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Open Access November 27, 2023

Physico-chemical and sensory characterization of bread based on green banana (Musa spp.) flour

Abstract The banana (Musa spp. [...] Read more.
The banana (Musa spp.) is a tropical fruit with excellent sensory characteristics in terms of aroma, flavor and texture, consumed worldwide and exploited in most tropical countries. Green banana flour is rich in flavonoids, which protect the gastric mucosa, has a high content of resistant starch, which acts in the body as a dietary fiber and thus has health benefits, and is an alternative option for bakery products, reducing waste of both the peel and the pulp. The aim of this study was to develop bread formulations with partial substitution of wheat flour with green banana flour (FBV), thus increasing the nutritional, technological and sensory value. 4 formulations, (A), standard sample; (B), bread with 10% FBV; (C), bread with 15% FBV and (D), bread with 20% FBV. Physico-chemical quality was assessed in terms of moisture content by drying at 105ºC, ash by incineration, fat by the Soxhlet method, protein by the biuret method, carbohydrates by difference calculation and calorific value by sum calculation and sensory analysis by affective methods. The data was evaluated using the RStudio 4.2.1 DCC statistical package. There were no significant differences in moisture content, lipids and calorific value. Differences were evident in the ash and protein content. Sensory acceptance of the standard formulation was 82.22%. The results obtained show that green banana flour can be used as a partial substitute for wheat flour to produce breads with functional properties.
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Open Access September 20, 2022

High Radio Frequencies interaction of Composite Materials Using Rectangular Waveguide

Abstract The main goal of this paper is studying the composite material behavior under microwave which they used in antennas reflectors. For that, a transmission line method based on X- band WR90 rectangular waveguide is used. The Bi-anisotropic electrical properties are defined as tensors in finite element model. The fibers of the single layer composite are oriented in different directions. The [...] Read more.
The main goal of this paper is studying the composite material behavior under microwave which they used in antennas reflectors. For that, a transmission line method based on X- band WR90 rectangular waveguide is used. The Bi-anisotropic electrical properties are defined as tensors in finite element model. The fibers of the single layer composite are oriented in different directions. The S-parameters (S11 and S12) are calculated using COMSOL Multiyphysics, the S-parameters and currents density behavior show that they very affected by the orientations of the fibers which mean must be considered in any design of RF equipments, more the fibers are parallel with the electrical field more the reflection coefficient get higher.
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Review Article
Open Access June 13, 2024

Evaluation of fiber characteristics of Musa balbisiana, Musa paradisiaca and Musa sapientum pseudo-stalks for pulp and paper production

Abstract Fiber characteristics of Musa balbisiana, Musa paradisiaca and Musa sapientum [...] Read more.
Fiber characteristics of Musa balbisiana, Musa paradisiaca and Musa sapientum pseudo-stalks were investigated. Fiber characteristics such as fiber length, fiber diameter, lumen width, and cell wall thickness were measured in the macerated banana pseudo-stalk by microscopy. Slenderness ratio, flexibility coefficient (%) and Runkel ratio were also determined from these microscopic measurements. Mean value of the properties evaluated for Musa sp. respectively were as follows: Fiber length- 2.96mm; Fiber diameter- 21.71µm; Lumen width- 13.55µm; Cell wall thickness- 3.86µm; Flexibility ratio- 66.35%; Runkel ratio- 0.66 and Relative fiber length- 159.12. Based on the findings of this study the Musa sp. pseudo stalk is suitable for pulp and paper production due to its high quality of fibers.
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Open Access December 23, 2023

Formulation, Characterization and Future Potential of Composite Materials from Natural Resources: the case of Kenaf and Date Palm Fibers

Abstract Thanks to their interesting mechanical properties, recyclability and low production costs, plant fiber-reinforced composites, derived from agricultural residues, are of particular interest to both manufacturers and scientists looking to incorporate new environmentally-friendly and biodegradable materials to replace synthetic fibers, particularly glass fibers. The growing use of these composites in [...] Read more.
Thanks to their interesting mechanical properties, recyclability and low production costs, plant fiber-reinforced composites, derived from agricultural residues, are of particular interest to both manufacturers and scientists looking to incorporate new environmentally-friendly and biodegradable materials to replace synthetic fibers, particularly glass fibers. The growing use of these composites in fields such as the automotive, construction and building industries, and soon in aeronautics, raises concerns about the reliability of the structures with which they are manufactured. This reliability must be guaranteed at the design stage, by a good knowledge of the properties of the material used. In this case, for composites, it is necessary to know the mechanical properties of their constituents, fibers and matrix, etc. In this context, this paper focuses firstly on the economic and industrial recovery of Kenaf (K) and Date Palm (DP) fibers, and secondly on their incorporation as a reinforcing element in cementitious matrix composites, for subsequent use in non-structural applications. This research highlights the development of cementitious matrix bio-composites reinforced with this type of fiber, based on Taguchi's statistical methodology, in order to minimize the cost and number of tests. The bio-composites developed are then mechanically characterized under static loading in compression and 3-point bending after a 30-day drying period.
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Open Access November 11, 2022

Biological Effects and Molecular Mechanisms of Platelet-Rich Plasma on Periodontal Bone Regeneration

Abstract Objective: The study investigated the biological effects and molecular mechanisms of platelet-rich plasma (PRP) on periodontal bone regeneration. Methods: Electronic and manual searches were searched up to 1 October 2022 in the following databases: Pubmed, Scopus, Cochrane Library and Embase. [Platelet rich plasma or platelet or growth factors] and [periodontal] or [bone regeneration [...] Read more.
Objective: The study investigated the biological effects and molecular mechanisms of platelet-rich plasma (PRP) on periodontal bone regeneration. Methods: Electronic and manual searches were searched up to 1 October 2022 in the following databases: Pubmed, Scopus, Cochrane Library and Embase. [Platelet rich plasma or platelet or growth factors] and [periodontal] or [bone regeneration or bone defect or bone reconstruction] were used for searching. This study reviewed and analyzed published papers associated with PRP and periodontal bone defect restoration or bone regeneration or bone reconstruction. Results: Different growth factors exhibited varied biological characteristics and function. In-vitro studies, animal experiments and clinical studies confirmed that PRP displayed assorted role in periodontal bone defects repair. The growth factors secreted from PRP can promote new bone formation, soft tissue regeneration and wound healing. The fiber three-dimensional structure in PRP is conducive to the growth and migration of cells and provides strong support for the regeneration of periodontal soft and hard tissues. The anti-inflammatory characteristics of PRP are also closely related to the repair of periodontal bone defects. Conclusion: PRP played an important biological effect on periodontal bone regeneration. The mechanism is closely related to PRP promoting the growth, proliferation, differentiation and migration of periodontal ligament cells and osteoblasts, and the fiber stereo configuration of PRP and the anti-inflammatory effect of leukocytes.
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Review Article
Open Access July 10, 2022

Spray Coated Cellulose Nanofiber (CNF) Film as an Eco-Friendly Substrate for Flexible and Printed Electronics

Abstract Cellulose nanofiber is an eco-friendly nanomaterial used for fabricating various functional materials. It is an alternative for synthetic plastic and other petroleum derived materials. Due to demand of CNF film, fast and rapid method for fabrication of CNF film is required. A new method on spray coating to prepare smooth cellulose nanofiber (CNF) films was developed. In this method, spraying CNF [...] Read more.
Cellulose nanofiber is an eco-friendly nanomaterial used for fabricating various functional materials. It is an alternative for synthetic plastic and other petroleum derived materials. Due to demand of CNF film, fast and rapid method for fabrication of CNF film is required. A new method on spray coating to prepare smooth cellulose nanofiber (CNF) films was developed. In this method, spraying CNF suspension onto a smooth and polished metal surface was carried out and then allowed the spray coated wet film to dry in air under standard laboratory conditions. Spraying has notable advantages such as contour coating and contactless coating with the base substrate. The basis weight and thickness of the CNF film is tailorable by adjusting CNF suspension in spraying process. CNF film prepared via spray coating has unique two-sided surface roughness with the surface in contact with the base substrate or metal side much smoother than the air-contact side. The surface roughness is one of the controlling parameter in the application of the CNF film as a substrate for flexible and printed electronics. The RMS roughness of the two surfaces investigated by Optical Profilometry [OP] was found to be 2087 nm on the rough side and 389 nm on the spray coated side, respectively. The spray coated CNF film has ultra-high smoothness on the side exposed to the polished stainless steel surface. The factors including the size of cellulose fibrils and surface smoothness of base surface that control the roughness of the film are currently being investigated and will be discussed in this chapter. The surface smoothness requirements for substrate applications in flexible and printed electronics will be discussed.
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Concept Paper
Open Access May 23, 2022

Cellulose Nanofiber Lamination of the Paper Substrates via Spray Coating – Proof of Concept and Barrier Performance

Abstract Cellulose nanofibre (CNF) is a biorenewable and biodegradable nanomaterial and belongs to fibrous based carbohydrate polymers applied in the fabrication of various functional materials such as coating, nanocomposite, flexible electronics substrates and biomedical devices. Recently, CNF can be used as coating material for papers and paperboards to replace synthetic plastics, wax and aluminum foil [...] Read more.
Cellulose nanofibre (CNF) is a biorenewable and biodegradable nanomaterial and belongs to fibrous based carbohydrate polymers applied in the fabrication of various functional materials such as coating, nanocomposite, flexible electronics substrates and biomedical devices. Recently, CNF can be used as coating material for papers and paperboards to replace synthetic plastics, wax and aluminum foil which is not recyclable and also a threat to environment. The coating of CNF on the paper substrates enhances their barrier and mechanical properties. Spray coating is a newly proposed technique to deposit CNF on the paper and produce CNF laminates on the surface of paper to block their surface pores and allowing improve their barrier performance against water vapor, air and oxygen. Various concentration of CNF was sprayed on various paper substrates such as newsprint papers, packaging paper (brown paper) and blotting papers. The air permeability of CNF laminated paper substrates is completely impermeable against air. The SEM micrograph reveals that the surface pores in the paper substrates are filled with sprayed CNF and formed a barrier film as a laminate on the paper substrates. As a result, a considerable drop in the air permeability of the paper substrates was observed. Given this correspondence, spraying of cellulose nanofiber on the paper substrates allows the improvement of barrier performance and proof of concept for coating CNF on the paper and paperboard.
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Article
Open Access February 24, 2022

Effects of Carbon Nanotube Structure, Purity, and Alignment on the Heat Conduction Properties of Carbon Films and Fibers

Abstract The increasing popularity of carbon nanotubes has created a demand for greater scientific understanding of the characteristics of thermal transport in nanostructured materials. However, the effects of impurities, misalignments, and structure factors on the thermal conductivity of carbon nanotube films and fibers are still poorly understood. Carbon nanotube films and fibers were produced, and the [...] Read more.
The increasing popularity of carbon nanotubes has created a demand for greater scientific understanding of the characteristics of thermal transport in nanostructured materials. However, the effects of impurities, misalignments, and structure factors on the thermal conductivity of carbon nanotube films and fibers are still poorly understood. Carbon nanotube films and fibers were produced, and the parallel thermal conductance technique was employed to determine the thermal conductivity. The effects of carbon nanotube structure, purity, and alignment on the thermal conductivity of carbon films and fibers were investigated to understand the characteristics of thermal transport in the nanostructured material. The importance of bulk density and cross-sectional area was determined experimentally. The results indicated that the prepared carbon nanotube films and fibers are very efficient at conducting heat. The structure, purity, and alignment of carbon nanotubes play a fundamentally important role in determining the heat conduction properties of carbon films and fibers. Single-walled carbon nanotube films and fibers generally have high thermal conductivity. The presence of non-carbonaceous impurities degrades the thermal performance due to the low degree of bundle contact. The thermal conductivity may present power law dependence with temperature. The specific thermal conductivity decreases with increasing bulk density. At room temperature, a maximum specific thermal conductivity is obtained but Umklapp scattering occurs. The specific thermal conductivity of carbon nanotube fibers is significantly higher than that of carbon nanotube films due to the increased degree of bundle alignment.
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Open Access February 15, 2022

Analytical Investigation on Hybrid Triple Skinned CFST Under the Effect of Sudden Impact

Abstract This paper is a continuation of the researches which were carried out by [1,2,3]. Accordingly, this manuscript proposes analytical analysis of a novel triple skin Concrete Filled Steel Tube (CFST) under the effect of sudden impact. Moreover, this is done by extending the double skinned CFST design and installing a third inner CFST inside the second inner tube to achieve the proposed triple skinned [...] Read more.
This paper is a continuation of the researches which were carried out by [1,2,3]. Accordingly, this manuscript proposes analytical analysis of a novel triple skin Concrete Filled Steel Tube (CFST) under the effect of sudden impact. Moreover, this is done by extending the double skinned CFST design and installing a third inner CFST inside the second inner tube to achieve the proposed triple skinned CFST design. Furthermore, the propositions consist of two parts. Where the first proposition is a novel triple skin CFST design under the effect of sudden impact, with first sandwich layer filled with Ultra High-Performance Fiber Reinforced Concrete (UHPFRC) and second sandwich layer filled with Normal Strength Concrete (NSC). While the second proposition is a novel triple skin CFST under the effect of sudden impact, with first sandwich layer filled with UHPFRC, second sandwich layer filled with NSC and third skin internal tube filled with NSC. It is strongly believed by the author of this manuscript that (1) the first proposition of novel triple skin CFST will increase the impact resistivity of the structural member by 25 to 32% and (2) it is predicted that the second proposition of novel triple skin CFST will boost the efficiency of the structural member under the even of sudden impact by 28 to 36%.
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Open Access December 18, 2021

Phytochemical Analysis and Evaluation of Bioactivities of Cola acuminata Extracts

Abstract Background: From centuries of evolution, knowledge and technological progress for mankind to one day rediscover nature. Currently, the control of bacterial infections is becoming complex due to the concern of antibiotic resistance, which has been a significant global health problem. The aim was to determine and compare phytochemical constituents and in the in vitro evaluation of antimicrobial and antioxidant activities of aqueous, methanol, acetate, dichloromethane extracts from Cola acuminata nuts grown in the Nord Ubangi Province, DRC. Methods: The nuts of Cola acuminata were harvested in April 2016 at Yakoma city, Nord-Ubangi, DRC. The microscopic features of this species were performed in order to identify specific histological structures. Three bacterial strains notably Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 8739 and Pseudomonas aeroginosa ATCC 9027 were used for the assessment of the antibacterial activity. The qualitative and quantitative phytochemical screening were used for compound identification using different fractions and fractions which presented a good extraction yield was used for further analysis. The antioxidant activity was evaluated using ABTS and DPPH scavenging tests while the antibacterial activity was performed using the diffusion method. Findings: The micrography of C. acuminata revealed the presence of following histological elements of which: fibers, spiral vessels, trichomes, ovoid starch grains, sclerenchyma and the fragments of endosperm. Only the methanol and aqueous extracts presented a good extraction yield. The phytochemistry shows the presence of flavonoids, anthocyanins, terpenes, iridoids and tannins. All fractions showed IC50 values lower than 10 µg/mL in the ABTS test and lower than 100 µg/mL in the DPPH test. The antibacterial activity of this plant was low against the three strains used. Conclusion: Seeing the potency of C. acuminata and different biological activities displayed, further analysis are required in order to identify and purify the active ingredients, to study the toxicity of cell lines in vitro [...] Read more.
Background: From centuries of evolution, knowledge and technological progress for mankind to one day rediscover nature. Currently, the control of bacterial infections is becoming complex due to the concern of antibiotic resistance, which has been a significant global health problem. The aim was to determine and compare phytochemical constituents and in the in vitro evaluation of antimicrobial and antioxidant activities of aqueous, methanol, acetate, dichloromethane extracts from Cola acuminata nuts grown in the Nord Ubangi Province, DRC. Methods: The nuts of Cola acuminata were harvested in April 2016 at Yakoma city, Nord-Ubangi, DRC. The microscopic features of this species were performed in order to identify specific histological structures. Three bacterial strains notably Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 8739 and Pseudomonas aeroginosa ATCC 9027 were used for the assessment of the antibacterial activity. The qualitative and quantitative phytochemical screening were used for compound identification using different fractions and fractions which presented a good extraction yield was used for further analysis. The antioxidant activity was evaluated using ABTS and DPPH scavenging tests while the antibacterial activity was performed using the diffusion method. Findings: The micrography of C. acuminata revealed the presence of following histological elements of which: fibers, spiral vessels, trichomes, ovoid starch grains, sclerenchyma and the fragments of endosperm. Only the methanol and aqueous extracts presented a good extraction yield. The phytochemistry shows the presence of flavonoids, anthocyanins, terpenes, iridoids and tannins. All fractions showed IC50 values lower than 10 µg/mL in the ABTS test and lower than 100 µg/mL in the DPPH test. The antibacterial activity of this plant was low against the three strains used. Conclusion: Seeing the potency of C. acuminata and different biological activities displayed, further analysis are required in order to identify and purify the active ingredients, to study the toxicity of cell lines in vitro, to perform the in vivo experiments and to test for other activities such as the anti-hypoglycemic and anti-inflammatory.
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Open Access November 23, 2021

BDNF, A Focus to Major Depression

Abstract Major depressive disorder is characterized, among other symptoms, by depressed mood and anhedonia associated with a high rate of suicidal ideation. In recent years, research has shown reduced expression of the brain-derived neurotrophic factor (BDNF) in limbic areas of individuals with depression. This reduction of BDNF is reversed by antidepressants in animal models of stress. Stress is one of [...] Read more.
Major depressive disorder is characterized, among other symptoms, by depressed mood and anhedonia associated with a high rate of suicidal ideation. In recent years, research has shown reduced expression of the brain-derived neurotrophic factor (BDNF) in limbic areas of individuals with depression. This reduction of BDNF is reversed by antidepressants in animal models of stress. Stress is one of the main triggers of mood disorders such as depression. Also, administration of BDNF increases the number of serotonergic fibers and serotonergic innervation, indicating an increase of serotonin in the synaptic cleft by this neurotrophin. Thus, BDNF appears to be one of the targets of antidepressant drugs for the increase of monoamines and remission of symptoms of major depression. The purpose of this review was to show the evidence that indicates BDNF as a molecular substrate for vulnerability to depression and the response of this substrate to the antidepressants.
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Review Article

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