Relevant Applications Research Articles

SO3 removal characteristics from flue gas of FCC regeneration process by activated carbon modified red mud adsorbent

Sulfur trioxide (SO3) is one of the major air pollutants in the flue gas of Fluid catalytic cracking (FCC) units during the regeneration process in refineries. However, it is difficult to remove SO3 with the existing desulfurization systems. Nowadays, alkaline adsorbent spraying technology has been a promising method to remove SO3. However, there is no relevant application research in the field of FCC regeneration flue gas. Therefore, in this paper, The SO3 removal characteristics from FCC flue gas by activated carbon modified red mud adsorbent were studied, including modification method, reaction temperature and flue gas components. Combined with characterization analysis of adsorbents, the mechanism of SO3 removal was studied. It was found that when the AC mass ratio is 10% and modification temperature is 400 ℃, the best LBRMAC adsorbent was achieved. When particle size is 0.096–0.125 mm and reaction temperature is 400 ℃, the highest SO3 adsorption efficiency is up to 83.4%. The addition of NO has little influence on the adsorption efficiency of SO3. The addition of SO2 leads to competitive adsorption between SO3 and SO2, resulting in a rapid decline in the removal efficiency of SO3. Meanwhile, the characterization analysis proves that the SO3 adsorption process mainly include chemical kinetics control stage and product layer diffusion stage.

A Versatile Surrogate Model of the Power Distribution Grid Described by a Large Number of Parameters

This paper aims to present a general-purpose Surrogate Model for the probabilistic analysis of power distribution grids with a large number of input parameters. The distinctive feature of the novel technique is the employment of the partial derivatives of output variables versus input parameters to tame the “curse of dimensionality” problem exhibited by prior surrogate model calculation techniques. The second important feature of the proposed Surrogate Model method is that it does not require any a priori assumption about the nature or statistical distribution of the input parameters. In fact, it can be applied whenever design parameters are deterministic variables as well as when they are uncertain and represented by continuous and/or discrete random variables. Relevant applications presented in the paper refer to the probabilistic analysis of the distribution grid in the presence of a large number of photovoltaic sources and electric vehicle charging stations.

Biosynthesis of metal nanoparticles: Bioreduction and biomineralization

Abstract The biosynthesis of metal nanoparticles by plants, bacteria, and cells has been receiving considerable attention in recent years. The traditional synthesis of metal nanoparticles always needed high temperatures, high pressure, and toxic agents. However, the biosynthesis process (including bioreduction and biomineralization) is simpler, safe, economical, and green. The process of biosynthesis can insulate toxic agents, streamline flux, increase the transition efficiency of interactants, and improve the product yield. The biosynthesized metal nanoparticles share similar characteristics with traditional ones, serving as photosensors to achieve light-to-heat/energy transduction, or a drug delivery system. The biosynthetic metal nanoparticles thus could be widely applied in the medical field for disease diagnosis and treatment. It contributed a novel modality for the facile and green synthesis of metal nanoparticles. Increasing studies have been exploring the mechanism for the biosynthesis of metal nanoparticles, devoted to a controllable biosynthesis process. Combined with our previous studies on the biosynthesis of gold nanoparticles with green tea, tumor cells, and cell components, we reviewed the green methods of bioreduction and biomineralization of metal nanoparticles including the internal mechanism, aimed to make a comprehensive introduction to the biosynthesis of metal nanoparticles and relevant biomedical applications, and inspired further research.

Recent Advances in Computational Convective Heat Transfer Study in a Sub-Channel for Nuclear Power Reactor and Future Directions

A nuclear power reactor's primary use is to generate thermal energy, which in turn produces electricity. The primary heat source is a nuclear fission event occurring inside the fuel rod. The convection heat is transmitted through the coolant by the heat energy generated at the fuel rod wall boundary. Better heat transfer is produced in the flow area by turbulence and irregularity. As a result, turbulent flow heat transfer may present a significant challenge when predicting and assessing the thermal performance of nuclear power reactors. Computational techniques in convective heat transfer have become indispensable for solving challenging issues in the fields of science and engineering thanks to the development of current sophisticated numerical methods and high-performance computer hardware. The development of novel computational techniques and models for complicated transport and multi-physical phenomena is constantly in demand throughout applicable disciplines. This chapter's objective is to provide some recent developments in computational techniques for convective heat transfer, taking into account research interests in the community of mass and heat transfer, and to showcase relevant applications in nuclear power plant engineering domains including future directions. This study describes the most recent advancements in nuclear reactor convective heat transfer research utilizing the computational fluid dynamics (CFD) method, particularly at Ansys Fluent. This work examines the convective heat transfer and fluid dynamics fluid dynamics for turbulent flows across three rod bundle sub-channels that are typical of those employed in the PWR-based VVER type reactor. In this paper, CFD analysis is carried out using the software tool Ansys Fluent. Temperature distribution profile, velocity profile, pressure drop, and turbulence properties were investigated in this study. Boundary conditions i.e. temperature, velocity, pressure, heat flux, and heat generation rate were applied in the sub-channel domain. The main obstacles and bright spots for the CFD methods in nuclear reactor engineering are discussed, which helps to further its further uses. We intend to research a full-length fuel bundle model for VVER-1200 in the future to gather specific fluid characteristic data and use the findings to analyze safety and operate nuclear power facilities in Bangladesh. This paper presents a thorough analysis of the sub-channel thermal hydraulic codes used in nuclear reactor core analysis. This review discusses several facets of previous experimental, analytical, and computational work on rod bundles and identifies potential future directions based on those earlier studies.

50 Years of uranium isotopic reference materials at JRC-Geel

The history of uranium isotopic reference materials from JRC-Geel during the last 50 years is reviewed by presenting certification methods and relevant applications. The certified isotope ratios are traceable to the SI via gravimetrical preparation, either directly through gravimetrical mixing of highly enriched materials, or indirectly using existing gravimetrically prepared reference materials for calibration of mass spectrometers used for certification measurements. Due to developments of mass spectrometers and analytical methods, certification measurements have improved regarding precision, uncertainties and accuracy. This has led to a comprehensive set of uranium isotopic reference materials available for nuclear safety, security and the scientific community.

Composite heterojunction of BiFeO3 and CdS: A photocathode for promoting efficient decomposition of water using piezoelectric photoelectrocatalysis

BiFeO3 has excellent potential as a narrow band gap semiconductor and piezoelectric material for photoelectrochemical decomposition of water (PEC) applications. However, because of its susceptibility to impurities and oxygen vacancy defects during preparation and its high complexation rate of photogenerated carriers, relevant applications are greatly limited. In this paper, BiFeO3/CdS heterojunction films were prepared on FTO conductive glass by a very simple and feasible sol-gel and chemical bath method to improve the efficiency of the photoelectrochemical decomposition of water. It was shown based on a series of PEC tests. The photocurrent density of the pure BiFeO3 thin film photocathode reached −85 μA/cm2 after giving ultrasonic stress conditions. Furthermore, the BiFeO3/CdS heterojunction photocathode achieved a photocurrent density of about −230 μA/cm2 at 0 V vs. RHE under the synergistic effect of piezoelectric polarization and the built-in electric field built in the heterostructure. In summary, semiconductor modification approaches using the construction of suitable heterojunction structures can effectively promote the separation and transfer of carriers between interfaces. The use of piezoelectric polarization and the search for appropriate energy level-matched semiconductors to construct heterojunctions can synergistically improve the efficiency of piezoelectric photocatalysis.

An advanced cement-based geocomposite with autonomous sensing and heating capabilities for enhanced intelligent transportation infrastructure

This study introduces an innovative multifunctional cementitious-based geocomposite with self-sensing and self-heating capability, generated for transportation infrastructural health monitoring and traffic recognition. In this route, hybrid graphene nanoplatelets (GNP) and carbon nanotubes (CNT) were uniformly dispersed within a matrix of stabilized sand containing 10% cement. The mechanical and microstructural performances of the composite were examined using various tests. The self-sensing capabilities of the composite were also investigated. In addition, the effects of temperature, moisture content, and loading shape, speed and magnitudes on the strain and stress sensing capability of the specimens were also investigated. The self-sensing performance of this cementitious geocomposite for the asphalt layer strain detection was assessed in a hybrid section including the asphalt mixture layer and smart geocomposite. Moreover, the research also examined the composite's capacity for self-heating, a highly relevant application within the transportation sector. The 0.98 ˚C/s heating rate, 526 mW/˚C heating power, and 251 ˚C maximum temperature proved the high heating potential of this geocomposite for deicing, self-healing, and temperature sensing applications. The specimens showed a supreme correlation between strain changes and fractional changes in electrical resistance (FCR) values in different loading patterns. Although increasing temperature amplified the piezoresistivity response of the composite, the introduction of humidity had adverse impacts. An appropriate correlation was observed between gauge factor, modulus, and digital image correlation analysis. The piezoresistive response of this geocomposite in the hybrid section including smart geocomposite and asphalt layer, representative of the common structural layers of urban pavements, showed the ability of this geocomposite in terms of strain and stress detection of itself and even in the asphalt layer. This study provides a bright horizon for smart materials development in civil infrastructures, particularly transportation and railways.

Digital transformation of college teacher education from the perspective of behaviorist psychology: initiatives, effectiveness and pitfalls

Abstract Behaviorist psychology can deeply reflect the perception of digital technology in teacher education in colleges and universities, and the digital transformation of teacher education is an effective path to improve the quality of education. Based on the TAM model, this paper analyzes the factors affecting the digital transformation of teacher education in colleges and universities, selects the relevant variables for research hypotheses, and obtains the relevant data for empirical analysis through questionnaires. In order to deeply analyze the initiatives, effectiveness and hidden worries brought about by the digital transformation of college teacher education from the perspective of behaviorist psychology, the combination of factor analysis and principal component analysis is used to carry out the extraction of common factors, which provides the basis for analyzing the factor loading coefficients of the influencing factors of digital transformation. The validity of the method was assessed using various methods, including descriptive statistics, reliability and validity tests, and structural equation modeling path fitting. The results show that the absolute values of skewness and kurtosis of the survey data in this paper are less than 1, which is in line with normal distribution, and the value of Cronbach’s Alpha coefficient of the reliability test is basically above 0.9, and the standardized factor loading coefficients are greater than 0.6. The direct effect of behavioral imagery on the actual application is 0.448, resulting in a significant difference at the 1% level. The digital transformation of teacher education in higher education needs to pay attention to the relevant applications of external environment and media technology so as to realize the improvement of the quality of teacher education in higher education.

Development of Electrochemical Paper-Based Devices for Field Assays

The birth of the modern field of paper-based analytical devices (PADs) was marked by the pioneering work by the Whitesides’ group which demonstrated that it was possible to perform complex manipulation of liquids within hydrophilic paper channels delimited by hydrophobic barriers [1]. The key features of paper as a platform are: a) flexibility; b) low thickness and lightness; c) absorbency; d) high surface-to-volume ratio; e) hydrophilicity and capillary action; f) chemical and biological inertness; g) disposability and biodegradability, and; h) low cost and wide availability. Among the various detection modes that are compatible with PADs, electrochemical detection is very attractive since electrochemical transducers can be readily and rapidly patterned on paper using various approaches. Combined with low-cost and portable instrumentation, electrochemical PADs (ePADs) are well suited to on-site assays and point-of-care testing and relevant applications have been developed in various fields such as clinical diagnostics, environmental monitoring and food quality control [2-4].The methods of patterning of the hydrophobic barriers and of depositing the electrodes are critical in the fabrication of ePADs and several approaches have been proposed in the literature [2-4]. Τhe aim of this work was the development of different approaches for the fabrication of ePADs. For this purpose, hydrophobic barriers were delimited using: x-y plotting with commercial hydrophobic marker pens, wax printing and thermal printing. Electrodes were deposited on the PADs using x-y plotting with commercial writing pencils and conductive inks formulated in-house and screen-printing. Different fabrication parameters were optimized including the selection of the paper substrate, the conditions for the formation of the hydrophobic barriers and the electrode deposition parameters. Applicability of the ePADs was demonstrated for different applications for on-site assays including the enzymatic amperometric detection of glucose, the determination of trace metals by stripping analysis and the voltammetric detection of organic compounds.

First Principles Modelling of Growth of Hybrid Organic-Inorganic Films

Hybrid organic-inorganic materials fabricated with molecular layer deposition (MLD) are a special class of materials that are attracting great interest in many economically and socially relevant technological applications due to their diphasic and tunable organic-inorganic structure. Despite the growing interest in these hybrid materials, knowledge around relevant precursor chemistries and reaction mechanisms, as well as details of many determined experimental results are unknown. Density functional theory (DFT) has proven to be a powerful tool to investigate and understand the atomic level details of the precursor chemistry and address aspects of the MLD experiments.In our work, we use first principles DFT calculations to examine key steps in the mechanism of hybrid film deposition through MLD by modelling precursor-surface and precursor-precursor reactions. We explore the growth mechanism of aluminium and titanium containing hybrid films, namely alucones and titanicones. Both materials are of high interest for passivation layers in batteries. For alucones we investigate in detail the chemistry of the MLD process between the post-trimethylaluminium (TMA) pulse methyl-terminated Al2O3 surface with aromatic compounds with hydroxy and/or amino groups as reactive groups: hydroquinone (HQ), 4-aminophenol (AP) and p-phenylenediamine (PD). Double reactions of HQ, AP and PDA with the Al2O3 surface are explored in detail to assist the interpretation of the experimental findings regarding the differences found for hybrid films grown with aromatic and aliphatic organic precursors. DFT calculations show that in contrast to aliphatic organics, an upright configuration will be present for HQ, AP and PD so that the molecules are self-assembled in an upright configuration, which leads to thicker hybrid films. We predict that aromatic molecules are the best choice for stable hybrid films and their chemistry can be manipulated without degrading stability. [1]We also investigate in detail the chemistry between the most common titanium precursors, namely titanium tetrachloride (TiCl4) and tetrakis(dimethylamido)titanium (Ti(DMA)4), and ethylene glycol (EG) and glycerol (GL) as the organic precursors for the fabrication of titanicone films. We analyse the impact of the substrate on the initial MLD reactions in titanicone film growth using three different surface models: anatase TiO2, rutile TiO2 and Al2O3. This work highlights the role of the phase of TiO2 and Ti-containing precursors in production of titanicone films and provides motivation to develop a new rutile TiO2 based hybrid film suggesting that the desired film growth, flexibility and stability can be achieved. [2][1] A. Muriqi, M. Karppinen and M. Nolan, Role of terminal groups in aromatic molecules on the growth of Al2O3-based hybrid materials, Dalton Transactions, 2021, 50, 17583-17593. doi.org/10.1039/D1DT03195C.[2] Arbresha Muriqi and Michael Nolan, “Role of Titanium and Organic Precursors in Molecular Layer Deposition of “Titanicone” Hybrid Materials”, Beilstein Journal of Nanotechnology, 2022, 13, 1240–1255. doi.org/10.3762/bjnano.13.103.

Investigating the Effects on Replacing Platinum by Molybdenum as Cathode Electrocatalysts in Proton Exchange Membrane Water Electrolysis

Water electrolysis coupled to renewable energy sources has become in a crucial technique for the green hydrogen production. Hydrogen economy is currently in the spotlight to solve energy demands due to its advantages such as clean, sustainable, low footprint, as well as high-power density which is 3 times above gasoline and diesel. To produce large quantities of hydrogen, proton exchange membrane water electrolysis (PEMWE) has arisen as a promising system to solve hydrogen demands. The heart of the PEMWE consists in a membrane electrode assembly (MEA), where two gas diffusion layers (GDLs), hosting the respective catalysts, are sandwiched between an ionomer membrane. Commonly, noble metals are needed as catalyst in the anode (Ir, Ru) and cathode (Pt) to reach high current densities maintaining low cell voltages. The large content of noble metals, their high cost, and accelerated corrosion rates at high cell voltages are some drawbacks that limit the industrialization and commercialization of PEMWE technology. Replacing, decreasing, or simply extending the operational lifetime of these noble metals have a positive impact on the hydrogen economy. Molybdenum is an earth-abundant metal with low-cost which has been already used to produce highly active electrocatalysts, that can potentially replace Pt. However, most electrocatalytic studies are restricted to three-electrode cells with different operational conditions than those employed in PEM cells. The latter makes a complicated task to predict the performance of the catalyst and stability under relevant instrial applications. Here, we investigated the viability of using three selected Mo-based nanomaterials (1T’-MoS2, Co-MoS2, and ß-Mo2C) as potential electrocatalysts to replace Pt in PEMWE systems. We investigated the effects of replacing Pt in the catalyst loading, charge transfer resistance, kinetics, operational stability, and hydrogen production efficiency during PEMWE operation. Furthermore, we developed a methodology to identify the effects of tuning the cathode catalyst while keeping the anode catalyst in the overall kinetics of PEMWE system. Our results point that electrochemical performance in traditional open cell might not strictly predict the performance that could be seen in PEMWE cells due to differences in interfaces, contact between the components and porosity of the macroscopic catalyst layers. Among the catalyst studied, 1T’-MoS2 exhibited low overpotential associated to low charge transfer resistance while reaching 1 A cm-2 at 1.9 V. Our study highlights the importance to continue developing efficient electrocatalysts to replace noble metals suitable for PEMWE systems. Figure 1

Predicting the Heat Generation Rate in Large Format Pouch-Type Lithium-Ion Battery Cells for Automotive Applications

Accurate prediction of the heat generation rate of lithium ion batteries is critical for driving towards a cost effective and efficient design of a thermal management system for various applications.[1, 2] because of the increase in battery cell dimensions associated with an increase in battery cell capacity to drive towards a reduction in range anxiety for automotive applications, as well as more aggressive operating conditions that are typically seen in the automotive industry, such as direct current fast charge and sustained driving under load, heat generation at the cell level must be considered as spatially nonuniform during operation. Proper design of the thermal management system requires prediction[3] of the heat generation of the battery cell in both a lumped fashion for system sizing, as well as a distributed mode in order to focus cooling appropriately to decrease local temperature extremes. Local temperature extremes can adversely affect the aging of the battery cell due to the non-uniformities in electrochemical utilization of the active material, increased local reaction rates, and increased mechanical stresses in active materials.In this work, we detail our efforts to characterize the heat generation[4] of a battery cell under a variety of operating conditions, quantify the impact of temperature non-uniformities[5] on the aging of the battery cell, and experimentally[6, 7] evaluate the localized aging in the battery electrodes based on local temperature conditions. Here, we will describe the modeling methods developed to link operating conditions, aging, and heat generation with the electrochemical performance of the battery cell. A discussion of the model performance for relevant automotive applications will also be included.References M. Song, Y. Hu, S.-Y. Choe and T. R. Garrick, J Electrochem Soc, 167, 120503 (2020).Y. Hu, S.-Y. Choe and T. R. Garrick, Electrochim Acta, 362, 137124 (2020).M. Song, Y. Hu, S.-Y. Choe and T. R. Garrick, J Electrochem Soc, 169, 070502 (2022).Y. Hu, S.-Y. Choe and T. R. Garrick, Applied Thermal Engineering, 189, 116709 (2021).Y. Hu, S.-Y. Choe and T. R. Garrick, J Power Sources, 532, 231350 (2022).U. Janakiraman, T. R. Garrick and M. E. Fortier, J Electrochem Soc, 167, 160552 (2020).T. R. Garrick, J. Gao, X. Yang and B. J. Koch, J Electrochem Soc, 168, 010530 (2021).

Flours from Spondias mombin and Spondias tuberosa seeds: Physicochemical characterization, technological properties, and antioxidant, antibacterial, and antidiabetic activities.

Yellow mombin (Spondias mombin) and Brazil plum (Spondias tuberosa) seeds are byproducts of exploiting their pulp and currently have no relevant food or industrial applications. Thus, the present study aimed to evaluate the physicochemical, technological, and functional characteristics of flours obtained from yellow mombin (YMF) and Brazil plum (BPF) residues. The flours presented a high percentage of insoluble fiber (68.8-70.2g/100g) and low carbohydrate (2.7-4.0g/100g) and caloric (91.9-95.3kcal) values. The flours showed potential for technological application. In addition, the highest concentration of total phenolic content (31.1-50.2mgGAE/g) was obtained with 70% acetone, which provided excellent results for antioxidant capacity evaluated by 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (81.0%-89.7%) and 2,2-diphenyl-1-picrylhydrazyl (60.6%-69.1%) radical scavenging capacity assays. Flour extracts in 70% acetone also exhibited inhibition of α-amylase (63.3%-78.8%) and amyloglucosidase (63.5%-71.0%). The antibacterial study revealed that extracts inhibited the growth of Escherichia coli, Burkholderia cepacia, and Burkholderia multivorans. Therefore, this study suggests the use of yellow mombin and Brazil plum residues for different food or industrial applications. PRACTICAL APPLICATION: The knowledge gained from this study will open a new approach to add value to yellow mombin and Brazil plum fruit seeds as sources of fiber and bioactive compounds, with promising application in the formulation of functional and nutraceutical products, benefiting both a sustainable environment and a sustainable industry.

Deconstructive Carboxylation of Activated Alkenes with Carbon Dioxide.

Carboxylation with carbon dioxide (CO2 ) represents one notable methodology to produce carboxylic acids. In contrast to carbon-heteroatom bonds, carbon-carbon bond cleavage for carboxylation with CO2 is far more challenging due to their inherent and less favorable orbital directionality for interacting with transition metals. Here we report a photocatalytic protocol for the deconstructive carboxylation of alkenes with CO2 to generate carboxylic acids in the absence of transition metals. It is emphasized that our protocol provides carboxylic acids with obviously unchanged carbon numbers when terminal alkenes were used. To show the power of this strategy, a variety of pharmaceutically relevant applications including the modular synthesis of propionate nonsteroidal anti-inflammatory drugs and the late-stage carboxylation of bioactive molecule derivatives are demonstrated.

Clinamen2: Functional-style evolutionary optimization in Python for atomistic structure searches

Clinamen2 is a versatile functional-style Python implementation of the covariance matrix adaptation evolution strategy (CMA-ES) utilizing Cholesky decomposition. On top of a problem-agnostic core algorithm, the software package offers a suite of utilities and library code enabling applications to important atomistic structure searches. Features include massively distributed computation and the BI-Population restart scheme. This article details the general code structure and introduces examples that illustrate some relevant applications for the materials science and chemistry worlds, including interfacing to density-functional-theory codes and machine-learned surrogate models. The functional design renders the code modular and adaptable, and makes the creation of interfaces to other atomistic software straightforward. Program summaryProgram Title: Clinamen2CPC Library link to program files:https://doi.org/10.17632/x7syr2txsd.1Developer's repository link:https://github.com/Madsen-s-research-group/clinamen2-public-releasesCode Ocean capsule:https://codeocean.com/capsule/4950229Licensing provisions: Apache-2.0Programming language: PythonSupplementary material:Nature of problem: Find optimal atomistic structures retaining full flexibility in the choice of the optimization target, the methodological approach and its implementation (e.g. CPU- vs. GPU-heavy calculations). Enable interfacing with relevant software, including but not limited to density-functional-theory (DFT) codes and machine-learning (ML) solutions.Solution method: The covariance matrix adaptation evolution strategy (CMA-ES) algorithm is implemented using Cholesky decompositions for efficiency. The core algorithm and application examples for specific problems are implemented in functional-style Python free of side effects, with data classes to keep track of the state of the evolution. Dask is used for job control to enable highly distributed workflows. Advanced strategies like BI-Population CMA-ES are easy to implement and illustrated in the examples.

A Case Example of Integrating Team-Based and Problem-Based Learning in Sex Therapy Courses in the U.S. and Austria

Introduction: Team-based learning and Problem-Based Learning can be integrated for in person and online psychology or behavioral health related courses in higher education. Statement of the Problem: Historically, team-based learning and problem-based learning have been considered separate (and seemingly competing) activities and not often conducted concurrently during a course. Literature Review: A review of the literature on team-based learning, however, has uncovered some cases where team-based learning and problem-based learning were integrated together in a course. Teaching Implications: The purpose of this article is to present a case example in which team-based learning and problem-based learning were integrated together in two master’s level sex therapy courses: one in the U.S. and one in Austria. The article describes how this integration was achieved through outlining the activities of the class and the possible benefits seen based on self-report. Conclusion: Integrating team-based learning and problem-based learning was an effective method for teaching two master’s level sex therapy courses and may have relevant application to psychology classes and/or treatment-oriented topics in behavioral health.

Deconstructive Carboxylation of Activated Alkenes with Carbon Dioxide

AbstractCarboxylation with carbon dioxide (CO2) represents one notable methodology to produce carboxylic acids. In contrast to carbon–heteroatom bonds, carbon–carbon bond cleavage for carboxylation with CO2 is far more challenging due to their inherent and less favorable orbital directionality for interacting with transition metals. Here we report a photocatalytic protocol for the deconstructive carboxylation of alkenes with CO2 to generate carboxylic acids in the absence of transition metals. It is emphasized that our protocol provides carboxylic acids with obviously unchanged carbon numbers when terminal alkenes were used. To show the power of this strategy, a variety of pharmaceutically relevant applications including the modular synthesis of propionate nonsteroidal anti‐inflammatory drugs and the late‐stage carboxylation of bioactive molecule derivatives are demonstrated.

3D networked MXene thin films for high performance supercapacitors

Maximizing the energy and power density of supercapacitors requires thick electrodes, enabling a high areal loading. Simultaneously, a sophisticated, hierarchical pore structure for the active material is needed, granting high accessibility for electrons and ions. However, porosity and thickness need to be carefully balanced to maximize the active material density while ensuring high performance. Here, we show that by forming hierarchical electrodes from Ti3C2Tx 2D nanosheets in the form of interconnected 3D networked thin films (up to ∼220 nm), we can fabricate high performance thick film electrodes of up to ∼50 µm with a well-defined, hierarchical, porous structure. By balancing porosity and thickness, we demonstrate electrodes that combine a high areal loading of up to ∼7.2 mg cm−2, high material density of ∼1440 mg cm−3, and high electrochemical performance of 240 F g−1 and 140 F cm−3. Thus, we achieve electrodes with a remarkable areal capacitance of ∼1.4 F cm−2, even at high rates of 200 mV s−1, outperforming other state of the art MXene based electrodes of comparable density and thickness. We anticipate that this concept, will pave the way to transfer the exceptional properties of nanomaterial thin film electrodes to the next, macroscopic level, enabling the development of advanced, high-performance electrodes for practically relevant energy storage applications and beyond.

Research and Development Status of Laser Cladding on Stainless Steel Alloys: A Review

Stainless steels as one of the most appealing structural material in many fields of industries because of its resistance to corrosion, high tensile strength, durability, temperature resistant etc. To improve its surface properties and overcome issues like large heat affected zones, poor surface quality, and limited dissolvability, researchers have explored surface modifications through laser cladding. This paper gives a detailed review about the work done in recent years, in the region of laser cladding of different grades of stainless-steel alloys with different coating materials highlighting on feeding ways of cladding material, laser cladding process parameters, types of lasers employed, types of coating & composite coating materials in enhancing the surface properties of the stainless-steel substrate and their relevant applications.

Rashba Effect and Spin-Dependent Excitonic Properties in Chiral Two-Dimensional/Three-Dimensional Composite Perovskite Films.

Among various chiral semiconductor materials, chiral two-dimensional (2D)/three-dimensional (3D) composite perovskites (CPs) offer the benefits of strong interface asymmetry and energy transfer between 2D and 3D phases, making the chiral CPs promising for spintronic devices. Therefore, understanding their spintronic properties will be greatly important for expanding their relevant applications. In this work, we synthesized one pair of chiral 2D/3D CP films. Their Rashba effect and spin relaxation process have been investigated by polarization-dependent femtosecond transient absorption spectroscopy. Interestingly, under left- and right-handed circularly polarized light (CPL) excitation, a two-photon emission intensity difference is observed in chiral 2D/3D CP films at 298 K. This work sheds light on the spin-dependent excitonic characteristics of chiral 2D/3D CPs and confirms the feasibility of their application in near-infrared CPL detection.