antimicrobial peptide production. For the kinetics of peptide production, the study explored different incubation periods and agitation levels. Remarkably, the highest activity of B. subtilis was observed at 24 h of incubation, with an inhibition rate of 44.93%. Finally, the study focused on the isolation of the antimicrobial peptide from the cell-free supernatant of B. subtilis using ammonium sulfate precipitation at various concentrations. The highest recorded activity was an impressive 89.72% achieved at an 80% concentration.
  5. Van Rostenberghe H, Short J, Ramli N, Geok TB, Subramaniam S, Che Yaakob CA, et al.
    Front Pediatr, 2014;2:115.
    PMID: 25478550 DOI: 10.3389/fped.2014.00115
    Even though in the corporate world psychological science has been widely used, the formal use of evidence-based psychology in important areas of clinical medicine has been scanty at best. It was the aim of this study to determine the efficacy of a psychologist-led 2-week nurse educator training on the infection rate in the neonatal intensive care unit (NICU).
  6. Keshavarzifard M, Zakaria MP, Hwai TS, Yusuff FF, Mustafa S, Vaezzadeh V, et al.
    Mar Pollut Bull, 2014 Nov 15;88(1-2):366-72.
    PMID: 25173594 DOI: 10.1016/j.marpolbul.2014.08.014
    In this study, the surface sediments of the Malacca and Prai Rivers were analyzed to identify the distributions, and sources of Polycyclic Aromatic Hydrocarbons (PAHs). The total PAH concentrations varied from 716 to 1210 and 1102 to 7938 ng g(-1)dw in the sediments of the Malacca and Prai Rivers, respectively. The PAH concentrations can be classified as moderate and high level of pollution in the sediments of the Malacca and Prai Rivers, respectively. The comparison of PAHs with the Sediment Quality Guidelines (SQGs) indicates that the PAHs in the sediments of the Malacca and Prai Rivers may have the potential to cause adverse toxicity effects on the sampled ecosystems. The diagnostic ratios of individual PAHs indicate both petrogenic- and pyrogenic-origin PAHs with dominance of pyrogenic source in both rivers. These findings demonstrate that the environmental regulations in Malaysia have effectively reduced the input of petrogenic petroleum hydrocarbons into rivers.
  7. Huat LB, Garcia AO, Ning TZ, Kin WW, Noordin R, Azham SS, et al.
    Asian Pac J Trop Biomed, 2014 Jun;4(6):446-50.
    PMID: 25182945 DOI: 10.12980/APJTB.4.2014C1169
    To characterize the Entamoeba histolytica (E. histolytica) antigen(s) recognized by moribound amoebic liver abscess hamsters.
  8. Kumar T, Onichandran S, Lim YA, Sawangjaroen N, Ithoi I, Andiappan H, et al.
    Am J Trop Med Hyg, 2014 Apr;90(4):682-9.
    PMID: 24567315 DOI: 10.4269/ajtmh.13-0266
    This study investigated the distribution of parasites as main contaminants in water environments of peninsular Malaysia (October 2011-December 2011) and the southeastern coast of Thailand (June 2012). Sixty-four water samples, 33 from Malaysia and 31 from Thailand, of various water types were examined according to U.S. Environmental Protection Agency guidelines. Drinking or household water types from both countries were free from parasitic contamination. The recreational/environmental (except a swimming pool in Malaysia) and effluent water types from these two countries were contaminated with waterborne parasites: Giardia (0.04-4 cysts/L), Cryptosporidium (0.06-2.33 oocysts/L), hookworm (6.67-350 ova/L), Ascaris (0.33-33.33 ova/L), and Schistosoma (9.25-13.33 ova/L). The most contaminated sites were recreational lake garden 3 in Malaysia and river 2 in Thailand. Higher concentrations of Giardia, Cryptosporidium, and hookworm were found in samples from Malaysia than in samples from Thailand. The presence of Giardia cysts showed a significant association with the presence of Cryptosporidium oocysts (P < 0.005).
  9. Hee TG, Shah SA, Ann HS, Hemdan SN, Shen LC, Al-Fahmi Abdul Galib N, et al.
    Asian Pac J Cancer Prev, 2013;14(11):6327-30.
    PMID: 24377526
    Haematuria is a common presentation of bladder cancer and requires a full urologic evaluation. This study aimed to develop a scoring system capable of stratifying patients with haematuria into high or low risk groups for having bladder cancer to help clinicians decide which patients need more urgent assessment. This cross- sectional study included all adult patients referred for haematuria and subsequently undergoing full urological evaluation in the years 2001 to 2011. Risk factors with strong association with bladder cancer in the study population were used to design the scoring system. Accuracy was determined by the area under the receiver operating characteristic (ROC) curve. A total of 325 patients with haematuria were included, out of which 70 (21.5%) were diagnosed to have bladder cancer. Significant risk factors associated with bladder cancer were male gender, a history of cigarette smoking and the presence of gross haematuria. A scoring system using 4 clinical parameters as variables was created. The scores ranged between 6 to 14, and a score of 10 and above indicated high risk for having bladder cancer. It was found to have good accuracy with an area under the ROC curve of 80.4%, while the sensitivity and specificity were 90.0% and 55.7%, respectively. The scoring system designed in this study has the potential to help clinicians stratify patients who present with haematuria into high or low risk for having bladder cancer. This will enable high-risk patients to undergo urologic assessment earlier.
  10. Onichandran S, Kumar T, Lim YA, Sawangjaroen N, Andiappan H, Salibay CC, et al.
    Parasitol Res, 2013 Dec;112(12):4185-91.
    PMID: 24046263 DOI: 10.1007/s00436-013-3610-1
    The objective of this study was to assess the physico-chemical parameters and waterborne parasites in selected recreational lakes from Malaysia. Samples were collected from seven stations of Recreational Lake A (RL-A) and six stations of Recreational Lake B (RL-B). The samples were processed to detect the presence of Giardia spp. and Cryptosporidium spp. using immunomagnetic separation kit, helminth eggs or ova by bright field microscopy and Acanthamoeba spp. by cultivation in non-nutrient agar. Chemical parameters such as ammonia, chlorine, fluoride, nitrate and nitrite and physical parameters such as dissolved oxygen, electrical conductivity, pH, salinity, temperature and total dissolved solid were also measured. Both lakes were freshwater with salinity ranging from 0.05 to 0.09 ppt. Most stations of these lakes were contaminated with Cryptosporidium spp., Giardia spp., Ascaris spp. and hookworm. Schistosoma spp. was found in RL-B only, while Acanthamoeba spp. was found in all stations. Of all sampling sites, station 5 of RL-B is the most contaminated. Linear regression and correlation analysis revealed that Giardia spp. and Schistosoma spp. showed a significant negative correlation with turbidity (p 
  11. Beng TS, Chin LE, Guan NC, Yee A, Wu C, Pathmawathi S, et al.
    Am J Hosp Palliat Care, 2015 Feb;32(1):15-28.
    PMID: 24023263 DOI: 10.1177/1049909113503395
    A qualitative study was conducted with semistructured interviews to explore the experiences of stress in 20 palliative care providers of University Malaya Medical Centre in Malaysia. The results were thematically analyzed. Nine basic themes were generated: (1) organizational challenges, (2) care overload, (3) communication challenges, (4) differences in opinion, (5) misperceptions and misconceptions, (6) personal expectations, (7) emotional involvement, (8) death and dying thoughts, and (9) appraisal and coping. A total care model of occupational stress in palliative care was conceptualized from the analysis. This model may inform the development of interventions in the prevention and management of stress in palliative care.
  12. de Luna MCT, Yang Q, Agus A, Ito S, Idrus Z, Iman RHS, et al.
    Front Vet Sci, 2022;9:1038362.
    PMID: 36583038 DOI: 10.3389/fvets.2022.1038362
    Asia is responsible for ~60% of global egg production. As in most of the world, nearly all of the egg-laying hens are housed in cages. While there is growing demand for cage-free eggs in many regions of the world, challenges have been reported when transitioning to these systems, which may affect the willingness of producers to transition. The aim of this research was to investigate the views of Asian egg producers on the feasibility of cage-free systems and what they perceive to be the main challenges and proposed solutions in adopting cage-free systems. A total of 224 egg producers (165 cage egg producers) completed questionnaires containing a mix of free-form, Likert scale and demographic items. Data were analyzed using thematic qualitative analysis and descriptive quantitative statistics. Responses indicated that cages are primarily used for their efficiency and ease of management. The most common reasons to consider adopting cage-free systems included improved animal welfare, increased market access, and increased product quality. A majority of producers (65%) responded "yes" or "maybe" when asked if they consider cage-free systems to be feasible in their country. Perceived challenges in adopting cage-free systems included reduced profitability, higher costs, and biosecurity and disease. Potential solutions included the development of the cage-free industry and market development. Most producers (72%) said more support is needed to establish cage-free farms, mostly pertaining to technical advice, training and resources. The findings of this study provide an enhanced understanding of the egg industry in these countries and potential areas for producer support in transitioning to cage-free systems.
  13. Le VT, Thuy Le MA, Nguyen DH, Tang LNP, Pham TA, Nguyen AM, et al.
    Epilepsia Open, 2022 Dec;7(4):710-717.
    PMID: 36136063 DOI: 10.1002/epi4.12650
    OBJECTIVE: Although epilepsy surgery is more effective than medical therapy for drug-resistant patients, it is underutilized in both high-income and low- and middle-income countries. In light of our efforts to establish an epilepsy surgery program in a resource-limited setting, this study aimed to determine the outcome of the epilepsy surgery program in Ho Chi Minh City (HCMC), Vietnam.

    METHODS: In 2018, we developed the HCMC epilepsy core multidisciplinary team with members from various hospitals and centers. The team typically included neurologists, neurosurgeons, neuropsychologists, psychiatrists, and nursing specialists. Presurgical evaluations were performed for patients with drug-resistant epilepsy, fulfilling the ILAE criteria, with an epileptogenic lesion (mesial temporal sclerosis, low-grade gliomas, or focal cortical dysplasia). All epilepsy surgeries were performed in two epilepsy surgery centers in HCMC between 2018 and 2021. The patients were followed up for at least 12 months.

    RESULTS: Fifty-two patients with drug-resistant epilepsy underwent presurgical evaluation, of which 35 underwent surgery. Among the 52 patients, 20 (38.5%) underwent surgery after showing concordance among the results of standard presurgical assessments such as semiology, scalp interictal or ictal electroencephalography, and brain imaging. Among the 26 people with epilepsy who required more advanced evaluations, 15 underwent surgery with intraoperative electrocorticography to delineate the optimal resection borders. The outcomes of Engel Class I and Class II were achieved in 29/35 (82.8%) and 6/35 (17.2%) patients, respectively.

    SIGNIFICANCE: The epilepsy surgery program with a multicentered collaborative model in a resource-limited setting showed favorable outcomes in HCMC, Vietnam.

  14. Robinson S, Moon TM, Eng TK, Yuen TT, Jong TJ, Selvarajah L, et al.
    Drugs Real World Outcomes, 2023 Jun;10(2):291-298.
    PMID: 36840826 DOI: 10.1007/s40801-023-00359-1
    BACKGROUND: Psoriasis imposes a substantial burden on patients' social, emotional, physical, and family life. Although psoriasis has no complete cure, various treatments are available to control its symptoms and improve a patients' quality of life.

    OBJECTIVE: We aimed to compare the effectiveness of biologic versus non-biologic treatments on health-related quality of life among patients with psoriasis in Malaysia.

    METHODS: This retrospective cross-sectional study evaluated data of adult patients diagnosed with psoriasis during 2007-18 from the Malaysian Psoriasis Registry. Baseline demographics, disease, and treatment characteristics were described. For a subset of patients treated with biologics and non-biologics who had baseline and 6-month follow-up data available, changes in the mean Dermatology Life Quality Index scores and the proportion of patients with a clinically relevant improvement (≥ 4 points) post-treatment were assessed.

    RESULTS: Overall, 15,238 adult patients with psoriasis from the Malaysian Psoriasis Registry were included in the analysis. Patients receiving biologics showed a statistically significant reduction in the mean Dermatology Life Quality Index scores after 6 months compared with those receiving non-biologic treatment (- 5.7 vs - 0.8%; p < 0.001). The proportion of patients who achieved a ≥ 4-point improvement in Dermatology Life Quality Index scores was approximately two times greater in the biologic-treated group versus the non-biologic-treated group (56.4 vs 27.7%).

    CONCLUSIONS: Biologic treatment showed a greater reduction in the Dermatology Life Quality Index scores of patients with psoriasis versus non-biologic treatment. These results highlight the importance of early treatment with more efficacious treatment options, such as biologic therapies, to improve the overall health-related quality of life of patients with psoriasis.

  15. Thoa LTK, Thao TTP, Nguyen-Thi ML, Chung ND, Ooi CW, Park SM, et al.
    Chemosphere, 2023 Jun;325:138392.
    PMID: 36921772 DOI: 10.1016/j.chemosphere.2023.138392
    The present study reported the improvement of biological treatment for the removal of recalcitrant dyes including aniline blue, reactive black 5, orange II, and crystal violet in contaminated water. The biodegradation efficiency of Fusarium oxysporum was significantly enhanced by the addition of mediators and by adjusting the biomass density and nutrient composition. A supplementation of 1% glucose in culture medium improved the biodegradation efficiency of aniline blue, reactive black 5, orange II, and crystal violet by 2.24, 1.51, 4.46, and 2.1 folds, respectively. Meanwhile, the addition of mediators to culture medium significantly increased the percentages of total removal for aniline blue, reactive black 5, orange II, and crystal violet, reaching 86.07%, 68.29%, 76.35%, and 95.3%, respectively. Interestingly, the fungal culture supplemented with 1% remazol brilliant blue R boosted the biodegradation up to 97.06%, 89.86%, 91.38%, and 86.67% for aniline blue, reactive black 5, orange II, and crystal violet, respectively. Under optimal culture conditions, the fungal culture could degrade these synthetic dyes concentration up to 104 mg/L. The present study demonstrated that different recalcitrant dye types can be efficiently degraded using microorganism such as F. oxysporum.
  16. Bhupatiraju L, Bethala K, Wen Goh K, Singh Dhaliwal J, Ching Siang T, Menon S, et al.
    J Med Life, 2023 Feb;16(2):307-316.
    PMID: 36937470 DOI: 10.25122/jml-2022-0151
    Food supplements are used to improve cognitive functions in age-related dementia. This study was designed to determine the Murraya koenigii leaves' effect on Alloxan-induced cognitive impairment in diabetic rats and the contents of oxidative stress biomarkers, catalase, reduced glutathione, and glutathione reductase in brain tissue homogenates. Wistar rats were divided into seven groups (six rats per group). Group I received saline water (1 ml, p.o.), Diabetes was induced in Groups II-VII with Alloxan (120 mg/kg/p.o). Group III was provided with Donepezil HCl (2.5 mg/kg/p.o.), Group IV, V, VI, and VII with Murraya koenigii ethanol extract (200 and 400 mg/kg/p.o.) and aqueous extract (200 and 400 mg/kg/p.o.), respectively, for 30 days. Behavior, acetylcholinesterase (AChE) activity, oxidative stress status, and histopathological features were determined in the hippocampus and cerebral cortex. Administration of Murraya koenigii ethanolic and aqueous extracts significantly (P<0.05, P<0.001) increased the number of holes crossed by rats from one chamber to another. There was an increase in the (1) latency to reach the solid platform, (2) number of squares traveled by rats on the 30th day, and (3) percentage of spontaneous alternation behavior compared to the control group. Administration for successive days markedly decreased AChE activity (P<0.05), decreased TBARS level, and increased catalase, GSH, and GR levels. Murayya koenigii could be a promising food supplement for people with dementia. However, more research into sub-chronic toxicity and pharmacokinetic and pharmacodynamics interactions is essential.
  17. Sabri MF, Said MA, Magli AS, Pin TM, Rizal H, Thangiah N, et al.
    Int J Environ Res Public Health, 2022 Sep 30;19(19).
    PMID: 36231818 DOI: 10.3390/ijerph191912520
    This cross-sectional study examined the relationships of financial literacy (FL) and financial behaviour (FB) with health-related quality of life (HRQOL) during the COVID-19 pandemic among low-income working population (20-60 years old) in Malaysia. A self-administered questionnaire survey was used with HRQOL data were gathered using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) tool. A generalised linear model was employed to examine the hypothesised relationships between the constructs. From 1186 respondents, the majority were employed (73.9%), had a monthly household income of less than RM 2500 (74.5%), and did not have any chronic medical conditions (74.5%). The mean (SD) values of FL, FB, and EQ-5D-5L were 5.95 (1.48), 22.08 (4.79), and 0.96 (0.10), respectively. The results of the adjusted model revealed lower age group, Malay ethnicity, Indian ethnicity, and increased FB score as significant determinants of higher EQ-5D-5L scores. With the addition of the chronic medical condition factor into the saturated model, the lower age group, ethnicity, and no chronic medical condition were significant determinants of higher HRQOL. The effects of FB on QOL were confounded by chronic diseases, implying that interventions that focus on improving FB for those with chronic medical condition may help to improve the QOL among the low-income working population.
  18. Saidon N, Anuar NA, Meng CK, Chuan OT, Mui TS, Gin GG, et al.
    Blood Cell Ther, 2020 Aug 25;3(3):44-47.
    PMID: 36714175 DOI: 10.31547/bct-2019-017
    Hematopoietic stem cell transplantation (HSCT) is now widely practiced worldwide. It has the potential to cure many hematological diseases, such as acute leukemia and thalassemia. As an emerging country, Malaysia has made advancements despite many challenges. HSCT has evolved rapidly since the first pediatric allogeneic HSCT case in 1987. The first adult HSCT was performed 5 years later in 1993. Currently, a total of 13 hospitals offer HSCT services throughout Malaysia. These include private healthcare services, substantially funded government hospitals governed by the Ministry of Health, and partially funded teaching hospitals governed by the Ministry of Education. Until 2015, 1,987 allogeneic and 1,648 autologous HSCT procedures were performed. This article narrates the history and development of HSCT in Malaysia and briefly discusses the challenging issues in this area.
  19. Jaafar MM, Mohd Razip Wee MF, Nguyen HT, Hieu LT, Rai R, Sahoo AK, et al.
    Sensors (Basel), 2023 Feb 23;23(5).
    PMID: 36904668 DOI: 10.3390/s23052464
    Gallium nitride (GaN), widely known as a wide bandgap semiconductor material, has been mostly employed in high power devices, light emitting diodes (LED), and optoelectronic applications. However, it could be exploited differently due to its piezoelectric properties, such as its higher SAW velocity and strong electromechanical coupling. In this study, we investigated the affect of the presence of a guiding layer made from titanium/gold on the surface acoustic wave propagation of the GaN/sapphire substrate. By fixing the minimum thickness of the guiding layer at 200 nm, we could observe a slight frequency shift compared to the sample without a guiding layer, with the presence of different types of surface mode waves (Rayleigh and Sezawa). This thin guiding layer could be efficient in transforming the propagation modes, acting as a sensing layer for the binding of biomolecules to the gold layer, and influencing the output signal in terms of frequency or velocity. The proposed GaN/sapphire device integrated with a guiding layer could possibly be used as a biosensor and in wireless telecommunication applications.
  20. Ahmad Khairi MH, Mazlan SA, Ubaidillah U, Khaidir REM, Nordin NA, Johari MAF, et al.
    Sci Rep, 2023 Apr 10;13(1):5810.
    PMID: 37037883 DOI: 10.1038/s41598-023-33171-6
    This paper aims to investigate the mechanical and rheological properties of magnetorheological elastomer (MRE) in marine ecosystems. The prepared samples comprised silicone rubber (SR) and 70 wt% micron-sized carbonyl iron particles (CIPs), immersed in an artificial marine ecosystem using salt water (Natrium Chloride) for 30 days. The mechanical properties of MRE samples were evaluated using hardness and quasi-static tensile tests. While the rheometer was used to investigate the rheological properties of their storage modulus condition with magnetic field stimulation. Further analysis of the defects and damages caused by salt water ageing was done through morphological observation using scanning electron microscope (SEM) technology. The results showed that the hardness and tensile strength of MRE samples that were soaked in salt water were affected over time. Lower values of hardness and tensile strength were obtained after 30 days due to the presence of Na+ and Cl-, which acted as an accelerator to the hydrolyzation process of the MRE. The process then, enhanced the water ingress capability into the matrix to cause the molecular changes. Interestingly, for rheological properties, 30 days of salt water ageing allowed the water molecules to move the MRE matrix molecular chains apart, a process known as plasticization and thus increasing the MR effect. Furthermore, morphological evidence was established to determine the MRE changes during salt water ageing. The research findings should greatly contribute to a better understanding of the effect of salt water on the performance of MRE.
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