As resource scarcity, extreme climate change, and pollution levels increase, economic growth must rely on more environmentally friendly and efficient production processes. Fuel cells are an ideal ...alternative to internal combustion (IC) engines and boilers on the path to greener industries because of their high efficiency and environmentally friendly operation. However, as a new energy technology, significant market penetration of fuel cells has not yet been achieved. In this paper, we perform a techno-economic and environmental analysis of fuel cell systems using life cycle and value chain activities. First, we investigate the procedure of fuel cell development and identify what activities should be undertaken according to fuel cell life cycle activities, value chain activities, and end-user acceptance criteria. Next, we present a unified learning of the institutional barriers in fuel cell commercialization. The primary end-user acceptance criteria are function, cost, and reliability; a fuel cell should outperform these criteria compared with its competitors, such as IC engines and batteries, to achieve a competitive advantage. The repair and maintenance costs of fuel cells (due to low reliability) can lead to a substantial cost increase and decrease in availability, which are the major factors for end-user acceptance. The fuel cell industry must face the challenge of how to overcome this reliability barrier. This paper provides a deeper insight into our work over the years on the main barriers to fuel cell commercialization, and discusses the potential pivotal role of fuel cells in a future low-carbon green economy. It also identifies the needs and points out some directions for this future low-carbon economy. Green energy, supplied with fuel cells, is truly the business mode of the future. Striving for a more sustainable development of economic growth by adopting green public investments and implementing policy initiatives encourages environmentally responsible industrial investments.
Offshore oil and gas production is increasingly growing popular globally. Produced water (PW), which is the largest byproduct of oil and gas production, is a complex mixture of dissolved and ...undissolved organic and inorganic substances. PW contributes considerably to oil pollution in the offshore petroleum and gas industry owing to the organic substances, which mainly include hydrocarbons; this is a major concern to researchers because of the long-term adverse effects on the ecosystem. Since the development of offshore petroleum and gas industry, the PW treatment process has been classified into pretreatment, standard-reaching treatment, and advanced purification treatment based on the characteristics of PW and has been coupled with the environmental, economic, and regulatory considerations. The mechanism, design principle, application, and development of conventional technologies for PW treatment, such as gravity and enhanced gravity sedimentation, hydrocyclone, gas flotation, and medium filtration, are summarized in this study. Novel methods for further application, such as tubular separation, combined fibers coalescence, and membrane separation, are also discussed. Enhancement of treatment with multiple physical fields and environmentally friendly chemical agents, coupled with information control technology, would be the preferred PW treatment approach in the future. Moreover, the PW treatment system should be green, efficient, secure, and intelligent to satisfy the large-scale, unmanned, and abyssal exploration of offshore oil and gas production in the future.
Classical offshore gas field platforms with connecting bridges in the South China Sea and the standby ship beside the platforms. Functions of three platforms in the figure are well drilling and workover, gas production, and accommodation of personnel Display omitted
•Produced water (PW) has danger or potential danger to the ocean environment.•Oil and suspend solid removal were two important steps for PW treatment.•PW management is based on fundamental characteristics, regulations and standards.•Intellectualization and automation will be the development trend for this industry.•Physical devices coupled with chemical agents are the realistic treatment process.
The RIG-I–like receptors (RLRs) retinoic acid–inducible gene I protein (RIG-I) and melanoma differentiation–associated protein 5 (MDA5) are cytosolic pattern recognition receptors that recognize ...specific viral RNA products and initiate antiviral innate immunity. Severe fever with thrombocytopenia syndrome virus (SFTSV) is a highly pathogenic member of the Bunyavirales. RIG-I, but not MDA5, has been suggested to sense some bunyavirus infections; however, the roles of RLRs in anti-SFTSV immune responses remain unclear. Here, we show that SFTSV infection induces an antiviral response accompanied by significant induction of antiviral and inflammatory cytokines and that RIG-I plays a main role in this induction by recognizing viral 5′-triphosphorylated RNAs and by signaling via the adaptor mitochondrial antiviral signaling protein. Moreover, MDA5 may also sense SFTSV infection and contribute to IFN induction, but to a lesser extent. We further demonstrate that the RLR-mediated anti-SFTSV signaling can be antagonized by SFTSV nonstructural protein (NSs) at the level of RIG-I activation. Protein interaction and MS-based analyses revealed that NSs interacts with the host protein tripartite motif–containing 25 (TRIM25), a critical RIG-I–activating ubiquitin E3 ligase, but not with RIG-I or Riplet, another E3 ligase required for RIG-I ubiquitination. NSs specifically trapped TRIM25 into viral inclusion bodies and inhibited TRIM25-mediated RIG-I-Lys-63–linked ubiquitination/activation, contributing to suppression of RLR-mediated antiviral signaling at its initial stage. These results provide insights into immune responses to SFTSV infection and clarify a mechanism of the viral immune evasion, which may help inform the development of antiviral therapeutics.
We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The ...concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology.
•Delayed channel evolution was revealed at multi-temporal scales.•Retrogressive aggradation migrated upstream beyond the backwater zone.•Conditions in previous ∼4 years cumulatively impact current ...channel evolution.
The delayed response of channel evolution upstream of dams to base-level changes has not yet been thoroughly understood. In this paper, we studied the delayed response of the morphological adjustment at the middle Yellow and lower Wei Rivers upstream of the Sanmenxia Dam, China, based on data of water volume, sediment load, cross-sectional profiles, and erosion/deposition volumes during 1960–2018. Channel evolution upstream of the dam obviously lagged behind the dynamic pool level fluctuation during the first approximately two decades following dam closure, when retrogressive aggradation/erosion phases were identified. The retrogressive aggradation migrated ∼200 km upstream to the tributary of the Yellow River, i.e., the Wei River. The impact of base-level rise may propagate backwards behind the beginning of the backwater reach, reflecting indirect backwater effects. The dam has been operated by the controlled release of “storing the clear water during nonflood seasons and discharging the turbid water during flood seasons” since 1974, and the reservoir has generally been eroded during flood seasons and aggraded during nonflood seasons. The erosion center was defined as the subreach between two adjacent cross-sections with the greatest erosion rate during the flood season, and the aggradation center was defined as that with the greatest aggradation rate during the nonflood season. The results showed that the erosion/deposition centers migrated towards the dam by ∼50–60 km during 1974–2010 and migrated upstream after ∼2010. The location of the erosion/deposition centers was related not only to the water and sediment conditions and backwater length in the current year but also to these conditions in the previous ∼4 years, reflecting the delayed response of channel adjustment or the cumulative impact of pervious conditions on channel morphology. This study helps to inform future reservoir management and the delayed channel response to base level change caused by different natural and anthropogenic disturbances.
•Local stability was obtained after the eruption but followed by a renewed incision.•The upstream migrating renewed incision may be triggered by erosion at lower reach.•Rates of renewed incision ...decreased considerably compared to initial change rates.•The improved alluvial phase space diagram is valid to study channel evolution.
The upper North Fork Toutle River (NFTR) has been evolving in a complex way since being disrupted by a 2.5-km3 debris avalanche deposit during the catastrophic eruption of Mount St. Helens in Washington State, USA in 1980. In this study, we improved the alluvial phase space diagram (APSD), which classifies channel adjustment into different stages based on bed elevation and cross-sectional area changes, and applied it to the NFTR at annual time scale in the 1980s. The results showed that in the early 1980s, the upstream narrow single-threaded reaches were degraded, while the downstream wide anabranching reaches were aggraded, with the middle transitional reach acting as the hinge zone. Gradually, the upstream channel reaches armoured, widened, bed slope and excess stream power decreased in the late 1980s, and quasi-equilibrium occurred locally and during short time periods. Sediment load decreased at the lower reaches, resulting in bed degradation and a transition from sediment sink to source. This reversal seemed to have triggered renewed incision, which migrated upstream. The renewed incision was characterised by Stage 1/2 (bed incision with limited bank erosion) followed by Stage 2 (degradation and widening) in the improved APSD. The degradation rate accelerated in the 1990s, especially due to the big flood in 1996, and then slowed down after ∼2000. Channel adjustment rates of the renewed incision were much smaller compared to those of the initial rapid degradation. The change rates of cross-sectional area and valley width decreased by ∼58% and ∼85%, respectively. The comparison between this study and existing studies highlights the significant role played by the time scale, at which the APSD is applied to study channel morphology adjustment.
Urea electrolysis is a promising route to utilize urea-rich wastewater as an energy source to produce hydrogen on the cathode or generate electricity through a direct urea fuel cell, which offers ...great potential for simultaneous water remediation and energy recovery. Here, we report a scalable synthetic strategy to prepare NiCo layer double hydroxide (NiCo LDH) as an efficient catalyst for urea electrooxidation. NiCo LDH with NO3 – intercalant exhibited the best electrocatalytic performance and selectivity toward urea oxidation with a low onset potential, high faradaic efficiency, and high durability. The interlayer spacing in the LDH structure was found to play a pivotal role in the urea oxidation electrocatalysis with higher activity/selectivity under larger spacings. Further analysis of the urea oxidation product could potentially enable selective urine treatment into environmentalally friendly products.
Crimean-Congo hemorrhagic fever virus (CCHFV) is a widespread, tick-borne pathogen that causes Crimean-Congo hemorrhagic fever (CCHF) with high morbidity and mortality. CCHFV is transmitted to humans ...through tick bites or direct contact with patients or infected animals with viremia. Currently, climate change and globalization have increased the transmission risk of this biosafety level (BSL)-4 virus. The treatment options of CCHFV infection remain limited and there is no FDA-approved vaccine or specific antivirals, which urges the identification of potential therapeutic targets and the design of CCHF therapies with greater effort. In this article, we discuss the current progress and some future directions in the development of antiviral strategies against CCHFV.
It is the major challenge to transform a laboratory scale production of fuel cells to an industrial scale one and to meet the requirements of throughput, operating life, low cost, reliability and ...high efficiency in R&D of fuel cells. Designs of uniform flow distribution are central to upscale fuel cells as well as to tackle critical issues of water, thermal and current management. However, in spite of our growing appreciation of designs of uniform flow distribution, there is little or no practical solution to ensure a uniform flow distribution across channels of a cell and cells of a stack in designs of flow fields. The purpose of this paper was to develop a discrete approach to find a design that met requirements of flow distribution uniformity and pressure drop in parallel channel configurations with Z-type arrangement through adjustments of configurations and normalised structural parameters. Variation of the frictional and the momentum coefficients with flow velocities was incorporated into the flow distribution equation to improve modelling accuracy. We also developed procedure, measures and guideline for the designs of flow distribution and pressure drop to bridge knowledge gap between the generalised theory and industrial applications. The results showed that the present approach could provide the practical guideline to evaluate quantitatively performance of different layout configurations, structures, and flow conditions.
► Development and use of discrete approach for designs of flow fields in fuel cells. ► Quantitative assessment of uniformity of flow distribution and pressure drops. ► Systematic approach to find a design that meets flow uniformity and pressure drop. ► Procedure, measures and guideline how to achieve uniform flow distribution. ► Sensitivity analysis of flow coefficients.
PDF
