Anthropogenic influences significantly modify the hydrochemical properties and material flow in riverine ecosystems across Asia, potentially accounting for 40–50% of global emissions. Despite the ...pervasive impact on Asian rivers, there is a paucity of studies investigating their correlation with carbon dioxide (CO2) emissions. In this study, we computed the partial pressure of CO2 (pCO2) using the carbonate equilibria-based model (pCO2SYS) and examined its correlation with hydrochemical parameters from historical records at 91 stations spanning 2013–2021 in the Ganga River. The investigation unveiled substantial spatial heterogeneity in the pCO2 across the Ganga River. The pCO2 concentration varied from 1321.76 μatm, 1130.98 μatm, and 1174.33 μatm in the upper, middle, and lower stretch, respectively, with a mean of 1185.29 μatm. Interestingly, the upper stretch exhibited elevated mean pCO2 and FCO2 levels (fugacity of CO2: 3.63 gm2d−1) compared to the middle and lower stretch, underscoring the intricate interplay between hydrochemistry and CO2 dynamics. In the context of pCO2 fluctuations, nitrate concentrations in the upper segment and levels of biological oxygen demand (BOD) and dissolved oxygen (DO) in the middle and lower segments are emerging as crucial explanatory factors. Furthermore, regression tree (RT) and importance analyses pinpointed biochemical oxygen demand (BOD) as the paramount factor influencing pCO2 variations across the Ganga River (n = 91). A robust negative correlation between BOD and FCO2 was also observed. The distinct longitudinal patterns of both parameters may induce a negative correlation between BOD and pCO2. Therefore, comprehensive studies are necessitated to decipher the underlying mechanisms governing this relationship. The present insights are instrumental in comprehending the potential of CO2 emissions in the Ganga River and facilitating riverine restoration and management. Our findings underscore the significance of incorporating South Asian rivers in the evaluation of the global carbon budget.
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•PCO2 concentration higher in upstream region than downstream region of Ganges.•Nitrate predict pCO2 well in upstream region.•BOD and DO are best predictors of pCO2 in downstream regions.•BOD emerged as a crucial influencing factor for pCO2 across the Ganga River.
Purpose
Producing biochar from forest residues can help resolve environmental issues by reducing forest fires and mitigating climate change. However, transportation and storage of biomass to a ...centralized facility are often cost-prohibitive and a major hurdle for the economic feasibility of producing biobased products, including biochar. The purpose of this study was to evaluate the environmental impacts and economic feasibility of manufacturing biochar from forest residues with small-scale portable production systems.
Methods
This study evaluated the environmental performance and economic feasibility of biochar produced through three portable systems (biochar solutions incorporated (BSI), Oregon Kiln (OK), and air curtain burner (ACB)) using forest residues in the United States (US). Cradle-to-grave life-cycle assessment (LCA) and techno-economic analysis (TEA) were used to quantify environmental impacts and minimal selling price (MSP) of biochar respectively considering different power sources, production sites, and feedstock qualities.
Results and discussions
The results illustrated that the global warming (GW) impact of biochar production through BSI, OK, and ACB was 0.25–1.0, 0.55, and 0.61-t CO
2
eq/t biochar applied to the field, respectively. Considering carbon-sequestration, 1-t of biochar produced with the portable system at a near-forest site and applied to the field reduced the GW impact by 0.89–2.6 t CO
2
eq. For biochar production, the environmental performance of the BSI system improved substantially (60–70%) when it was powered by a gasifier-based generator instead of a diesel generator. Similarly, near-forest(off-grid) biochar production operations performed better environmentally than the operations at in-town sites due to the reduction in the forest residues transportation emissions. Overall, the net GW impact of biochar produced from forest residues can reduce environmental impacts (i.e., 1–10 times lower CO
2
eq emissions) compared with slash-pile burning. The MSP per tonne of biochar produced through BSI, OK, and ACB was $3,000–$5,000, $1,600, and $580 respectively considering 100 working days per year. However, with improved BSI systems when allowed to operate throughout the year, the MSP can be reduced to below $1000/t of biochar. Furthermore, considering current government grants and subsidies (i.e.,$12,600/ha for making biochar production from forest residues), the MSP of biochar can be reduced substantially (30–387%) depending on the type of portable system used.
Conclusion
The portable small-scale production systems could be environmentally beneficial and economically feasible options to make biochar from forest residues at competitive prices given current government incentives in the US where excess forest biomass and forest residues left in the forest increase the risk of forest fires.
The current work investigates various bimetallic catalysts supported on Al2O3−Zn−ZrO2 to determine a catalyst with minimal CO selectivity at high temperature for methanol steam reforming. ...Characterization tools employed in this study include temperature programmed reduction, X‐ray diffraction, X‐ray photoelectron spectroscopy and transmission electron microscopy. Activity testing for all the catalysts synthesized were performed in the temperature range of 150 to 500 °C. Bimetallic catalyst with addition of Fe as second metal to Cu in 50 : 50 molar ratio was observed with an interesting synergy which resulted in reduced particle size and enhanced reducibility. It was further observed that Cu−Fe with lower Fe content and up to 75 % Cu led to zero CO selectivity for temperature up to 450 °C. A structure‐activity relationship of Cu−Fe/Al2O3−Zn−ZrO2 was therefore elucidated. Further, reaction mechanism for the same was also proposed based on in‐situ diffuse reflectance infrared Fourier transform spectroscopy.
Metal‐metal and metal support interaction in Cu−Fe at 50 : 50 to 75 : 25 molar ratios supported on Al2O3−Zn−ZrO2 was found optimal for CO free hydrogen generation using methanol steam reforming. Presence of CuFe2O4 spinel in this catalyst promotes high water‐gas shift activity that resulted in no detectable CO in the reformate up to 450 °C.
Membrane reactors are a potential tool to produce high purity hydrogen on-site but sufferfrom immense losses in hydrogen recovery under reaction conditions. For high-temperature operations, these ...losses mostly occur due to the presence of lesser permeable gases in the reformate that develop into a concentration polarization barrier around the membrane. Based on our previous findings, a multi-pass design was manifested to alleviate hydrogen losses through the membrane tested with synthetic gas mixtures. The same design is currently employed to establish improvement in hydrogen recovery under reaction conditions. Having a catalyst and membrane integrated into a single unit termed as a membrane reactor, its performance is optimized with varying membrane assembly and catalyst bed configurations. This study shows that a packed bed multi-pass membrane reactor is an optimal design to target high hydrogen recovery. Further, multi-pass membrane reactor design also improves the hydrogen recovery in fluidized bed operations which opens immense scope for future studies.
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•Methanol fed membrane reactor in a multi-pass reactor design is presented.•Multi-pass reduces concentration polarization barrier effect on hydrogen permeation.•Optimal membrane-gas contacting with multi-pass design improves hydrogen recovery.•Optimally designed packed bed membrane reactor showed best performance.•Multi-pass membrane reactor design improves hydrogen recover.
Although the adoption of Internet-of-Things (IoT) in various business contexts has been prevailing, and the benefits of such adoption are well-established, IoT adoption in port logistics is still not ...very prominent. This article aims to explore the success factors for IoT adoption in port logistics and how these factors play different roles depending on the port-type and domain of the managers. We classify the factors based on the technological-organizational-environmental framework and calculate their relative weights using fuzzy analytic network process. We develop a hierarchical framework using total interpretative structuring modeling for identifying the relationships among the factors, and perform Matrice Impacts Croisés Multiplication Appliqués à un Classement analysis to derive the driving power and dependence power of the factors. This deeper understanding of the factors is important for the ports and the IoT service providers to ensure successful IoT adoption. For example, while technological readiness is identified as the most significant factor, sustainability and globalization drive IoT adoption through optimal utilization of infrastructure and investment. Furthermore, we show that the factor scores and their inter-relationships vary depending on the type of port and the domain of the managers, suggesting that one strategy would not fit all in the context of IoT adoption. These findings will also assist policymakers promoting maritime transport and port management to develop strategies to achieve the requirements of Industry 4.0.
The Letter reports a hybrid (i.e. organic-inorganic) perovskite CH 3 NH 3 PbI 3 and inorganic only perovskite BiFeO 3 based heterojunction diode for near-infrared detection applications. The hybrid ...halide CH 3 NH 3 PbI 3 is synthesized by using sol-gel chemical route while the BiFeO 3 is synthesized by using a solid-state route. A layer of uniformly distributed BiFeO 3 thin film is first grown on an indium doped tin oxide (ITO) coated glass substrate using BiFeO 3 nanoparticles with an average size of ~65 nm. Then, CH 3 NH 3 PbI 3 nanoparticles of average size ~45 nm with a tetragonal phase are deposited BiFeO 3 film for fabricating the heterojunction device under study. The photoresponse is measured by using a monochromatic light over the wavelengths from 400 to 900 nm. The device shows a dual-band photoresponsivity originated from the individual absorption characteristics of BiFeO 3 and CH 3 NH 3 PbI 3 perovskites used for the heterojunction. The proposed photodetector shows the maximum responsivity of ~2 A/W at 800 nm for 2 V bias while the detectivity is estimated as <inline-formula> <tex-math notation="LaTeX">\sim {7.8}\times {10}^{{12}} </tex-math></inline-formula> cmHz 1/2 /W. The photodetector has a reasonably good photoresponse with a rise time and fall time of 0.74 s and 0.088 s, respectively.
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•Self-supported Pd-Ag performance as separator was compared with membrane reformer.•No significant inhibition of CO, CO2 and steam was observed at 673K and 3bar.•Flux and H2 purity ...for both systems were found comparable.•At optimized conditions, membrane reformer performance is equivalent to separator.
Integration of methanol steam reforming with hydrogen selective dense Pd-Ag membranes makes membrane reformers compact and efficient for ‘on-board’ hydrogen generation. However, hydrogen permeation through standalone dense Pd-Ag membranes is largely reported to be limited by gas mixtures such as CO, CO2 and steam. These gas mixtures are also basic constituents of methanol reformate with approximately 60% hydrogen by mole. Therefore, it is mostly assumed that such gas inhibition behavior would significantly affect membrane reformer performance. Apparently, this assumption is not valid until a comparison is made under similar experimental conditions for the same membrane. Using 100µm thick self-supported dense Pd-Ag membrane, the current work compares the performance of membrane reformer with membrane separator under similar operating conditions. By definition, membrane separator is principally a purifier which is used to separate hydrogen from various components such as CO2, H2O, CH4 and CO. On the other hand, membrane reformer is a system which generates hydrogen from a reaction such as steam reforming and simultaneously separates it using membranes, integrated in the same physical device. In this study, membrane reformer performance was optimized with effect of steam/methanol ratio, temperature and pressure. Under optimal conditions, synthetic gases of similar composition as of produced reformate were used to evaluate membrane separator performance. No significant inhibition was observed due to CO, CO2 and steam at optimal temperature 673K and pressure 3bar. Presence of excess steam however dilutes the hydrogen partial pressure in reformate which reduced hydrogen flux. Comparison of membrane reformer vs. membrane separator further showed equivalent flux as well as high hydrogen purity indicating a good feasibility of these systems to be tested further for pilot scale studies.
Cells regularly synthesize new proteins to replace old or damaged proteins. Deposition of various aberrant proteins in specific brain regions leads to neurodegeneration and aging. The cellular ...protein quality control system develop various defense mechanisms against the accumulation of misfolded and aggregated proteins. The mechanisms underlying the selective recognition of specific crucial protein or misfolded proteins are majorly governed by quality control E3 ubiquitin ligases mediated through ubiquitin-proteasome system. Few known E3 ubiquitin ligases have shown prominent neurodevelopmental functions, but their interactions with different developmental proteins play critical roles in neurodevelopmental disorders. Several questions are yet to be understood properly. How E3 ubiquitin ligases determine the specificity and regulate degradation of a particular substrate involved in neuronal proliferation and differentiation is certainly the one, which needs detailed investigations. Another important question is how neurodevelopmental E3 ubiquitin ligases specifically differentiate between their versatile range of substrates and timing of their functional modulations during different phases of development. The premise of this article is to understand how few E3 ubiquitin ligases sense major molecular events, which are crucial for human brain development from its early embryonic stages to throughout adolescence period. A better understanding of these few E3 ubiquitin ligases and their interactions with other potential proteins will provide invaluable insight into disease mechanisms to approach toward therapeutic interventions.
Cancer is characterized by persistent cell proliferation driven by aberrant cell cycle regulation and stimulation of cyclin-dependent kinases (CDKs). A very intriguing and potential approach for the ...development of antitumor medicines is the suppression of CDKs that lead to induction of apoptosis and cell cycle arrest. The shift of the cell cycle from the G0/G1 phase to the S phase, which is characterized by active transcription and synthesis, depends on the development of the cyclin D-CDK4/6 complex. A precise balance between anticancer activity and general toxicity is demonstrated by CDK inhibitors, which can specifically block CDK4/6 and control the cell cycle by reducing the G1 to S phase transition. CDK4/6 inhibitors have recently been reported to exhibit significant cell growth inhibition via modulating the tumour microenvironment in cancerous cells. One significant new understanding is that these inhibitors serve important functions in the interaction among tumour cells and the host immune system in addition to being cytostatic. Herein, we discuss the biological significance of CDK4/6 inhibitors in cancer therapeutics, as well as their biological impact on T cells and other important immune cells. Furthermore, we explore the integration of preclinical findings of these pharmaceuticals' ability to enhance antitumor immunity.
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