Electric vehicles with longer driving mileage and unmanned aerial vehicles with prolonged cruise duration require urgently higher energy density of batteries. (1?4) Lithium–carbon dioxide (Li–CO₂) battery, which demonstrates a high theoretical energy density of 1876 W h·kg–1 and a high discharge plateau (?2.8 V vs Li⁺/Li), has attracted increasing attention as one of the promising next-generation metal-gas batteries. (5?7) Li–CO₂ batteries can simultaneously realize the fixation of greenhouse gas CO₂ and high energy density supply, which show enormous application potentiality in CO2-rich situations such as deep-sea work and Mars exploration (96% of its atmosphere on Mars is CO₂). The main reaction process involved in aprotic Li–CO₂ batteries is as follows: 4Li⁺ + 3CO₂ + 4e^- ? Li₂CO₃ + C. (8?10) However, the sluggish kinetics of the discharged product Li₂CO₃ with stable chemical stability during recharging have greatly restricted the rate performance and cycling stability of Li–CO2 batteries. Meanwhile, the arduous decomposition of insulating Li₂CO₃ during recharging also leads to high overpotential and consequent electrolyte degradation. (11?13) The continuous accumulation of undecomposed Li2CO3 on the cathode occupies the reaction sites and severely blocks the CO₂ diffusion channels, further resulting in large polarization and poor cycling performance of the batteries. Therefore, efficient cathode catalysts are highly imperative to boost the decomposition of Li₂CO₃ and facile reaction kinetics.

In recent years, several kinds of cathode catalysts, including carbon materials, (14?20) noble metals, (10,12,21?26) transition metals and their compounds, (27?36) metal–organic frameworks, (37,38) and covalent organic frameworks, (39,40) have been developed and improved the electrochemical performance of Li–CO₂ batteries. Among them, integrating an efficient metal catalyst into highly conductive carbon have shown significantly facilitated kinetics in Li–CO₂batteries as well as other gas-involved catalytic reactions. (29,32,36) A variety of carbon/metal composite catalysts, such as ultrathin Ir nanosheets on N-doped carbon fibers, (21) RuO₂ on carbon nanotubes (CNTs), (22) ultrafine Ru nanoparticles on activated carbon nanofibers, (23) ZnS quantum dots on N-doped reduced graphene oxide(GO), (27) adjacent Co single atom/GO, (35) Ru–Cu nanoparticles on graphene, (41) Mo2C/CNTs, (42) Ru–Co nanoparticles on carbon nanofibers, (43) etc., have been prepared and showed outstanding catalytic activity and remarkably reduced the voltage gap between CO₂ reduction and evolution process. However, reported carbon/metal composite catalysts have several drawbacks: weak bonding strength between carbon and metal catalysts, uneven distribution of the nanoparticles, and limited catalyst utilization, leading to the formation of large aggregates and high loading but partly inefficient catalytic behavior. Moreover, the loading amount, crystal structure, and catalytic sites of metal catalysts are difficult to precisely regulate to further improve and optimize their catalytic activity.

The emerged graphdiyne (GDY) material is a novel allotrope of carbon (44) which contains both sp and sp2 hybridized carbon atoms in the carbon framework and possesses a large specific surface area, uniform pore structure, and excellent electrochemical stability. Different from traditional carbon materials like graphene and CNTs, it was suggested that the coexistence of sp and sp2 carbon atoms is favorable for chelating metal atoms and facilitating the charge transfer between metal atoms and GDY. (45) These merits make GDY an ideal substrate for anchoring metal catalysts with suppressed aggregation. So, GDY/metal composite catalysts such as GDY-WS2 (46) and MoS₂/N-GDY (47) have shown efficient catalytic activity in hydrogen evolution reaction (HER). In addition, single metal atoms can be stably anchored and evenly dispersed on GDY, such as Ni(Fe)/GDY, (48) Pd/GDY, (49) and Mo/GDY, (50) with highly efficient catalytic activity to the HER and the nitrogen reduction reaction. At the same time, GDY can be synthesized through a copper-catalyzed C–C cross-coupling reaction, which makes it possible to precisely adjust its morphology and chemical properties, including conductivity, pore structure, and affinity for metal atoms, thereby conveniently optimizing the catalytic activity of the GDY/metal catalyst...

Week beginning on November 19, 2023: 421.21 ppm
Weekly value from 1 year ago: 418.38 ppm
Weekly value from 10 years ago: 395.26 ppm
Last updated: November 26, 2023

Drinkers rushed to support owners Jess and Rich Fierro after finding out about their involvement in the Club Q shooting

The numbers are here: 2023 World Energy Outlook published by the International Energy Agency (IEA)Table A.1a on Page 264 .

Worldwide, more than 260 river basins are divided and shared by multiple nations. Managing and preserving transboundary watersheds, their water resources, and cultural heritage is exceptionally difficult because political borders rarely coincide with watershed boundaries, and governments may have conflicting regulatory approaches. (1?3) Without cooperative resource management between governments, transboundary waterways are uniquely vulnerable to the influences of human land use on water quality and ecosystem integrity. One example is large scale mining and the alteration of land surfaces and aquifers due to placement of waste rock, which are known to profoundly influence groundwater and surface water quality. (4?6) Mining supports regional and national economies but has been shown to alter water, solute, and sediment dynamics and harm aquatic ecosystems. (7) Understanding environmental and water-quality impacts from mines located near borders provides information that may be used to protect, restore, and manage natural resources in the complex regulatory setting of transboundary watersheds. (8)

Koocanusa Reservoir (KOC, also called “Lake Koocanusa”) is a transboundary reservoir that is split between northwestern Montana (MT), United States (U.S.), and southeastern British Columbia (B.C.), Canada (CA). The reservoir was impounded in 1972 by the Libby Dam, near Libby, MT (Figure 1). KOC encompasses the headwaters of the Kootenai (Kootenay in CA) River Basin. Including KOC, the Kootenai River crosses the U.S./CA border twice and drains into the Columbia River just north of where the river crosses the international border a third time (Figure 1). The Kootenai and Columbia Rivers have significant cultural importance─the watershed itself is the basis for the Ktunaxa Creation Story. (9) Ecologically and culturally important fish resources in the Kootenai Watershed (U.S.) include the federally endangered Kootenai River White Sturgeon (Acipenser transmontanus), the threatened Bull Trout (Salvelinus confluentus), and two species of concern, Burbot (Lota lota) and Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi). (10) The headwater drainages for KOC are present on both sides of the border. However, the three largest tributaries are in B.C., and the second largest is the Elk River, which drains a watershed that contains several open-pit, coal mining operations (Figure 1). (11,12)

COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel ?-coronavirus that shares genetic similarity with other coronaviruses that have caused disease outbreaks among humans, including SARS-CoV and MERS-CoV. (1) SARS-CoV-2 is a positive-sense single-stranded RNA virus, with a genome size of roughly 29.9 kb. (2) SARS-CoV-2 transmission is largely associated with aerosols that originate in the respiratory systems of infected individuals, although fomites may also contribute to transmission. (3)

Beyond COVID-19, it is likely that other disease outbreaks, epidemics, and pandemics will continue and perhaps become more prevalent in the future. (4) History suggests that these outbreaks are likely to be associated with airborne respiratory pathogens. As such, a clear need for the development of rational, predictable control measures against airborne pathogens has emerged...

...UV-C-based systems accomplish pathogen inactivation by inducing photochemical damage to critical biomolecules. Damage to nucleic acids is observed across the entire UV-C spectrum (200 nm ? ? ? 280 nm). For wavelengths less than about 240 nm, photochemical damage to proteins becomes an important contributor to pathogen inactivation. (7?9) For SARS-CoV-2, this behavior has been demonstrated by comparison of the inactivation action spectrum with the absorption spectrum for RNA extracted from the virus (see Figure SI-1). (10) In general, the wavelength dependence of SARS-CoV-2 inactivation by exposure to UV-C radiation follows the same shape as the RNA absorbance spectrum. However, for wavelengths less than about 240 nm, SARS-CoV-2 inactivation is greater than that predicted by the trend of RNA absorbance; this behavior is assumed to be attributable to protein damage. For applications that involve simultaneous exposure to UV-C radiation at 222 and 254 nm, a synergistic inactivation response has been reported that involves lipid peroxidation. (11)

Recent research has demonstrated the potential for new UVGI system configurations to be developed based on Far UV-C radiation, informally defined as radiation with wavelengths in the range 200 nm ≲ ? ≲ 230 nm. (12) The most common source of Far UV-C radiation for these applications is the optically filtered krypton chloride excimer (KrCl*) lamp, although solid-state Far UV-C devices are being developed. A typical output spectrum for an optically filtered KrCl* lamp is illustrated in Figure SI-2. Far UV-C radiation is strongly absorbed by proteins. Because of this, Far UV-C radiation has limited potential to penetrate the germinative cells of human skin or eyes, resulting in substantial reductions of the potential for damage to these tissues, relative to conventional UV-C radiation. In recognition of this behavior, the Threshold Limit Values (TLVs) for exposure to Far UV-C radiation have been substantially increased by the American Conference of Governmental Industrial Hygienists (ACGIH)...

^a Values of virus emission rate represent the median or mean of reported values for each activity type reported from the references listed.

^a For each assumed operating condition (designated by a lower-case letter), assumed parameter values are listed to define ? as well as the contributions to ? from each process: physical air exchange (A), natural decay (kD), and UVC irradiation (fEavgk). For each assumed operating condition, an estimate of the time-dependent risk of SARS-CoV-2 infection was developed for each of eight assumed virus emission scenarios (designated by uppercase letters), as illustrated in Figure 3.

Figure 3. Estimates of the risk of COVID-19 transmission in a 500 m³ room with a single infected individual as an emitter in the room; the emitter was assumed to be releasing aerosolized, infective viruses at rates that correspond with the conditions indicated by capital letters (see legend and Table 2). Conditions of operation of the HVAC and UVGI systems are indicated by lower-case letters (see the bottom right of each panel and Table 4). Horizontal dashed lines indicate a reference risk of 10^–3, as suggested by Buonanno et al. (29) The terms Amin and Amax represent practical minimum and maximum values of physical air exchange, respectively, that are likely to be applied, based on guidance from ASHRAE (19) and CDC. (20) The black star in panel (a) indicates measured disease transmission from the Skagit Valley Chorale group Superspreader event.

Modern innovative products tend to utilize a broad range of elements because each element has a unique fundamental property. (1) Magnetism is one of the major properties needed for clean energy technologies (e.g., power electric vehicles). Dysprosium (Dy), a rare-earth element, is effective in ensuring the magnetic strength of the most widely used magnet, neodymium–iron–boron (Nd–Fe–B). (2,3) Thus, the transition to clean energy is projected to be accompanied by an exponential increase in Dy demands. (4) However, only a few regions have provided Dy-bearing mineral resources in the last three decades. Approximately, 90% of minerals were produced by China and Burma in 2018 (Figure S1). Due to the growing demand and supply risk, Dy availability has received considerable attention. (4,5) Particularly in the United States (US), Dy has been regarded as a critical raw material since early 2012. (6) A recent study enhanced concerns about Dy supplies in the US because of the difficulty in recovering and reusing it. (7) Particularly in this post-pandemic period, supply risks are amplified by trade policy changes and suspended operations. Since 2009, throughout the globe, governments, companies, and research institutes have taken actions to minimize the potential impact of Dy shortage, (8) for example, by supporting the development of low-Dy Nd–Fe–B magnets by the Japanese government (9) and the recycling of Dy-bearing secondary resources by the European Commission. (10)

Exploring Dy flows between products and across countries is essential to devise strategic plans. Some researchers attempted to identify and quantify the major factors that contribute to the US Dy availability and supply risks, (11–13) such as the depletion time of domestic reserves, country concentration, and governance, and they primarily focus on Dy ore supply. Several other studies evaluated Dy demands for finished products under specific scenarios, such as for wind turbines driven by the Wind Vision Project (14) and Blue Map (15), and electric vehicles by automotive electrification, (16,17) which informed the decision-makers of potential material-related issues in particular initiatives. (18–23) Furthermore, several studies were conducted to identify particular sources of certain products (e.g., domestic extraction of ores, (24) cross-border trade of alloys (8,20,25), and finished products (23,26)). Owing to scarce data, element-specific material flow analysis (MFA) of rare-earth elements in the US has not been conducted, and information on domestic demands for Dy-bearing chemicals and alloys is unavailable. Element-specific information is crucial for making decisions on capacity planning (business level), industrial development (industry level), and national strategy formulation (country level). One such example is the volume of national strategic stockpiles (mostly composed of chemicals) determined according to the demands of manufacturing industries. So far, the information about Dy flows is still incomplete.

Thus, to bridge the knowledge gap related to the US Dy, we performed a dynamic MFA covering the period from 1987 to 2018. The MFA has been used as an effective tool to explore material flows into, out of, and within a certain system by analyzing material production, consumption, and international trade from a lifecycle perspective. (27,28) Notably, in this study, we explored the comprehensive coverage of products, processes, and periods. First, the MFA framework adopted in our study considers all types of Dy-bearing products available in the US market including ores, concentrates, chemicals, alloys, and finished products. Second, it distinguishes the US from the rest of the world, allowing for comparative analyses of domestic and overseas supply and demand. Third, it explores the scenario starting from 1987, when the first Dy chemicals were produced by factories in the US. The results reveal the temporal evolutions of the whole Dy supply chain as well as the causes and consequences and provide quantitative information on the Dy flows in the US. Based on these results, the progress of actions and policies, as well as near-term implications, are discussed...

Figure 2. Cumulative Dy flows in the US from 1987–2018. Values are measured using the metallic equivalent weight (in metric ton Dy). According to the mass-balance principle, the domestic demands for the upstream products equal domestic supplies for the downstream industries. For example, the domestic demand for concentrates drives compound production. According to the results of the uncertainty analysis, the total domestic demand for finished products is likely to range from 6200 to 11,000 t Dy, with a 97.5% confidence.

Figure 3. Dy demand (measured in t Dy) in percentage. (A) Average, (B) by years and amounts, and (C) for finished products.

Figure 4. Total supplies (i.e., domestic production plus imports), import dependency, and demands (i.e., domestic consumption plus exports) of (a) concentrates, (b) chemicals, (c) alloys, and (d) finished products. Consumption is represented by the domestic production of downstream industries.

Hydrogen (H2) is the main component in numerous industrial processes, such as ammonia and methanol synthesis, oil refining, and steel production. (1) Due to its widespread usage, H2 production has tripled since 1975, reaching ?70 million tonnes per year (MtH2/yr) in 2018. (1,2) Its versatility in production and transportation makes it an attractive decarbonization technique for various industries, including power generation and fuel supply for vehicles and ships. (1) The increased demand for H2 requires advanced developments for the scaleup of existing production technologies. Currently, 76% of H2 is sourced from natural gas, predominantly steam methane reforming (SMR). (1) SMR involves the reaction between purified natural gas and superheated steam in a high-temperature and high-pressure reformer furnace, producing mainly carbon monoxide (CO), water (H2O), and H2. Due to the high temperatures (800–900 °C) of the system, traditional SMR requires ample heat duties provided by the combustion of fossil fuels. Consequently, global H2 production leads to CO2 emissions of ?850 MtCO2/yr as of 2017. SMR’s large energy demand and carbon footprint introduce significant challenges when scaling-up its production to meet the increasing H2 demands while prioritizing decarbonization. (2) Alternative low-carbon technologies, such as electrolysis, can mitigate these emissions, but currently are not economically competitive with traditional SMR. To address the challenges associated with the simultaneous scaleup and decarbonization of H2 technologies, the International Energy Agency (IEA) issued seven key recommendations, addressing H2’s role in long-term energy projects, its commercial demand, and the various production and transportation techniques. (1) An essential recommendation outlined the development of current production facilities for less costly and less carbon-intensive H2 production. An alternative IEA study outlines the latter statement by simulating and costing the decarbonization of SMR plants with various carbon capture and storage techniques. (2) The study showed significant capital and operating expenses tied to the integration of various carbon capture technologies. Therefore, addressing the second recommendation for less costly and efficient H2 production is essential to the simultaneous scaleup and decarbonization of SMR.

One particular development in SMR involves process intensification through H2 selective membrane reactors. (3) The continuous equilibrium shift, caused by the removal of H2, significantly increases the efficiency of the traditional reformer and shift reactors. The lower-temperature operation (450–650 °C) promotes a three-reaction system, shown in reactions 1–3, with methane steam reforming (MSR), water–gas shift (WGS), and the overall reaction (OVR)...

Hydrogen is almost entirely supplied from natural gas and coal today. Hydrogen is already with us at industrial scale all around the world, but its production is responsible for annual CO2 emissions equivalent to those of Indonesia and the United Kingdom combined. Harnessing this existing scale on the way to a clean energy future requires both the capture of CO2 from hydrogen production from fossil fuels and greater supplies of hydrogen from clean electricity.

Supplying hydrogen to industrial users is now a major business globally. Demand for hydrogen, which has grown more than threefold since 1975, continues to rise (Figure 1). Demand for hydrogen in its pure form is around 70 million tonnes per year (MtH2/yr). This hydrogen is almost entirely supplied from fossil fuels, with 6% of global natural gas and 2% of global coal going to hydrogen production.1 As a consequence, production of hydrogen is responsible for carbon dioxide (CO2) emissions of around 830 million tonnes of carbon dioxide per year (MtCO2/yr), equivalent to the CO2 emissions of Indonesia and the United Kingdom combined. In energy terms, total annual hydrogen demand worldwide is around 330 million tonnes of oil equivalent (Mtoe), larger than the primary energy supply of Germany.

Circulating fluidized beds (CFB) have attracted enormous interest in large-scale process industries like metallurgy, petrochemicals, and energy. (1) The CFBs have been widely used in combustion, catalytic cracking, and synthesis due to their benefits, including good heat and mass transfer performances, high efficiency in gas–solid contact, and status as a classic gas–solid contact reactor. In 1922 Winkler first used fluidized bed for coal gasification. The number of fluidized beds and circulating fluidized bed reactors has increased manifold over the past century. (2) In a reactor similar to a circulating fluidized bed, the structure of the gas–solid flow affects heat, mass, momentum transfer, and particle residence time. These variables directly affect the reaction rate and yield while also regulating the overall performance of the reactor. When the solid particles are distributed evenly, the overall efficiency of the riser is increased. However, most of the CFB operates at a high solids circulation rate and low gas flow rate, which causes both axial and radial uniformity of solid concentration. (3) Gas–solid flow in a riser can have distinct radial and axial flow structures based on gas flow rate, solid flux, and riser geometry. In general, axial flow structures are described as having a dense bottom region, a diluted upper section, and a transition region in between them. Based on the exit geometry of the riser, a relatively dense region can occasionally be seen at the top.

Most of the solid velocity data are reported in the literature (4?10) at the middle section or fully developed section of the riser. Some researchers (11?14) have investigated the influence of the outlet configuration on the flow pattern in CFBs using computational fluid dynamics (CFD). De Wilde et al. (13) have reported that strong restrictions on outlet geometry can alter flow patterns throughout the riser. The exit effect, however, is only visible in the immediate proximity of the outlet section in no-restricted outlet configurations...

...Detailed experimental setup configuration has been presented already in previously published (9,19) works for the middle section and residence time distribution (RTD) measurements. The radioactive particle tracking (RPT) technique is used to track the motion of the solid phase. In the current experiment, a tracer particle made of the high-energy 46Sc isotope is doped in a glass bead of the same size as the bed material used as the solid phase. Ten scintillation (NaI) detectors are installed strategically around the riser’s bottom section from 30 to 80 cm. Details of detector positions are provided in the Supporting Information section, Table S1...