260 research outputs found

    Investigating the impacts of introducing emission trading scheme to shipping industry

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    Although international shipping is the most energy efficient means of transportation in terms of unit CO2 emission per tone-mile cargo shipped, due to enormous cargo volume and continuous growth, it still contributes a significant part of global emissions. In order to reduce the CO2 emission from the international shipping industry, International Maritime Organization (IMO) is considering possible market-based measures (MBM). One of the most promising alternatives is the Emission trading Scheme (ETS). Our study thus proposes an economic model to theoretically analyze and benchmarks two different ETS mechanisms for international maritime transport industry, namely an open ETS scheme and a Maritime only ETS (METS) scheme. The model is also calibrated using maritime industry real operational data in year 2007. Our study quantifies the differential impacts of ETS on container shipping and dry bulk shipping sectors. It is suggested that ETS scheme, whether open or maritime only, will decrease ship’s cruising speed, throughput and fuel consumption for both container and bulk sectors. Under open ETS scheme, we find that dry-bulk sector will have higher proportional output reduction and sell more (or use less) emission permits. Under maritime only ETS, the emission permit trading price is endogenously determined, and the emission reduction objective will definitely be reached. Container carriers will buy emission permits from the dry-bulk side. The collusiveness of one sector will only affect itself in open ETS, while it will affect the other less colluded sector in the METS. Specifically, when the sector that sells (buys) permits in METS is more collusive (competitive), the permit price will rise

    Modeling the Impacts of Alternative Emission Trading Schemes on International Shipping

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    Various market-based measures have been proposed to reduce CO2 emissions from international shipping. One promising mechanism under consideration is the Emission Trading Scheme (ETS). This study analyzes and benchmarks the economic implications of two alternative ETS mechanisms, namely, an open ETS compared to a Maritime only ETS (METS). The analytical solutions and model calibration results allow us to quantify the impacts of alternative ETS schemes on the container shipping sector and the dry bulk shipping sector. It is found that an ETS, whether open or maritime only, will decrease shipping speed, carrier outputs and fuel consumption for both the container and dry bulk sectors, even in the presence of a “windfall” profit to shipping companies. Under an open ETS, the dry bulk sector will suffer from a higher proportional reduction in output than the container sector, and will thus sell more emission permits or purchase fewer permits. Under an METS, container carriers will buy emission permits from the dry bulk side. In addition, under an METS the degree of competition within one sector will have spill-over effects on the other sector. Specifically, when the sector that sells (buys) permits is more collusive (competitive), the equilibrium permit price will rise. This study provides a framework for identifying the moderating effects of market structure and competition between firms on emission reduction schemes, and emphasizes the importance of understanding the differential impacts of ETS schemes on individual sectors within an industry when considering alternative policies

    Determination method of fatigue strength and precursors of fatigue failure of porous weakly cemented siltstone

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    In order to study the fatigue behavior of porous weakly cemented siltstone, a quantitative calculation method of characteristic stress was established based on uniaxial step loading and unloading tests of siltstone. Then uniaxial cyclic loading and unloading tests of constant amplitude were carried out to study the volumetric strain, bulk compliance, and acoustic emission evolution of siltstone where the upper limit stress was in different stress ranges. The new method separates volumetric strain into the linear elastic strain of solid-phase dominated by rock skeleton, the non-linear elastic strain of gas-phase dominated by void, and the irreversible plastic strain. The peak points of gas-phase and plastic volumetric strain are taken as crack closure stress and crack initiation stress, besides the points of gas-phase volumetric strain and total volumetric strain changes from positive to negative are taken as crack damage stress and absolute dilatation stress, solving the problem that the calculation of characteristic stress is affected by subjective factors. The crack damage stress and absolute dilatancy stress determined by the new method can be regarded as the threshold stress of low-cycle and high-cycle fatigue failure. When the upper limit stress is lower than the crack damage stress, the continuous friction and slippage between the skeleton particles and the microstructure rearrangement under cyclic loading and unloading result in the specimen being gradually compressed. As the times of cyclic loading-unloading increase, the residual volumetric strain, bulk compliance, and cumulative acoustic emission count tend to be stable. When the upper limit stress is higher than the crack damage stress, due to the generation of a large number of cracks, the residual volumetric strain and bulk compliance continue to decrease while the cumulative acoustic emission count continues to increase, resulting in a fatigue failure of the specimen. The change of bulk compliance from positive to negative can be regarded as the early precursor of fatigue failure. The number of acoustic emission events NAE and k are approximately in a logarithmic-linear relationship. On this basis, it is proposed slope \begin{document}bk {b_k} \end{document} to describe the fracture pattern. The sudden increase of \begin{document}bk {b_k} \end{document} can be regarded as the early precursor and critical precursor of fatigue failure

    Sulfate diffusion in coal pillar : experimental data and prediction model

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    The stability of coal pillar dams is crucial for the long-term service of underground reservoirs storing water or heat. Chemical damage of coal dams induced by ions-attacking in coal is one of the main reasons for the premature failure of coal dams. However, the diffusion process of harmful ions in coal is far from clear, limiting the reliability and durability of coal dam designs. This paper investigates sulfate diffusion in coal pillar through experimental and analytical methods. Coal specimens are prepared and exposed to sulfate solutions with different concentrations. The sulfate concentrations at different locations and time are measured. Based on experimental data and Fick's law, the time-dependent surface concentration of sulfate and diffusion coefficient are determined and formulated. Further, an analytical model for predicting sulfate diffusion in coal pillar is developed by considering dual time-dependent characteristics and Laplace transformations. Through comparisons with experimental data, the accuracy of the analytical model for predicting sulfate diffusion is verified. Further, sulfate diffusions in coal dams for different concentrations of sulfate in mine water are investigated. It has been found that the sulfate concentration of exposure surface and diffusion coefficient in coal are both time-dependent and increase with time. Conventional Fick's law is not able to predict the sulfate diffusion in coal pillar due to the dual time-dependent characteristics. The sulfate attacking makes the coal dam a typical heterogeneous gradient structure. For sulfate concentrations 0.01–0.20 mol/L in mine water, it takes almost 1.5 and 4 years for sulfate ions to diffuse 9.46 and 18.92 m, respectively. The experimental data and developed model provide a practical method for predicting sulfate diffusion in coal pillar, which helps the service life design of coal dams

    Transcriptome and proteomic analysis of mpox virus F3L-expressing cells

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    BackgroundMonkeypox or mpox virus (mpox) is a double-stranded DNA virus that poses a significant threat to global public health security. The F3 protein, encoded by mpox, is an apoenzyme believed to possess a double-stranded RNA-binding domain (dsRBD). However, limited research has been conducted on its function. In this study, we present data on the transcriptomics and proteomics of F3L-transfected HEK293T cells, aiming to enhance our comprehension of F3L.MethodsThe gene expression profiles of pCAGGS-HA-F3L transfected HEK293T cells were analyzed using RNA-seq. Proteomics was used to identify and study proteins that interact with F3L. Real-time PCR was used to detect mRNA levels of several differentially expressed genes (DEGs) in HEK293T cells (or Vero cells) after the expression of F3 protein.ResultsA total of 14,822 genes were obtained in cells by RNA-Seq and 1,672 DEGs were identified, including 1,156 up-regulated genes and 516 down-regulated genes. A total of 27 cellular proteins interacting with F3 proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and 19 cellular proteins with large differences in abundance ratios were considered to be candidate cellular proteins. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the DEGs were significantly enriched in immune-related pathways, including type I interferon signaling pathway, response to virus, RIG-I-like receptor signaling pathway, NOD-like receptor signaling pathway, etc. Moreover, some selected DEGs were further confirmed by real-time PCR and the results were consistent with the transcriptome data. Proteomics data show that cellular proteins interacting with F3 proteins are mainly related to RNA splicing and protein translation.ConclusionsOur analysis of transcriptomic and proteomic data showed that (1) F3L up-regulates the transcript levels of key genes in the innate immune signaling pathway, such as RIGI, MDA5, IRF5, IRF7, IRF9, ISG15, IFNA14, and elicits a broad spectrum of antiviral immune responses in the host. F3L also increases the expression of the FOS and JNK genes while decreasing the expression of TNFR2, these factors may ultimately induce apoptosis. (2) F3 protein interacts with host proteins involved in RNA splicing and protein translation, such as SNRNP70, POLR2H, HNRNPA1, DDX17, etc. The findings of this study shed light on the function of the F3 protein
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