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1
STEPINA, I. V., and M. SODOMON. "BIOSTABLE VEGETAL COMPOSITE FOR THERMAL INSULATION." Building and reconstruction 103, no. 5 (2022): 115–23. http://dx.doi.org/10.33979/2073-7416-2022-103-5-115-123.
Анотація:
Composites of different composition and structure have been obtained on the basis of crushed porous stems of Sosnovsky's hogweed modified with borazote for biostability with the use of organopolymer binders. The particle size of the plant material varied from 1 to 10 mm. Polyvinyl acetate, polyurethane, and casein were used as binders. The ratio of the components (vegetable raw material: polymer) in the composites was 3:1 by mass. Biostability and thermophysical properties of the composites obtained were investigated by applying appropriate GOST methods. It was established that the preliminary modification of vegetable raw material particles with monoethanolamine (NB)-trihydroxyborate provides 100% biostability of composite materials based on used raw materials and organopolymer binders. The use of the above modifier is equally effective for all composites obtained using different types of binders: polyurethane, polyvinyl acetate, and casein. The composites obtained on the basis of modified plant raw materials and organopolymer binders are heat-insulating materials characterized by appropriate coefficients of thermal conductivity and density. Composites based on polyurethane binders have lower thermal conductivity compared to composites based on polyvinyl acetate and casein binders and belong to class A. The polyurethane binder provides the resulting composites with a particle size of 5 mm with an increased compressive strength as compared to the composites based on polyvinyl acetate and casein binders. Thus, the optimal composition of biostable heat insulating material is the composition based on modified plant raw materials with a particle size of 5 mm and polyurethane binder.
2
Gavrilescu, Dan, Bogdan Marian Tofanica, Adrian Catalin Puitel, and Puiu Petrea. "SUSTAINABLE USE OF VEGETAL FIBERS IN COMPOSITE MATERIALS. SOURCES OF VEGETAL FIBERS." Environmental Engineering and Management Journal 8, no. 3 (2009): 429–38. http://dx.doi.org/10.30638/eemj.2009.058.
3
Kageura, H., and K. Yamana. "Pattern formation in 8-cell composite embryos of Xenopus laevis." Development 91, no. 1 (February 1, 1986): 79–100. http://dx.doi.org/10.1242/dev.91.1.79.
Анотація:
We have shown in defect experiments that an 8-cell embryo of Xenopus laevis consists of three kinds of cells, that is, animal, vegetal dorsal and vegetal ventral cells, and that cells of different kinds are distinctly different in their developmental capacity. Complete pattern formation occurs in any defect embryo which contains at least two animal, one vegetal dorsal and one vegetal ventral cell. In the present transplantation experiments, we replaced one or two cells of one 8-cell embryo by those of another to obtain 29 series of composite embryos, in which the cell composition of an embryo and/or the dorsoventral orientation of individual cells differed from those of a normal 8-cell embryo. The resulting embryos were examined macroscopically when controls reached stage 26 (tailbud stage) and later. The results showed that both the two animal dorsal cells or one vegetal dorsal cell could be replaced by animal ventral cells or a vegetal ventral cell, respectively, without any detectable effect on pattern formation, irrespective of the ventrodorsal direction of the ventral cells. On the other hand, replacement of an animal ventral or a vegetal ventral cell by an animal dorsal or a vegetal dorsal cell, respectively, made most composite embryos twins. Twins were also formed when a left-handed vegetal dorsal cell was replaced by a right-handed counterpart and vice versa. In these composite embryos, the dorsoventral orientation of the transplanted cell was different from that of a resident dorsal cell or cells of a recipient, and several lines of evidence show that the dorsal cell transplanted in an off-axis orientation is responsible for twin formation. Thus, dorsal cells have the capacity to form dorsal axial structures at later stages and this capacity is localized on the dorsal side, and endows the cells with polarity. On the other hand, ventral cells did not have this capacity or polarity, judging from the fact that their orientation had no effect on pattern formation. One vegetal dorsal or ventral cell could be replaced by an animal dorsal or ventral cell, respectively, without any marked effect. However, replacement of two vegetal cells by animal ones and of one or two animal cells by vegetal ones resulted in deficiency of vegetal cells and oedema and in deficiency of animal cells and incomplete invagination, respectively. Twin formation in composite embryos with animal dorsal cells in place of animal ventral ones is discussed in consideration of findings in recombination experiments by Nieuwkoop.
4
Miraoui, Imed, and Hedi Hassis. "Mechanical Model for Vegetal Fibers-Reinforced Composite Materials." Physics Procedia 25 (2012): 130–36. http://dx.doi.org/10.1016/j.phpro.2012.03.061.
5
Mintova, Svetlana, Valentin Valtchev, Brian Schoeman, and Johan Sterte. "Preparation of zeolite Y-vegetal fiber composite materials." Journal of Porous Materials 3, no. 3 (1996): 143–50. http://dx.doi.org/10.1007/bf01134025.
6
Gil, Lluís, Luis Mercedes, Virginia Mendizabal, and Ernest Bernat-Maso. "Shear Performance of the Interface of Sandwich Specimens with Fabric-Reinforced Cementitious Matrix Vegetal Fabric Skins." Applied Sciences 14, no. 2 (January 19, 2024): 883. http://dx.doi.org/10.3390/app14020883.
Анотація:
The utilization of the vegetal fabric-reinforced cementitious matrix (FRCM) represents an innovative approach to composite materials, offering distinct sustainable advantages when compared to traditional steel-reinforced concrete and conventional FRCM composites employing synthetic fibers. This article introduces a design for sandwich solutions based on a core of extruded polystyrene and composite skins combining mortar as a matrix and diverse vegetal fabrics as fabrics such as hemp and sisal. The structural behavior of the resulting sandwich panel is predominantly driven by the interaction between materials (mortar and polyurethane) and the influence of shear connectors penetrating the insulation layer. This study encompasses an experimental campaign involving double-shear tests, accompanied by heuristic bond-slip models for the potential design of sandwich solutions. The analysis extends to the examination of various connector types, including hemp, sisal, and steel, and their impact on the shear performance of the sandwich specimens. The results obtained emphasize the competitiveness of vegetal fabrics in achieving an effective composite strength comparable to other synthetic fabrics like glass fiber. Nevertheless, this study reveals that the stiffness of steel connectors outperforms vegetal connectors, contributing to an enhanced improvement in both stiffness and shear strength of the sandwich solutions.
7
Ornaghi Júnior, Heitor L., Matheus Poletto, Felipe G. Ornaghi, Ademir J. Zattera, and Sandro C. Amico. "Dynamic mechanical properties and the dynamic fragility concept applied to vegetal fiber on vegetal composite materials." Journal of Composite Materials 50, no. 18 (September 4, 2015): 2469–75. http://dx.doi.org/10.1177/0021998315604208.
8
Sederholm, Helena. "Slow Life of Vegetal, Animal, and Some Composite Organisms." Research in Arts and Education 2022, no. 1 (May 27, 2022): 1–3. http://dx.doi.org/10.54916/rae.119452.
9
Grădinaru, Cătălina Mihaela, Adrian Alexandru Șerbănoiu, Radu Muntean, and Bogdan Vasile Șerbănoiu. "The Synergy between Bio-Aggregates and Industrial Waste in a Sustainable Cement Based Composite." Materials 14, no. 20 (October 17, 2021): 6158. http://dx.doi.org/10.3390/ma14206158.
Анотація:
The effects of the fly ash and of the sunflower stalks and corn cobs within a cement-matrix composite were studied under the aspects of density, compressive strength, splitting tensile strength, elasticity modulus, and resistance to repeated freeze-thaw cycles. In the research were developed 20 recipes of cement-based composite, including the reference composite. Fly ash was used as partial cement replacement (10, 20 and 30% by volume), and the vegetal aggregates made by corn cobs and sunflower stalks as partial replacement of the mineral aggregates (25 and 50% by volume). The study results revealed that a lightweight composite can be obtained with 50% of vegetal aggregates, and the fly ash, no matter its percentage, enhanced the compressive strength and splitting tensile strength of the compositions with 50% of sunflower aggregates and the freeze-thaw resistance of all compositions with sunflower stalks.
10
Santos, Paulo A., Marcia A. S. Spinacé, Karen K. G. Fermoselli, and Marco-A. De Paoli. "Polyamide-6/vegetal fiber composite prepared by extrusion and injection molding." Composites Part A: Applied Science and Manufacturing 38, no. 12 (December 2007): 2404–11. http://dx.doi.org/10.1016/j.compositesa.2007.08.011.
11
Nicollin, Arnaud, Xinjun Li, Pierre Girods, Antonio Pizzi, and Yann Rogaume. "Fast Pressing Composite Using Tannin-Furfuryl Alcohol Resin and Vegetal Fibers Reinforcement." Journal of Renewable Materials 1, no. 4 (November 1, 2013): 311–16. http://dx.doi.org/10.7569/jrm.2013.634124.
12
Ionescu, Ştefania Miţa, and Petronela Nechita. "Thermo-Insulating Panels Based on Composite Structures from Vegetal Fibres and Polymeric Matrix." Advanced Materials Research 1143 (February 2017): 154–59. http://dx.doi.org/10.4028/www.scientific.net/amr.1143.154.
Анотація:
The study presents the experimental results on the use of composite structures based on vegetal fibres and polymeric matrix for obtaining thermoisolant panels for buildings. The use of the natural materials brings important contributions to human health but also to air protection. As vegetable fibers, hashed hemp, paper offals and recycled cellulose fiber were used in combination with formaldehyde resins and consolidation agent. The obtained samples were pressed at 50 bar and dried at environmental temperature. The testing of the samples was made for determining the coefficient of thermal conductivity, the base characteristic of the thermoisolant materials, and the thermal resistance. The obtained results led to the conclusion that these materials can be used as the filling material structure of the thermoisolant panels.
13
Abdal-Hay, Abdalla, Do Yeon Jung, Kang Il Lee, G. T. Abdel-Jaber, and Jae Kyoo Lim. "Study on Water Absorption and Impact Properties of Vegetal Composites Material: Composite Structures." Advanced Materials Research 530 (June 2012): 34–39. http://dx.doi.org/10.4028/www.scientific.net/amr.530.34.
Анотація:
The delamination and fibers pull out have been the main factors failure application of natural fibers in various engineering fields. To address these problems, particles reinforced composites are the promising candidate. The present paper investigates on vegetal particles (date palm seed particles/DPSp) and applies it as composites material reinforced unsaturated polyester (USP). The influence of alkali treatment on the surface morphology and structure of DPSp was investigated. They investigated by SEM and Energy Dispersive Spectroscopy (EDS) mapping. The water absorption results showed directly proportion with the particles loading as the relative increases were 0.645% and 7.345% for 10 wt% and 40 wt% of DPSp content, respectively. In addition, the water absorption ability of the composites showed low value comparing with many natural fibers. In addition, the fracture toughness of the composites was studied. Overall, addition of the proposed DPSp particles may be opens a new avenue to exploit the utilized natural cheap material to produce a green composite.
14
Suárez-Castañeda, Jose Luis, Jose William Restrepo-Montoya, and Fredy Andres Mercado-Navarro. "In-and-out-of plane mechanical properties of hand lay-up vegetal fiber reinforced polyester resin composites." Revista Facultad de Ingeniería Universidad de Antioquia, no. 90 (December 14, 2018): 16–27. http://dx.doi.org/10.17533/udae.redin.n90a03.
Анотація:
The results presented in this paper belong to the mechanical characterization of vegetal woven fabric reinforced composites with polyester resin as the matrix and fabrics made of cotton, jute and flax fibers. Test specimens were manufactured using a simple hand lay-up molding process. A group of test specimens was reinforced with the woven fabrics as delivered by the supplier, while another group was reinforced with woven fabrics that were chemically treated with Sodium hydroxide NaOH at 6% w/v for 48 hours. The fabrics were then neutralized and dried in an oven. Mechanical characterizations were performed using traction, compression, in-plane shear and interlaminar (out of plane) shear tests. Results show that the untreated flax fiber composite has the best specific properties among the three vegetal composites.
15
Paula, Edgley Alves de Oliveira, Rafael Bezerra Azevedo Mendes, Claudia Yanara Meira da Costa, Rafael Rodolfo de Melo, Alexandre Santos Pimenta, Ramona Rodrigues Amaro de Oliveira, and Joana Alice Galdino de Souza. "MECHANICAL CHARACTERIZATION OF A POLYESTER MATRIX COMPOSITE REINFORCED WITH NATURAL FIBERS FROM Luffa cylindrica Hoen." Nativa 9, no. 5 (December 18, 2021): 558–62. http://dx.doi.org/10.31413/nativa.v9i5.12830.
Анотація:
The growing demand for renewable products has led to many studies of alternative materials. The present work describes the production of a composite based in polyester resin reinforced with fibers from the climber plant Luffa cylindrica and evaluates its mechanical performance. The composite was produced with two perpendicularly-crossed layers of vegetable fibers. The lamination was performed in a mold with two glass plates pressed by a hydraulic press. To characterize the properties of the produced composite, density, tensile and bending strength tests were performed. The final composite had a mean density of 1.16 g cm-3, making it light due to the reinforcement with vegetable fibers. Tensile and bending strengths were 13.91 and 26.70 MPa, respectively. The experimental results showed that the composite with vegetable fibers as reinforcement had lower density than the pure polyester matrix and composites produced with glass fibers. The tensile strength was higher than the polyester matrix itself, although it was still low. Also, when submitted to bending stress, the composite presented lower resistance than the matrix. Overall, the composite can be a viable alternative for non-structural applications where light materials are required such as handicrafts and office partition. Keywords: sustainable material; vegetable fibers; mechanical properties; technical feasibility. Caracterização mecânica de um compósito com matriz de poliéster reforçado com fibras naturais de bucha vegetal (Luffa cylindrica Hoen) RESUMO: A crescente demanda por produtos renováveis tem levado a muitos estudos de materiais compósitos reforçado com fibras vegetais. A planta trepadeira Luffa cylindrica, conhecida popularmente como bucha vegetal, também apresenta potencial para este uso. O presente trabalho avalia o desempenho de um compósito à base de resina de Poliéster reforçado com bucha vegetal. O compósito foi produzido com duas camadas de fibras vegetais dispostas perpendicularmente entre si. A laminação foi realizada em um molde com duas placas de vidro prensadas por uma prensa hidráulica. Como propriedade física foi determinada a densidade e para as propriedades mecânicas, foram realizados ensaios de resistência à tração e flexão. O compósito final apresentou densidade média de 1,16 g cm-3, tornando-o leve devido ao reforço com fibras vegetais. As resistências à tração e flexão foram de 13,91 e 26,70 MPa, respectivamente. Os resultados experimentais mostraram que o compósito com fibras vegetais como reforço apresentou densidade menor que a matriz de poliéster pura e compósitos produzidos com fibras de vidro. A resistência à tração foi maior do que a própria matriz de poliéster. Além disso, quando submetido a tensões de flexão, o compósito apresentou menor resistência do que a matriz. No geral, o composto pode ser uma alternativa viável para aplicações não estruturais onde materiais leves são necessários, como artesanatos e paredes divisórias. Keywords: material sustentável; fibras vegetais; propriedades mecânicas; viabilidade técnica.
16
Ilczyszyn, Florent, Abel Cherouat, and Guillaume Montay. "Effect of Hemp Fibre Morphology on the Mechanical Properties of Vegetal Fibre Composite Material." Advanced Materials Research 875-877 (February 2014): 485–89. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.485.
Анотація:
The hemp fibres present specific fibre morphology and a complex non homogeneous cross section which changes in function of the location along the fibre length. Thus the mechanical properties of hemp fibres request a specific characterization method. In this study, firstly, a digital treatment method was developed allowing to consider different geometrical modelling methods: homogeneous or non-homogenous cross section, average global cross section, and cross section measured at the rupture location, including a 3D CAD model reconstruction of the fibre.
17
Chegdani, Faissal, Mohamed El Mansori, Sabeur Mezghani, and Alex Montagne. "Scale effect on tribo-mechanical behavior of vegetal fibers in reinforced bio-composite materials." Composites Science and Technology 150 (September 2017): 87–94. http://dx.doi.org/10.1016/j.compscitech.2017.07.012.
18
Mendizabal, Virginia, Borja Martínez, Luis Mercedes, Ernest Bernat-Maso, and Lluis Gil. "Vegetal-FRCM Failure under Partial Interaction Mechanism." Applied Sciences 12, no. 24 (December 16, 2022): 12964. http://dx.doi.org/10.3390/app122412964.
Анотація:
FRCM is a strengthening system based on composite material made of a cementitious matrix and fabrics. This strengthening system has been studied and researched, obtaining analytical predictive models where it is common to assume full composite action between components. Through using non-typical materials for these composites, it has been seen that, in some cases, the previous assumption cannot be taken. In this situation, traditional analytical models such as ACK or tri-linear ones do not offer a reasonable prediction. This work researches the behavior of synthetic and naturally coated vegetal-FRCM with partial interaction through the characterization of the materials through tensile tests. Yarns, meshes and different FRCM coupons were manufactured and mechanically tested using different types of coatings and fabrics. The use of colophony and Arabic gum as natural coatings provided similar mechanical properties to the cotton and hemp yarns and meshes conformed. Partial interaction was found when using epoxy as a natural resin to coat the reinforcement while maintaining the mechanical properties in the same order of magnitude. A new two-stage model is proposed to fit stress–strain mechanical test, and it is reliable and accurate for cotton specimens.
19
Rosas-Díaz, Felipe, David Gilberto García-Hernández, José M. Mendoza-Rangel, Bernardo T. Terán-Torres, Sergio Arturo Galindo-Rodríguez, and Cesar A. Juárez-Alvarado. "Development of a Portland Cement-Based Material with Agave salmiana Leaves Bioaggregate." Materials 15, no. 17 (August 30, 2022): 6000. http://dx.doi.org/10.3390/ma15176000.
Анотація:
Depending on the morphology of the natural fibers, they can be used as reinforcement to improve flexural strength in cement-based composites or as aggregates to improve thermal conductivity properties. In this last aspect, hemp, coconut, flax, sunflower, and corn fibers have been used extensively, and further study is expected into different bioaggregates that allow diversifying of the raw materials. The objective of the research was to develop plant-based concretes with a matrix based on Portland cement and an aggregate of Agave salmiana (AS) leaves, obtained from the residues of the tequila industry that have no current purpose, as a total replacement for the calcareous aggregates commonly used in the manufacturing of mortars and whose extraction is associated with high levels of pollution, to improve their thermal properties and reduce the energy demand for air conditioning in homes. Characterization tests were carried out on the raw materials and the vegetal aggregate was processed to improve its compatibility with the cement paste through four different treatments: (a) freezing (T/C), (b) hornification (T/H), (c) sodium hydroxide (T/NaOH), and (d) solid paraffin (T/P). The effect of the treatments on the physical properties of the resulting composite was evaluated by studying the vegetal concrete under thermal conductivity, bulk density, and compressive strength tests with a volumetric ratio between the vegetal aggregate and the cement paste of 0.36 and a water/cement ratio of 0.35. The hornification treatment showed a 15.2% decrease in the water absorption capacity of the aggregate, resulting in a composite with a thermal conductivity of 0.49 W/mK and a compressive strength of 8.66 MPa, which allows its utilization as a construction material to produce prefabricated blocks.
20
ZOUARI, RIADH, and EMILIA VISILEANU. "Deep insight on the behaviour of short fibres within a composite under uniaxial tensile." Industria Textila 72, no. 06 (December 21, 2021): 659–65. http://dx.doi.org/10.35530/it.072.06.1850.
Анотація:
This work presents an investigation of the mechanical properties of a composite structure manufactured from polypropylene matrix reinforced with jute waste fibres collected from textile industry with extrusion followed by injection techniques. Mechanical tests under uniaxial strain shows that this lightweight vegetal fibre significantly enhanced the mechanical performances of the whole composite with a very slight quantity of compatibilizer which positively influences the final price of the composite. The fracture surfaces showed highly tethered as well as weakly anchored fibres to the matrix. Moreover, in order to have a deep insight on that anchoring behaviour, uniaxial tensile deformation was applied under Scanning Electron Microscopy and evidenced how the fibre/matrix interface plays a high role to strengthen the whole structure. The fibre and matrix interface is not simply resumed to high or weak anchoring but there is a combination of sticking and slipping of reinforcement on the polymeric walls.
21
Tita, SPS, R. Medeiros, JR Tarpani, E. Frollini, and V. Tita. "Chemical modification of sugarcane bagasse and sisal fibers using hydroxymethylated lignin: Influence on impact strength and water absorption of phenolic composites." Journal of Composite Materials 52, no. 20 (January 25, 2018): 2743–53. http://dx.doi.org/10.1177/0021998317753886.
Анотація:
Chemical modification of fiber surfaces can increase wettability of composites reinforced by vegetal fibers and, consequently, the dispersion of the fiber in the matrix and mechanical properties can be improved. Although there are some studies about agents for chemical modifications of vegetal fiber surfaces, there are few data and discussion about the usage of lignin. In the present work, chemical modifications of sugarcane bagasse and sisal fibers using lignin (previously hydroxymethylated) were carried out under different reaction times (15, 30, and 60 min). The composition (holocellulose, hemicelluloses, cellulose, and lignin contents) of the treated and untreated fibers was evaluated. Phenolic composites were prepared using unmodified and modified fibers via compression molding process under temperature. Izod impact, water absorption tests, and scanning electron microscopy were performed to evaluate composite properties. The resin and lignin were characterized by size exclusion chromatography. Results showed that there was a tendency of reducing water absorption for composites prepared from modified fibers. Impact strengths of composites reinforced with sugarcane bagasse with modified fibers were similar to the ones with unmodified fibers (around 20 J/m). However, impact strengths for composites reinforced with modified sisal fibers (around 104 J/m for 15 min of reaction time) were higher than the ones with unmodified fibers (around 95 J/m). Therefore, the usage of lignin as a modifier agent of vegetal fiber surfaces to increase fiber–matrix adhesion for phenolic composites is a strategic alternative for improving products through simple, eco-friendly, and low-cost procedures.
22
Ho, Y. C., I. Norli, Abbas F. M. Alkarkhi, and N. Morad. "Enhanced turbidity removal in water treatment by using emerging vegetal biopolymer composite: a characterization and optimization study." Desalination and Water Treatment 57, no. 4 (November 14, 2014): 1779–89. http://dx.doi.org/10.1080/19443994.2014.976768.
23
Mendizabal, Virginia, Luis Mercedes, Ernest Bernat-Maso, and Lluis Gil. "Debonding of Vegetal FRCM from Concrete Beams Subjected to Bending Loads." Key Engineering Materials 916 (April 7, 2022): 449–56. http://dx.doi.org/10.4028/p-m59g07.
Анотація:
The increasing need of society to develop more sustainable and renewable materials has made vegetal fibers an interesting potential substitute for synthetic fibers in strengthening systems, due to their considerable strength and deformation capacity. This paper aims to increase the knowledge on how the materials interact between them in vegetal FRCM composites to strengthen concrete structures. To do it, two fibers were selected: cotton (CO), due to its good deformation capacity, and hemp (HE), due to its high strength. A low-viscosity and high adherence epoxy resin was used to coat the yarns to protect them from the alkali environment of the cementitious matrix. To study the FRCM-substrate interaction, an adaptation of the test methodology described in ISO 10080:2005 was developed and performed. Three different lengths (30, 40, and 50 cm) were used to obtain the optimal bonding length for hemp case. A single case (50 cm) for cotton was tested to compare its behaviour against hemp. In the FRCM-substrate interaction, it is noticed that hemp-FRCM shows complete bonding as all except one specimen failed by mesh failure. In the case of cotton-FRCM, its deformation capacity (at least 4 times hemp-FRCM) made all specimens deform until the geometric end of the testing set up without the mesh breakage, bearing a lower load but keeping it constant through fiber-matrix friction. In terms of load, hemp-FRCM reached the highest load, 10% higher than cotton-FRCM’s peak load. To conclude, the testing method for assessing steel reinforcement bonding in reinforced concrete was proved to be satisfactory at assessing FRCM-concrete interaction, being able to transmit the load from the substrate to the composite without the slippage of the vegetal-FRCM.
24
Ferreira Luz, F., Sandro Campos Amico, A. de Lima Cunha, E. Santos Barbosa, and Antônio Gilson Barbosa de Lima. "Applying Computational Analysis in Studies of Resin Transfer Moulding." Defect and Diffusion Forum 326-328 (April 2012): 158–63. http://dx.doi.org/10.4028/www.scientific.net/ddf.326-328.158.
Анотація:
Resin Transfer Moulding (RTM) as it is most known process in the Resin Injections family, is an extensively studied and used processing method. This process is used to manufacture advanced composite materials made of fibres embedded in a thermoset polymer matrix. Fibre reinforcement in RTM processing of polymer composites is considered as a fibrous porous medium regarding its infiltration by the polymer resin. In this sense, the present work aims the computational analysis of a fluid in a porous media for a RTM composite moulding by using the ANSYS CFX® commercial software. In order to validate the numerical study of the fluid flow in a known RTM system, experiments was carried out in laboratory to characterize the fluid (vegetal oil) flowing into the porous media (0/90 glass fibre woven), were pressure and fibre volume fraction have been fixed. The numerical simulation provides information about volume fraction, pressure and velocity distribution of the phases (resin and air) inside the porous media. The predicted results were compared with the experimental data and its has shown a solid relationship between them.
25
Wang, Honggang, Zhi Fu, Yu Liu, Ping Cheng, Kui Wang, and Yong Peng. "Exploring Anisotropic Mechanical Characteristics in 3D-Printed Polymer Biocomposites Filled with Waste Vegetal Fibers." Symmetry 16, no. 1 (January 4, 2024): 70. http://dx.doi.org/10.3390/sym16010070.
Анотація:
The fiber-filled polymer composite is one of the best materials which provides a symmetrical superior strength and stiffness to structures. With the strengthening of people’s environmental protection and resource reuse consciousness, the development of renewable materials, especially natural fiber-filled polymer composites, is receiving great attention. This study investigated the mechanical properties of polymer composites incorporating waste materials from the food processing industry and agricultural sources. Waste vegetal fiber-filled polymer biocomposites (WVFFPBs) with varying fiber types and 3D printing orientations were systematically fabricated. Subsequently, the tensile tests were executed to comprehensively assess the anisotropic mechanical behaviors of the WVFFPBs. The results demonstrated that WVFFPBs performed excellent anisotropic mechanical properties compared to pristine matrix samples as print orientation changed. As the printing angle increased from 0° to 90°, the tensile mechanical properties of the WVFFPBs displayed a decreasing trend. Moreover, the print orientation–anisotropic mechanical behavior relationship of 3D-printed WVFFPBs was revealed through the analysis of the material manufacturing characteristics and damage features.
26
Zgura, Irina, Monica Enculescu, Cosmin Istrate, Raluca Negrea, Mihaela Bacalum, Liviu Nedelcu, and Marcela Elisabeta Barbinta-Patrascu. "Performant Composite Materials Based on Oxide Semiconductors and Metallic Nanoparticles Generated from Cloves and Mandarin Peel Extracts." Nanomaterials 10, no. 11 (October 28, 2020): 2146. http://dx.doi.org/10.3390/nano10112146.
Анотація:
In this work, the metal and semiconducting nanoparticles (AgNPs, ZnONPs and AgZnONPs) were phyto-synthesized using aqueous vegetal extracts from: Caryophyllus aromaticus L. (cloves) and Citrus reticulata L. (mandarin) peels. The morphological, structural, compositional, optical and biological properties (antibacterial activity, and cytotoxicity) of the prepared composites were investigated. The most effective sample proved to be AgZnONPs, derived from cloves, with a minimum inhibitory concentration (MIC) value of 0.11 mg/mL and a minimum bactericidal concentration (MBC) value of 2.68 mg/mL. All the other three composites inhibited bacterial growth at a concentration between 0.25 mg/mL and 0.37 mg/mL, with a bactericidal concentration between 3 mg/mL and 4 mg/mL. The obtained composites presented biocidal activity against Staphylococcus aureus, and biocompatibility (on human fibroblast BJ cells) and did not damage the human red blood cells. Additionally, an important result is that the presence of silver in composite materials improved the bactericidal action of these nanomaterials against the most common nosocomial pathogen, Staphylococcus aureus.
27
Santiago, Gislene A., Vagner R. Botaro, Nilo C. Consoli, and Lucas Festugato. "Mechanical Behavior of Curauá Treated Fiber-Reinforced Sand." Materials Science Forum 730-732 (November 2012): 355–60. http://dx.doi.org/10.4028/www.scientific.net/msf.730-732.355.
Анотація:
The inclusion of artificial fibers in the soil has been studied by many researchers during the last years and has shown efficient by improving the mechanical properties of the soil. This kind of association results in an interesting composite material for geotechnical engineering applications. In this context, the aim of this research is to analyze the behavior of a granular soil reinforced with random inclusion of short and curauá fibers superficially treated with recycled EPS (expanded polystyrene). The non-reinforced and reinforced soil samples were subjected to triaxial tests. Through the obtained results, it was observed that the addition of randomly distributed natural treated fibers presented significant improvements on the mechanical properties of this soil. The polymer used was shown quite applicable to the proposed analysis, promoting the decrease of the water absorption of the vegetal fibers.
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Vailati, Marco, Micaela Mercuri, Michele Angiolilli, and Amedeo Gregori. "Natural-Fibrous Lime-Based Mortar for the Rapid Retrofitting of Heritage Masonry Buildings." Fibers 9, no. 11 (October 30, 2021): 68. http://dx.doi.org/10.3390/fib9110068.
Анотація:
The present work aims to define the mechanical behavior of a new composite material for the preservation and enhancement of the vast historical and architectural heritage particularly vulnerable to environmental and seismic actions. The new composite represents a novelty in the landscape of the fibrous mortars and consists of natural hydraulic lime (NHL)-based mortar, strengthened by Sisal short fibers randomly oriented in the mortar matrix. The developed mortar ensures the chemical-physical compatibility with the original features of the historical masonry structures (especially in stone and clay) aiming to pursue the effectiveness and durability of the intervention. The use of vegetal fibers (i.e., the Sisal one) is an exciting challenge for the construction industry considering that they require a lower level of industrialization for their processing, and therefore, their costs are considerably lower, as compared to the most common synthetic/metal fibers. Samples of Sisal-composite are tested in three-point bending, aiming to estimate both their bending stress and fracture energy. Tensile and compressive tests were also performed on the composite samples, while water retention and slump test were performed on the fresh mix. At last, the tensile tests on the Sisal strand were performed to evaluate the tensile stress of both strand and wire. An original mechanical interpretation is proposed to explain two interesting phenomena that arose from the analysis of experimental data. The comparison among the performances of unreinforced and reinforced mortar suggests that the use of short fibers is recommendable as coating in the retrofitting interventions alternatively to the long uni or bi-directional fiber strands adopted in the classic fibrous reinforcement (i.e., FRCM). The proposed composite also ensures mix-independent great workability, excellent ductility, and strength, and it can be considered a promising alternative to the classic fiber-reinforcing systems. As final remarks, the use of fiber F1 (length of 24 mm) with respect to fiber F2 (length of 13 mm) is more recommendable in the retrofitting interventions of historical buildings, ensuring higher strength and/or ductility for the composite.
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Uchendu, U. I., C. Kanu, K. C. Kanu, and C. I. Mpamah. "Spatial pattern of Land Surface Temperature over Umuahia North and Bende LGA, Abia State, Nigeria." Nigerian Journal of Environmental Sciences and Technology 3, no. 2 (October 2019): 210–17. http://dx.doi.org/10.36263/nijest.2019.02.0138.
Анотація:
This study evaluated the Spatial pattern of Land Surface Temperature (LST) over Umuahia North (Urban Area) and Bende LGA (Rural Area), Abia State, Southeast Nigeria. LANDSAT Imagery spanning Row 056 and Path 188, with 30m spatial resolution was captured on the 17th of May, 2018. Temperature and relative humidity were measured using a thermometer and multi-purpose Hydro-20 - 100 % model. Eight measurements were taken for each parameter at an interval of 8 hours at an elevation of 1.5m above the ground. Coordinates and elevation of the points were captured using a Garmin Handheld GPS. Data obtained were imported in compatible formats with ArcGIS 10.5 and the values for the un-sampled locations within the study area was determined through the interpolation of the collected data. A subset covering the study area was extracted for bands 1,2,3,4 and 5. Bands 1, 2 and 3 which are visible bands were used in generating a true colour composite image of the study area; the bands 4 and 5 which are not visible bands were used for the NDVI (Normalized Differential Vegetation Index). Result showed that Bende LGA had a vegetal cover of 45,741.26hectares out of a total of 60,152.76 hectares while Umuahia North had 19,689.09 hectares of vegetal cover out of a total of 24,459.75 hectares. Umuahia North had an average daily temperature of 31.309̊ C while Bende had 27.405̊ C. The average relative humidity in Bende LGA was 82.37% while Umuahia North was 67.274%. In conclusion, the study showed the existence of heat islands in the urban areas in Umuahia North LGA which was characterized by higher temperature but lower relative humidity. The heat island could be attributed to the gradual loss of vegetation cover and the increase in built-up environments in Umuahia North LGA.
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Lanzillotti, Haydee Serrão, and Maria Elisa Barros. "EVIDÊNCIAS DO QUESTIONÁRIO “ADOÇÃO DO ÓLEO VEGETAL IN NATURA DE ACRÉSCIMO NA DIETA INFANTIL”: UMA REVISITA." Inova Saúde 11, no. 2 (May 22, 2021): 94. http://dx.doi.org/10.18616/inova.v11i2.6017.
Анотація:
O objetivo do estudo foi reavaliar a estrutura do questionário “Adoção do óleo vegetal in natura de acréscimo na dieta infantil". Amostra: responsável pela alimentação das crianças (n=300). Modelos: Análise Fatorial Confirmatória Estrita (AFCe), Análise Fatorial Exploratória (AFE), Análise Fatorial Exploratória/Confirmatória (E/AFC), Análise Fatorial Confirmatória (AFC). Validade convergente: Variância Média Extraída (VME) e validade discriminante (raiz VME). Confiabilidade: composite reliability (CR). Adesão à prática dietética: média dos escores brutos. Os resultados mostraram: Modelo SCFA: ajuste inadequado pelo Root Mean Square Error of Approximation (RMSEA=0,08); Modelo EFA: bidimensionalidade do questionário confirmado; Modelo E/CFA: limite superior de RMSEA=0,07, modelo com reinspeção recomendada; Modelo CFA: RMSEA=0,02 (IC 90%: 0,00-0,05, Prob=0,05), confirmado como modelo final, mostrando validades alcançadas: convergente (AVE: F1=0,7107 e F2=0,8850) e discriminante (raiz VME: F1=0,8430 e F2=0,9407, correlação F1: F2=-0,1467); e os coeficientes de confiabilidade foram: plausíveis F1 (a=0,59) e satisfatórios: F2 (a=0,80). Perfil de adesão: Itens positivos aprox. 2,5, itens negativos aprox. 3.5 Redução de itens: 11 para 8. Conclui-se que o modelo final, com duas dimensões, mostrou validade e confiabilidade.
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Zanette, Jéssica C., Márcia T. Veit, Gilberto C. Gonçalves, Soraya M. Palácio, Fernando R. Scremin, Alex S. Torquato, and Márcia R. S. A. Vieira. "A study on the removal of prednisone from aqueous solutions by adsorption onto a vegetal activated carbon." Water Science and Technology 78, no. 11 (December 17, 2018): 2328–37. http://dx.doi.org/10.2166/wst.2018.515.
Анотація:
Abstract This study evaluated the prednisone removal from aqueous solutions using adsorption by an activated carbon of vegetal origin (VAC). A central composite rotatable design (CCRD) and the response surface methodology (RSM) were used to verify the influence of the parameters: pH, adsorbent dose and prednisone concentration in a batch adsorption process. Among the analyzed parameters, only the adsorbent dose and the prednisone concentration were statistically significant (α = 0.05) and the critical values obtained were adsorbent dose: 1.87 g/L, pH 7.56 and prednisone concentration: 3.66 mg/L with 77.51% of prednisone removal by VAC. The kinetic study of the adsorption of prednisone reached the equilibrium in 4 h. The pseudo-first-order model described adequately the kinetics data behavior. The equilibrium experimental data obtained at different temperatures showed that the VAC has a maximum adsorption capacity of 18.04 mg/g at a temperature of 30 °C. The prednisone removal decreased by the increasing temperature and the Langmuir isotherm well described the experimental data (R² > 0.98). Thermodynamic results shown that the prednisone removal of aqueous solutions by VAC is spontaneous and favorable process.
32
Giraldelli, Mariana Aparecida, Osvaldo Alves Pereira, Samuel Felipe Dos Santos, Mirela Aguiar Brasil, and Stefani Karoline Teodoro Pinheiro. "Propriedade da Fibra de Coco: Uma Revisão Sistemática." UNICIÊNCIAS 24, no. 1 (February 11, 2021): 34–38. http://dx.doi.org/10.17921/1415-5141.2020v24n1p34-38.
Анотація:
O coco é um fruto presente na agricultura de diversos países, estimando-se um consumo 61,3 milhões de toneladas colhidas por ano em cerca de 12 milhões de hectares. O principal consumo do fruto está relacionado com a indústria alimentícia, sendo consumida a sua água, a polpa que é a parte comestível do fruto e que gera demais derivados alimentícios. Entretanto, após a utilização das partes comestíveis do fruto, é possível utilizar o seu subproduto extraindo a fibra do mesocarpo do fruto, sendo este compósito conhecido como fibra de coco. A fibra vegetal proveniente do coco, fibra de coco, é amplamente utilizada em diversos setores econômicos em função de suas características de durabilidade, rigidez, impermeabilidade, resistência contra ataques biológicos, resistência à tração e termoacústica, se destacando das demais fibras vegetais. Estas características estão ligadas com a sua composição de lignocelulósicos desta fibra, sendo que esta apresenta maiores concentrações de lignina (45 – 46%) em comparação com outras fibras naturais. Esta revisão narrativa é baseada em livros, artigos, seminários e demais obras científicas que abordam o tema de fibras vegetais e fibra de coco, sendo que o principal objetivo é fazer um levantamento sobre este compósito abordando sua origem, comportamentos químicos, físicos, mecânicos e características gerais.
Palavras-chave: Fibra de Coco. Coco. Fibra Vegetal.
Abstract
Coconut is a fruit present in agriculture in several countries, with an estimated consumption of 61.3 million tons of tons per year in about 12 million hectares. The main fruit consumption is related to the food industry, being consumed its water, the pulp that is the edible part of the fruit and that generates other food derivatives. However, after using the edible parts of the fruit, it is possible to use its by-product by extracting the fiber from the fruit's mesocarp, this composite being known as coconut fiber. Vegetable fiber from coconut, coconut fiber, is widely used in several different sectors due to its characteristics of durability, rigidity, impermeability, resistance against biological resistance, tensile and thermoacoustic resistance, standing out from other vegetable fibers. These characteristics are associated with its lignocellulosic composition of this fiber, being present higher lignin (45 - 46%) in comparison with other natural fibers. This narrative review is based on books, articles, seminars and other scientific works that address the topic of vegetable fibers and coconut fiber, and the main objective is to survey this composite addressing its origin, chemical, organic, mechanical and general features.
Keywords: Coconut Fiber. Coconut. Vegetable Fiber.
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Nechita, Petronela, and Mirela Roman (Iana-Roman). "Review on Polysaccharides Used in Coatings for Food Packaging Papers." Coatings 10, no. 6 (June 15, 2020): 566. http://dx.doi.org/10.3390/coatings10060566.
Анотація:
Paper and board show many advantages as packaging materials, but the current technologies employed to obtain adequate barrier properties for food packaging use synthetic polymers coating and lamination with plastic or aluminium foils—treatments which have a negative impact on packaging sustainability, poor recyclability and lack of biodegradability. Recently, biopolymers have attracted increased attention as paper coatings, which can provide new combinations in composite formulas to meet the requirements of food packaging. The number of studies on biopolymers for developing barrier properties of packaging materials is increasing, but only a few of them are addressed to food packaging paper. Polysaccharides are viewed as the main candidates to substitute oil-based polymers in food paper coating, due to their film forming ability, good affinity for paper substrate, appropriate barrier to gases and aroma, and positive effect on mechanical strength. Additionally, these biopolymers are biodegradable, non-toxic and act as a matrix for incorporation additives with specific functionalities for coated paper (i.e., active-antimicrobial properties). This paper presents an overview on the availability and application of polysaccharides from vegetal and marine biomass in coatings for foods packaging paper. The extraction methods, chemical modification and combination routes of these biopolymers in coatings for paper packaging are discussed.
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Illampas, Rogiros, Daniel V. Oliveira, and Paulo B. Lourenço. "Design of Strain-Hardening Natural TRM Composites: Current Challenges and Future Research Paths." Materials 16, no. 13 (June 24, 2023): 4558. http://dx.doi.org/10.3390/ma16134558.
Анотація:
This paper discusses the challenges in using natural fibers for the development of textile-reinforced mortar (TRM) composites with pseudo-strain-hardening and multiple cracking behavior. The particular characteristics of natural vegetal fibers are analyzed with reference to data from the literature. It is concluded that the efficient use of these fibers as composite reinforcement requires the development of treatment or impregnation protocols for overcoming durability issues, eliminating crimping effects in tensile response and imparting dimensional stability. Relevant experimental research on the synthesis and performance of natural TRMs is reviewed, showing that the fabrication of such systems is, at present, largely based on empirical rather than engineering design. In order to set a framework regarding the properties that the constituents of natural TRM must meet, a comparative analysis is performed against inorganic matrix composites comprising synthetic, mineral and metallic reinforcement. This highlights the need for selecting matrix materials compatible with natural fibers in terms of stiffness and strength. Furthermore, a rational methodology for the theoretical design of natural TRM composites is proposed. First-order analysis tools based on rule-of-mixtures and fracture mechanics concepts are considered. Based on the findings of this study, paths for future research are discussed.
35
Cometa, Stefania, Francesco Busto, Andrea Castellaneta, Andrea Cochis, Ziba Najmi, Rosanna Rizzi, Ilario Losito, and Elvira De Giglio. "Development, Analytical Characterization, and Bioactivity Evaluation of Boswellia serrata Extract-Layered Double Hydroxide Hybrid Composites." Molecules 28, no. 18 (September 5, 2023): 6449. http://dx.doi.org/10.3390/molecules28186449.
Анотація:
Boswellia serrata Roxb. extract (BSE), rich in boswellic acids, is well known as a potent anti-inflammatory natural drug. However, due to its limited aqueous solubility, BSE inclusion into an appropriate carrier, capable of improving its release in the biological target, would be highly desirable. Starting with this requirement, new hybrid composites based on the inclusion of BSE in a lamellar solid layered double hydroxide (LDH), i.e., magnesium aluminum carbonate, were developed and characterized in the present work. The adopted LDH exhibited a layered crystal structure, comprising positively charged hydroxide layers and interlayers composed of carbonate anions and water molecules; thus, it was expected to embed negatively charged boswellic acids. In the present case, a calcination process was also adopted on the LDH to increase organic acid loading, based on the replacement of the original inorganic anions. An accurate investigation was carried out by TGA, PXRD, FT-IR/ATR, XPS, SEM, and LC-MS to ascertain the nature, interaction, and quantification of the active molecules of the vegetal extract loaded in the developed hybrid materials. As a result, the significant disruption of the original layered structure was observed in the LDH subjected to calcination (LDHc), and this material was able to include a higher amount of organic acids when its composite with BSE was prepared. However, in vitro tests on the composites’ bioactivity, expressed in terms of antimicrobial and anti-inflammatory activity, evidenced LDH–BSE as a better material compared to BSE and to LDHc–BSE, thus suggesting that, although the embedded organic acid amount was lower, they could be more available since they were not firmly bound to the clay. The composite was able to significantly decrease the number of viable pathogens such as Escherichia coli and Staphylococcus aureus, as well as the internalization of toxic active species into human cells imposing oxidative stress, in comparison to the BSE.
36
Misra, B. K., and G. K. B. Navale. "Panandhro lignite from Kutch (Gujarat), India: Petrological nature, genesis, rank and sedimentation." Journal of Palaeosciences 39, no. (1-3) (December 31, 1990): 236–49. http://dx.doi.org/10.54991/jop.1990.1692.
Анотація:
Biopetrological investigation of four lignite seams and associated sediments of Lower Eocene (Ypresian) age from Panandhro Lignite field, district Kutch, Gujarat reveals that the lignite seams, under normal reflected light, are rich in huminite macerals with subordinate amounts of liptinite and inertinite macerals. Associated mineral matter (early diagenetic pyrite, calcite, clay and quartz) are low to moderately high. Under blue light excitation, they have quite high liptinite macerals formed chiefly of liptodetrinite and resinite. Fluorinite is sporadic and exsudatinite is rare. Alginite (Botryococcus and Pleurocapsa) are common to frequent. The rank of the lignite seams and associated sediments varies between R0 max. 0.43 to 0.44 per cent probably in response to persistently low geothermal gradient since Eocene and also shallow depth of burial. The lignite seams were formed mainly from autochthonous mangrove-mixed angiospermous forest vegetation with prolific undergrowths growing under humid tropical climate. Nonperennial herbs and shrubs, especially the pteridophytes, were mostly responsible for the formation of in situ inertinite macerals during dry periods and/or periodic lowering of water table. The peat accumulation for Seam Nos. 1, 2 and 4 took place under highly anaerobic and elevated pH (> 6) conditions of the swamp water which favoured precipitation of high amount of syngenetic pyrite and calcite. With the result vegetal matter were subjected to high microbial degradation and a fair amount of plant-derived mineral matter were released in situ for incorporation in the ancient peat. On the other hand, formation of Seam No.3 was from a peat that accumulated under conditions favourable for vegetal preservation with relatively low pH of the swamp water. Its higher pyrite content is the result of leaching from the overlying highly pyriteous grey shales. It has been presumed that minor parting bands associated with lignite seams were formed in situ from severe degradation of organic matter. The formation of authigenic partings caused splitting of a single basal seam into three separate ones which may be considered as parts of as a single composite seam. The lignite seams were formed in a lagoon from rheotrophic peat swamp near the then existing shore-line; the brackish water influence appears to have been significant.
The petrographic composition suggests that the lignite Seam Nos. 1 and 4 can be utilized better for the manufacture of organic chemicals, and the high amount of pyrite in lignite seams and associated sediments can be used for the production of sulphuric acid or even fertilizers.
37
Espinosa, Wilfred Edilberto, Luis Carlos Arturo Garzón, and Oscar Julio Medina. "Microwave-assisted extraction in dry fruit of andean species Vaccinium meridionale: Experimental conditions on the recovery of total polyphenols." Ciência e Agrotecnologia 41, no. 6 (December 2017): 701–12. http://dx.doi.org/10.1590/1413-70542017416016117.
Анотація:
ABSTRACT Due to their nutraceutical properties, the fruits of the species Vaccinium meridionale, which inhabit the Andean region, are of scientific interest. Microwave-assisted extraction has been applied to different vegetal matrices for to extract efficiently polyphenolic compounds. In this work we study in microwave assisted extraction processes, the effect on the extraction of total polyphenols in dried fruits of Vaccinium meridionale, using response surface methodology. The main objective of this research was to analyze the relationships between power, temperature, solid-liquid ratio, time and ethanol concentration in aqueous media on the effectiveness of total polyphenols recovery in dry fruits of Vaccinium meridionale. A central composite design face-centered with three levels for each variable was used: P = 300 - 900 W; T = 70 -110 °C; L:Srat. = 30:1 - 70:1 w/w; t = 5 - 15 min; [EtOH] = 0 - 80%. In this sense, the effect of the input variables on the recovery of total polyphenols, the optimization process for maximum extraction, and the comparison to other solid-liquid extractions in terms of quantity of total polyphenols, are reported. It was found that the significant variables in the extraction process were ethanol concentration, temperature and time; the best yields were obtained in the range [EtOH] = 44 - 49%, T = 110 °C, and t = 10 - 15 min. In terms of quantity, time and consumption of energy, microwave-assisted extraction technique is more efficient than other solid-liquid extraction processes for the extraction of total polyphenols.
38
Garcia, Leonardo, Renata Garcia, Georgia Pacheco, Felipe Sutili, Rodrigo De Souza, Elisabeth Mansur, and Ivana Leal. "Optimized Extraction of Resveratrol from Arachis repens Handro by Ultrasound and Microwave: A Correlation Study with the Antioxidant Properties and Phenol Contents." Scientific World Journal 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/5890897.
Анотація:
The vegetal species Arachis repens, commonly known as peanut grass, was studied and, for the first time, we detected the presence of the bioactive compound trans-resveratrol (t-RSV). We compared the efficiency of three different methodologies (conventional maceration [CM], ultrasound-assisted extractions [UAE], and microwave-assisted extractions [MAE]) concerning total phenolics (TP) and resveratrol (t-RSV) content, followed by antioxidant activity (AA) evaluation. By CM, at 1 h, the highest RSV content (1.024±0.036 mg/L) and, correspondingly, the highest DPPH capture (23.90±0.04%) were found. The TP contents, at 1 h, presented the highest value (27.26±0.26 mg/g GAE). By the UAE, the maximum yields of TP (357.18 mg/g GAE) and RSV (2.14 mg/L), as well as, the highest AA (70.95%), were obtained by 5 min after a maceration pretreatment, on the solid-solvent ratio 1 : 40 w/v. For MAE, a central composite rotatable design (CCRD) was applied followed by the FFD design in order to evaluate the statistical effects of four independent variables on the extraction of RSV. The optimal conditions established for obtaining the highest recovery (2.516 mg/g) were 20 min; 90% MeOH aq.; 120 rpm; 60°C; and solid-solvent ratio: 1 : 35 w/v. Relevant correlations were established considering the TP and RSV contents, as well as the AA, corroborating obvious advantages of such techniques in terms of high extraction efficiency in shorter times.
39
Belin, Sophie, and Fabien Kenig. "Relationships between depositional conditions and microtextures in the organic-rich Lower Oxford Clay sediments (U.K.)." Paleontological Society Special Publications 6 (1992): 24. http://dx.doi.org/10.1017/s2475262200005840.
Анотація:
Six representative samples of the Lower Oxford Clay (LOC) and the Middle Oxford Clay (MOC) sediments have been assessed for total organic carbon (TOC from 1.2 to 14.2%), hydrogen indices (HI from 813 to 130), and carbon isotopic values (δ13C from −23.1 to −27.7±) (Kenig et al., this symposium), and have been extensively studied using petrographic techniques. The use of the scanning electron microscope and particularly the backscattered electron mode was emphasized as it is the most suitable tool to study the relationships between organic matter and minerals at a micrometric scale.The bulk mineralogy appears similar in all samples studied. The argillaceous matrix is predominantly composed of illite and kaolinite with detrital mineral grains of quartz, feldspar, mica (biotite and muscovite) and calcitic bioclasts (e.g. coccoliths). Diagenetic features consist mainly of dissolution of quartz grains, rim epigenization of quartz grains to kaolinite, and the presence of pyrite. The concentration of pyrite increases with the concentration of organic matter. Both framboidal and euhedral forms of pyrite are present Euhedral pyrite crystals are more abundant in organic-rich samples, indicative of the more reducing conditions occurring in the organic-rich sediments. In organic-rich samples, coccoliths are concentrated in well preserved fecal pellets, suggesting a relatively high sedimentation rate. Preservation of coccospheres indicates a low energy environment of deposition and mild diagenesis. Unusually well-preserved biotite crystals may be indicative of the proximity of sediment sources and of the weakness of diagenetic processes.In organic-rich samples, organic matter is encountered as elongated “patches” 20 to 50 μm in length and composed of several particles of marine phytoplanktonic origin; and as thin isolated particles closely associated with clays. These thin particles are both of marine phytoplanktonic and of terrestrial origin (woody debris, vegetal tissues and rare palynomorphs). In organic-poor samples, the frequency and the size (5 to 20 μm) of the patchy composite particles of phytoplanktonic organic matter decrease. Palynological studies indicated that 80% to 95% of the organic matter is amorphous and probably of marine origin. However, the proportion of structured organic matter, woody debris and vegetal tissues, increases from 5% to 20% as the TOC decreases.None of the samples studied exhibited laminations at a sub-millimetric scale. However, the organic “patches” in the organic-rich samples lie parallel to the plane of stratification even if there is no obvious stratification of the mineral matrix. Clay minerals show a random and disorganized distribution that may be indicative of microbioturbation, even in the most organic-rich samples.Organic and mineral microtextures are controlled by the environment of deposition and the diagenetic history of the sediments and are related to geochemical parameters as HI, δ13C and TOC. Microbioturbation would indicate that the water column was never anoxic. In contrast, euhedral pyrites crystals suggest anoxia in the organic-rich sediments. The decrease in size of organic “patches” with decrease in TOC, as well as the variable distribution of coccoliths, may be indicative of changes in primary productivity and sedimentation rate.
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Poletto, Matheus, Janaína Junges, Ademir J. Zattera, and Ruth M. C. Santana. "MADERA PLÁSTICA DE POLIPROPILENO REFORZADO CON HARINA DE MADERA: EFECTO DE LA ADICIÓN DE AGENTES COMPATIBILIZANTES PROVENIENTES DE RECURSOS RENOVABLES." Revista Cientifica TECNIA 19, no. 1 (May 10, 2017): 23. http://dx.doi.org/10.21754/tecnia.v19i1.110.
Анотація:
Compósitos de polipropileno reciclado (PPr) con harina de madera de la espécie Pinus elliottii (PIE) fueron desarrollados utilizando aceite de soya, ácido esteárico, ácido caprílico y polipropileno graftizado con ácido itacónico (PPgAI) como agentes compatibilizantes. Los compósitos fueron procesados en extrusora de doble husillo co-rotante y posteriormente moldados por inyección. Los materiales fueron caracterizados a través de ensayos mecánicos, termogravimétricos, morfológicos, físicos y por ángulo de contacto. Los resultados de los ensayos mecánicos demostraron que el aceite de soya actuó como plastificante y redujo las propiedades mecánicas de los compósitos. Por otro lado, la adición de ácido esteárico, ácido caprílico y PPgAI generó en un aumento de la resistencia a flexión de 8, 20 y 29%, respectivamente, comparado al compósito sin compatibilizante. El compósito desarrollado con el agente compatibilizante comúnmente utilizado, el polipropileno graftizado con anhidrido maleico (PPgAM), presentó un aumento de 35% en la resistencia a la flexión. Resultados del análisis termogravimétrica (TGA), del compósito de PPr con aceite de soya presentó una reducción de su estabilidad térmica en 3% de pérdida de masa, lo que puede estar asociado a la mayor cantidad de oxígeno en su estructura molecular, lo que facilita mayor movilidad de las cadenas con el aumento de la temperatura y que pueden acelerar el proceso de degradación. En el caso de los compósitos con ácido caprílico y PPgAI mostraron un aumento superior a 10°C en la temperatura de 3% de perda de masa cuando comparados al compósito sin compatibilizante, indicando un aumento de la estabilidad térmica de estos compósitos. Los resultados de los análisis de microscopia electrónica de Barrido comprobaron la mayor interacción entre las fases (harina de madera y la matriz de PPr) para los compósitos desarrollados con ácido caprílico y PPgAI; y en relación a los resultados del ángulo de contacto de los materiales, mostraron que la incorporación del agente compatibilizante graftizado originó un aumento de la energía superficial de la matriz polimérica promoviendo una mejor interacción con la carga vegetal (hidrofílica). Palabras clave.-.- Madera plástica, Reciclaje mecánica, Agente compatibilizantes, Harina de madera. ABSTRACTWood plastic composites of recycled polypropylene PPr and Pinus elliottii (PIE) were developed using soybean oil, stearic acid, caprylic acid and itaconic acid grafted with polypropylene (PPgAI) as coupling agents. The composites were processed in a co-rotating twin screw extruder and injection molded. The materials were characterized by mechanical properties, thermogravimetric analysis, morphological, physical and contact angle. The results showed that soybean oil acted as a plasticizer and reduced mechanical properties of composites. On the other hand, the addition of stearic acid, caprylic acid and PPgAI resulted in an increase in flexural strength of 8, 20 and 29%, respectively, when compared to the composite without compatibilizer. The composites developed with coupling agent commonly used, polypropylene grafted with maleic anhydride (PPgAM) had a 35% increase in flexural strength. TGA results showed that the composite with soybean oil showed a reduction of thermal stability by 3% mass loss, which may be associated with more oxygen in their molecular structure and promote greater mobility of the polymer chains with increase the temperature and which may accelerate the degradation process. Composites with caprylic acid and PPgAI showed an increase above 10 ° C in temperature of 3% mass loss when compared to the composite without compatibilizer. SEM analysis showed the greater interaction between the wood flour and PPr for composites developed with PPgAI and caprylic acid. The results of contact angle showed that the incorporation of a PPgAM caused an increase in surface energy of the polymer matrix which may promote better interaction with hydrophilic wood flour. Keywords.- Wood plastic composites, Mechanical recycling, Coupling agent, Wood flour.
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Fernandes, Anny Karollyne Brandão, Sofia Santos Donaire Chura, and Guilherme Carneiro. "Analysis of the Influence of Lipid Components on the Spreadability of Hair Heat Protectants by Central Composite Design." Ensaios e Ciência C Biológicas Agrárias e da Saúde 27, no. 3 (November 29, 2023): 327–31. http://dx.doi.org/10.17921/1415-6938.2023v27n3p327-331.
Анотація:
AbstractThermal procedures aiming hair dressing, such as hair brushes, hair dryers or hair straighteners, usually involve higher temperatures, which progressively damages the hair fiber structure. The search for heat protectants for reducing this thermal damage has been growing, especially containing green components from vegetable source. To be efficient, the heat protectants should adequately spread throughout the entire hair shaft, covering the entire surface to be protected. Thus, the influence of the lipids in the in vitro spreadability of heat protectants was determined in this study. This influence was determined in a central composite rotational design 23, and spreadability was the dependent variable. Cetostearyl alcohol, shea butter and coconut oil concentration ranged between 0.64 and 7.36% (w/w) and the emulsions were prepared by hot homogenization with mechanical stirring. In vitro spreadability was determined by using an apparatus containing a square glass plate positioned on a circular plate with a 1 cm diameter hole in the center, on which a fixed amount of sample was applied to be pressed onto the surface by a fixed weight (5 g). Changes in the concentration of the components directly influenced the product spreadability (p < 0.05), which was higher around the central point for shea butter and coconut oil concentrations (4%) and at low concentrations of cetostearyl alcohol (0.64%). The studied components directly influenced the spreadability of the final product, which can be optimized in a rational pathway to obtain an adequate coverage throughout the hair shaft and desired thermal protection. Keywords: Cosmetics. Factorial design. Hair coverage. Hair damage. Thermoprotective. ResumoProcedimentos térmicos para pentear os cabelos, como escovas, secadores ou chapinhas, geralmente envolvem temperaturas elevadas, o que danifica progressivamente a estrutura da fibra capilar. A busca por protetores térmicos para redução deste dano térmico vem crescendo, principalmente contendo componentes verdes de origem vegetal. Para serem eficientes, os protetores térmicos devem se espalhar adequadamente por toda a haste capilar, cobrindo toda a superfície a ser protegida. Assim, a influência dos lipídios na espalhabilidade in vitro de protetores térmicos foi determinada neste estudo. Essa influência foi determinada em um delineamento composto central rotacional 23 e a espalhabilidade foi a variável dependente. As concentrações de álcool cetoestearílico, manteiga de karité e óleo de coco variaram entre 0,64 e 7,36% (p/p) e as emulsões foram preparadas por homogeneização a quente com agitação mecânica. A espalhabilidade in vitro foi determinada por meio de um aparato contendo uma placa de vidro quadrada posicionada sobre uma placa circular com um orifício central de 1 cm de diâmetro, na qual foi aplicada uma quantidade fixa de amostra para ser pressionada na superfície por um peso fixo (5 g). A variação na concentração dos componentes influenciou diretamente na espalhabilidade do produto (p < 0,05), sendo maior em torno do ponto central para as concentrações de manteiga de karité e óleo de coco (4%) e em baixas concentrações de álcool cetoestearílico (0,64%). Os componentes estudados influenciaram diretamente na espalhabilidade do produto final, que pode ser otimizado de forma racional para se obter uma cobertura adequada em toda a haste capilar e a proteção térmica desejada. Palavras-chave: Cosméticos. Planejamento Fatorial. Cobertura CAPILAR. Danos Capilares. Termoprotetor
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Ferreira, Saulo Rocha, Flávio de Andrade Silva, Paulo Roberto Lopes Lima, and Romildo Dias Toledo Filho. "Effect of Natural Fiber Hornification on the Fiber Matrix Interface in Cement Based Composite Systems." Key Engineering Materials 668 (October 2015): 118–25. http://dx.doi.org/10.4028/www.scientific.net/kem.668.118.
Анотація:
Several fiber treatments can be applied to mitigate the high water absorption of vegetal fibers. Wetting and drying cycles are usually performed in the industry of paper and cellulose to reduce the volume variation of the natural fibers. This procedure stiffens the polymeric structure of the fiber-cells (process known as hornification) resulting in a higher dimensional stability. The aim of this study is to determine the effect of the hornification on the interface of natural fibers. For this purpose, cycles of wet and drying was applied on Sisal, Curaua and Jute fibers. Fiber pull-out tests were performed in embedment lengths of 25mm. Furthermore, the influence of the hornification in the fibers mechanical (under tensile loading) and microstructural (surface modifications of the fiber and changes in the fiber-cell structure) behavior were investigated. The results indicate changes on the tensile strength and strain capacity of the studied fibers, showing that morphology and chemical composition play an important role on the efficiency rate of hornification.
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Jardim, Mário Augusto Gonçalves, Ana Caroline De Souza Campos, and Salustiano Vilar Costa Neto. "Fatores edáficos como indicadores da regeneração em uma savana na Amazônia Oriental." Revista Brasileira de Geografia Física 15, no. 2 (April 21, 2022): 926. http://dx.doi.org/10.26848/rbgf.v15.2.p926-935.
Анотація:
Atualmente as savanas amazônicas sofrem com a perda de biodiversidade vegetal e animal decorrente de ações antrópicas e que alteram diversos fatores ambientais como a composição e fertilidade do solo. O objetivo da pesquisa foi relacionar a ocorrência da regeneração com a composição físico-química do solo com intuito de contribuir com estratégias de conservação. O estudo foi realizado na localidade de Itapuá no município de Vigia de Nazaré, Pará em 677 parcelas de 1m x 1m onde foram quantificadas as espécies com altura ≤ 1 m e identificadas em família, gênero, espécie e forma de vida. Para análise físico-química do solo de cada área foram coletadas cinco subamostras de solo na profundidade de 0-10 cm para compor uma única amostra composta. As amostras foram encaminhadas ao laboratório de análise de solos da Empresa Brasileira de Pesquisa Agropecuária-Embrapa Amazônia Oriental e realizadas análises físicas (areia grossa, fina e total, silte, argila) e químicas (Fe, Zn, Cu, Mn, pH (H2O), Ca, Mg, Ca:Mg, K, Al, P, C, MO, N, C:N, Na, H+Al, SB, CTC (T), CTC (t), V e m). Foram registrados 36.190 indivíduos distribuídos em 43 famílias, 86 gêneros e 119 espécies. A forma de vida dominante foi herbácea com 55 espécies correspondente a 61,88% do total de espécies. Os elementos do solo com maiores concentrações foram o carbono, matéria orgânica, relação Carbono/Nitrogênio, Potássio, Sódio, Ferro, Areia grossa e Areia fina. Conclui-se que esses elementos do solo foram responsáveis pela dominância de plantas herbáceas caracterizadas em espécies de monocotiledôneas e espécies de pequeno porte.Palavras-chave: Florística; química do solo; conservação. Edaphic factors as indicators of regeneration in a savanna in the Eastern AmazonA B S T R A C TCurrently, the Amazon savannas suffer from the loss of plant and animal biodiversity resulting from anthropic actions that alter various environmental factors such as the composition and fertility of the soil. The objective of the research was to relate the occurrence of regeneration with the physicochemical composition of the soil in order to contribute to conservation strategies. The study was carried out in the town of Itapuá in the municipality of Vigia de Nazaré, Pará, in 677 plots of 1m x 1m; Species with height ≤ 1 m were quantified and identified in family, genera, species and life form. For physicochemical analysis of the soil in each area, five soil sub-samples were collected at a depth of 0-10 cm, to compose a single composite sample. The samples were sent to the soil analysis laboratory of the Brazilian Agricultural Research of Embrapa Eastern Amazon and physical (coarse, fine and total sand, silt, clay) and chemical (Fe, Zn, Cu, Mn, pH (H2O) analyzes were carried out ), Ca, Mg, Ca:Mg, K, Al, P, C, MO, N, C:N, Na, H+Al, SB, CTC (T), CTC (t), V and m). A total of 36.190 individuals were registered, distributed in 43 families, 86 genera and 119 species. The dominant life form was herbaceous with 55 species corresponding to 61.88% of the total species. The soil elements with the highest concentrations were carbon, organic matter, Carbon/Nitrogen ratio, Potassium, Sodium, Iron, sand and Fine sand. It is concluded that these soil elements were responsible for the dominance of herbaceous plants characterized in monocotyledonous species and small species.Keywords: Floristic; soil chemistry; conservation.
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Silva, Alana, Florindo Gaspar, and Aliaksandr Bakatovich. "Composite Materials of Rice Husk and Reed Fibers for Thermal Insulation Plates Using Sodium Silicate as a Binder." Sustainability 15, no. 14 (July 19, 2023): 11273. http://dx.doi.org/10.3390/su151411273.
Анотація:
The civil construction industry is responsible for a large part of the world’s energy consumption; therefore, in recent years, sustainable practices in this sector have become increasingly common to minimize the environmental impacts of civil construction during the life cycle of buildings. As a result, new materials and more sustainable building techniques are being sought. In Portugal, rice husk is an abundant agricultural waste with great potential to be used as a raw material in thermal insulation materials, as well as giant reed, which is considered an invasive plant. In this study, thermal insulation plates composed of rice husks and/or reed fiber were developed, using sodium silicate as a binder in various proportions and with dimensions of 30 × 30 × 3 cm and density ranging between 0.219 and 0.352 g/cm3. The main objective of the study is to evaluate the thermal characteristics of the plates, such as thermal conductivity, as well as the mechanical resistance to bending and water absorption. The results of the thermal conductivity tests were promising for all compositions, with values in the range between 0.0602 and 0.0745 W/m·K, meeting the requirements to be considered as thermal insulation materials. The results for bending strength and water absorption presented values within the expected range for materials of vegetal origin.
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Arisaca-Parillo, Adaliht J., Victor Choquehuanca-Cáceres, and Vladimiro Ibañez-Quispec. "Efecto del enriquecido y fortificado con Hierro y Acido Iinolénico en el Pan Blanco." Revista de Investigaciones Altoandinas - Journal of High Andean Research 18, no. 2 (June 24, 2016): 169. http://dx.doi.org/10.18271/ria.2016.197.
Анотація:
<p>La carencia de hierro (Fe) y ácido linolénico (omega 3) en la dieta diaria de la población, es una de las causas de desnutrición y del incremento de enfermedades cardiovasculares, con la finalidad de evaluar la influencia de la adición de hierro y ácido linolénico de origen vegetal en el pan blanco, para su enriquecido y fortificado en base a los requerimiento nutricionales. Se determinó las características físico-químicas, sensoriales y biológicas en la absorción de hierro y Relación de Eficiencia Proteica (PER). Se formularon 25 tratamientos, utilizando el Diseño Central Compuesto Rotable (DCCR) para las variables de sustitución de la harina de quinua (2.5±1.12), cañihua (4.0±2.0), maca (2.5±1.12), y linaza (3.5±1.12); la harina de trigo se mantuvo entre 80-95%. Se realizó la prueba afectiva de satisfacción, y evaluados por la prueba estadística de Friedman (p≤0.01), se seleccionó la muestra T-20 (15.5% de sustitución), por presentar valores significativos elevados en todos los atributos analizados. La muestra T-20 presentó 6.77 mg Fe/100g, 0.71g de ácido linolénico/100g, la absorción de hierro y PER estudiadas <em>in vivo</em> se reportó 3.8 mg Fe/l de sangre y PER=1.13, en ambos casos los valores fueron superiores al grupo control (pan blanco) que presentó 0.1 mg Fe/l de sangre y PER=0.96. Los resultados encontrados responden al objetivo planteado, siendo las variables estudiadas una fuente de hierro y omega 3, mejorando significativamente las características físico-químicas, sensoriales y biológicas del pan blanco en comparación a los panes comerciales.</p><p> </p><p> </p><p align="center"><strong>“EFFECT OF ENRICHED AND FORTIFIED WITH IRON AND LINOLENIC ACID IN THE WHITE BREAD”</strong></p><p> </p><p><strong>ABSTRACT</strong></p><p>The deficiency of iron (Fe) and linolenic acid (omega 3) in the daily diet of population, is one of the causes of malnutrition and increased cardiovascular disease, therefore, the aim of the study was to evaluate the influence of the addition iron and linolenic acid in vegetable source on the white bread, for enriched and fortified according to the nutrition requirements. Likewise, the physical and chemical, sensory and biological analysis like iron absorption and Protein Efficiency Ratio (PER) was determined characteristics. For to get a better sample, 25 treatments were made using the formulas of Central Composite Design CCD, with the substitution variables quinoa flour (2.5±1.12), cañihua (4.0±2.0), maca (2.5±1.12), and linseed (3.5±1.12); the wheat flour was kept between 80-95%. Through a hedonic acceptability – sensory analysis and evaluated by the Friedman statistical test (p≤0.01) the sample T-20 (15.5 subtitution) was selected for its high significant values in all attributes analyzed. This sample showed 6.77 mg Fe/100g, 0.71g of linolenic acid/100g. The absorption of iron and PER studied <em>in vivo</em> was reported 3.8 mg Fe/l of blood and PER=1.13, in both cases the values were higher than the control group (white bread) that provided 0.1 mg Fe/l of blood and PER=0.96. The results correspond to the stated objective, where the variables studied are good source of iron and omega 3, significantly improving the physic-chemical, sensory and biological characteristics of white bread compared to commercial breads.</p><p><strong>Keywords: </strong>Linolenic acid, enriched, fortified, iron, bread.</p>
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Ponsoni, Lara Vasconcellos, Marina Kauling de Almeida, Kristian Madeira, Gustavo Pacheco Militão, and Matheus Vinícius Gregory Zimmermann. "Statistical analysis of the substitution of inorganic fibers and fillers with vegetable fibers and fillers in polystyrene composites." Journal of Applied Polymer Science, March 28, 2024. http://dx.doi.org/10.1002/app.55497.
Анотація:
AbstractThermoplastic composites exhibit improved mechanical performance compared to pure matrices, and the fiber is usually the most influential component of the composite. Recently, studies related to the use of vegetable fibers have grown significantly, but few works report the direct comparative between inorganic and vegetable fibers and fillers as reinforcements. In this work, composites were produced with polystyrene (PS) matrix, reinforced with inorganic fibers (glass), vegetal fibers (kapok), particulate inorganic (CaCO3), and vegetal (wood) fillers. The composites were mixed by a twin‐screw co‐rotating extruder and after processed in an injection‐molding machine. Statistical analyses of density, tensile and flexural strength abrasion resistance were made, along with analyzes of thermal deflection temperature, dynamic mechanical analysis, and scanning electron microscopy were performed on the composites. The main results indicate that all reinforcing agents (vegetal and inorganic fibers and fillers) show a regular trend of increasing the mechanical properties proven by statistical comparison, presenting p < 0.01 that proves a significant increase. By dynamic mechanical analysis, vegetable reinforcements showed a higher coefficient of effectiveness when compared to composites produced with inorganic reinforcements.
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Matute Heredia, Francisco Javier. "Comportamiento de la grasa vegetal en la elaboración de emulsificaciones cárnicas." La Técnica: Revista de las Agrociencias. ISSN 2477-8982, December 15, 2017, 35. http://dx.doi.org/10.33936/la_tecnica.v0i0.959.
Анотація:
Behavior of Fat Vegetable in the Preparation of Meat Emulsifications
RESUMEN
La presente investigación, tiene como objetivo el estudio del comportamiento de la manteca vegetal en la elaboración de productos cárnicos, para medir, evaluar y analizar los diferentes parámetros bromatológicos, sabor del producto final y porcentajes de inclusión de grasa vegetal en su elaboración y producción, estableciendo un protocolo de aprovechamiento y utilización de la grasa vegetal. Se utilizaron procedimientos ya establecidos por el Instituto Ecuatoriano de Normalización (INEN), específicamente por la norma NTE INEN 1338:96 referente a los valores nutricionales mínimos y máximos de las diferentes componentes de los productos cárnicos (Carmona, 2009). Obteniéndose a través del diseño experimental resultados concluyentes de la investigación que con una inclusión porcentual de entre el 20% y 30% de grasa vegetal para la fabricación de emulsificaciones cárnicas, se conservan las características bromatológicas, se mantiene el sabor propio de los embutidos y se reduce la inclusión de grasa animal, logrando obtener un producto de calidad que conserve su sabor y con un índice de grasa animal saturada claramente reducido.
Palabras clave: Alimento, Análisis químico, Carne, Compuesto orgánico, Producción alimentaria.
ABSTRACT
The present investigation has as main objective the study of the behavior of the vegetable shortening in the elaboration of meat products, to measure, evaluate and analyze the different bromatological parameters, flavor of the final product and percentages of inclusion of vegetal fat for the elaboration and production, establishing a protocol for the utilization and utilization of vegetable fat. Procedures already established by the Ecuadorian Institute of Normalization (INEN), specifically by the NTE INEN 1338: 96 standard were used referring to the minimum and maximum nutritional values of the different components of the meat products (Carmona, 2009). Obtained through the experimental design conclusive results of the investigation, with an inclusion percentage of between 20% and 30% of vegetable fat for the manufacture of meat emulsions, the characteristics of the meat are preserved, the characteristic flavor of the sausages is preserved and the inclusion of animal fat is reduced, achieving a quality product that preserves its flavor and a clearly reduced index of saturated animal fat.
Key words: Food, Chemical analysis, Meat, Organic composite, Food production.
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Guerfala, Wassim, Patrick Rozycki, and Christophe Binetruy. "Development of flax/basalt/PA11 bio-composites: optimal formulation and modelling of the quasi-static behaviour." Frontiers in Materials 10 (June 15, 2023). http://dx.doi.org/10.3389/fmats.2023.1176408.
Анотація:
Environmental impact is becoming increasingly important in the automotive industry, with car manufacturers looking to reduce CO2 emissions through cleaner engines and structural weight reduction. Composite materials offer an excellent alternative to standard steels with significant weight reduction and the ability to produce functional parts (Rangappa et al., Polymer Composites, 2022,43, 645–691), (Jeyaguru et al., Polymer Composites, 2022, 43, 3902–3914), (Sanjay et al., Journal of Cleaner Production, 2018, 172, 566–581). The main objective of this study is to investigate the potential of a new and unique hybrid bio-composite material combining flax and basalt fibers and PA11 polymer. This material design is studied with the idea of reducing the moisture sensitivity, variabilities, and uncertainties of vegetal fibers by the presence of basalt fibers. The first step consists of developing a new hybrid composite material and studying its quasi-static mechanical behaviour when subjected to different humidity levels. Then, a multi-scale non-linear homogenization approach is proposed to support the interpretation of the characterization test results. The experimental results show the benefits of the hybridization. In fact, the hybrid composite is 20% stiffer than the flax/PA11 composite, 8% lighter than the basalt/PA11 composite and has a reduced dispersion of its mechanical properties, 52% lower than the flax/ PA11 composite. Considering the promising properties of the hybrid composite, we have investigated the possibility of developing the front hood of a sports car using this material. The first results highlight a potential mass gain of 18% at iso-performance with the original front hood. The following steps will be devoted to the numerical and experimental validation.
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Teacă, Carmen-Alice, Mauruşa-Elena Ignat, Marioara Nechifor, Fulga Tanasă, and Leonard Ignat. "In-soil degradation of polymer materials waste – A survey of different approaches in relation with environmental impact." BioResources 18, no. 1 (November 9, 2022). http://dx.doi.org/10.15376/biores.18.1.teaca.
Анотація:
Vegetal fibers from different sources, including wood fibers and plant-derived fibers, together with polymer plastics per se (natural, synthetic, and their blends), as well as their combinations as composite materials may generate significant amounts of wastes. These will undergo degradation process under exposure to different environmental factors including microorganisms, climatic changes – e.g. droughts, oxygen, temperature, soil dynamics, UV radiation, etc. This survey offers a concise review of degradation under environmental conditions, mainly after in-soil exposure, of waste made of polymer materials and natural fibers. It also describes the most common methods for evaluation of bioconversion and degradation, as well as the structural properties after degradation (e.g. macroscopic investigation; weight loss; spectrometry – UV, FTIR, NMR; X-ray diffraction for crystalline changes; SEM microscopy; and thermal stability).
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Romero, Francisco, Zaida Ortega, Jessica Castellano, Antonio N. Benítez, María Dolores Marrero, and Luis Suárez. "Use of Ricinus communis shredded material as filler in rotational molded parts to improve the bio-disintegration behavior." Polymer Bulletin, November 30, 2022. http://dx.doi.org/10.1007/s00289-022-04593-5.
Анотація:
AbstractThis paper focuses on the use of castor oil plant (Ricinus communis) as filler in rotomolded parts using polyethylene (PE) and polylactic acid (PLA) as polymer matrixes. The vegetable shredded material was used in 5 and 10% weight following a dry blending procedure and then rotomolded to obtain cube test parts. This material was characterized to determine its chemical composition, thermal stability, and structure. The NaOH-treated material shows reduced hemicellulose content and higher thermal stability. Obtained composite materials were characterized in terms of mechanical (tensile, flexural, and impact) and thermal properties, morphology, and bio-disintegration behavior. The use of Ricinus as filler in rotomolded PE composite decreases, in general terms, mechanical properties of neat PE, while no significant changes in thermal or bio-disintegration properties are found. On the contrary, PLA composites show higher tensile strength and similar Young's modulus than the matrix, although with reduced flexural and impact properties. Alkali-treated Ricinus material produces parts with higher porosity and thus, lower mechanical properties than composites with untreated material. Finally, the incorporation of this vegetal material modifies to a great extent the thermal properties of the PLA matrix. The bio-disintegration rate increases due to the use of fibers, probably because of the higher moisture absorption of composites.