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1
Michael Jacob Ioelovich. "Microcellulose Vs Nanocellulose – A Review". World Journal of Advanced Engineering Technology and Sciences 5, n. 2 (30 marzo 2022): 001–15. http://dx.doi.org/10.30574/wjaets.2022.5.2.0037.
Testo completoAbstract (sommario):
Cellulose is the most abundant and renewable natural semi-crystalline polysaccharide. This biopolymer is an inexhaustible source of natural fibers (NFs), and valuable raw material for the production of microparticles of microcrystalline (MCC) and powdered cellulose (PC), as well as other cellulose micro-products, which are widely used in biomedicine, production of food additives, plastics, and other materials. In addition, cellulose has a nano-fibrillar architecture that promotes the release of free cellulose nanofibers (CNFs) and nanocrystals (CNCs). This review article describes the preparation methods, structural characteristics, properties, and applications of different types of micro- (NFs, MCC, and PC) and nano-cellulose (CNFs, CNCs). Two main shortcomings hindering the wide application of various types of Nano cellulose (NC) were discovered, such as high production expenses and the difficulty of competing with commercial types of micro-cellulose. To reduce the production cost of NC, a waste-free technology can be used, which allows completely utilize materials and chemicals, and produce cheap nanocrystalline aggregates (NCA) with zero emission of liquid and solid waste. Due to the low cost, such a nanostructured product, NCA, will be quite competitive with commercial micro-celluloses (MCC, PC, etc.) and can be used, e.g., as filler and thickener.
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Jedvert, Kerstin, e Thomas Heinze. "Cellulose modification and shaping – a review". Journal of Polymer Engineering 37, n. 9 (27 novembre 2017): 845–60. http://dx.doi.org/10.1515/polyeng-2016-0272.
Testo completoAbstract (sommario):
Abstract This review aims to present cellulose as a versatile resource for the production of a variety of materials, other than pulp and paper. These products include fibers, nonwovens, films, composites, and novel derivatized materials. This article will briefly introduce the structure of cellulose and some common cellulose derivatives, as well as the formation of cellulosic materials in the micro- and nanoscale range. The challenge with dissolution of cellulose will be discussed and both derivatizing and nonderivatizing solvents for cellulose will be described. The focus of the article is the critical discussion of different shaping processes to obtain a variety of cellulose products, from commercially available viscose fibers to advanced and functionalized materials still at the research level.
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Correia, Viviane Costa, Sergio Francisco Santos, Holmer Savastano Jr e Vanderley Moacyr John. "Utilization of vegetable fibers for production of reinforced cementitious materials". RILEM Technical Letters 2 (4 aprile 2018): 145–54. http://dx.doi.org/10.21809/rilemtechlett.2017.48.
Testo completoAbstract (sommario):
Vegetable fibers produced from agroindustrial resources in the macro, micro and nanometric scales have been used as reinforcement in cementitious materials. The cellulosic pulp, besides being used as the reinforcing element, is also the processing fiber that is responsible for the filtration system in the Hatcheck method. On the other hand, the nanofibrillated cellulose has the advantage of having good mechanical performance and high specific surface, which contributes to improve the adhesion between fiber and matrix. In the hybrid reinforcement, with micro and nanofibers, the cellulose performs bonding elements with the matrix and acts as stress transfer bridges in the micro and nano-cracking network with the corresponding strengthening and toughening of the cementitious composite. Some strategies are studied to mitigate the degradation of the vegetable fibers used in cost-effective and non-conventional fiber cement, as well as to reach a sustainable fiber cement production. As a practical example, the accelerated carbonation curing at early age is a developing technology to increase the durability of composite materials: it decreases porosity, promotes a higher density in the interface generating a good fiber–matrix adhesion and a better mechanical behavior. Thus, the vegetable fibers are potentially applicable to produce high mechanical performance and sustainable cementitious materials for use in the Civil Construction.
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Kmetty, Á., J. Karger-Kocsis e T. Czigány. "Production and properties of micro-cellulose reinforced thermoplastic starch". IOP Conference Series: Materials Science and Engineering 74 (17 febbraio 2015): 012008. http://dx.doi.org/10.1088/1757-899x/74/1/012008.
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Ansharullah, Ansharullah, Nur Muhammad Abdillah Saenuddin, RH Fitri Faradilla, Asranuddin Asranudin, Asniar Asniar e Muhammad Nurdin. "Production of Micro Crystalline Cellulose from Tapioca Solid Waste: Effect of Acid Concentration on its Physico-chemical Properties". Jurnal Kimia Sains dan Aplikasi 23, n. 5 (1 maggio 2020): 147–51. http://dx.doi.org/10.14710/jksa.23.5.147-151.
Testo completoAbstract (sommario):
This study was aimed to examine the production of microcrystalline cellulose (MCC) from tapioca solid waste (TSW), using HCl hydrolysis with various concentrations, i.e., 2 N, 2.5 N, 3 N, and 3.5 N. MCC was produced by delignifying the TSW with NaOH 20%, and bleaching with NaOCl 3.5% to produce α-cellulose, and subsequently hydrolyzing α-cellulose with three different HCl concentrations to produce MCC. The physicochemical properties of MCC were then analyzed, including Scanning Electron Micrograph (SEM), X-ray diffraction (XRD), and FTIR spectra. The results showed that hydrolysis with 2.0 N HCl resulted in a higher yield of 61.28%, α-cellulose content of 56.33%, moisture 6.25%, pH of 6.54; ash 0.23%, and water solubility 0.34%. SEM analysis showed the morphology and size of the MCC produced were like those of a commercial MCC (Avicel PH101), while the XRD analysis showed the higher concentration of HCl gave rise to an increased crystalline index. FT-IR spectrum analysis indicated that TSW, MCC produced, and commercial MCC had similar functional groups.
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Krindges, Aline, Vanusca Dalosto Jahno e Fernando Morisso. "Incorporation of micro/nanoparticles of PCL with essential oil of Cymbopogon nardus in bacterial cellulose". International Journal of Advances in Medical Biotechnology - IJAMB 1, n. 2 (15 marzo 2018): 37. http://dx.doi.org/10.25061/2595-3931/ijamb/2018.v1i2.18.
Testo completoAbstract (sommario):
Incorporation studies of particles in different substrates with herbal assets growing. The objective of this work was the preparation and characterization of micro/nanoparticles containing cymbopogon nardus essential oil; and the incorporation of them on bacterial cellulose. For the development of the membranes was used the static culture medium and for the preparation of micro/nanoparticles was used the nanoprecipitation methodology. The incorporation of micro/nanoparticles was performed on samples of bacterial cellulose in wet and dry form. For the characterization of micro/nanoparticles were carried out analysis of SEM, zeta potential and particle size. For the verification of the incorporation of particulate matter in cellulose, analyses were conducted of SEM and FTIR. The results showed that it is possible the production and incorporation of micro/nanoparticles containing essential oil in bacterial cellulose membranes in wet form with ethanol.
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Armaini, Abdi Dharma, Sumaryati Syukur e Jamsari. "OPTIMASI NUTRISI MEDIA PERTUMBUHAN BAKTERI TERMOFIL PENGHASIL SELULASE DARI SUMBER AIR PANAS RIMBO PANTI". Jurnal Riset Kimia 5, n. 1 (12 febbraio 2015): 1. http://dx.doi.org/10.25077/jrk.v5i1.165.
Testo completoAbstract (sommario):
Optimization have been done on the media for the growth of the isolated thermophiles bacteria from hot springs Rimbo Panti, the nutrients comprising variety of carbon sources such as CMC (carboxymethyl cellulose), avicell (micro crystalline cellulose), and cellobiose, with a variety of sources organic nitrogen, peptone, extracts yeast, tryptone, and urea, as well as variations consist of inorganic nitrogen sources, KNO3, NaNO3, (NH4)2SO4, and (NH4)NO3. Determination of cellulase activity performed using DNS reagent (3,5-dinitro salicylic acid). Maximum cellulase production with high activity based on the results of this research, the best of carbon source is CMC with optimum concentration 0.125%, inorganic nitrogen source is peptone with the optimum concentration of 0.3 to 0.4% and the inorganic nitrogen source is (NH4)2SO4 with optimum concentration of 0.2 - 0.25%. Optimization of size of inoculums obtained the optimum amount of inoculums 2%. Keywords: Optimization, thermophiles bacteria, cellulose, carbon sources, nitrogen sources
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Stepanova, Mariia, e Evgenia Korzhikova-Vlakh. "Modification of Cellulose Micro- and Nanomaterials to Improve Properties of Aliphatic Polyesters/Cellulose Composites: A Review". Polymers 14, n. 7 (5 aprile 2022): 1477. http://dx.doi.org/10.3390/polym14071477.
Testo completoAbstract (sommario):
Aliphatic polyesters/cellulose composites have attracted a lot attention due to the perspectives of their application in biomedicine and the production of disposable materials, food packaging, etc. Both aliphatic polyesters and cellulose are biocompatible and biodegradable polymers, which makes them highly promising for the production of “green” composite materials. However, the main challenge in obtaining composites with favorable properties is the poor compatibility of these polymers. Unlike cellulose, which is very hydrophilic, aliphatic polyesters exhibit strong hydrophobic properties. In recent times, the modification of cellulose micro- and nanomaterials is widely considered as a tool to enhance interfacial biocompatibility with aliphatic polyesters and, consequently, improve the properties of composites. This review summarizes the main types and properties of cellulose micro- and nanomaterials as well as aliphatic polyesters used to produce composites with cellulose. In addition, the methods for noncovalent and covalent modification of cellulose materials with small molecules, polymers and nanoparticles have been comprehensively overviewed and discussed. Composite fabrication techniques, as well as the effect of cellulose modification on the mechanical and thermal properties, rate of degradation, and biological compatibility have been also analyzed.
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Weerasinghe, Weerasinghe Mudiyanselage Lakshika Iroshani, Dampe Acharige Tharindu Madusanka e Pathmalal Marakkale Manage. "Isolation and Identification of Cellulase Producing and Sugar Fermenting Bacteria for Second-Generation Bioethanol Production". International Journal of Renewable Energy Development 10, n. 4 (10 aprile 2021): 699–711. http://dx.doi.org/10.14710/ijred.2021.35527.
Testo completoAbstract (sommario):
Over the last decades, the negative impacts of fossil fuel on the environment and increasing demand for energy due to the unavoidable depletion of fossil fuels, has transformed the world’s interests towards alternative fuels. In particular, bioethanol production from cellulosic biomass for the transportation sector has been incrementing since the last decade. The bacterial pathway for bioethanol production is a relatively novel concept and the present study focused on the isolation of potential “cellulase-producing” bacteria from cow dung, compost soil, and termite gut and isolating sugar fermenting bacteria from palm wine. To select potential candidates for cellulase enzyme production, primary and secondary assays were conducted using the Gram’s iodine stain in Carboxy Methyl Cellulose (CMC) medium and the Dinitrosalicylic acid (DNS) assays, respectively. Durham tube assay and Solid-Phase Micro-Extraction (SPME) coupled with Gas Chromatography-Mass Spectrometry (GC-MS) was used to evaluate the sugar fermenting efficiency of the isolated bacteria. Out of 48 bacterial isolates, 27 showed cellulase activity where Nocardiopsis sp. (S-6) demonstrated the highest extracellular crude enzyme activity of endoglucanase (1.56±0.021 U) and total cellulase activity (0.93±0.012 U). The second-highest extracellular crude enzyme activity of endoglucanase (0.21±0.021 U) and total cellulase activity (0.35±0.021 U) was recorded by Bacillus sp. (T-4). Out of a total of 8 bacterial isolates, Achromobacter sp. (PW-7) was positive for sugar fermentation resulting in 3.07% of ethanol in broth medium at 48 h incubation. The results of the study revealed that Nocardiopsis sp. (S-6) had the highest cellulase enzyme activity. However, the highest ethanol percentage was achieved with by having both Bacillus sp. (T-4) and Achromobacter sp. (PW-7) for the simultaneous saccharification and fermentation (SSF) method, as compared to separate hydrolysis and fermentation (SHF) methodologies.
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Magalhães, Marta I., e Ana P. C. Almeida. "Nature-Inspired Cellulose-Based Active Materials: From 2D to 4D". Applied Biosciences 2, n. 1 (15 marzo 2023): 94–114. http://dx.doi.org/10.3390/applbiosci2010009.
Testo completoAbstract (sommario):
Multifunctional materials and devices with captivating properties can be assembled from cellulose and cellulose-based composite materials combining functionality with structural performance. Cellulose is one of the most abundant renewable materials with captivating properties, such as mechanical robustness, biocompatibility, and biodegradability. Cellulose is a low-cost and abundant biodegradable resource, CO2 neutral, with a wide variety of fibers available all over the world. Over thousands of years, nature has perfected cellulose-based materials according to their needs, such as function vs. structure. Mimicking molecular structures at the nano-, micro-, and macroscales existing in nature is a great strategy to produce synthetic cellulose-based active materials. A concise background of cellulose and its structural organization, as well as the nomenclature of cellulose nanomaterials, are first addressed. Key examples of nature-designed materials with unique characteristics, such as “eternal” coloration and water-induced movement are presented. The production of biomimetic fiber and 2D fiber-based cellulosic materials that have attracted significant attention within the scientific community are represented. Nature-inspired materials with a focus on functionality and response to an external stimulus are reported. Some examples of 3D-printed cellulosic materials bioinspired, reported recently in the literature, are addressed. Finally, printed cellulosic materials that morph from a 1D strand or 2D surface into a 3D shape, in response to an external stimulus, are reported. The purpose of this review is to discuss the most recent developments in the field of “nature-inspired” cellulose-based active materials regarding design, manufacturing, and inspirational sources that feature existing tendencies.
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Khalil, H. P. S. Abdul, Fauziah Jummaat, Esam Bashir Yahya, N. G. Olaiya, A. S. Adnan, Munifah Abdat, Nasir N. A. M. et al. "A Review on Micro- to Nanocellulose Biopolymer Scaffold Forming for Tissue Engineering Applications". Polymers 12, n. 9 (8 settembre 2020): 2043. http://dx.doi.org/10.3390/polym12092043.
Testo completoAbstract (sommario):
Biopolymers have been used as a replacement material for synthetic polymers in scaffold forming due to its biocompatibility and nontoxic properties. Production of scaffold for tissue repair is a major part of tissue engineering. Tissue engineering techniques for scaffold forming with cellulose-based material is at the forefront of present-day research. Micro- and nanocellulose-based materials are at the forefront of scientific development in the areas of biomedical engineering. Cellulose in scaffold forming has attracted a lot of attention because of its availability and toxicity properties. The discovery of nanocellulose has further improved the usability of cellulose as a reinforcement in biopolymers intended for scaffold fabrication. Its unique physical, chemical, mechanical, and biological properties offer some important advantages over synthetic polymer materials. This review presents a critical overview of micro- and nanoscale cellulose-based materials used for scaffold preparation. It also analyses the relationship between the method of fabrication and properties of the fabricated scaffold. The review concludes with future potential research on cellulose micro- and nano-based scaffolds. The review provides an up-to-date summary of the status and future prospective applications of micro- and nanocellulose-based scaffolds for tissue engineering.
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Ishizu, Y., K. Kaneki e K. Izawa. "Smoke Production from Cell Wall Materials of Tobacco Leaves". Beiträge zur Tabakforschung International/Contributions to Tobacco Research 15, n. 1 (1 agosto 1991): 1–10. http://dx.doi.org/10.2478/cttr-2013-0616.
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AbstractMajor components of cell wall materials, that is a-cellulose, hemicellulose, pectin and lignin, were isolated from tobacco leaves. They were heated in a micro-thermobalance in different atmospheres and at different heating rates. The weight loss rate of the sample materials, production rates of carbon oxides and smoke particles produced were measured. In general, materials which produce more carbon oxides produce less smoke particulate mass. In helium at a heating rate of 240°C/min, which attempts to approximate the burning conditions of a cigarette, weight ratios of smoke particles to the sample weight were 32 % for a-cellulose, 24 % for lignin, 3 % for hemicellulose and 0.4 % for pectin. Since a-cellulose is a major constituent of the cell wall of tobacco leaves and has the highest production rate, it can be concluded that a-cellulose is a major contributor to the production of smoke particles from cigarettes. On the contrary, pectin contributes the least.
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Patel, Dinesh K., Yu-Ri Seo, Sayan Deb Dutta e Ki-Taek Lim. "Enhanced osteogenesis of mesenchymal stem cells on electrospun cellulose nanocrystals/poly(ε-caprolactone) nanofibers on graphene oxide substrates". RSC Advances 9, n. 62 (2019): 36040–49. http://dx.doi.org/10.1039/c9ra06260b.
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Algellay, Marwan, Matthew Roberts, Lucy Bosworth, Satyajit D. Sarker, Amos A. Fatokun e Touraj Ehtezazi. "The Use of Micro-Ribbons and Micro-Fibres in the Formulation of 3D Printed Fast Dissolving Oral Films". Pharmaceuticals 16, n. 1 (5 gennaio 2023): 79. http://dx.doi.org/10.3390/ph16010079.
Testo completoAbstract (sommario):
Three-dimensional printing (3DP) allows production of novel fast dissolving oral films (FDFs). However, mechanical properties of the films may not be desirable when certain excipients are used. This work investigated whether adding chitosan micro-ribbons or cellulose microfibres will achieve desired FDFs by fused deposition modelling 3DP. Filaments containing polyvinyl alcohol (PVA) and paracetamol as model drug were manufactured at 170 °C. At 130 °C, filaments containing polyvinylpyrrolidone (PVP) and paracetamol were also created. FDFs were printed with plain or mesh patterns at temperatures of 200 °C (PVA) or 180 °C (PVP). Both chitosan micro-ribbons and cellulose micro-fibres improved filament mechanical properties at 1% w/w concentration in terms of flexibility and stiffness. The filaments were not suitable for printing at higher concentrations of chitosan micro-ribbons and cellulose micro-fibres. Furthermore, mesh FDFs containing only 1% chitosan micro-ribbons disintegrated in distilled water within 40.33 ± 4.64 s, while mesh FDFs containing only 7% croscarmellose disintegrated in 55.33 ± 2.86 s, and croscarmellose containing films showed signs of excipient scorching for PVA polymer. Cellulose micro-fibres delayed disintegration of PVA mesh films to 108.66 ± 3.68 s at 1% w/w. In conclusion, only chitosan micro-ribbons created a network of hydrophilic channels within the films, which allowed faster disintegration time at considerably lower concentrations.
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Ibarra, David, Raquel Martín-Sampedro, Bernd Wicklein, Úrsula Fillat e María E. Eugenio. "Production of Microfibrillated Cellulose from Fast-Growing Poplar and Olive Tree Pruning by Physical Pretreatment". Applied Sciences 11, n. 14 (13 luglio 2021): 6445. http://dx.doi.org/10.3390/app11146445.
Testo completoAbstract (sommario):
Motivated by the negative impact of fossil fuel consumption on the environment, the need arises to produce materials and energy from renewable sources. Cellulose, the main biopolymer on Earth, plays a key role in this context, serving as a platform for the development of biofuels, chemicals and novel materials. Among the latter, micro- and nanocellulose have been receiving increasing attention in the last few years. Their many attractive properties, i.e., thermal stability, high mechanical resistance, barrier properties, lightweight, optical transparency and ease of chemical modification, allow their use in a wide range of applications, such as paper or polymer reinforcement, packaging, construction, membranes, bioplastics, bioengineering, optics and electronics. In view of the increasing demand for traditional wood pulp (e.g., obtained from eucalypt, birch, pine, spruce) for micro/nanocellulose production, dedicated crops and agricultural residues can be interesting as raw materials for this purpose. This work aims at achieving microfibrillated cellulose production from fast-growing poplar and olive tree pruning using physical pretreatment (PFI refining) before the microfibrillation stage. Both raw materials yielded microfibrillated cellulose with similar properties to that obtained from a commercial industrial eucalypt pulp, producing films with high mechanical properties and low wettability. According to these properties, different applications for cellulose microfibers suspensions and films are discussed.
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Zhang, Zhi Ping, Quan Guo Zhang, Yi Wang e Jian Zhi Yue. "Study of Hydrogen Producing Capacity and Micro-Structure of the Crop Stalks after Ball Milling". Advanced Materials Research 347-353 (ottobre 2011): 2697–704. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.2697.
Testo completoAbstract (sommario):
Utilized the reducing sugar amount and cumulative hydrogen production that produced by the enzymolysis of the biomass crushed by the ball mill as reference, the experiments on the relationship between different sort of raw material and different reducing sugar yield show that the corncob reducing sugar yield and cumulative hydrogen production uptake after enzymolysis is highest, reaching 1088mL.Observed the microstructure of the crushing cornstalk and corncob with canning electron microscope and X-ray diffraction, the analysis results showed that: after ball mill crushing, biomass cell wall was effectively opened, specific surface increased, particle size decreased, the microstructure changed and became loose and porous, the cellulose degree of crystallinity were all aggressively lowered, cellulase accessibility increased, the biomass degrees of saccharifying rate improved, made the hydrogen producing capacity increased efficiency.
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Karagiannidis, Emmanouil, Charles Markessini e Eleftheria Athanassiadou. "Micro-Fibrillated Cellulose in Adhesive Systems for the Production of Wood-Based Panels". Molecules 25, n. 20 (21 ottobre 2020): 4846. http://dx.doi.org/10.3390/molecules25204846.
Testo completoAbstract (sommario):
Micro-Fibrillated Cellulose (MFC) is a new type of bio-based additive, coming from wood cellulose. It can compete and substitute oil derived chemicals in several application fields. In the present work, the use of micro-fibrillated cellulose, in waterborne adhesive systems applied in the manufacture of composite wood-based panels was evaluated. Research was conducted to test the potential of improving the performance of wood-based panel types such as particleboard, waferboard or randomly-oriented strand board and plywood, by the application of MFC and the substitution of conventional and non-renewable chemical compounds. The approaches followed to introduce MFC into the adhesive systems were three, i.e., MFC 2% suspension added during the adhesive resin synthesis, MFC 10% paste admixed with the already prepared adhesive resin and MFC 2% suspension admixed with the already prepared resin. It was found that MFC improves not only the performance of the final wood panel products but also the behaviour of the applied adhesive polymer colloids (e.g., rheology improvement), especially when admixed with the already prepared resins. Moreover, it was proven that when MFC is introduced into the adhesive resin system, there is a possibility of decreasing the resin consumption, by maintaining the board performance. MFC’s robustness to pH, shear and temperature makes it a highly interesting new additive for adhesive producers. In addition, its natural origin can give adhesive producers the opportunity to move over to more environmentally friendly product solutions.
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Tozluoglu, Ayhan, Bayram Poyraz e Zeki Candan. "Examining the efficiency of mechanic/enzymatic pretreatments in micro/nanofibrillated cellulose production". Maderas. Ciencia y tecnología, ahead (2018): 0. http://dx.doi.org/10.4067/s0718-221x2018005001601.
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Tyshkunova, Irina V., Daria N. Poshina e Yury A. Skorik. "Cellulose Cryogels as Promising Materials for Biomedical Applications". International Journal of Molecular Sciences 23, n. 4 (12 febbraio 2022): 2037. http://dx.doi.org/10.3390/ijms23042037.
Testo completoAbstract (sommario):
The availability, biocompatibility, non-toxicity, and ease of chemical modification make cellulose a promising natural polymer for the production of biomedical materials. Cryogelation is a relatively new and straightforward technique for producing porous light and super-macroporous cellulose materials. The production stages include dissolution of cellulose in an appropriate solvent, regeneration (coagulation) from the solution, removal of the excessive solvent, and then freezing. Subsequent freeze-drying preserves the micro- and nanostructures of the material formed during the regeneration and freezing steps. Various factors can affect the structure and properties of cellulose cryogels, including the cellulose origin, the dissolution parameters, the solvent type, and the temperature and rate of freezing, as well as the inclusion of different fillers. Adjustment of these parameters can change the morphology and properties of cellulose cryogels to impart the desired characteristics. This review discusses the structure of cellulose and its properties as a biomaterial, the strategies for cellulose dissolution, and the factors affecting the structure and properties of the formed cryogels. We focus on the advantages of the freeze-drying process, highlighting recent studies on the production and application of cellulose cryogels in biomedicine and the main cryogel quality characteristics. Finally, conclusions and prospects are presented regarding the application of cellulose cryogels in wound healing, in the regeneration of various tissues (e.g., damaged cartilage, bone tissue, and nerves), and in controlled-release drug delivery.
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Sjöstrand, Björn, Christophe Barbier, Henrik Ullsten e Lars Nilsson. "Dewatering of softwood kraft pulp with additives of microfibrillated cellulose and dialcohol cellulose". BioResources 14, n. 3 (20 giugno 2019): 6370–83. http://dx.doi.org/10.15376/biores.14.3.6370-6383.
Testo completoAbstract (sommario):
The addition of nano- and micro-fibrillated cellulose to conventional softwood Kraft pulps can enhance the product performance by increasing the strength properties and enabling the use of less raw material for a given product performance. However, dewatering is a major problem when implementing these materials to conventional paper grades because of their high water retention capacity. This study investigated how vacuum dewatering is affected by different types of additives. The hypothesis was that different types of pulp additions behave differently during a process like vacuum suction, even when the different additions have the same water retention value. One reference pulp and three additives were used in a laboratory-scaled experimental study of high vacuum suction box dewatering. The results suggested that there was a linear relationship between the water retention value and how much water that could be removed with vacuum dewatering. However, the linear relationship was dependent upon the pulp type and the additives. Additions of micro-fibrillated cellulose and dialcohol cellulose to the stock led to dewatering behaviors that suggested their addition in existing full-scale production plants can be accomplished without a major redesign of the wire or high vacuum section.
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Betlej, Izabela, Katarzyna Rybak, Małgorzata Nowacka, Andrzej Antczak, Sławomir Borysiak, Barbara Krochmal-Marczak, Karolina Lipska e Piotr Boruszewski. "Structural Properties of Bacterial Cellulose Film Obtained on a Substrate Containing Sweet Potato Waste". Crystals 12, n. 9 (25 agosto 2022): 1191. http://dx.doi.org/10.3390/cryst12091191.
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The paper presents the results of research on the microstructure of bacterial cellulose (BC-SP) obtained on a medium containing sweet potato peel, which was compared to cellulose obtained on a synthetic medium containing sucrose and peptone (BC-N). The properties of cellulose were analyzed using the methods: size exclusion chromatography (SEC), X-ray diffraction (XRD), scanning electron microscope (SEM), and computer microtomograph (X-ray micro-CT). BC-SP was characterized by a higher degree of polymerization (5680) and a lower porosity (1.45%) than BC-N (4879, 3.27%). These properties give great opportunities to cellulose for various applications, e.g., the production of paper or pulp. At the same time, for BC-SP, a low value of relative crystallinity was found, which is an important feature from the point of view of the mechanical properties of the polymer. Nevertheless, these studies are important and constitute an important source of knowledge on the possibility of using cheap waste plant materials as potential microbiological substrates for the cultivation of cellulose-synthesizing micro-organisms with specific properties.
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Mabhegedhe, Munamato. "Cellulolytic Activities of the Dung Beetle, Euoniticellus Intermedius, Larva Gut Micro-Flora". Open Biotechnology Journal 11, n. 1 (14 dicembre 2017): 105–13. http://dx.doi.org/10.2174/1874070701711010105.
Testo completoAbstract (sommario):
Background:The life style and biology of dung beetles offer a significant opportunity for innovation in biofuel production. The larvae of the African dung beetle,Euoniticellus intermedius, feed solely on cow dung, eating and digesting the fibre while adults live on juices found in fresh dung. The larval gut system consists of a small, almost unrecognizable foregut and two distinct chambers; the midgut and hindgut. It is clear that these two chambers are the centres in which the dung material whose composition includes cellulose is processed. The goal of this study was to assess the cellulolytic activities of cultured gut micro-flora derived fromE. intermedius, (Coleoptera: Scarabaeida).Method:Late second to third instar stageE. intermediuslarvae were dissected and the isolated gut micro-flora consortia aerobically cultured in media containing cellulose (filter paper) as the sole carbon source. Genomic DNA isolation was done on the gut consortia cultures after 10 days of culturing, using the ZR Fungal/Bacterial DNA MiniPrep kit (Zymo Research, USA). A complete and unbiased primary cosmid library was then constructed from the isolated genomic DNA using a cloning ready, pWEB-TNC™ Cosmid Cloning kit (EPICENTRE Biotechnologies, USA). The primary cosmid library clones were screened for endo-glucanase and cellobiohydrolase activities using Carboxymethyl Cellulose (CMC) and 4-Methylumbelliferyl-β-D-Cellobioside (MUC) plate assays respectively.Results:Results indicate that a total of 7 colonies out of 160 screened colonies showed positive CMC and MUC activities.Conclusion:This proves thatE. intermediusis a potential source of cellulolytic micro-organisms and enzymes that can be used for cellulose derived biofuel production.
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Yurid, F., A. S. Handayani, F. D. Maturbongs, Y. Irawan, Y. Sampora, Y. A. Devy, M. Septiyanti et al. "Production of nanocellulose using controlled acid hydrolysis from large-scale production of micro-fibrillated cellulose derived from oil palm empty fruit bunches". IOP Conference Series: Earth and Environmental Science 1201, n. 1 (1 giugno 2023): 012078. http://dx.doi.org/10.1088/1755-1315/1201/1/012078.
Testo completoAbstract (sommario):
Abstract Nanocellulose is generally known as a versatile material, which is suitable for various applications due to its unique physicochemical properties, including light weight, ease of tunable surface functionalization, and excellent mechanical properties. This research aims to characterize and synthesize nanocellulose produced from acid hydrolysis of large-scaled micro-fibrillated cellulose (MFC) derived from oil palm empty fruit bunches by varying concentrations of H2SO4 from 20 to 35 v/v %. The obtained large-scaled MFC had a density of 1.01 kg/m3 and was dominantly composed of 71% cellulose. After acid hydrolysis of MFC, there were gradual changes in the colour of the obtained cellulose nanocrystals (CNC) dispersion from light white to a darker color with the increase of acid concentration, in which the over hydrolysis occurs at 35% of acid concentration. The use of 25-30% H2SO4 showed the optimum condition to avoid over-hydrolysis and resulted in bright white color of CNC dispersion with excellent stability at zeta potential value of -74.2±0.1 to -88.4±0.2 mV. It was supported by Fourier transform infrared (FTIR) due to the presence of negatively charged sulfonyl and hydroxyl groups upon CNC formation to offer excellent dispersion stability. Based on transmission electron microscope (TEM), rod-like shape CNC with a low aspect ratio of 11.8 at the dimension of 12.8 ± 6.7 nm in width and 151.9 ± 38.3 nm in length was successfully produced. Based on X-ray diffraction (XRD) analysis, the crystallinity of the sample was 76%.
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Zeleke, Nehemiah Mengistu, Devendra Kumar Sinha e Getinet Asrat Mengesha. "Chemical Composition and Extraction of Micro Crystalline Cellulose from Outer Skin Isolated Coffee Husk". Advances in Materials Science and Engineering 2022 (13 dicembre 2022): 1–13. http://dx.doi.org/10.1155/2022/7163359.
Testo completoAbstract (sommario):
Coffee husk (CH) is a sustainable and abundantly available cellulosic waste material. Its fiber consists of cellulose as the major structural part which leads to potential utilization for the manufacturing of microcrystalline cellulose (MCC) products that can be utilized for different industrial applications. In the present study, chemical composition of outer skin-isolated coffee husk was determined and sequential treatments of various untreated (UT) sample, ethanol—toluene treated sample through dewaxed (DW) treatment, sodium hydroxide (NaOH)—treated sample through alkali (AT) treatment, and sulfuric acid (H2SO4)—treated sample through bleaching (BL) treatment have been carried out. The Micro Crystalline Cellulose (MCC) has been extracted through hydrogen peroxide (H2O2) after BL treatment. The BL treatment for MCC extraction process was conducted without chlorine and additional harsh acid treatment, respectively. The characterization of chemically treated samples was carried out to investigate their morphological, physico-chemistry, and thermal behavior through a scanning electron microscope (SEM), Fourier transform infrared—ray (FTIR), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), and differential temperature analyzer (DTA). From the chemical composition analysis; the cellulose, hemicellulose, lignin, and extractive content were determined and its values were (52.9%), (12.5%), (24.3%), and (9.4%), respectively. In the morphological examination, the great untreated (UT) fiber sample was greatly reduced into a micro-sized BL sample, revealing that (from FTIR analysis) the lignin and hemicellulose contents were greatly removed during chemical treatments and the presence of a micro crystalline cellulose region with 54.7% yield. Also, the sample AT and BL showed the lowest amorphous region in X-RD due to the removal of hemicellulose and lignin. The highest crystallinity index has been determined for the BL sample, i.e., 89.9%. Additionally, the thermal analysis shows that the AT and BL sample has great thermal stability than other (UT and DW) samples at high temperature. Therefore, the outer skin separated coffee husk was prepared from agricultural waste was subjected to eco-friendly chemical treatments to yield MCC. Thus, the extracted MCC is expected to be reliable for replacing other plant materials for the production of crystalline nanomaterial and reinforcing constituent for the fabrication of bio composite.
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Morais, Flávia P., Ana M. M. S. Carta, Maria E. Amaral e Joana M. R. Curto. "Computational Simulation Tools to Support the Tissue Paper Furnish Management: Case Studies for the Optimization of Micro/Nano Cellulose Fibers and Polymer-Based Additives". Polymers 13, n. 22 (18 novembre 2021): 3982. http://dx.doi.org/10.3390/polym13223982.
Testo completoAbstract (sommario):
Tissue paper production frequently combines two main types of raw materials: cellulose fibers from renewable sources and polymer-based additives. The development of premium products with improved properties and functionalities depends on the optimization of both. This work focused on the combination of innovative experimental and computational strategies to optimize furnish. The main goal was to improve the functional properties of the most suitable raw materials for tissue materials and develop new differentiating products with innovative features. The experimental plan included as inputs different fiber mixtures, micro/nano fibrillated cellulose, and biopolymer additives, and enzymatic and mechanical process operations. We present an innovative tissue paper simulator, the SimTissue, that we have developed, to establish the correlations between the tissue paper process inputs and the end-use paper properties. Case studies with industrial interest are presented in which the tissue simulator was used to design tissue paper materials with different fiber mixtures, fiber modification treatments, micro/nano fibrillated cellulose, and biopolymer formulations, and to estimate tissue softness, strength, and absorption properties. The SimTissue was able to predict and optimize a broader range of formulations containing micro/nanocellulose fibers, biopolymer additives, and treated-fiber mixtures, saving laboratory and industrial resources.
26
Fouad, H., Lau Kia Kian, Mohammad Jawaid, Majed D. Alotaibi, Othman Y. Alothman e Mohamed Hashem. "Characterization of Microcrystalline Cellulose Isolated from Conocarpus Fiber". Polymers 12, n. 12 (7 dicembre 2020): 2926. http://dx.doi.org/10.3390/polym12122926.
Testo completoAbstract (sommario):
Conocarpus fiber is an abundantly available and sustainable cellulosic biomass. With its richness in cellulose content, it is potentially used for manufacturing microcrystalline cellulose (MCC), a cellulose derivative product with versatile industrial applications. In this work, different samples of bleached fiber (CPBLH), alkali-treated fiber (CPAKL), and acid-treated fiber (CPMCC) were produced from Conocarpus through integrated chemical process of bleaching, alkaline cooking, and acid hydrolysis, respectively. Characterizations of samples were carried out with Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared-Ray (FTIR), X-ray Diffraction (XRD), Thermogravimetric (TGA), and Differential Scanning Calorimetry (DSC). From morphology study, the bundle fiber feature of CPBLH disintegrated into micro-size fibrils of CPMCC, showing the amorphous compounds were substantially removed through chemical depolymerization. Meanwhile, the elemental analysis also proved that the traces of impurities such as cations and anions were successfully eliminated from CPMCC. The CPMCC also gave a considerably high yield of 27%, which endowed it with great sustainability in acting as alternative biomass for MCC production. Physicochemical analysis revealed the existence of crystalline cellulose domain in CPMCC had contributed it 75.7% crystallinity. In thermal analysis, CPMCC had stable decomposition behavior comparing to CPBLH and CPAKL fibers. Therefore, Conocarpus fiber could be a promising candidate for extracting MCC with excellent properties in the future.
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Rajnish, K. Narayanan, Melvin S. Samuel, Ashwini John J, Saptashwa Datta, Narendhar Chandrasekar, Ramachandran Balaji, Sujin Jose e Ethiraj Selvarajan. "Immobilization of cellulase enzymes on nano and micro-materials for breakdown of cellulose for biofuel production-a narrative review". International Journal of Biological Macromolecules 182 (luglio 2021): 1793–802. http://dx.doi.org/10.1016/j.ijbiomac.2021.05.176.
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Wang, Wei, Yancai Cao, Liyue Sun e Mingshuai Wu. "Effect of Temperature on Formaldehyde Diffusion in Cellulose Amorphous Region: A Simulation Study". BioResources 16, n. 2 (11 marzo 2021): 3200–3213. http://dx.doi.org/10.15376/biores.16.2.3200-3213.
Testo completoAbstract (sommario):
A formaldehyde-cellulose amorphous region model at the micro-level was established using the molecular dynamics software Materials Studio to simulate the change of cellulose and formaldehyde molecules in an external temperature field. The diffusion coefficients of formaldehyde molecules increased as the temperature increased. Moreover, the total number of hydrogen bonds decreased, and the interaction energy in the formaldehyde-cellulose model was reduced, which confirmed this conclusion and indicated that temperature increase could enhance the diffusion of formaldehyde in cellulose. The mechanical parameters of cellulose were analyzed in terms of Young’s modulus, shear modulus, bulk modulus, Poisson’s ratio, and the ratio of bulk modulus to shear modulus (K/G), which were affected by the temperature. The elastic modulus (E, G, and K) of cellulose decreased as the temperature increased, while the Poisson’s ratio V and K/G values increased. The results of the research explain how elevated temperature can promote the release of formaldehyde in furniture from a microscopic perspective, which supports each other with the results of previous experimental data and practical applications in production.
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Brilian, Albertus, Veasna Soum, Sooyong Park, Soojin Lee, Jungwook Kim, Kuktae Kwon, Oh-Sun Kwon e Kwanwoo Shin. "A Simple Route of Printing Explosive Crystalized Micro-Patterns by Using Direct Ink Writing". Micromachines 12, n. 2 (21 gennaio 2021): 105. http://dx.doi.org/10.3390/mi12020105.
Testo completoAbstract (sommario):
The production of energetic crystalized micro-patterns by using one-step printing has become a recent trend in energetic materials engineering. We report a direct ink writing (DIW) approach in which micro-scale energetic composites composed of 1,3,5-trinitro-1,3,5-triazinane (RDX) crystals in selected ink formulations of a cellulose acetate butyrate (CAB) matrix are produced based on a direct phase transformation from organic, solvent-based, all-liquid ink. Using the formulated RDX ink and the DIW method, we printed crystalized RDX micro-patterns of various sizes and shapes on silicon wafers. The crystalized RDX micro-patterns contained single crystals on pristine Si wafers while the micro-patterns containing dendrite crystals were produced on UV-ozone (UVO)-treated Si wafers. The printing method and the formulated all-liquid ink make up a simple route for designing and printing energetic micro-patterns for micro-electromechanical systems.
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Aguado, Roberto, Quim Tarrés, Maria Àngels Pèlach, Pere Mutjé, Elena de la Fuente, José L. Sanchez-Salvador, Carlos Negro e Marc Delgado-Aguilar. "Micro- and Nanofibrillated Cellulose from Annual Plant-Sourced Fibers: Comparison between Enzymatic Hydrolysis and Mechanical Refining". Nanomaterials 12, n. 9 (9 maggio 2022): 1612. http://dx.doi.org/10.3390/nano12091612.
Testo completoAbstract (sommario):
The current trends in micro-/nanofibers offer a new and unmissable chance for the recovery of cellulose from non-woody crops. This work assesses a technically feasible approach for the production of micro- and nanofibrillated cellulose (MNFC) from jute, sisal and hemp, involving refining and enzymatic hydrolysis as pretreatments. Regarding the latter, only slight enhancements of nanofibrillation, transparency and specific surface area were recorded when increasing the dose of endoglucanases from 80 to 240 mg/kg. This supports the idea that highly ordered cellulose structures near the fiber wall are resistant to hydrolysis and hinder the diffusion of glucanases. Mechanical MNFC displayed the highest aspect ratio, up to 228 for hemp. Increasing the number of homogenization cycles increased the apparent viscosity in most cases, up to 0.14 Pa·s at 100 s−1 (1 wt.% consistency). A shear-thinning behavior, more marked for MNFC from jute and sisal, was evidenced in all cases. We conclude that, since both the raw material and the pretreatment play a major role, the unique characteristics of non-woody MNFC, either mechanical or enzymatically pretreated (low dose), make it worth considering for large-scale processes.
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Guo, Qian, Yuan Hong Xie, Hong Xing Zhang, Hui Liu, Zheng Xing Lian e Bao Hua Kong. "Isolation and Partial Function Analysis of Bacillus coagulans L-g6". Advanced Materials Research 1092-1093 (marzo 2015): 1543–46. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.1543.
Testo completoAbstract (sommario):
A bacterium strain named L-g6 isolated from kitchen garbage, through 16s rRNA sequencing and Biolog GEN III MicroPlate analyzes, was identified asBacillus coagulans. In the present study, the optimal growth conditions ofB.coagulansL-g6 was at 45°C, pH 7 and in the growth of 6 h reached the end of logarithmic phase.B.coagulansL-g6 can break down cellulose, starch, protein, fat; and the best decomposition effect is protein, followed by starch and cellulose, less fat. In total,B.coagulansL-g6 can be used as a starter production scale degradation of kitchen waste. The research will contribute to the development of micro-ecological preparation ofB.coagulansL-g6.
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Agic, Rukie, Mariјa Zdravkovska, Gordana Popsimonova, Daniela Dimovska, Zvezda Bogevska e Margarita Davitkovska. "Yield and Quality of Beetroot (Beta vulgaris ssp. esculenta L. ) as a Result of Microbial Fertilizers". Contemporary Agriculture 67, n. 1 (1 marzo 2018): 40–44. http://dx.doi.org/10.2478/contagri-2018-0006.
Testo completoAbstract (sommario):
Summary The purpose of this study is to examine the effect of two different types of microbial fertilizers, namely Micro-Vita I (containing several groups of Azotobacter, nitrifying microorganisms and phosphate-solubilizing microorganisms) and Micro-Vita II (containing Azotobacter, nitrifying microorganisms, phosphate-solubilizing microorganisms and iron), on the yield and quality of beetroot (Beta vulgaris ssp. esculenta, cv Kestrel). Beetroots grown in the field without using microbial fertilizers served as the experimental control. The experiments were conducted in a field located in the village of Jurumleri, near Skopje, characterized by a well-drained and sandy soil, in 2013. The purpose of the study is to determine how different microbial fertilizers influence the production and quality of beetroot. The yields obtained were significantly higher in the beetroot grown using Micro-Vita II (69.43 t ha−1) and Micro-Vita I (58.13 t·ha−1) fertilizers, compared to the control yield (54.8 t/ha). The beetroot grown under the Micro-Vita I regime indicated significantly higher contents of vitamin C (6.86%), cellulose (13.79%) and protein (18.18%) compared to the control crops. Furthermore, the beetroot grown under the Micro-Vita II regime indicated significantly higher contents of vitamin C (14.71%), cellulose (27.59%), protein (44.62%), minerals (6.25%) and Fe (100%) compared to the control crops. According to the results obtained, the application of microbiological fertilizers is recommended for beetroot (cv. Kestrel), with regard to the beetroot quality and bioactive compounds, and can be used in organic farming.
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Tsyntsarski, Boyko, Ivanka Stoycheva, Georgi Georgiev, Nartzislav Petrov, Angelina Kosateva, Bilyana Petrova, Anna Bouzekova-Penkova, Tanya Tsoncheva e Gloria Issa. "Refuse-derived Fuel Based Cobalt Catalysts for Hydrogen Production". Proceedings of the Bulgarian Academy of Sciences 75, n. 9 (30 settembre 2022): 1295–302. http://dx.doi.org/10.7546/crabs.2022.09.06.
Testo completoAbstract (sommario):
Refuse-derived fuel (RDF) is a mixed industrial waste, which often contains combustible materials (cellulose, polymers, rubber, biomass, etc.). The RDF waste precursor is subjected to thermo-oxidation treatment at 300℃, followed by carbonizations at 600℃, and high temperature hydropyrolysis at 800℃. The obtained nanoporous carbon material was subjected to detailed characterization by low temperature nitrogen sorption, elemental analysis, etc. Carbon derived from RDF is distinguished by micro/mesoporous texture and moderately high surface area (650 m2 g-1). The catalyst obtained is tested in the process of methanol decomposition, leading to production of hydrogen as a fuel. The influence of the physico-chemical characteristics of the synthesized carbon on the catalytic activity of carbon-based cobalt catalyst is studied.
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Liu, Enhai, Baozhong Zhu, Shengyong Liu, Hailong Yu, Zhiping Zhang, Huifan Zheng, Jiaxin Pan e Wenyun Zhang. "Biodegradation mechanism of biogas production by modified rice straw fermentation". BioResources 15, n. 4 (9 ottobre 2020): 8862–82. http://dx.doi.org/10.15376/biores.15.4.8862-8882.
Testo completoAbstract (sommario):
Based on the literature on the degradation mechanism and the change of micro-functional groups in the fermentation process of modified rice straw, this study aimed to solve the problems of low biogas production rate and poor stability of the biogas production system. In this work, mathematical equations were developed and combined with duck dung and rice straw mixed raw material to perform a fermentation test. The molecular micro-functional group changes of cellulose, hemicellulose, and lignin were studied to obtain the optimal ratio of mixed raw materials for fermentation and to explore the optimization mechanism of its fermentation biogas production. Experimental results showed that the optimal ratio of mixed raw materials was 2.8:1, and the inclusion of a suitable amount of Mn2+(concentration of 2 mol × L-1) was able to strengthen MnP activity and improve the ability of white-rot fungi to rupture β-O-4 bonds. A modification pre-treatment via activated carbon-based solid acid was performed, and the experimental group generated 15.8% more cumulative biogas than the control group. The biogas yield reached its peak when 300 g of inoculum was added to the pre-treatment at a concentration of 30%.
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Cao, Ying, Wei Wang e Wei Ma. "Analysis on the diffusion and mechanical properties of eucalyptus dried via supercritical carbon dioxide". BioResources 17, n. 3 (10 maggio 2022): 4018–29. http://dx.doi.org/10.15376/biores.17.3.4018-4029.
Testo completoAbstract (sommario):
Using the molecular dynamics software Materials Studio, a micro-level carbon dioxide – cellulose model was established to study the supercritical carbon dioxide drying of eucalyptus wood. The change of the primary components of the eucalyptus wood cellulose were also studied, by simulating various pressures, i.e., 10, 15, 20, 25, and 30 Pa, and simulating a temperature of 323 K. Results showed that the diffusion coefficient of carbon dioxide decreases as the pressure increases, and it reaches the maximum at 20 Pa, which was confirmed by the number of hydrogen bonds in the carbon dioxide cellulose model. Combined with the comprehensive analysis of the mechanical parameters, the Poisson’s ratio γ and the ratio of bulk modulus to shear modulus (K/G) values of cellulose first increased and then decreased as the pressure increased, and the Young’s modulus increased as the pressure increased. From a microscopic point of view, the study shows that eucalyptus cellulose has good mechanical properties when dried by supercritical carbon dioxide under a pressure of 20 Pa. The simulation results of the dynamic model agreed well with the measured results, and the simulation results support the previous experimental data and the practical application results in production.
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Morales-Juárez, Abraham Azael, Luis Daniel Terrazas Armendáriz, Juan Manuel Alcocer-González e Leonardo Chávez-Guerrero. "Potential of Nanocellulose as a Dietary Fiber Isolated from Brewer’s Spent Grain". Polymers 15, n. 17 (31 agosto 2023): 3613. http://dx.doi.org/10.3390/polym15173613.
Testo completoAbstract (sommario):
Steady growth in beer production is increasing the number of by-products named brewers’ spent grain. Such by-products are a source of several components, where cellulose is usually present in high amounts. The aim of this study was to develop a protocol to obtain a mix of cellulose microfibers with an average diameter of 8–12 µm and cellulose nanoplatelets with an average thickness of 100 nm, which has several applications in the food industry. The process comprised one alkaline treatment followed by acid hydrolysis, giving a new mix of micro and nanocellulose. This mix was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and laser scanning microscopy corroborating the presence and measurements of the cellulose nanostructure, showing an aspect ratio of up to 500. Finally, we demonstrated that the administration of this new type of nanocellulose allowed us to control the weight of mice (feed intake), showing a significant percentage of weight reduction (4.96%) after 15 days compared with their initial weight, indicating the possibility of using this material as a dietary fiber.
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Martínez, Héctor, Christian Brackmann, Annika Enejder e Paul Gatenholm. "Mechanical stimulation of fibroblasts in micro-channeled bacterial cellulose scaffolds enhances production of oriented collagen fibers". Journal of Biomedical Materials Research Part A 100A, n. 4 (24 gennaio 2012): 948–57. http://dx.doi.org/10.1002/jbm.a.34035.
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Sumarno, Sumarno, Yeni Rahmawati, P. N. T. Risanti e N. E. Mayangsari. "The Effect of Decomposition Time on Cellulose Degradation in Ionic Liquid/Acid with Pressurized CO2". Modern Applied Science 9, n. 7 (1 luglio 2015): 69. http://dx.doi.org/10.5539/mas.v9n7p69.
Testo completoAbstract (sommario):
Cellulose material is the most abundant carbohydrate that has a simple polymer structure, but it forms ofcrystalline micro-fibrils lead it insoluble in various solvent and highly resistant for hydrolysis process. Thedegradation of cellulose into glucose will increase the raw material for production of ethanol, isopropanol orbutanol. The conversion into oligomer can be applied for pharmaceutical, food additives, etc. There are manytechnologies for conversion of cellulose such as degradation with ionic liquids, acid, enzymatic/fermentation,and hydrothermal. In this work, we studied cellulose decomposition by hydrothermal process, and a combinationwith ionic liquids. We used NaCl as a simple ionic liquid, oxalic acid as a catalyst, and CO2 as pressurizing gasin order to enhance the degradability of cellulose in water. Cellulose and NaCl/oxalic acid solution (20 gr L-1)was conducted under 70 bar of subcritical CO2 in 125ºC and various decomposition times (1 to 5 h). Afterdecomposition time was achieved, the sample was separated between liquid and solid. For liquid product wereanalyzed by Dinitrosalicylic acid method (DNS method) using spectrophotometry UV-Vis and LiquidChromatography – Mass Spectrometry (LC-MS). And solid products were analyzed by using X-Ray Diffraction(XRD) and Scanning Electron Microscopy (SEM). The result shows that the glucose concentrations was increasewith an increasing decomposition time and reach a maximum at 4 hour. SEM and XRD showed the changes inthe morphology and the structure of cellulose.
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C., Onuguh I., Ikhuoria E. U. e Obibuzo J. U. "Bioethanol Production From Rice Husk Through Shcf And Sscf Processing Strategies". International Journal of Research In Science & Engineering, n. 21 (22 gennaio 2022): 13–20. http://dx.doi.org/10.55529/ijrise.21.13.20.
Testo completoAbstract (sommario):
In many developing countries, there is great quest for achieving sustainable energy from the conversion of the huge biomass of organic wastes into useful biofuels such as bioethanol. Bioethanol is a renewable clean-liquid biofuel produced by fermentation of sugars or converted starch or cellulose from plant based feedstocks. It is conventionally produced from sugar and starch containing feedstocks. However, these feedstocks are unable to meet the global demand of bioethanol production due to their primary food value and legal pursuits against the legitimacy of their schemes. This study investigated and improved on the feasibility of producing bioethanol from rice husk agro-waste generated from rice production. It was first subjected to different physico-chemical pretreatments in order to optimize the hydrolysate sugar yield and identify the most effective process. It was further hydrolyzed by cellulase enzymes from Trichoderma ressei micro-organism isolated from the soil. Separate hydrolysis and co-fermentation (SHCF) and simultaneous saccharification and co-fermentation (SSCF) strategies/methods were adopted using both hydrometer and Pycnometer measurements. The fermentation results revealed that the maximum bioethanol yield through SHCF and SSCF strategies were 4.64 and 6.45 (% w/v dry biomass) respectively. SSCF strategy was more effective as it gave better bioethanol yield and was less time consuming. This study also shows that rice husk agro-waste of no or little commercial value can be utilized in the production of good quality bioethanol with implications for improved waste management, income and efficient energy generation.
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I.C., Onuguh, Ikhuoria E.U. e Obibuzo J.U. "Bioethanol Production from Rice Husk through SHCF and SSCF Processing Strategies". June-July 2022, n. 24 (29 luglio 2022): 1–7. http://dx.doi.org/10.55529/jmc.24.1.7.
Testo completoAbstract (sommario):
In many developing countries, there is great quest for achieving sustainable energy from the conversion of the huge biomass of organic wastes into useful biofuels such as bioethanol. Bioethanol is a renewable clean-liquid biofuel produced by fermentation of sugars or converted starch or cellulose from plant based feedstocks. It is conventionally produced from sugar and starch containing feedstocks. However, these feedstocks are unable to meet the global demand of bioethanol production due to their primary food value and legal pursuits against the legitimacy of their schemes. This study investigated and improved on the feasibility of producing bioethanol from rice husk agrowaste generated from rice production. It was first subjected to different physico-chemical pretreatments in order to optimize the hydrolysate sugar yield and identify the most effective process. It was further hydrolyzed by cellulase enzymes from Trichoderma ressei micro-organism isolated from the soil. Separate hydrolysis and co-fermentation (SHCF) and simultaneous saccharification and co-fermentation (SSCF) strategies/methods were adopted using both hydrometer and Pycnometer measurements. The fermentation results revealed that the maximum bioethanol yield through SHCF and SSCF strategies were 4.64 and 6.45 (% w/v dry biomass) respectively. SSCF strategy was more effective as it gave better bioethanol yield and was less time consuming. This study also shows that rice husk agro-waste of no or little commercial value can be utilized in the production of good quality bioethanol with implications for improved waste management, income and efficient energy generation.
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Najaf Zadeh, Hossein, Daniel Bowles, Tim Huber e Don Clucas. "A Novel Additive Manufacturing Method of Cellulose Gel". Materials 14, n. 22 (18 novembre 2021): 6988. http://dx.doi.org/10.3390/ma14226988.
Testo completoAbstract (sommario):
Screen-additive manufacturing (SAM) is a potential method for producing small intricate parts without waste generation, offering minimal production cost. A wide range of materials, including gels, can be shaped using this method. A gel material is composed of a three-dimensional cross-linked polymer or colloidal network immersed in a fluid, known as hydrogel when its main constituent fluid is water. Hydrogels are capable of absorbing and retaining large amounts of water. Cellulose gel is among the materials that can form hydrogels and, as shown in this work, has the required properties to be directly SAM, including shear thinning and formation of post-shearing gel structure. In this study, we present the developed method of SAM for the fabrication of complex-shaped cellulose gel and examine whether successive printing layers can be completed without delamination. In addition, we evaluated cellulose SAM without the need for support material. Design of Experiments (DoE) was applied to optimize the SAM settings for printing the novel cellulose-based gel structure. The optimum print settings were then used to print a periodic structure with micro features and without the need for support material.
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Kim, Sang Yun, Sun Young Jung, Yung Bum Seo e Jung Soo Han. "Preparation of Flexible Calcium Carbonate by In Situ Carbonation of the Chitin Fibrils and Its Use for Producing High Loaded Paper". Materials 16, n. 8 (9 aprile 2023): 2978. http://dx.doi.org/10.3390/ma16082978.
Testo completoAbstract (sommario):
Flexible calcium carbonate (FCC) was developed as a functional papermaking filler for high loaded paper, which was a fiber-like shaped calcium carbonate produced from the in situ carbonation process on the cellulose micro-or nanofibril surface. Chitin is the second most abundant renewable material after cellulose. In this study, a chitin microfibril was utilized as the fibril core for making the FCC. Cellulose fibrils for the preparation of FCC were obtained by fibrillation of the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) treated wood fibers. The chitin fibril was obtained from the β-chitin from the born of squid fibrillated in water by grinding. Both fibrils were mixed with calcium oxide and underwent a carbonation process by the addition of carbon dioxide, thus the calcium carbonate attached on the fibrils to make FCC. When used in papermaking, both the FCC from chitin and cellulose gave a much higher bulk and tensile strength simultaneously than the conventional papermaking filler of ground calcium carbonate, while maintaining the other essential properties of paper. The FCC from chitin caused an even higher bulk and higher tensile strength than those of the FCC from cellulose in paper materials. Furthermore, the simple preparation method of the chitin FCC in comparison with the cellulose FCC may enable a reduction in the use of wood fibers, process energy, and the production cost of paper materials.
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Chongkhong, Sininart, e Chakrit Tongurai. "Alkaline Delignification of Banana Peel for Producing Pulp". Advanced Materials Research 1033-1034 (ottobre 2014): 183–86. http://dx.doi.org/10.4028/www.scientific.net/amr.1033-1034.183.
Testo completoAbstract (sommario):
Delignification of banana peel, agricultural waste, is considered in the pulp production because lignin is a major obstacle to the gain of cellulose. The soda process as a conventional method and micro-morphology observed by scanning electron microscopy were fulfilled to investigate an optimal condition in this study. The results pointed the potent sequence of operating factors was delignification temperature > solid-liquid ratio > soda concentration > time. The removal of lignin could achieve 92% under the optimal condition using 12%w soda concentration with 1:8 solid-liquid ratio at 100°C for 40 min. This shows that the alkaline delignification is productively sufficient for the pulp production.
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Kusumaningrum, Wida Banar, R. Rochmadi e S. Subyakto. "PEMBUATAN SELULOSA TERASETILASI DARI PULP BAMBU BETUNG (Dendrocalamus asper) SERTA PENGARUHNYA TERHADAP SIFAT MEKANIS BIOKOMPOSIT POLIPROPILENA". Reaktor 17, n. 1 (5 maggio 2017): 25. http://dx.doi.org/10.14710/reaktor.17.1.25-35.
Testo completoAbstract (sommario):
Abstract ACETYLATED CELLULOSE FROM BETUNG BAMBOO (Dendrocalamus asper) PULP PRODUCTION AND ITS EFFECT ON MECHANICAL PROPERTIES OF POLYPROPYLENE COMPOSITES. The utilization of natural fiber as reinforcing agent for biocomposite products have some drawbacks, such as its hydrophilicity that are incompatible with PP. Isolation from bundle fibers into micro fibers could improves the biocomposite properties. However, more moisture absorption of micro fiber makes it difficult to handle. Therefore, modification with acetylation is needed to facilitate good interfacial adhesion between cellulose and PP. The objectives of this research are to obtain acetylated micro fibers from betung bamboo pulp for reinforcing agent and to investigate the effect of acetylated cellulose on mechanical properties of PP biocomposites. Acetate anhydride as acetylating agent and sulfuric acid as a catalyst were used for acetylation process. Acetylated cellulose from betung bamboo pulp with fibrous form, hydrophobic condition, and relatively on high aspect ratio was obtained in 2% of catalyst concentration and 120 of reaction time. Strength enhancement were achieved up to 79 and 87% for tensile while 24 and 69% for flexural, respectively for biocomposites with 10% and 20% of acetylated cellulose than that PP. Modulus improvement were obtained up to 53 and 70% for tensile while 96 and 149% for flexural, respectively for biocomposites with 10% and 20% of acetylated cellulose than that PP. Keywords: acetylation; betung bamboo; biocomposite; polypropylene; cellulose Abstrak Penerapan serat alam untuk produk biokomposit memiliki beberapa kelemahan terutama perbedaan sifat antara matrik dengan serat yang menyebabkan ikatan antar muka yang kurang baik. Pengolahan serat bundle menjadi serat mikro dapat meningkatkan sifat-sifat biokomposit, akan tetapi sifat dari serat mikro yang mudah menyerap air membuat penanganannya menjadi lebih komplek. Modifikasi kimia serat dengan asetilasi merupakan upaya untuk meningkatkan keterbasahan dan ikatan antar muka dengan matrik PP. Tujuan dari penelitian ini adalah untuk memperoleh serat mikro terasetilasi dari pulp bambu betung agar dapat digunakan sebagai penguat dan mempelajari pengaruhnya terhadap sifat mekanis biokomposit PP. Proses asetilasi menggunakan asetat anhidrat sebagai bahan pengasetilasi dan asam sulfat sebagai katalis. Serat mikro bambu betung terasetilasi yang bersifat hidrofobik dan memiliki aspek rasio tinggi diperoleh pada jumlah katalis 2% dengan waktu 120 menit. Peningkatan kuat tekuk mencapai 76 dan 87% sedangkan kuat tarik sekitar 24 dan 69% masing-masing untuk biokomposit dengan selulosa terasetilasi 10% dan 20% terhadap PP murni. Keteguhan tarik meningkat hingga 53 dan 70% sedangkan keteguhan tekuk mencapai 96 dan 149% berturut-turut untuk biokomposit dengan 10% dan 20% selulosa terasetilasi dibandingkan PP. Selulosa terasetilasi dari pulp bambu betung mampu berfungsi sebagai bahan pembentuk inti untuk biokomposit PP. Kata kunci: asetilasi; bambu betung; biokomposit; polipropilena; selulosa
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MOON, ROBERT J., CECILIA LAND HENSDAL, STEPHANIE BECK, ANDREAS FALL, JULIO COSTA, Eiji Kojima, Tiffany Abitbol, Vikram Raghuwanshi, Colleen Walker e Warren Batchelor. "Setting priorities in CNF particle size measurement: What is needed vs. what is feasible". February 2023 22, n. 2 (1 marzo 2023): 116–37. http://dx.doi.org/10.32964/tj22.2.116.
Testo completoAbstract (sommario):
Measuring the size of cellulose nanomaterials can be challenging, especially in the case of branched and entangled cellulose nanofibrils (CNFs). The International Organization for Standardization, Technical Committee 6, Task Group 1—Cellulosic Nanomaterials, is exploring opportunities to develop standard methods for the measurement of CNF particle size and particle size distribution. This paper presents a summary of the available measuring techniques, responses from a survey on the measurement needs of CNF companies and researchers, and outcomes from an international workshop on cellulose nanofibril measurement and standardization. Standardization needs differed among groups, with Japanese companies mostly requiring measurements for product specification and production control, and other companies mostly needing measurements for safety/regulatory purposes and for grade definitions in patents. Among all the companies, average length and width with percentiles (D(10), D(50), D(90)) were the most desired measurands. Workshop participants concurred that defining the location(s) on the CNF at which to measure the width and the length is an urgent and complex question. They also agreed that methods are needed for rapid particle size measurement at the nanoscale. Our recommendation within ISO is to start work to revise the definition of CNFs and develop sample preparation and measurement guidelines. It was also recommended that further research be done to reproducibly prepare hierarchical branched CNF structures and characterize them, develop automated image analysis for hierarchical branched CNF structures, and develop a classification system encompassing measurements at multiple size ranges from micro- to nanoscale to fully characterize and distinguish CNF samples.
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Bastida, Gabriela Adriana, Carla Natalí Schnell, Paulina Mocchiutti, Yamil Nahún Solier, María Cristina Inalbon, Miguel Ángel Zanuttini e María Verónica Galván. "Effect of Oxalic Acid Concentration and Different Mechanical Pre-Treatments on the Production of Cellulose Micro/Nanofibers". Nanomaterials 12, n. 17 (24 agosto 2022): 2908. http://dx.doi.org/10.3390/nano12172908.
Testo completoAbstract (sommario):
The present work analyzes the effect of process variables and the method of characterization of cellulose micro/nanofibers (CMNFs) obtained by different treatments. A chemical pre-treatment was performed using oxalic acid at 25 wt.% and 50 wt.%. Moreover, for mechanical pre-treatments, a rotary homogenizer or a PFI mill refiner were considered. For the mechanical fibrillation to obtain CMNFs, 5 and 15 passes through a pressurized homogenization were considered. The best results of nanofibrillation yield (76.5%), transmittance (72.1%) and surface charges (71.0 µeq/g CMNF) were obtained using the PFI mill refiner, 50 wt.% oxalic acid and 15 passes. Nevertheless, the highest aspect ratio (length/diameter) determined by Transmission Electron Microscopy (TEM) was found using the PFI mill refiner and 25 wt.% oxalic acid treatment. The aspect ratio was related to the gel point and intrinsic viscosity of CMNF suspensions. The values estimated for gel point agree with those determined by TEM. Moreover, a strong relationship between the intrinsic viscosity [η] of the CMNF dispersions and the corresponding aspect ratio (p) was found (ρ[η] = 0.014 p2.3, R2 = 0.99). Finally, the tensile strength of films obtained from CMNF suspensions was more influenced by the nanofibrillation yield than their aspect ratio.
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Kadhom, Mohammed, Noor Albayati, Suhaib Salih, Mustafa Al-Furaiji, Mohamed Bayati e Baolin Deng. "Role of Cellulose Micro and Nano Crystals in Thin Film and Support Layer of Nanocomposite Membranes for Brackish Water Desalination". Membranes 9, n. 8 (15 agosto 2019): 101. http://dx.doi.org/10.3390/membranes9080101.
Testo completoAbstract (sommario):
Reverse osmosis is a major process that produces soft water from saline water, and its output represents the majority of the overall desalination plants production. Developing efficient membranes for this process is the aim of many research groups and companies. In this work, we studied the effect of adding cellulose micro crystals (CMCs) and cellulose nano crystals (CNCs) to the support layer and thin film nanocomposite (TFN) membrane on the desalination performance. SEM, TEM, ATR-FTIR, and contact angle measurements were used to characterize the membrane’s properties; and membrane’s performance were evaluated by water flux and NaCl rejection. Filling 2% of CNCs gel in the support layer improved the water flux by +40%, while salt rejection maintained almost the same, around 95%. However, no remarkable improvement was gained by adding CNCs gel to m-phenylenediamine (MPD) solution, which was used in TFN membrane preparation. Filling CMCs powder in TFN membrane led to a slight improvement in terms of water flux.
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Hamid, Sharifah Bee Abd, Mohammad Ziaul Karim e Md Eaqub Ali. "Green Catalytic Approach for the Synthesis of Functionalized Nanocellulose from Palm Tree Biomass". Advanced Materials Research 925 (aprile 2014): 57–61. http://dx.doi.org/10.4028/www.scientific.net/amr.925.57.
Testo completoAbstract (sommario):
Oil palm is a major agricultural product in Malaysia and it covers approximately 5 million hectares of land. Palm tree biomass is a by-product of oil palm cultivation. Biomass is a complex structure composed of cellulose, hemicelluloses and lignin. Cellulose, which gives the mechanical properties to the natural fiber, is organized in micro-fibrils enclosed by the other two main components: hemicellulose and lignin. Cellulose microfibrils can be found as intertwined microfibrils in the cell wall (220 μm in diameter and 100 40,000 nm in length). Cellulose microfibrils are in turn exist in cellulose nanofibers having diameter of 550 nm and length several millimeters conformed by nanocrystalline domains and amorphous regions. Nanocellulose, which is a degradation product of cellulose, has recently come to public attention because of its great mechanical properties combined with low molecular weight, renewability and biodegradability. Another advantage of nanofibrillar cellulose is that their production does not interfere with the food chain, therefore, they can be considered as socially sustainable raw materials. However, before the nanocellulose can be fully utilized to fabricate smart and environmentally friendly new high-tech products. Most common applications of nanocellulose are for polymer composite, bioplastics, films, foams, gels, cosmetics, dimensionally stable thickener and emulsion, implant material, biodegradable tissue scaffold, suture, drug delivery vehicle, filter paper, speaker membrane, battery membrane, concrete, drilling muds & enhanced oil recovery, water treatment, etc. Several methods have been proposed for the extraction/preparations of nanocellulose which involve extensive chemical and mechanical treatments which are not environmentally friendly. This paper reviewed various methods along with their limitations for the controlled structure synthesis of functionalized nanocellulose from palm tree biomass. The green catalytic approaches are schematically outlined.
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Rahman, Muhammad M., e Anil N. Netravali. "Micro-fibrillated cellulose reinforced eco-friendly polymeric resin from non-edible ‘Jatropha curcas’ seed waste after biodiesel production". RSC Advances 6, n. 52 (2016): 47101–11. http://dx.doi.org/10.1039/c6ra07749h.
Testo completoAbstract (sommario):
Eco-friendly polymeric resin with desirable mechanical and physical properties was developed from non-edible protein extracted from Jatropha curcas (Jatropha) seed cake, so far considered as an agro-waste after oil extraction for bio-diesel conversion.
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Besharati, M., A. Taghizadeh e A. Ansari. "Effect of adding different levels of probiotic on in vitro gas production". Proceedings of the British Society of Animal Science 2009 (aprile 2009): 187. http://dx.doi.org/10.1017/s175275620003026x.
Testo completoAbstract (sommario):
Probiotics present an attractive alternative to the use of chemical and hormonal promoters in the livestock growth production industry. Preparations that contain micro-organisms have been safely used for many years and are generally accepted by both the farmer and the final consumer. Saccharomyces cerevisiae supplementation in ruminant diets can increase DMI, production performance, cellulose degradation, and nutrient digestibility (Callaway and Martin, 1997). The gas measuring technique has been widely used for the evaluation of nutritive value of feeds. Gas measurement provides useful data on digestion kinetics of both soluble and insoluble fractions of feedstuffs (Getachew et al., 1998). In the gas method, kinetics of fermentation can be studied on a single sample and therefore a relatively small amount of sample is required or a larger number of samples can be evaluated at time. The purpose of this study was to study effect of adding different levels of Saccharomyces cerevisiae on in vitro gas production from a dried grape by-product.