The hydrogen evolution reaction (HER) is a crucial step in electrochemical water splitting and demands an efficient, durable and cheap catalyst if it is to succeed in real applications. For an ...energy-efficient HER, a catalyst must be able to trigger proton reduction with minimal overpotential and have fast kinetics. The most efficient catalysts in acidic media are platinum-based, as the strength of the Pt-H bond is associated with the fastest reaction rate for the HER. The use of platinum, however, raises issues linked to cost and stability in non-acidic media. Recently, non-precious-metal-based catalysts have been reported, but these are susceptible to acid corrosion and are typically much inferior to Pt-based catalysts, exhibiting higher overpotentials and lower stability. As a cheaper alternative to platinum, ruthenium possesses a similar bond strength with hydrogen (∼65 kcal mol
), but has never been studied as a viable alternative for a HER catalyst. Here, we report a Ru-based catalyst for the HER that can operate both in acidic and alkaline media. Our catalyst is made of Ru nanoparticles dispersed within a nitrogenated holey two-dimensional carbon structure (Ru@C
N). The Ru@C
N electrocatalyst exhibits high turnover frequencies at 25 mV (0.67 H
s
in 0.5 M H
SO
solution; 0.75 H
s
in 1.0 M KOH solution) and small overpotentials at 10 mA cm
(13.5 mV in 0.5 M H
SO
solution; 17.0 mV in 1.0 M KOH solution) as well as superior stability in both acidic and alkaline media. These performances are comparable to, or even better than, the Pt/C catalyst for the HER.
This paper proposes a multi-objective evolutionary algorithm (MOEA)-based task scheduling approach for determining Pareto optimal solutions with simultaneous optimization of performance ( P ), energy ...( E ), and temperature ( T ). Our algorithm includes problem-specific solution encoding, determining the initial population of the solution space, and the genetic operators that collectively work on generating efficient solutions in fast turnaround time. Multiple schedules offer a diverse range of values for makespan, energy consumed, and peak temperature and thus present an efficient way of identifying trade-offs among the desired objectives, for a given application and machine pair. We also present a methodology for selecting one solution from the Pareto front given the user's preference. The proposed algorithm for scheduling tasks to cores achieves three-way optimization with fast turnaround time. The proposed algorithm is advantageous because it reduces both energy and temperature together rather than in isolation. We evaluate the proposed algorithm using implementation and simulation, and compare it with integer linear programming as well as with other scheduling algorithms that are energy- or thermal-aware. The time complexity of the proposed scheme is considerably better than the compared algorithms.
Hydrogen adsorption/desorption behavior plays a key role in hydrogen evolution reaction (HER) catalysis. The HER reaction rate is a trade-off between hydrogen adsorption and desorption on the ...catalyst surface. Herein, we report the rational balancing of hydrogen adsorption/desorption by orbital modulation using introduced environmental electronegative carbon/nitrogen (C/N) atoms. Theoretical calculations reveal that the empty d orbitals of iridium (Ir) sites can be reduced by interactions between the environmental electronegative C/N and Ir atoms. This balances the hydrogen adsorption/desorption around the Ir sites, accelerating the related HER process. Remarkably, by anchoring a small amount of Ir nanoparticles (7.16 wt%) in nitrogenated carbon matrixes, the resulting catalyst exhibits significantly enhanced HER performance. This includs the smallest reported overpotential at 10 mA cm
(4.5 mV), the highest mass activity at 10 mV (1.12 A mg
) and turnover frequency at 25 mV (4.21 H
s
) by far, outperforming Ir nanoparticles and commercial Pt/C.
Despite ample evidence of increasing research misconduct in India, little attention has been paid to understanding researchers' perception of research integrity and research misconduct among young ...Indian researchers. Interviews among 30 research scholars were conducted at Pondicherry University in India to understand their experience and perception of research misconduct. The top three influencing factors for scientific misconduct, according to the participants, were unavailability of adequate funds (35%), pressure from research supervisors (29%), and desperation to publish articles (25%). The participants had witnessed research misconduct in different forms i.e., data fabrication, falsification, and plagiarism. However, plagiarism was the most often cited cause of misbehavior in our interviews. Majority of participants have witnessed or personally encountered multiple instances where authorship conflicts occurred. The other questionable research practices highlighted in the study were improper citations, authorship disputes like gift and ghost authorships, misrepresentation of statistical data, failure to publish negative results. In an increasingly diverse and changing research environment, our research calls for practical research guidelines based on honesty, openness, and accountability that can help articulate and strengthen scientists' core values. More importantly, scientific misconduct can only be prevented by using a multifaceted strategy that includes identifying instances of scientific misconduct and implementing suitable deterrents and treatments that could change the behavior associated with such misconduct.
Agriculture plays an important role in a country’s economy. The sector is challenged by many stresses, which led to huge loss in plant productivity worldwide. The ever-increasing population, rapid ...urbanization with shrinking agricultural lands, dramatic change in climatic conditions, and extensive use of agrochemicals in agricultural practices that caused environmental disturbances confront mankind of escalating problems of food security and sustainability in agriculture. Escalating environmental problems and global hunger have led to the development and adoption of genetic engineering and other conventional plant breeding approaches in developing stress-tolerant varieties of crops. However, these approaches have drawn flaws in their adoption as the process of generating tolerant varieties takes months to years in bringing the technology from the lab to the field. Under such scenario, sustainable and climate-smart agricultural practices that avail bacterial usage open the avenues in fulfilling the incessant demand for food for the global population. Ensuring stability on economic fronts, bacteria minimizes plant salt uptake by trapping ions in their exopolysaccharide matrix besides checking the expression of Na
+
/H
+
and high-affinity potassium transporters. Herein we describe information on salinity stress and its effect on plant health as well as strategies adopted by plant growth-promoting rhizobacteria (PGPR) in helping plants to overcome salinity stress and in mitigating loss in overall plant productivity. It is believed that acquisition of advanced knowledge of plant-beneficial PGPR will help in devising strategies for sustainable, environment-friendly, and climate-smart agricultural technologies for adoption in agriculture to overcome the constrained environmental conditions.
Herein, we report a green and efficient synthetic route for the construction of diverse functionalized coumarins in good-to-excellent yields (60–98%) via the Pechmann condensation. The optimized ...synthetic route involves a biodegradable, reusable, and inexpensive deep eutectic solvent (DES) of choline chloride and l-(+)-tartaric acid in a ratio of 1:2 at 110 °C. Interestingly, phloroglucinol and ethyl acetoacetate, upon reaction, furnished the functionalized coumarin (20) in 98% yield within 10 min. On the other front, the same DES at relatively lower reaction temperature (90 °C) was found to provide the bis-coumarins in decent yields (81–97%) within 20–45 min. Moreover, this particular method was found to be quite effective for large-scale coumarin synthesis without noteworthy reduction in the yields of the desired products. Noticeably, in this versatile approach, the DES plays a dual role as solvent as well as catalyst, and it was effectively recycled and reused four times with no significant drop-down in the yield of the product.
The quest for receptors endowed with the selective complexation and detection of negatively charged species continues to receive substantial consideration within the scientific community worldwide. ...This study is encouraged by the utilization of anions in nature in a plethora of biological systems such as chloride channels and proteins and as polyanions for genetic information. The molecular recognition of anionic species is greatly interesting in terms of their favourable interactions. In this comprehensive review, in addition to giving accounts of some selected syntheses, we illustrated diverse applications ranging from molecular containers to ion transporters and drug carriers of a supramolecular receptor named calix4pyrrole. We believe that the present review may act as a catalyst in enhancing the novel applications of calix4pyrrole and its congeners in the other dimensions of science and technology.
The quest for receptors endowed with the selective complexation and detection of negatively charged species continues to receive substantial consideration within the scientific community worldwide.
The current study aimed to explore some important insights into the breast cancer mortality (BCM) trends and projections among four Asian countries by using five advanced stochastic mortality models. ...BCM data over 28 years from 1990-2017 with ages 20-84 were retrieved from the Global Burden of Disease (GBD) Study 2017 for four Asian countries, namely, China, India, Pakistan, and Thailand. Five stochastic mortality models with the family of generalized age-period-cohort were implemented to find the present and future BCM trends in these four Asian countries. Based on Cairns-Blake-Dowd (CBD) model and Lee-Carter model (LCM), overall, results revealed that BCM increased with the passage of time. Aging factor was the most influential factor of elevated BCM in each Asian country under consideration. Projection of BCM showed that mortality rates might continue to grow with time, especially in older ages in each Asian country under study. The highest forecasted BCM rates were observed in Pakistan as compared to other countries. The obvious increase in BCM suggested that earlier tactics should be implemented to reduce the subsequent morbidity and mortality due to breast cancer. The last but not least, some additional tactics to mitigate the BCM in older ages must be adopted.
Developing efficient and durable electrocatalysts is key to optimizing the electrocatalytic hydrogen evolution reaction (HER), currently one of the cleanest and most sustainable routes for producing ...hydrogen. Here, a unique and efficient approach to fabricate and embed uniformly dispersed Ir nanoparticles in a 3D cage‐like organic network (CON) structure is reported. These uniformly trapped Ir nanoparticles within the 3D CON (Ir@CON) effectively catalyze the HER process. The Ir@CON electrocatalyst exhibits high turnover frequencies of 0.66 and 0.20 H2 s−1 at 25 mV and small overpotentials of 13.6 and 13.5 mV while generating a current density of 10 mA cm−2 in 0.5 m H2SO4 and 1.0 m KOH aqueous solutions, respectively, as compared to commercial Pt/C (18 and 23 mV) and Ir/C (20.7 and 28.3 mV). More importantly, the catalyst shows superior stability in both acidic and alkaline media. These results highlight a potentially powerful approach for the design and synthesis of efficient and durable electrocatalysts for HER.
Encapsulating iridium nanoparticles inside a 3D cage‐like organic network, the prepared catalyst (Ir@CON) is evaluated as an efficient and durable electrocatalyst for the hydrogen evolution reaction. This new study should provide insights to guide the design and development of materials for future organic and hybrid materials for electrocatalysis.
Polybrominated diphenyl ethers (PBDEs) are synthetic brominated flame retardants with extensive applications in daily-life consumer products. However, PBDEs have become ubiquitous environmental ...contaminants due to their leach-out capability. The hazardous human health effects and endocrine-disrupting activity of PBDEs have led many governmental organizations to impose ban on their manufacture, causing their gradual phase out from commercial products. However, PBDEs and their metabolites are still being detected from biological and environmental samples owing to their persistence and bioaccumulation. The PDBE metabolites in these samples are present in concentrations often higher and even with higher toxic potential than parent PBDEs. The two commonly detected environmental PBDE congeners, 2,2′,4,4′-tetra-bromodiphenyl ether (BDE-47) and 2,2′,4,4′,5-penta-bromodiphenyl ether (BDE-99), and their HO- and MeO- metabolites were considered in this study for their potential disrupting activity on thyroid hormone transport. Specifically, the study involved structural binding characterization of BDE-47 and BDE-99 including their two HO- and two MeO- metabolites with thyroxine-binding globulin (TBG), which is the main thyroid hormone transport protein in blood. The results showed that the binding pattern and molecular interactions of above two PBDEs and their metabolites exhibited overall similarity to native ligand, thyroxine in dock score, binding energy, and amino acid interactions with TBG. The BDE-99 and its metabolites were predicted to have stronger binding to TBG than BDE-47 with the metabolite 5-MeO-BDE-99 showing equal binding affinity to that of thyroxine. It is concluded that BDE-47 and BDE-99 and their metabolites have the potential to disrupt thyroid hormone transport and interfere in thyroid function.
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![New dimensions in calix[4]p...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2046-2069/small "New dimensions in calix[4]pyrrole: the land of opportunity in supramolecular chemistry")
