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  • Open Access


    Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF)-Mass Spectrometry and 13C-NMR-Identified New Compounds in Paraberlinia bifoliolata (Ekop-Beli) Bark Tannins

    Liliane Nga1, Benoit Ndiwe1,2, Achille Bernard Biwolé1, Antonio Pizzi3,*, Jean Jalin Eyinga Biwole1, Joseph Zobo Mfomo1

    Journal of Renewable Materials, Vol.12, No.3, pp. 553-568, 2024, DOI:10.32604/jrm.2023.046568

    Abstract Extracts of plant origin, particularly tannins, are attracting growing interest for the sustainable development of materials in the industrial sector. The discovery of new tannins is therefore necessary. The aim of this work was to contribute to the understanding of the properties of Paraberlinia bifoliolata tannin by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy MALDI-TOF/MS and Carbon 13 Nuclear Magnetic Resonance (13C NMR). The chemical composition of tannin extracted from Paraberlinia bifoliolata bark was determined, as was the mechanical strength of the resin hardened with Acacia nilotica extracts. Yield by successive water extraction was 35%. MALDI-TOF/MS… More >

  • Open Access


    Experimental and Numerical Research on Water Transport during Adsorption and Desorption in Cement-Based Materials

    Xiang Zhang1,*, Miao Su1, Wenjie Yu2, Zhen Lei1, Jun Ren1, Juntong Qu1

    CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1487-1507, 2023, DOI:10.32604/cmes.2023.025799

    Abstract The durability of cement-based materials is related to water transport and storage in their pore network under different humidity conditions. To understand the mechanism and characteristics of water adsorption and desorption processes from the microscopic scale, this study introduces different points of view for the pore space model generation and numerical simulation of water transport by considering the “ink-bottle” effect. On the basis of the pore structure parameters (i.e., pore size distribution and porosity) of cement paste and mortar with water-binder ratios of 0.3, 0.4 and 0.5 obtained via mercury intrusion porosimetry, randomly formed 3D… More >

  • Open Access


    Study on Hydrogen Storage Properties, Anti-Oxide Ability and Rate Limiting Step of ZrCr-Based Alloy after Introducing Cobalt as Additive

    Dongfang Huang1,4, Peng Lv1,2,3,4,*, Changlin Zhong1,2, Xingsheng Zhou1,2, Zhichen Liu4

    Journal of Renewable Materials, Vol.11, No.3, pp. 1383-1400, 2023, DOI:10.32604/jrm.2022.023261

    Abstract In this work, the microstructure, hydrogen storage properties, anti-oxide ability and rate limiting step of Zr(Cr1−xCox)2 (x = 0, 0.2, 0.4 and 0.6) alloys have been investigated. After studying the crystal structure, we found that all alloy samples could show C14-type phase but the alloy sample x = 0 could also show a small amount of Cr phase. Rietveld fitting showed that lattice parameter and unit cell volume of C14-type phase decreased with increasing x. After further research, it was clear that the first hydrogen absorption capacity decreased with increasing x. But introducing more Co content had a positive influence More >

  • Open Access


    Matrix-Assisted Laser Desorption-Ionization Time of Flight (MALDI-TOF) Mass Spectrometry of Phenol-FormaldehydeChestnut Tannin Resins

    M.C. Lagel1,*, A. Pizzi1,2, S. Giovando3

    Journal of Renewable Materials, Vol.2, No.3, pp. 207-219, 2014, DOI:10.7569/JRM.2014.634111

    Abstract Natural hydrolysable chestnut tannin extracts used to partially substitute phenol in Phenol-Formaldehyde (PF) resins for phenolic rigid foams were analysed by matrix-assisted desorption ionization time of fl ight (MALDI-TOF) mass spectrometry. PF only, chestnut only and PF-chestnut copolymerised oligomer types and distribution were determined. MALDI-TOF analyses of a PF control resin (with the same molar ratio) and of chestnut tannin extracts were performed in order to identify the peaks of molecular weights corresponding to copolymers of chestnut tannins with phenol and formaldehyde. More >

  • Open Access


    Desorption Behavior and Thermogravimetric Analysis of Bio-Hardeners

    Benoit Ndiwe1,2,3, Antonio Pizzi4,*, Hubert Chapuis5, Noel Konai6, Lionel Karga7, Pierre Girods4, Raidandi Danwe6,8

    Journal of Renewable Materials, Vol.10, No.8, pp. 2015-2027, 2022, DOI:10.32604/jrm.2022.019891

    Abstract In this work, the thermal degradation and drying of bio-hardeners are investigated. Four bio-hardeners based on exudates of Senegalia senegal, Vachellia nilotica, Vachellia seyal, and Acacia Siebteriana were analyzed by FTIR and thermogravimetric analysis, and a desorption study was also conducted. The analysis by infrared spectroscopy indicates the existence of oligomers of different types all giving 5-hydroxy-2-hydroxymethylfuran and 2, 5-dihydroxymethylfuran which are then the real hardening molecules. The pyrolysis of these extracts reveals three main regions of mass loss, a first region is located between 25°C and 110°C reflecting the loss of water from the adhesive and the formation More > Graphic Abstract

    Desorption Behavior and Thermogravimetric Analysis of Bio-Hardeners

  • Open Access


    Research on Reliability of Desorption Indexes of Drilling Cuttings (K1 and ∆h2): A Case-Based on Pingdingshan Mining Region, China

    Jianguo Zhang1, Biao Hu2,*, Xiyuan Li1, Hongxing Zhou2, Zhixu Dai3, Yanlei Lu3, Deyang Wang2

    Energy Engineering, Vol.118, No.3, pp. 605-614, 2021, DOI:10.32604/EE.2021.014655

    Abstract To accurately predict the risk of coal and gas outburst and evaluate the reliability of desorption indexes of drilling cuttings (K1 and ∆h2) in No. 16 coal seam of Pingmei No. 12 coal mine, two sets of coal samples were selected from the target coal seams for proximate analyses, methane adsorption/desorption tests, and desorption indexes of drilling cuttings tests. The results indicated that the desorption volume in the initial stage of desorption is large, and increases slowly in the later stage. The methane desorption volume of PMD1 and PMD2 coal samples accounts for 15.14%–18.09% and 15.72%–18.17%… More >

  • Open Access


    Adsorption and Desorption Characteristics of Cadmium Ion by Ash-Free Biochars

    Li Fu1,2, Xianying Xu1,2,*, Guiquan Fu2, Renduo Zhang3, Hujun Liu2

    Journal of Renewable Materials, Vol.8, No.7, pp. 801-818, 2020, DOI:10.32604/jrm.2020.09369

    Abstract The aim of this study was to investigate adsorption and desorption characteristics of cadmium ion (Cd(II)) by ash-free biochars and the adsorption mechanism. Biochars were prepared using peanut shell, bamboo, and Sophora japonica Linn. Ash-free biochars were obtained by treating the biochars with acid elution. Adsorption and desorption data from batch experiments were analyzed using the Langmuir and Freundlich models and three adsorption kinetics models (i.e., the Pseudo second-order, Elovich model, and the Intraparticle diffusion models). Results showed that the acid elution improved the pore structure of biochars, increased C content and aromatic functional group… More >

  • Open Access


    Nuclear Magnetic Resonance Spectrum Experiment of Gas Absorption and Desorption in Coal under Tridimensional Load and Unload

    J.P. Tang*, Y.S. Pan

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.4, pp. 107-108, 2011, DOI:10.3970/icces.2011.016.107

    Abstract Nuclear Magnetic Resonance (NMR) as an advanced non-damaged measurement technique was introduced into the research of gas adsorption and desorption in coal to simulate physically and evaluate influence of tridimensional load and unload . Coal is typical heterogeneous material which can adsorb gas. Load and unload condition play important roles for gas storage and transport in coal. Gas in coal has two states, free and absorbed which act balance dynamically. The home-made triaxial osmoscope made up of non-magnetic polycarbonate material which has coal sample were placed into the magnetic bore of NMR spectrum equipment. The More >

  • Open Access


    A Phenomenological Model for Desorption in Polymers

    J.A.Ferreira1,2, P. de Oliveira2, P. da Silva3, D. M. G. Comissiong4

    CMC-Computers, Materials & Continua, Vol.13, No.1, pp. 17-48, 2009, DOI:10.3970/cmc.2009.013.017

    Abstract A phenomenological formulation is adopted to investigate desorption in polymers. The speed of the front is studied and the well-posedness of the general model is analyzed. Numerical simulations illustrating the dynamics of the desorption process described by the proposed model are included. More >

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