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1.
Polymers (Basel) ; 15(10)2023 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-37242939

RESUMEN

Cymbopogan citratus fibre (CCF) is an agricultural waste plant derived from a natural cellulosic source of fibre that can be used in various bio-material applications. This paper beneficially prepared thermoplastic cassava starch/palm wax blends incorporated with Cymbopogan citratus fibre (TCPS/PW/CCF) bio-composites at different CCF concentrations of 0, 10, 20, 30, 40, 50 and 60 wt%. In contrast, palm wax loading remained constant at 5 wt% concentration using the hot moulding compression method. TCPS/PW/CCF bio-composites were characterised in the present paper via their physical and impact properties. The addition of CCF significantly improved impact strength by 50.65% until 50 wt% CCF loading. Furthermore, it was observed that the inclusion of CCF resulted in a little decrement in biocomposite solubility compared to neat TPCS/PW biocomposite from 28.68% to 16.76%. Water absorption showed higher water resistance in the composites incorporating 60 wt.% fibre loading. The TPCS/PW/CCF biocomposites with different fibre contents had 11.04-5.65% moisture content, which was lower than the control biocomposite. The thickness of all samples decreased gradually with increasing fibre content. Overall, these findings provide evidence that CCF waste can be utilised as a high-quality filler in biocomposites due to its diverse characteristics, including improving the properties of biocomposites and strengthening their structural integrity.

2.
Materials (Basel) ; 16(4)2023 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-36837376

RESUMEN

Fibre-reinforced polymer (FRP) composites have been selected as an alternative to conventional wooden timber cross arms. The advantages of FRP composites include a high strength-to-weight ratio, lightweight, ease of production, as well as optimal mechanical performance. Since a non-conductive cross arm structure is exposed to constant loading for a very long time, creep is one of the main factors that cause structural failure. In this state, the structure experiences creep deformation, which can result in serviceability problems, stress redistribution, pre-stress loss, and the failure of structural elements. These issues can be resolved by assessing the creep trends and properties of the structure, which can forecast its serviceability and long-term mechanical performance. Hence, the principles, approaches, and characteristics of creep are used to comprehend and analyse the behaviour of wood and composite cantilever structures under long-term loads. The development of appropriate creep methods and approaches to non-conductive cross arm construction is given particular attention in this literature review, including suitable mitigation strategies such as sleeve installation, the addition of bracing systems, and the inclusion of cross arm beams in the core structure. Thus, this article delivers a state-of-the-art review of creep properties, as well as an analysis of non-conductive cross arm structures using experimental approaches. Additionally, this review highlights future developments and progress in cross arm studies.

3.
Materials (Basel) ; 15(11)2022 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-35683149

RESUMEN

In the era of globalisation, decreasing synthetic resources, especially petroleum, have encouraged global communities to apply biomass waste as a substitute material for green technology development. The development of plastic products from lignocellulosic fibre-reinforced composites has been a hot topic among material scientists and engineers due to their abundance, sustainable in nature, and less toxic towards health. For the Malaysian scenario, sugar palm is a plant found in the wild and locally planted in certain areas in Malaysia and Indonesia. Generally, sugar palm can be harvested for traditional foods, fruits, starch sugar (gula kabung), and alcohol, whereas sugar palm fibre (SPF) is used in conventional products (brushes and brooms). Various researchers are working on the characterisation of fibre and its composites for engineering and packaging products. The main drawback of SPF is its hydrophilic behaviour, which leads to high moisture uptake and inhibits a good bond between the fibre and the matrix. Thus, a solution for this problem is by implementing chemical treatments on the fibre. From the literature review, no comprehensive review paper has been published on the influence of chemical treatment on the mechanical behaviour of SPF-reinforced polymer composites. Thus, the present review examines recent studies on the mechanical properties of sugar palm lignocellulosic fibres with various chemical treatments to evaluate their potential in structural applications.

4.
Polymers (Basel) ; 14(8)2022 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-35458295

RESUMEN

Biomimetics is the field of obtaining ideas from nature that can be applied in science, engineering, and medicine. The usefulness of cellulose nanocrystals (CNC) and their excellent characteristics in biomimetic applications are exciting and promising areas of present and future research. CNCs are bio-based nanostructured material that can be isolated from several natural biomasses. The CNCs are one-dimensional with a high aspect ratio. They possess high crystalline order and high chirality when they are allowed to assemble in concentrated dispersions. Recent studies have demonstrated that CNCs possess remarkable optical and chemical properties that can be used to fabricate liquid crystals. Research is present in the early stage to develop CNC-based solvent-free liquid crystals that behave like both crystalline solids and liquids and exhibit the phenomenon of birefringence in anisotropic media. All these characteristics are beneficial for several biomimetic applications. Moreover, the films of CNC show the property of iridescent colors, making it suitable for photonic applications in various devices, such as electro-optical devices and flat panel displays.

5.
Polymers (Basel) ; 14(7)2022 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-35406199

RESUMEN

The reinforcement of natural fibre and fillers in polymer resin is the latest trend followed by research groups and industries for the development of sustainable composites. Basalt fibre and waste marble powder are naturally occurring substances used to enhanced polymer properties. The present research examined the effect of both basalt fibre and waste marble powder in epoxy resin. The hand lay-up method was employed to fabricate the composite and test for mechanical and wear behaviour. The tensile, flexural, and impact energy were enhanced up to 7.5 wt. % of WMP, and the Vickers hardness of epoxy enhanced every state of reinforcement of WMP. The specific wear rate was observed to be increased with the addition of WMP until 7.5 wt. %. Scanning electron microscopy was performed to examine the nature of fractured surface wear phenomena.

6.
Polymers (Basel) ; 14(5)2022 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-35267697

RESUMEN

There has been much effort to provide eco-friendly and biodegradable materials for the next generation of composite products owing to global environmental concerns and increased awareness of renewable green resources. This review article uniquely highlights the use of green composites from natural fiber, particularly with regard to the development and characterization of chitosan, natural-fiber-reinforced chitosan biopolymer, chitosan blends, and chitosan nanocomposites. Natural fiber composites have a number of advantages such as durability, low cost, low weight, high specific strength, non-abrasiveness, equitably good mechanical properties, environmental friendliness, and biodegradability. Findings revealed that chitosan is a natural fiber that falls to the animal fiber category. As it has a biomaterial form, chitosan can be presented as hydrogels, sponges, film, and porous membrane. There are different processing methods in the preparation of chitosan composites such as solution and solvent casting, dipping and spray coating, freeze casting and drying, layer-by-layer preparation, and extrusion. It was also reported that the developed chitosan-based composites possess high thermal stability, as well as good chemical and physical properties. In these regards, chitosan-based "green" composites have wide applicability and potential in the industry of biomedicine, cosmetology, papermaking, wastewater treatment, agriculture, and pharmaceuticals.

7.
Polymers (Basel) ; 14(5)2022 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-35267742

RESUMEN

New product development review article aims to consolidate the principles and current literature on design for sustainability to seek the field's future direction. In this point of view, the design for sustainability methods can be established under the idea of sustainability in dimensions of ecology, economy and social pillars. Design for sustainability concept is implemented in concurrent engineering, including concept, embodiment and detail design processes. Integrating sustainability in engineering designs is crucial to producing greener products, system innovation, and services aligned with current market demand. Currently, many concurrent engineering studies related to natural fibre-reinforced polymer composites associated with sustainability enhance the application of design for sustainability techniques by professional designers. However, the current literature is scarce in bridging the design for sustainability concept with concurrent engineering during the design development stage, and these areas should be further developed. Several other future research directions, such as the need for aligning with principles and applications, along with exploring the relationships between the design for sustainability techniques and views of sustainability, are presented in this review paper.

8.
Molecules ; 27(3)2022 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-35164163

RESUMEN

Fruits and vegetables are important components of a healthy diet. They are rich sources of vitamins and minerals, dietary fibre and a host of beneficial non-nutrient substances including plant sterols, flavonoids and other antioxidants. It has been reported that reduced intake of fruits and vegetables may increase the risk of non-communicable diseases (NCDs). Chili pepper, is a common and important spice used to enhance taste and nutrition. Over the years, reports have shown its potential as antioxidant and an anti-obesity agent. Obesity is a serious health concern as it may initiate other common chronic diseases. Due to the side effects of synthetic antioxidants and anti-obesity drugs, scientists are now focusing on natural products which produce similar effects to synthetic chemicals. This up-to-date review addresses this research gap and presents, in an accessible format, the nutritional, antioxidant and anti-obesity properties of different chili peppers. This review article serves as a reference guide for use of chili peppers as anti-obesity agents.


Asunto(s)
Fármacos Antiobesidad , Antioxidantes , Capsicum , Alimentos Funcionales , Animales , Fármacos Antiobesidad/química , Fármacos Antiobesidad/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Capsicum/química , Alimentos Funcionales/análisis , Humanos , Valor Nutritivo , Obesidad/terapia , Especias/análisis
9.
Antioxidants (Basel) ; 10(8)2021 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-34439463

RESUMEN

Six different solvents were used as extraction medium (water, methanol, ethanol, acidified methanol, benzene and acetone) to check their phenolics extraction efficacy from flour of two rye cultivars. Rye extracts with different solvents were further analyzed for the estimation of phytochemicals and antioxidant properties. Different tests (TPC, TAC, DPPH, FRAP, ABTS, RPA and CTC) were performed to check the antioxidant properties and tannin contents in extracts. A bioactive profile of a rye cultivar indicated the presence of total phenolic compounds (0.08-2.62 mg GAE/g), total antioxidant capacity (0.9-6.8 mg AAE/g) and condensed tannin content (4.24-9.28 mg CE/100 g). HPLC was done to check phenolics in rye extract with the best solvent (water), which indicated the presence of Catechol (91.1-120.4 mg/100 g), resorcinol (52-70.3 mg/100 g), vanillin (1.3-5.5 mg/100 g), ferulic acid (1.4-1.5 mg/100 g), quercetin (4.6-4.67 mg/100 g) and benzoic acid (5.3 mg/100 g) in rye extracts. The presence of DNA damage protection potential in rye extracts indicates its medicinal importance. Rye flour could be utilized in the preparation of antioxidant-rich health-benefiting food products.

10.
Biosci. j. (Online) ; 35(6): 1968-1978, nov./dec. 2019. ilus, tab, graf
Artículo en Inglés | LILACS | ID: biblio-1049177

RESUMEN

The purpose of this study was to determine and compare fat composition and chemical properties of fish fillets of selected warm-water fish obtained from Straits of Malacca. A cold water fish, namely salmon was used for comparison. Moisture content, crude fat, fatty acids composition and chemical characteristics of fish fillets of Yellowstripe scad, Japanese threadfin bream and salmon were determined. Japanese threadfin bream fillet had highest moisture and crude fat contents, followed by fillets of Yellowstripe scad and salmon. A significantly strong and negative correlation was found between moisture and crude fat contents of these fish fillets. Fillets of Japanese threadfin bream and Yellowstripe scad also had higher total saturated fatty acids than total unsaturated fatty acids. Although salmon fillet had lowest percentage of saturated fatty acids, it had highest monounsaturated fatty acids and polyunsaturated fatty acids (PUFA) compared with the two warm-water fish. Palmitic acid and oleic acid were the major fatty acids in the fish fillets. Chemical properties of the oils extracted from the warm-water fish fillets were varied compared to salmon. The selected warm-water fish fillets offer favorable fatty acids composition and chemical properties, which can potentially be used as good sources of PUFA.


O objetivo deste estudo foi determinar e comparar a composição gordurosa e as propriedades químicas de filés de peixes selecionados de água quente obtidos no Estreito de Malaca. Um peixe de água fria, o salmão, foi usado para comparação. Foram determinados o teor de umidade, a gordura bruta, a composição de ácidos graxos e as características químicas dos filés de yellowstripe scad, sargo japonês e salmão. Os filés de sargo japonês apresentaram maior teor de umidade e de gordura bruta, seguidos por filés de yellowstripe scad e de salmão. Foi encontrada uma correlação significativamente forte e negativa entre a umidade e o teor de gordura bruta desses filés de peixe. Filés de sargo japonês e de yellowstripe scad também apresentaram ácidos graxos saturados totais mais altos do que os ácidos graxos insaturados totais. Embora o filé de salmão tenha menor porcentagem de ácidos graxos saturados, ele apresentou os maiores ácidos graxos monoinsaturados e ácidos graxos poliinsaturados (PUFA em comparação com os dois peixes de água quente. O ácido palmítico e o ácido oleico foram os principais ácidos graxos dos filés de peixe. As propriedades químicas dos óleos extraídos dos filés de peixe de água quente foram variadas em comparação ao salmão. Os filés de peixe de água quente selecionados oferecem composição favorável de ácidos graxos e propriedades químicas, que podem ser potencialmente usadas como boas fontes de PUFAs.


Asunto(s)
Fenómenos Químicos , Grasas , Peces
11.
Int J Occup Saf Ergon ; 24(4): 493-506, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28849991

RESUMEN

The construction industry plays a significant role in contributing to the economy and development globally. During the process of construction, various hazards coupled with the unique nature of the industry contribute to high fatality rates. This review refers to previous published studies and related Malaysian legislation documents. Four main elements consisting of human, worksite, management and external elements which cause occupational accidents and illnesses were identified. External and management elements are the underlying causes contributing to occupational safety and health (OSH), while human and worksite elements are more apparent causes of occupational accidents and illnesses. An effective OSH management approach is required to contain all hazards at construction sites. An approach to OSH management constructed by elements of policy, process, personnel and incentive developed in previous work is explored. Changes to the sub-elements according to previous studies and the related Malaysian legislation are also covered in this review.


Asunto(s)
Industria de la Construcción/organización & administración , Salud Laboral , Administración de la Seguridad/organización & administración , Prevención de Accidentes/métodos , Industria de la Construcción/métodos , Humanos , Malasia , Administración de la Seguridad/legislación & jurisprudencia , Lugar de Trabajo
12.
Asia Pac J Clin Nutr ; 24(3): 515-24, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26420195

RESUMEN

The aim of this study was to determine the level of exposure to polychlorinated biphenyls (PCBs) and selected heavy metals among fishermen via dietary intake of fish and other seafood from the eastern coast along the Straits of Malacca. This study determined the neurobehavioural performances (based on neurobehavioural core test battery scores) of the fishermen and evaluated the correlations between scores of neurobehavioural core test battery and exposure factors. Ninety fishermen participated in the study. The total fish intakes of the fishermen were measured using a set of food frequency questionnaires. The PCBs contents in the seafood samples ranged between 0.2 and 0.6 pg/g fresh sample. The concentrations of mercury (Hg), arsenic (As), cadmium (Cd), and lead (Pb) in the seafood samples were 1.1-5.4, 0.3-4.4, 0.6-36.1, and 0.02-0.3 µg/g fresh sample, respectively. The PCBs, Hg, As, Cd, and Pb exposures of the fishermen was estimated to be 2.8, 0.02, 4.5, 0.09, and 0.5 pg/kg body weight/day, respectively. PCB and heavy metal exposures through dietary intake of fish and seafood were within the tolerable daily limits. The results of neurobehavioural core test battery revealed that the neurobehavioural performances of the fishermen were not affected due to PCB and heavy metal intoxication. No correlations were found between the exposure and neurobehavioural performance among the fishermen. These data are useful for policy makers to assure the safety and quality of seafood in relation to sea pollution. Although the levels of exposure were low, periodic assessment of the quality of fish and fish products is required due to the polluted seawater.


Asunto(s)
Explotaciones Pesqueras/estadística & datos numéricos , Peces , Metales Pesados/efectos adversos , Enfermedades del Sistema Nervioso/epidemiología , Bifenilos Policlorados/efectos adversos , Alimentos Marinos/efectos adversos , Adulto , Anciano , Animales , Dieta/efectos adversos , Humanos , Malasia/epidemiología , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas/estadística & datos numéricos , Enfermedades Profesionales/epidemiología , Encuestas y Cuestionarios , Adulto Joven
13.
BMC Public Health ; 15: 683, 2015 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-26194098

RESUMEN

BACKGROUND: Exposure to PCDD/PCDF (dioxin and furan) through consumption of fish and shellfish is closely related to the occurrence of skin diseases, such as chloracne and hyperpigmentation. This study aimed to determine the exposure of PCDD/PCDF and its congeners in fish and shellfish obtained from different regions of the Straits of Malacca among the fishing community. METHODS: The risk of fish and shellfish consumption and exposure to PCDD/PCDF among fishermen living in coastal areas of the Straits were evaluated based on a cross-sectional study involving face to face interviews, blood pressure and anthropometric measurements, and administration of food frequency questionnaires (FFQ). Skin examination was done by a dermatologist after the interview session. Determination of 17 congeners of PCDD/PCDF in 48 composite samples of fish and shellfish was performed based on HRGC/HRMS analysis. RESULTS: The total PCDD/PCDF in the seafood samples ranged from 0.12 to 1.24 pg WHO-TEQ/g fresh weight (4.6-21.8 pg WHO-TEQ/g fat). No significant difference found for the concentrations of PCDD/PCDF between the same types of seafood samples obtained from the three different regions. The concentrations of the most potent congener, 2,3,7,8-TCDD in the seafood samples ranged from 0.01 to 0.11 pg WHO-TEQ/g FW (1.9 pg WHO-TEQ/g fat). A positive moderate correlation was found between the fat contents and concentrations of PCDD/PCDF determined in the seafood samples. The total PCDD/PCDF in all seafood samples were below the 1 pg WHO-TEQ/g fresh weight, with the exception of grey eel-catfish. The respondents had consumed fish and shellfish with the amounts ranging between 2.02 g and 44.06 g per person per day. The total PCDD/PCDF exposures through consumption of fish and shellfish among the respondents were between 0.01 and 0.16 pg WHO-TEQ/kg BW/day. With regard to the two PCDD/PCDF-related skin diseases, no chloracne case was found among the respondents, but 2.2% of the respondents were diagnosed to have hyperpigmentation. CONCLUSION: Intake of a moderate amount of fish and shellfish from the area is safe and does not pose a risk for skin diseases. An over-consumption of seafood from the potentially polluted area of the Straits should be monitored in future.


Asunto(s)
Peces , Furanos/análisis , Exposición Profesional/análisis , Dibenzodioxinas Policloradas/análogos & derivados , Mariscos/análisis , Adolescente , Adulto , Animales , Presión Sanguínea , Pesos y Medidas Corporales , Estudios Transversales , Femenino , Humanos , Entrevistas como Asunto , Malasia , Masculino , Persona de Mediana Edad , Dibenzodioxinas Policloradas/análisis , Alimentos Marinos/análisis , Adulto Joven
14.
Biomed Res Int ; 2013: 284329, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23509703

RESUMEN

This study was conducted to quantitatively determine the fatty acid contents of 20 species of marine fish and four species of shellfish from Straits of Malacca. Most samples contained fairly high amounts of polyunsaturated fatty acids (PUFAs), especially alpha-linolenic acid (ALA, C18:3 n3), eicosapentaenoic acid (EPA, C20:5 n3), and docosahexaenoic acid (DHA, C22:6 n3). Longtail shad, yellowstripe scad, and moonfish contained significantly higher (P < 0.05) amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA), respectively. Meanwhile, fringescale sardinella, malabar red snapper, black pomfret, Japanese threadfin bream, giant seaperch, and sixbar grouper showed considerably high content (537.2-944.1 mg/100 g wet sample) of desirable omega-3 fatty acids. The polyunsaturated-fatty-acids/saturated-fatty-acids (P/S) ratios for most samples were higher than that of Menhaden oil (P/S = 0.58), a recommended PUFA supplement which may help to lower blood pressure. Yellowstripe scad (highest DHA, ω - 3/ω - 6 = 6.4, P/S = 1.7), moonfish (highest ALA, ω - 3/ω - 6 = 1.9, P/S = 1.0), and longtail shad (highest EPA, ω - 3/ω - 6 = 0.8, P/S = 0.4) were the samples with an outstandingly desirable overall composition of fatty acids. Overall, the marine fish and shellfish from the area contained good composition of fatty acids which offer health benefits and may be used for nutraceutical purposes in the future.


Asunto(s)
Suplementos Dietéticos/análisis , Ácidos Grasos/análisis , Animales , Cromatografía de Gases , Ácidos Grasos Omega-3/análisis , Ácidos Grasos Insaturados/análisis , Peces , Análisis de los Alimentos , Malasia , Reproducibilidad de los Resultados , Alimentos Marinos , Mariscos
15.
ScientificWorldJournal ; 2012: 403574, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22649292

RESUMEN

The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.


Asunto(s)
Agua Potable/química , Minerales/análisis , Abastecimiento de Agua/normas , Arsénico/análisis , Fluoruros/análisis , Hierro/análisis , Malasia , Manganeso/análisis , Aguas Minerales/análisis
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