Lignocellulosic biomass is a renewable and abundant source that can be used as a replacement for fossil resources in the sustainable production of speciality chemicals and transportation fuels. Over ...the last several decades, it has been demonstrated that one of the most effective methodology is to converse the high concentration of oxygen functionalized biomass monomers (e.g., cellulose, hemicelluloses) through de-functionalization into levulinic acid (LA) that has low oxygen content, followed by catalytic transformation of LA into fuels and valuable chemicals. This strategy currently seems to be the logical and promising alternative for sustainable development in the context of economic and environmental considerations. Besides, LA has been identified as one of the most promising platform chemicals for the sustainable production of fuels and commodity chemicals. This review is an up-to-date progress of literatures available on the subject of speciality chemicals and fuels derived from biomass through LA platform. The mechanism and current technologies for the production of LA are reviewed and compared. The potential theoretical calculation methods such as ab initio methods and density functional theories to predict the reaction pathway was also commented. The various transformation methods started from LA to speciality chemicals and fuels are critically reviewed. Among the various products, γ-valerolactone, 2-methyltetrahydrofuran and levuinate esters have been identified as promising fuels. The commercial diphenolic acid and delta-aminolevulinic acid have been widely utilized in many areas. The potential applications as well as fuel properties of these products are also discussed.
Catering supplier selection is multi-criteria decision-making (MCDM) problem faced by airline industry. The evaluation process primarily involves the assessment of several complex factors for ...selecting a catering supplier that will best meet the airline requirements. There are a few applications of the catering supplier selection model. The approach of this paper is towards the solution for catering supplier selection. This study integrates the analytical hierarchy process (AHP) with a type of performance rating involving the determination a degree of utility by additive ratio assessment (ARAS) and multi-choice goal programming (MCGP). A real-life case study in selecting a catering supplier is also presented.
•How to choose the best catering supplier to increase customer's satisfaction is crucial for the airline.•An integrated method combining AHP, ARAS and MCGP is proposed to solve the MCDM problem of catering supplier selection.•This new model considers both qualitative and quantitative decision criteria to select the best catering supplier.•This paper is to propose an efficient and simple method to assist airlines in choosing the best catering supplier.
•Ecofriendly and noble-metal-free Cu–Fe catalysts were fabricated using the metal nitrates.•Cu–Fe catalyst was efficient for hydrogenation of biomass-derived furfural and levulinic acid.•Biofuel ...2-methylfuran with 51% yield was highly selectively achieved at 99% conversion of furfural.•Biofuel γ-valerolactone with 90% yield was efficiently achieved at 98.7% conversion of levulinic acid.
A series of chromium-free and noble-metal free Cu–Fe catalysts were successfully synthesized utilizing the inexpensive metal nitrates. Ecofriendly Cu–Fe catalysts exhibited highly efficient performance in the hydrogenation of biomass-derived furfural and levulinic acid, where biofuels (2-methylfuran and γ-valerolactone) were obtained at 51% and 90% yield under mild conditions, respectively. The synthesized Cu–Fe catalysts were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and Temperature-programmed desorption of ammonia (NH3-TPD) to elucidate the relationship between the physical property and their catalytic performance. Reaction parameters and the reaction pathways were also investigated. The Cu–Fe catalyst developed in this work is inexpensive, simple, and amenable to scale up, which makes it a promising candidate for the general conversion of biomass-derived monomers to biofuels.
As our high dependence on the supply of diminishing fossil fuel reserves raise great concerns in its environmental, political and economic consequences, utilization of renewable biomass as an ...alternative resource has become increasingly important. Along this background, furfural as a building block, offers a promising, rich platform for lignocellulosic biofuels and value-added chemicals. These include 2-methylfuran and 2-methyltetrahydrofuran, furfuryl alcohol, tetrahydrofurfuryl alcohol, furan, tetrahydrofuran as well as various cyclo-products (e.g., cyclopentanol, cyclopentanone). The various production routes started from furfural to various fuel additives and chemicals are critically reviewed, and the current technologies for efficient production are identified. Their potential applications as well as the fuel properties of these products are discussed. Challenges and areas that need improvement are also highlighted in the corresponding area. In short, we conduct a comprehensive review of the strategies to produce furfural, new approaches and numerous possibilities to utilize furfural in industrial and laboratory sector for the production of fuel additives and value-added chemicals.
Quantum emitters are an integral component for a broad range of quantum technologies, including quantum communication, quantum repeaters, and linear optical quantum computation. Solid-state color ...centers are promising candidates for scalable quantum optics due to their long coherence time and small inhomogeneous broadening. However, once excited, color centers often decay through phonon-assisted processes, limiting the efficiency of single-photon generation and photon-mediated entanglement generation. Herein, we demonstrate strong enhancement of spontaneous emission rate of a single silicon-vacancy center in diamond embedded within a monolithic optical cavity, reaching a regime in which the excited-state lifetime is dominated by spontaneous emission into the cavity mode. We observe 10-fold lifetime reduction and 42-fold enhancement in emission intensity when the cavity is tuned into resonance with the optical transition of a single silicon-vacancy center, corresponding to 90% of the excited-state energy decay occurring through spontaneous emission into the cavity mode. We also demonstrate the largest coupling strength (g/2π = 4.9 ± 0.3 GHz) and cooperativity (C = 1.4) to date for color-center-based cavity quantum electrodynamics systems, bringing the system closer to the strong coupling regime.
Human beings are “machines” that use endogenously produced biomolecules as “components” in signaling and for the maintenance of the body. These biomolecules consist of proteins, nucleic acids, and ...carbohydrates, which can either be extracted from biological substrates or synthesized by chemical/biochemical methods. These biomolecules have the ability to recognize/interact with other biomolecules that are overexpressed in disease cells. For targeted theranostics, strategies to chemically incorporate these natural biomolecules with advanced materials to treat human diseases by imaging‐guided drug delivery or photodynamic/photothermal therapy are proposed, with improved biocompatibility. Herein, recent research on construction of quantum dots, nanoparticles, and 2D material platforms decorated with antibodies, peptides, nucleic acid aptamers, carbohydrates, and folic acid for targeted diagnosis and treatment are summarized and discussed. In addition, the various strategies required to construct effective functional materials for targeted cancer therapy are highlighted. The hope is that this review can inspire and guide those that are interested in the field of biomedicine to rationally design and develop new target‐based theranostic materials.
Recent research progress on the construction of quantum dots, inorganic nanoparticles, conjugated polymers, and 2D material platforms decorated with antibodies, peptides, nucleic acid aptamers, carbohydrates, and folic acid for targeted diagnosis and treatment are summarized and discussed. In addition, the various strategies required to construct effective functional materials for targeted cancer therapy are highlighted.
Biomass-derived platform intermediate furfural and levulinic acid were efficiently hydrogenated to the value-added furfuryl alcohol and promising biofuel γ-valerolactone, respectively, using a ...noble-metal-free Cu–Cr catalyst, which was facilely and successfully synthesized by a modified co-precipitation method using the cheap metal nitrates. In the first hydrogenation of furfural, 95% yield of furfuryl alcohol was highly selectively produced at 99% conversion of furfural under the mild conditions. For the hydrogenation of levulinic acid, 90% yield of γ-valerolactone was highly selectively produced at 97.8% conversion. Besides, the physical properties of the resulting Cu–Cr catalysts were studied by XRD (X-ray diffraction), EDX (Energy-dispersive X-ray), TEM (Transmission electron microscopy) and XPS (X-ray photoelectron spectroscopy) to reveal their influence on the catalytic performance. Subsequently, different reaction parameters were studied and it was found that Cu2+/Cr3+ ratios (0.5, 1 and 2), reaction temperature (120–220 °C) and hydrogen pressure (35–70 bar) presented important influence on the catalytic activities. In the end, the stability of the Cu–Cr catalysts was also studied.
•A noble-metal-free Cu–Cr catalyst was successfully synthesized using metal nitrates.•Cu–Cr catalysts were highly selective hydrogenation of biomass-derived furfural to FA.•Cu–Cr catalysts were efficient for hydrogenation of biomass-derived LA to biofuel GVL.•The physical properties of the resulting Cu–Cr catalysts were systematically studied.•Reaction parameters and stability in the hydrogenation of furfural were studied in details.
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Differential equations are a powerful tool for evaluating Feynman integrals. Their solution is straightforward if a transformation to a canonical form is found. In this paper, we present an ...algorithm for finding such a transformation. This novel technique is based on a method due to Höschele et al. and relies only on the knowledge of a single integral of uniform transcendental weight. As a corollary, the algorithm can also be used to test the uniform transcendentality of a given integral. We discuss the application to several cutting-edge examples, including non-planar four-loop HQET and non-planar two-loop five-point integrals. A Mathematica implementation of our algorithm is made available together with this paper.
Lithium metal is the ideal anode for the next generation of high-energy-density batteries. Nevertheless, dendrite growth, side reactions and infinite relative volume change have prevented it from ...practical applications. Here, we demonstrate a promising metallic lithium anode design by infusing molten lithium into a polymeric matrix. The electrospun polyimide employed is stable against highly reactive molten lithium and, via a conformal layer of zinc oxide coating to render the surface lithiophilic, molten lithium can be drawn into the matrix, affording a nano-porous lithium electrode. Importantly, the polymeric backbone enables uniform lithium stripping/plating, which successfully confines lithium within the matrix, realizing minimum volume change and effective dendrite suppression. The porous electrode reduces the effective current density; thus, flat voltage profiles and stable cycling of more than 100 cycles is achieved even at a high current density of 5 mA cm(-2) in both carbonate and ether electrolyte. The advantages of the porous, polymeric matrix provide important insights into the design principles of lithium metal anodes.
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