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  • Open Access

    REVIEW

    Key Steps and Catalyst Performance for Conversion of Cellulose to Isosorbide: A Review

    Dan Wang, Jihuan Song, Qiyuan Wang, Chenmeng Cui, Ying Yang*

    Journal of Renewable Materials, Vol.13, No.1, pp. 49-78, 2025, DOI:10.32604/jrm.2024.056644 - 20 January 2025

    Abstract Upgrading of abundant cellulosic biomass to isosorbide can reduce the dependence on limited fossil resources and provide a sustainable way to produce isosorbide, utilized for polymers, medicine and health care product synthesis. This review comprehensively examines the key steps and catalytic systems involved in the conversion of cellulose to isosorbide. Initially, the reaction pathway from cellulose to isosorbide is elucidated, emphasizing three critical steps: cellulose hydrolysis, glucose hydrogenation, and the two-step dehydration of sorbitol to produce isosorbide. Additionally, the activation energy and acidic sites during cellulose hydrolysis, the impact of metal particle size and catalyst More > Graphic Abstract

    Key Steps and Catalyst Performance for Conversion of Cellulose to Isosorbide: A Review

  • Open Access

    ARTICLE

    Orthogonal Probability Approximation for Highly Accurate and Efficient Orbit Uncertainty Propagation

    Pugazhenthi Sivasankar1,*, Austin B. Probe2, Tarek A. Elgohary1

    Digital Engineering and Digital Twin, Vol.2, pp. 169-205, 2024, DOI:10.32604/dedt.2024.052805 - 31 December 2024

    Abstract In Space Situational Awareness (SSA), accurate and efficient uncertainty quantification and propagation are essential for various applications, such as conjunction analysis, track correlation, and orbit prediction. The propagation of the probability density function (PDF) in nonlinear systems results in non-Gaussian distributions, which are difficult to approximate. Furthermore, the computational cost of approximating the PDF increases exponentially with the number of random variables, a phenomenon known as the curse of dimensionality. To address these challenges, the Orthogonal Probability Approximation (OPA) method is presented for high-fidelity uncertainty propagation and PDF approximation in nonlinear dynamical systems. The method… More >

  • Open Access

    ARTICLE

    The Relationship between Psychological Vulnerability, Aging Attitudes and Life Meaning in Elderly Patients with Comorbidities

    Jiaojiao Wu1,#, Dou Fu2,#, Lili Zhang1,*, Xiangying Xie3, Xinmei Wang2, Xiangying Shen1, Shanshan Liu2, Xu Xu4, Hui Cheng5, Xiaojie Ma1, Doudou Lin1

    International Journal of Mental Health Promotion, Vol.26, No.11, pp. 897-904, 2024, DOI:10.32604/ijmhp.2024.056223 - 28 November 2024

    Abstract Background: With the rapid aging of China’s population and the increasing prevalence of comorbidities in the elderly, psychological crises have become more common. This study aims to investigate the present status of psychological vulnerability, aging attitudes, and life meaning in elderly patients with comorbidities. Methods: A total of 685 elderly inpatients and outpatients at Renmin Hospital of Wuhan University between July and December 2022 were selected using the simple random sampling method. Social demographic data were collected, and the Attitudes to aging Questionnaire (AAQ), the Chinese Life Meaning Questionnaire (C-MLQ), and the Psychological Vulnerability Scale… More >

  • Open Access

    REVIEW

    Research Progress of Biomass-Based Porous Oil-Absorbing Materials

    Yifan Sun1, Yuanyuan Zhang1,2, Ziyi Tian1, Hailang Liu1, Siying Chen1, Xujuan Huang1,*, Zhaosheng Cai1, Bo Fang3

    Journal of Renewable Materials, Vol.12, No.11, pp. 1837-1856, 2024, DOI:10.32604/jrm.2024.055933 - 22 November 2024

    Abstract As oil is now an important resource for the survival and development of mankind, the consumption of oil continues to increase each year, and there have been a number of major oil spills in history, such as the oil spill from the Deepwater Horizon drilling rig. Therefore, oil spills during storage and transportation have become an issue of serious concern. Current methods such as incineration and chemical methods cause secondary environmental pollution and fail to enable resource recovery. The adsorption method by porous materials has attracted worldwide attention due to its simplicity, portability, and efficiency.… More > Graphic Abstract

    Research Progress of Biomass-Based Porous Oil-Absorbing Materials

  • Open Access

    ARTICLE

    Modeling of the Adsorption Allowing for the Changing Adsorbent Activity at Various Stages of the Process

    Marat Satayev1,2,*, Abdugani Azimov2, Arnold Brener2, Nina Alekseyeva1, Zulfia Shakiryanova2

    Frontiers in Heat and Mass Transfer, Vol.22, No.5, pp. 1533-1558, 2024, DOI:10.32604/fhmt.2024.052901 - 30 October 2024

    Abstract The goal of this work is, first of all, to construct a mathematical model of the mass transfer process in porous adsorption layers, taking into account the fact that in most cases the adsorption process is carried out in non-stationary technological modes, which requires a clear description of its various stages. The scientific contribution of the novel model is based on a probability approach allowing for deriving a differential equation that takes into account the diffusion migration of adsorbed particles. Solving this equation allows us to calculate the reduced degree of the adsorption surface coverage… More >

  • Open Access

    ARTICLE

    Why Sustainable Porous Carbon Should be Further Explored as Radar-Absorbing Material? A Comparative Study with Different Nanostructured Carbons

    Alan F.N. Boss1, Manuella G.C. Munhoz1, Gisele Amaral-Labat2, Rodrigo G.A. Lima2, Leonardo I. Medeiros2,3, Nila C.F.L. Medeiros2,3, Beatriz C.S. Fonseca2, Flavia L. Braghiroli4,*, Guilherme F.B. Lenz e Silva1

    Journal of Renewable Materials, Vol.12, No.10, pp. 1639-1659, 2024, DOI:10.32604/jrm.2024.056004 - 23 October 2024

    Abstract Radar Absorbing Materials (RAM) are a class of composites that can attenuate incident electromagnetic waves to avoid radar detection. Most carbon allotropes that have the potential to be used as RAM are either carbon nanotubes (CNTs), graphene, carbon black (CB) and ultimately, sustainable porous carbon (SPC). Here, black wattle bark waste (following tannin extraction) was used as a sustainable source to produce SPC made from biomass waste. It was characterized and used as a filler for a silicone rubber matrix to produce a flexible RAM. The electromagnetic performance of this composite was compared with composites… More > Graphic Abstract

    Why Sustainable Porous Carbon Should be Further Explored as Radar-Absorbing Material? A Comparative Study with Different Nanostructured Carbons

  • Open Access

    PROCEEDINGS

    Distribution Transport: A High-Efficiency Method for Orbital Uncertainty Propagation

    Changtao Wang1, Honghua Dai1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.3, pp. 1-2, 2024, DOI:10.32604/icces.2024.010943

    Abstract Orbital uncertainty propagation is fundamental in space situational awareness-related missions such as orbit prediction and tracking. Linear models and full nonlinear Monte Carlo simulations were primarily used to propagate uncertainties [1]. However, these methods hampered the application due to low precision and intensive computation. Over the past two decades, numerous nonlinear uncertainty propagators have been proposed. Among these methods, the state transition tensor (STT) method has been widely used due to its controllable accuracy and high efficiency [2]. However, this method has two drawbacks. First, its semi-analytical formulation is too intricate to implement, which hinders… More >

  • Open Access

    PROCEEDINGS

    Vibration Characteristics of Multilayer Airborne Equipment Integrated Platform

    Binjie Mu1, Jun Liu2,*, Yuanfang Chen1

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.4, pp. 1-2, 2024, DOI:10.32604/icces.2024.011110

    Abstract With the improvement of aircraft design requirements, the development of airborne equipment towards lightweight, miniaturization and weight reduction has brought great challenges to the structural design of airborne equipment. Usually, airborne equipment needs to be connected to the fuselage through supporting brackets. In the process of airplane flight, due to the influence of vibration and other complex load conditions, the mounting bracket of airborne equipment is prone to damage caused by the unreasonable structural design of airborne equipment. Some sensitive airborne electronic equipment has special requirements for the dynamic characteristics of the bracket. Therefore, the… More >

  • Open Access

    ARTICLE

    Orbit Weighting Scheme in the Context of Vector Space Information Retrieval

    Ahmad Ababneh1, Yousef Sanjalawe2, Salam Fraihat3,*, Salam Al-E’mari4, Hamzah Alqudah5

    CMC-Computers, Materials & Continua, Vol.80, No.1, pp. 1347-1379, 2024, DOI:10.32604/cmc.2024.050600 - 18 July 2024

    Abstract This study introduces the Orbit Weighting Scheme (OWS), a novel approach aimed at enhancing the precision and efficiency of Vector Space information retrieval (IR) models, which have traditionally relied on weighting schemes like tf-idf and BM25. These conventional methods often struggle with accurately capturing document relevance, leading to inefficiencies in both retrieval performance and index size management. OWS proposes a dynamic weighting mechanism that evaluates the significance of terms based on their orbital position within the vector space, emphasizing term relationships and distribution patterns overlooked by existing models. Our research focuses on evaluating OWS’s impact… More >

  • Open Access

    ARTICLE

    Heat Transfer Enhancement of the Absorber Tube in a Parabolic Trough Solar Collector through the Insertion of Novel Cylindrical Turbulators

    Yasser Jebbar1,2,*, Fadhil Fluiful2, Wisam Khudhayer3

    FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1279-1297, 2024, DOI:10.32604/fdmp.2024.050753 - 27 June 2024

    Abstract This study includes an experimental and numerical analysis of the performances of a parabolic trough collector (PTC) with and without cylindrical turbulators. The PTC is designed with dimensions of 2.00 m in length and 1.00 m in width. The related reflector is made of lined sheets of aluminum, and the tubes are made of stainless steel used for the absorption of heat. They have an outer diameter of 0.051 m and a wall thickness of 0.002 m. Water, used as a heat transfer fluid (HTF), flows through the absorber tube at a mass flow rate… More >

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