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1 – 10 of 15Onukwuli O.D. and Ernest Mbamalu Ezeh
This paper aims to examine the fire retardant property potentials of cow horn ash particles (CHAp) bio-additive and aluminium trihydrate (AH), a traditional inorganic…
Abstract
Purpose
This paper aims to examine the fire retardant property potentials of cow horn ash particles (CHAp) bio-additive and aluminium trihydrate (AH), a traditional inorganic fire-retardant additive, respectively, in banana peduncle fibre (BPF) reinforced polyester composites. An attempt was made to comparatively analyse the fire retardant capacity potentials of CHAp, a bio-material waste that is readily available, at no cost, as a potential fire retardant material for composites manufacture with a conventional inorganic fire retardant additive (AH).
Design/methodology/approach
The fibre used in this research was derived from the banana peduncle. The matrix is unsaturated polyester. A scanning electron microscope was used to analyze the particle size of the carbonized CHAp. The composites were compounded using 0%, 2.5%, 5%, 7.5% and 10% of CHAp and AH, respectively. A cone calorimeter instrument was used in the analysis to obtain combustion information of CHAp and AH formulated polyester-BPF composites. Test samples were cut to the dimensions of 100 × 100 mm. All materials are conditioned at 23 ± 30 °C and the relative humidity of 50 ± 5% for 24 h before testing. The samples were wrapped with aluminium foil around the back and edges before placing the samples on the holder and then into the cone calorimeter. The samples were backed with a non-combustible insulating refractory material (brick). The samples were orientated horizontally and exposed to irradiances of 50 kW/m2 at a temperature of approximately 6000 °C. The samples were pilot ignited and ran in triplicate; the average readings of the three runs were taken.
Findings
The results obtained from the analysis depicted similar fire retardant properties for formulations with CHAp and AH, respectively. Composites formulated with CHAp exhibited delayed ignition time of 25%, increased end of burning time of 14.24% and reduced total heat release rate of 9.07% for the developed composites. The developed BPF/CHAp/polyester composites yield composites with fire retardancy, which would find relevance in the engineering material industry.
Originality/value
CHAp, therefore, would suffice as an alternative to the inorganic, expensive and non-environmental friendly, conventional fire retardant additives used in composites manufacture.
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U. Gianfranco Spizzirri, Paolino Caputo, Rosa Nicoletti, Pasquale Crupi, Fabrizio D'Ascenzo, Cesare Oliverio Rossi, Maria Lisa Clodoveo, Francesca Aiello and Donatella Restuccia
This study aims to investigate unripe carob pod as a source of antioxidant molecules useful in the eco-friendly synthesis of a gelatin conjugate. This one was involved in the…
Abstract
Purpose
This study aims to investigate unripe carob pod as a source of antioxidant molecules useful in the eco-friendly synthesis of a gelatin conjugate. This one was involved in the preparation of gummies able to produce remarkable human health benefits.
Design/methodology/approach
Eco-friendly strategies (ultrasound-assisted extraction, low temperatures and eco-friendly solvents) were employed in the extraction of active molecules. Antioxidant molecules were involved in the grafting reaction with gelatin chains (ascorbic acid/hydrogen peroxide couple as initiator system). Gelatin conjugate represents a useful material able to prepare gummies with remarkable rheological and antioxidant performances over time.
Findings
Experimental results confirmed that the green approach allowed the achievement of extracts with remarkable antioxidant properties due to the presence of phenolic moieties. Gelatin conjugate synthesis preserved these functionalities, usefully exploited in the preparation of gummies with significant structural and biological features.
Originality/value
Compared to the literature data the preparation of the gummies with outstanding biological properties was performed by employing functional gelatin synthesized by an eco-friendly approach.
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Karen Desta Agulei, John T. Githaiga, Benson Dulo and Eric Oyondi Nganyi
This study aims to identify the bioactive compounds in the Onion (Allium burdickii [A.B]) bulb using Raman and Fourier transform infrared spectroscopy (FTIR) spectroscopy. It…
Abstract
Purpose
This study aims to identify the bioactive compounds in the Onion (Allium burdickii [A.B]) bulb using Raman and Fourier transform infrared spectroscopy (FTIR) spectroscopy. It assessed the extraction conditions of bioactive compounds from A.B. while evaluating the best extraction conditions.
Design/methodology/approach
The research opted for an experimental qualitative approach. It examined the extraction conditions of A.B., namely, temperature (°C), time (min) and mass-to-liquor ratio (M:R) using ultraviolet-visible spectrophotometry. Identification of bioactive compounds present in the dye was performed using Raman spectroscopy and the validation of the results was done by FTIR spectroscopy.
Findings
The study determined the best extraction conditions (time, temperature, M:R) for A.B bulb. The study confirmed the presence of bioactive compounds.
Research limitations/implications
The limitation was quantification of bioactive compounds in A.B bulb.
Practical implications
The findings prove that the A.B. bulb can provide a sustainable source of bioactive compounds (functionalized compounds). The study provides suitable extraction conditions for A.B. and further elaborates on the techniques for identifying bioactive compounds in A.B. bulb extracts.
Social implications
The study provides A.B. as a source of bioactive compounds and a clean dye for textile coloration.
Originality/value
To the best of the authors’ knowledge, there is no documented study on the qualitative analysis of bioactive compounds in A.B using Raman and FTIR. Therefore, the study fulfils the identified need to ascertain alternative procedures for the analysis of bioactive compounds.
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Nur Ain Syuhada Zamri, Noor Azlina Kamaruding and Shahrulzaman Shaharuddin
The use of Spirulina sp. in food is limited by its bitter flavour and low absorption in the gastrointestinal system. The purpose of this study is to develop encapsulated Spirulina…
Abstract
Purpose
The use of Spirulina sp. in food is limited by its bitter flavour and low absorption in the gastrointestinal system. The purpose of this study is to develop encapsulated Spirulina-alginate beads and to determine the physicochemical properties, the release efficiency in the simulated gastrointestinal fluid and the sensory acceptance of the beads when added into a rose syrup beverage.
Design/methodology/approach
Spirulina-alginate beads were prepared based on 3 × 3 factorial experiments consisting of three concentrations (1%, 2% and 3%) of plain sodium alginate and three concentrations (1, 3 and 5%) (w/v) of Spirulina. Encapsulated Spirulina-alginate beads were evaluated for their encapsulation effectiveness, size, texture, morphology, colour, in vitro release rate and sensory properties.
Findings
Sample H (3% sodium alginate + 1% Spirulina) had higher encapsulation efficiency (82.3%) but less protein (38.2 ppm) than Sample J (3% sodium alginate + 5% Spirulina) which produced more protein (126.4 ppm) but had lower encapsulation efficiency (54.5%). Alginate was the primary factor affecting bead size, and the texture became harder at 3% sodium alginate but softer at 5% Spirulina. As the concentration of Spirulina increased, the intensity of the green colour diminished. The encapsulated samples released test was better than the control samples, and Sample B (1% sodium alginate + 1% Spirulina) was preferred by the panellists in the sensory study.
Originality/value
This newly developed encapsulated Spirulina will improve the beverage acceptability, minimize the bitterness and increase the release percentage of Spirulina in simulated gastrointestinal.
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Amanda Norazman, Zulhanafi Paiman, Syahrullail Samion, Muhammad Noor Afiq Witri Muhammad Yazid and Zuraidah Rasep
The purpose of this paper is to investigate the performance of bio-based lubricants (BBL), namely, palm mid-olein (PMO) enriched with an antioxidant agent…
Abstract
Purpose
The purpose of this paper is to investigate the performance of bio-based lubricants (BBL), namely, palm mid-olein (PMO) enriched with an antioxidant agent, tertiary-butylhydroquinone (TBHQ) and a viscosity improver, ethylene-vinyl acetate (EVA), in journal bearing (JB) applications.
Design/methodology/approach
Samples of the BBL were prepared by blending it with TBHQ and EVA at various blending ratios. The oxidative stability (OS) and viscosity of the BBL samples were examined using differential scanning calorimetry and a viscometer, respectively. Meanwhile, their performance in JB applications was evaluated through the use of a JB test rig with a 0.5 length-to-diameter ratio at various operating conditions.
Findings
It was found that the combination of PMO + TBHQ + EVA demonstrated a superior oil film pressure and load-carrying capacity, resulting in a reduced friction coefficient and a smaller attitude angle compared to the use of only PMO or VG68. However, it was observed that the addition of TBHQ and EVA to the PMO did not have a significant impact on the minimum oil film thickness.
Practical implications
The results would be quite useful for researchers generally and designers of bearings in particular.
Originality/value
This study used PMO as the base stock, and its compatibility with TBHQ and EVA was investigated in terms of its OS and viscosity. The performance of this treated BBL was evaluated in a hydrodynamic JB.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2023-0363/
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Ernest Mbamalu Ezeh, Ezeamaku U Luvia and Onukwuli O D
Gourd fibres (GF) are a natural biodegradable fibre material with excellent mechanical properties and high tensile strength. The use of natural fibres in composite materials has…
Abstract
Purpose
Gourd fibres (GF) are a natural biodegradable fibre material with excellent mechanical properties and high tensile strength. The use of natural fibres in composite materials has gained popularity in recent years due to their various advantages, including renewability, low cost, low density and biodegradability. Gourd fibre is one such natural fibre that has been identified as a potential reinforcement material for composites. However, it has low surface energy and hydrophobic nature, which makes it difficult to bond with matrix materials such as polyester. To overcome this problem, chemically adapted gourd fibre has been proposed as a solution. Chemical treatment is one of the most widely used methods to improve the properties of natural fibres. This research evaluates the feasibility and effectiveness of incorporating chemically adapted gourd fibre into polyester composites for industrial fabrication. The purpose of this study is to examine the application of chemically modified GF in the production of polyester composite engineering materials.
Design/methodology/approach
This work aims to evaluate the effectiveness of chemically adapted gourd fibre in improving the adhesion of gourd fibre with polyester resin in composite fabrication by varying the GF from 5 to 20 wt.%. The study involves the preparation of chemically treated gourd fibre through surface modification using sodium hydroxide (NaOH), permanganate (KMnO4) and acetic acid (CH3COOH) coupling agents. The mechanical properties of the modified fibre and composites were investigated. It was then characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to determine the changes in surface morphology and functional groups.
Findings
FTIR characterization showed that NaOH treatment caused cellulose depolymerization and caused a significant increase in the hydroxyl and carboxyl groups, showing improved surface functional groups; KMnO4 treatment oxidized the fibre surface and caused the formation of surface oxide groups; and acetic acid treatment induced changes that primarily affected the ester and hydroxyl groups. SEM study showed that NaOH treatment changed the surface morphology of the gourd fibre, introduced voids and reduced hydrophilic tendencies. The tensile strength of the modified gourd fibres increased progressively as the concentration of the modification chemicals increased compared to the untreated fibres.
Originality/value
This work presents the designed composite with density, mechanical properties and microstructure, showing remarkable improvements in the engineering properties. An 181.5% improvement in tensile strength and a 56.63% increase in flexural strength were got over that of the unreinforced polyester. The findings from this work will contribute to the understanding of the potential of chemically adapted gourd fibre as a reinforcement material for composites and provide insights into the development of sustainable composite materials.
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Shakiba Narjabadi Fam and Ramona Massoud
Food safety is among the most important topics in the world. According to WHO guidelines, aflatoxins are one of the most hazardous food toxins. Therefore, their detection in food…
Abstract
Purpose
Food safety is among the most important topics in the world. According to WHO guidelines, aflatoxins are one of the most hazardous food toxins. Therefore, their detection in food products seems crucial due to health problems. The purpose of this paper is to discuss the different types of biosensors in aflatoxin determination.
Design/methodology/approach
Traditional detection methods are time consuming and expensive. As fast and accurate detection is important in monitoring food contaminants, alternative analytical methods would be essential. Biosensors are the intelligent design of sensitive sensors for precise detection of toxins in a short time. Various biosensors are being applied for aflatoxins detection in food products with many advantages over the traditional methods.
Findings
Biosensors are cost-effective, stable and have possessed high selectivity, specificity and accuracy in aflatoxins detection. Applying biosensors has been increased recently, so biosensing methods (optical, electrochemical, piezoelectrical, immunosensors, surface plasmon resonance and calorimetric) are discussed along with their advantages in this article.
Research limitations/implications
More efforts should be occurred to detect and decrease the aflatoxins by biosensors, and some traits like accuracy and selectivity would be the purpose of future projects. The combination of various techniques would also help in toxin detection issue in food products, so high efforts in this regard are also required for the upcoming years.
Originality/value
This article also reviews different types of biosensors simultaneously and explains their specificity for aflatoxin determination in different food products and also the future trends and requirements.
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Fan Yang, Jihui Wang, Changzeng Wang, Junlei Chen and Anxin Ding
In order to find an appropriate method to synthesize a new high-efficiency flame retardant for epoxy resin.
Abstract
Purpose
In order to find an appropriate method to synthesize a new high-efficiency flame retardant for epoxy resin.
Design/methodology/approach
In this work, a flame retardant with heterocyclic groups, HOMP, was acquired after removing the obstacle from triazines which was not readily soluble. The molecular structure, thermal and flame retardant properties were fully characterized and analyzed. Also, the mechanism was researched through multi-methodologies. As well, the authors evaluated the effects of HOMP on mechanical properties.
Findings
The results suggested that HOMP helped extinguish the combustion of specimens and could reach an LOI value of 29.2% and the V0 level in the UL-94 test with a phosphorus content of only 0.6wt%. With respect to the mechanism, HOMP was a gas-phase flame retardant and helped generate a thicker carbon protective coating. However, for the mechanical properties, the addition of HOMP enhanced the compressibility, while the tensile strength decreased significantly.
Originality/value
The approach not only simplified the operations but also obtained HOMP with excellent flame retardant properties.
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Mohamed H. Sharaf, Adham M. Nagiub, Salem S. Salem, Mohamed H. Kalaba, Esmail M. El Fakharany and Hamada Abd El-Wahab
This study aims to focus on the preparation and characterization of the silver nanowire (AgNWs), as well as their application as antimicrobial and antivirus activities either with…
Abstract
Purpose
This study aims to focus on the preparation and characterization of the silver nanowire (AgNWs), as well as their application as antimicrobial and antivirus activities either with incorporation on the waterborne coating formulation or on their own.
Design/methodology/approach
Prepared AgNWs are characterized by different analytical instruments, such as ultraviolet-visible spectroscope, scanning electron microscope and X-ray diffraction spectrometer. All the paint formulation's physical and mechanical qualities were tested using American Society for Testing and Materials, a worldwide standard test procedure. The biological activities of the prepared AgNWs and the waterborne coating based on AgNWs were investigated. And, their effects on pathogenic bacteria, antioxidants, antiviral activity and cytotoxicity were also investigated.
Findings
The obtained results of the physical and mechanical characteristics of the paint formulation demonstrated the formulations' greatest performance, as well as giving good scrub resistance and film durability. In the antimicrobial activity, the paint did not have any activity against bacterial pathogen, whereas the AgNWs and AgNWs with paint have similar activity against bacterial pathogen with inhibition zone range from 10 to 14 mm. The development of antioxidant and cytotoxicity activity of the paint incorporated with AgNWs were also observed. The cytopathic effects of herpes simplex virus type 1 (HSV-1) were reduced in all three investigated modes of action when compared to the positive control group (HSV-1-infected cells), suggesting that these compounds have promising antiviral activity against a wide range of viruses, including DNA and RNA viruses.
Originality/value
The new waterborne coating based on nanoparticles has the potential to be promising in the manufacturing and development of paints, allowing them to function to prevent the spread of microbial infection, which is exactly what the world requires at this time.
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Rouhollah Ostadhossein and Siamak Hoseinzadeh
The main objective of this paper is to investigate the response of human skin to an intense temperature drop at the surface. In addition, this paper aims to evaluate the…
Abstract
Purpose
The main objective of this paper is to investigate the response of human skin to an intense temperature drop at the surface. In addition, this paper aims to evaluate the efficiency of finite difference and finite volume methods in solving the highly nonlinear form of Pennes’ bioheat equation.
Design/methodology/approach
One-dimensional linear and nonlinear forms of Pennes’ bioheat equation with uniform grids were used to study the behavior of human skin. The specific heat capacity, thermal conductivity and blood perfusion rate were assumed to be linear functions of temperature. The nonlinear form of the bioheat equation was solved using the Newton linearization method for the finite difference method and the Picard linearization method for the finite volume method. The algorithms were validated by comparing the results from both methods.
Findings
The study demonstrated the capacity of both finite difference and finite volume methods to solve the one-dimensional and highly nonlinear form of the bioheat equation. The investigation of human skin’s thermal behavior indicated that thermal conductivity and blood perfusion rate are the most effective properties in mitigating a surface temperature drop, while specific heat capacity has a lesser impact and can be considered constant.
Originality/value
This paper modeled the transient heat distribution within human skin in a one-dimensional manner, using temperate-dependent physical properties. The nonlinear equation was solved with two numerical methods to ensure the validity of the results, despite the complexity of the formulation. The findings of this study can help in understanding the behavior of human skin under extreme temperature conditions, which can be beneficial in various fields, including medical and engineering.
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