Efficient Pathway Research Articles

Enhancing the Conductivity and Thermoelectric Performance of Semicrystalline Conducting Polymers through Controlled Tie Chain Incorporation.

Conjugated polymers are promising materials for thermoelectric applications, however, at present few effective and well-understood strategies exist to further advance their thermoelectric performance. Here a new model system is reported for a better understanding of the key factors governing their thermoelectric properties: aligned, ribbon-phase poly[2,5-bis(3-dodecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT) doped by ion-exchange doping. Using a range of microstructural and spectroscopic methods, the effect of controlled incorporation of tie-chains between the crystalline domains is studied through blending of high and low molecular weight chains. The tie chains provide efficient transport pathways between crystalline domains and lead to significantly enhanced electrical conductivity of 4810 S cm-1, which is not accompanied by a reduction in Seebeck coefficient or a large increase in thermal conductivity. Respectable power factors of 173 µW m-1 K-2 are demonstrated in this model system. The approach is generally applicable to a wide range of semicrystalline conjugated polymers and could provide an effective pathway for further enhancing their thermoelectric properties and overcome traditional trade-offs in optimization of thermoelectric performance.

Coherent optical coupling to surface acoustic wave devices

Surface acoustic waves (SAW) and associated devices are ideal for sensing, metrology, and hybrid quantum devices. While the advances demonstrated to date are largely based on electromechanical coupling, a robust and customizable coherent optical coupling would unlock mature and powerful cavity optomechanical control techniques and an efficient optical pathway for long-distance quantum links. Here we demonstrate direct and robust coherent optical coupling to Gaussian surface acoustic wave cavities with small mode volumes and high quality factors (>105 measured here) through a Brillouin-like optomechanical interaction. High-frequency SAW cavities designed with curved metallic acoustic reflectors deposited on crystalline substrates are efficiently optically accessed along piezo-active directions, as well as non-piezo-active (electromechanically inaccessible) directions. The precise optical technique uniquely enables controlled analysis of dissipation mechanisms as well as detailed transverse spatial mode spectroscopy. These advantages combined with simple fabrication, large power handling, and strong coupling to quantum systems make SAW optomechanical platforms particularly attractive for sensing, material science, and hybrid quantum systems.

Unveiling the gut-eye axis: how microbial metabolites influence ocular health and disease.

The intricate interplay between the gut microbiota and ocular health has surpassed conventional medical beliefs, fundamentally reshaping our understanding of organ interconnectivity. This review investigates into the intricate relationship between gut microbiota-derived metabolites and their consequential impact on ocular health and disease pathogenesis. By examining the role of specific metabolites, such as short-chain fatty acids (SCFAs) like butyrate and bile acids (BAs), herein we elucidate their significant contributions to ocular pathologies, thought-provoking the traditional belief of organ sterility, particularly in the field of ophthalmology. Highlighting the dynamic nature of the gut microbiota and its profound influence on ocular health, this review underlines the necessity of comprehending the complex workings of the gut-eye axis, an emerging field of science ready for further exploration and scrutiny. While acknowledging the therapeutic promise in manipulating the gut microbiome and its metabolites, the available literature advocates for a targeted, precise approach. Instead of broad interventions, it emphasizes the potential of exploiting specific microbiome-related metabolites as a focused strategy. This targeted approach compared to a precision tool rather than a broad-spectrum solution, aims to explore the therapeutic applications of microbiome-related metabolites in the context of various retinal diseases. By proposing a nuanced strategy targeted at specific microbial metabolites, this review suggests that addressing specific deficiencies or imbalances through microbiome-related metabolites might yield expedited and pronounced outcomes in systemic health, extending to the eye. This focused strategy holds the potential in bypassing the irregularity associated with manipulating microbes themselves, paving a more efficient pathway toward desired outcomes in optimizing gut health and its implications for retinal diseases.

Thymus vulgaris-assisted growth of nickel nanoparticles onto Luffa fibers: A robust and recyclable catalyst for the reduction of organic pollutants

A green and efficient synthetic pathway was developed to prepare nickel@Luffa nanocomposite. Thymus vulgaris extract was used to functionalize the surface of Luffa fibers with hydroxyl, carbonyl, and amide groups, which assisted in the adsorption of nickel ions. The scanning electron microscope images revealed that nickel nanoparticles grew as aggregates of semi-spherical particles and randomly dispersed on the Luffa fibers. The X-ray diffraction pattern of the nickel@Luffa nanocomposite showed the diffraction pattern of a face-centered cubic Ni crystal. XPS spectrum indicated the formation of metallic Ni at the Luffa surface. The prepared nickel@Luffa was used to catalyze the degradation of 4-nitrophenol, methyl orange, bromophenol blue and a mixture of both. The reaction rate constant for nickel@Luffa nanocomposite was calculated as 15.47 × 10−3 s−1 at pH = 10 and even after ten cycles its conversion was about 90%. The nickel nanoparticles could be recycled/reused for ten catalytic cycles with adequate catalytic activity. Such synthetic pathways encourage the application of renewable natural resources to fabricate separable/recyclable heterogeneous catalyst for many important reactions. The proposed nanocomposite is industrially applicable and environmentally-benign, fulfilling the requirements for the sustainable development.

Molecular Autonomous Pathfinder Using Deep Reinforcement Learning.

Diffusion in solids is a slow process that dictates rate-limiting processes in key chemical reactions. Unlike crystalline solids that offer well-defined diffusion pathways, the lack of similar structural motifs in amorphous or glassy materials poses great challenges in bridging the slow diffusion process and material failures. To tackle this problem, we propose an AI-guided long-term atomistic simulation approach: molecular autonomous pathfinder (MAP) framework based on deep reinforcement learning (DRL), where the RL agent is trained to uncover energy efficient diffusion pathways. We employ a Deep Q-Network architecture with distributed prioritized replay buffer, enabling fully online agent training with accelerated experience sampling by an ensemble of asynchronous agents. After training, the agents provide atomistic configurations of diffusion pathways with their energy profile. We use a piecewise nudged elastic band to refine the energy profile of the obtained pathway and the corresponding diffusion time on the basis of transition-state theory. With the MAP framework, we demonstrate atomistic diffusion mechanisms in amorphous silica with time scales comparable to experiments.

A multiple criteria decision analysis to establish the use cases and candidate point of care tests to enter into a platform trial of multiple in vitro diagnostic point of care tests in the prehospital environment

Background There are increasing demands on Emergency Medical Services. More efficient treatment pathways are required to support conveyance decision making and patient referral in prehospital care. Point of Care testing is increasingly available and utilised across the NHS to support optimal ways of working. We aimed to design and conduct a Multiple Criteria Decision Analysis to prioritise in vitro point of care tests and use cases for inclusion in a platform trial of in vitro point of care testing in UK Emergency Medical Services. Methods We designed a Multiple Criteria Decision Analysis that included systematic scoping reviews stakeholder recruitment, two stakeholder surveys and two stakeholder workshops to scope the use cases, explore criteria and map use cases, evaluate the criteria and measure the use cases against the criteria. Results We recruited 32 stakeholders. We developed a scoring matrix with 4 criteria for scoring the use cases and 8 criteria for scoring the point of care tests and applied weighting determined from survey results. Use cases were scored by the stakeholders against 4 criteria. The 3 highest scoring use cases were point of care troponin testing in: possible Acute Myocardial Infarction, lactate testing in suspected sepsis and in trauma. We developed the process for scoring the point of care tests to be completed close to a proposed trial to allow for a changes in technology. Conclusions We successfully designed a Multiple Criteria Decision Analysis to identify use cases and candidate tests for inclusion in a future platform trial of in vitro point of care testing in UK Emergency Medical Services. We identified 3 use cases for evaluation in a platform trial of in vitro point of care testing: troponin testing in possible acute myocardial infarction, lactate testing in suspected sepsis and lactate testing to identify occult haemorrhage in trauma.

A “two cooking with one fish” strategy for modulating both polyaniline cathode and zinc anode towards enhanced kinetics and cycling stability for aqueous zinc ion batteries

The adverse stability of both polyaniline (PANI) and Zn anode remains a challenge to the long−term cyclability and rate capability of aqueous Zn−PANI batteries. Herein, a “two–cooking with one fish” strategy is presented to modulate both PANI cathode and Zn anode, in which nanoscale graphene sheets in cathode can promote ordered growth of PANI array, being conducive to provide large electrochemical active area and efficient transport pathways and alleviate volume variation during repeated charging/discharging process. Meanwhile, the honeycomb–like structure of graphene sheets as protective layer can accelerate zinc ion transport kinetics and suppress side reactions and zinc dendrite growth. Consequently, the optimized G/Zn symmetric cell delivers a remarkable lifespan over 1000 h at 1 mA cm−2 with 1 mAh cm−2. Furthermore, the assembled PANI/G/CC||G/Zn battery could deliver a specific capacity of 265.8 mAh g−1 at 0.2 A g−1, excellent rate capability (145.5 mAh g−1 at 20 A g−1), a maximum energy density of 246.9 W h kg−1 and power density of 8675.9 W kg−1, and especially capacity retention of 91.1 % after 10000 cycles. Combining with additional merits of low cost, eco–friendliness, and safe operation, our design will shed light on resolving the issues on cyclability and rate capability of aqueous Zn−PANI batteries.

Demineralization effects on physicochemical and combustion characteristics of biomass: Insights into distributed kinetics, flue gas evolution, and slag formation

Biomass as the only carbon-bearing renewable energy has enormous potential to challenge the established energy structure dominated by fossil resources, and incineration technology is one of the most direct and efficient pathways for utilizing biomass resources, unfortunately enduring the inevitable sintering and slagging problems owing to the excessive alkali metals. Herein, we comparatively investigated the effects of five leaching solvents (water, acetic acid, wood vinegar, hydrochloric acid, and oxalic acid) on the physicochemical properties and ash-removal capabilities of wheat straw (WS) and rice husk (RH), with a view to achieving better performance in the subsequent combustion characteristics, kinetic examination, flue gas, and slag evolution. Results indicated with ionization ability increased (water < acetic acid < hydrochloric acid), the WS exhibited a strong demineralization performance (maximum 61.1%), further leading to a steep weight loss in its combustion characteristic curve at approximately 350 °C and a delayed peak temperature after the removal of alkali metal. Multiple distributed activation energy model and sensitivity analysis revealed that leaching pretreatment enhanced the activation energy (189–191.8 kJ mol−1) and optimized energy distribution at the preliminary stage of the combustion reaction. In addition, the absence of alkali metals suppressed the catalytic oxidation reaction in the flue gas, remarkably limiting the formation of CO2 but facilitating the release of CO and CH4. Meanwhile, a considerable optimal in biomass ash slagging, in which the initial temperature of the liquid phase slag for WS ash increased to 991 °C. Notably, HCl showed the strongest demineralization performance among the five leaching solvents during pretreatment, but the high-temperature slag content was still higher than that of acetic acid. Therefore, slagging performance is not only associated with the demineralization ability of leaching solvents, but also with ash composition.

Robust Gaussian Process Regression Method for Efficient Tunneling Pathway Optimization: Application to Surface Processes.

Simulation of surface processes is a key part of computational chemistry that offers atomic-scale insights into mechanisms of heterogeneous catalysis, diffusion dynamics, and quantum tunneling phenomena. The most common theoretical approaches involve optimization of reaction pathways, including semiclassical tunneling pathways (called instantons). The computational effort can be demanding, especially for instanton optimizations with an ab initio electronic structure. Recently, machine learning has been applied to accelerate reaction-pathway optimization, showing great potential for a wide range of applications. However, previous methods still suffer from numerical and efficiency issues and were not designed for condensed-phase reactions. We propose an improved framework based on Gaussian process regression for general transformed coordinates, which has improved efficiency and numerical stability, and we propose a descriptor that combines internal and Cartesian coordinates suitable for modeling surface processes. We demonstrate with 11 instanton optimizations in three representative systems that the improved approach makes ab initio instanton optimization significantly cheaper, such that it becomes not much more expensive than a classical transition-state theory rate calculation.

Mixing is easy: New insights for cosmochemical evolution from pre-stellar core collapse

Signposts of early planet formation are ubiquitous in substructured young discs. Dense, hot, and high-pressure regions that formed during the gravitational collapse process, integral to star formation, facilitate dynamical mixing of dust within the protostellar disc. This provides an incentive to constrain the role of gas and dust interaction and resolve potential zones of dust concentration during star and disc formation stages. We explore whether the thermal and dynamical conditions that developed during protostellar disc formation can generate gas flows that efficiently mix and transport the well-coupled gas and dust components. We simulated the collapse of dusty molecular cloud cores with the hydrodynamics code PLUTO augmented with radiation transport and self-gravity. We used a two-dimensional axisymmetric geometry and followed the azimuthal component of the velocity. The dust was treated as Lagrangian particles that are subject to drag from the gas, whose motion is computed on a Eulerian grid. We considered 1, 10, and 100 micron-sized neutral, spherical dust grains. Importantly, the equation of state accurately includes molecular hydrogen dissociation. We focus on molecular cloud core masses of 1 and 3 $M_ odot $ and explore the effects of different initial rotation rates and cloud core sizes. Our study underlines mechanisms for the early transport of dust from the inner hot disc regions via the occurrence of two transient gas motions, namely meridional flow and outflow. The vortical flow fosters dynamical mixing and retention of dust, while the thermal pressure driven outflow replenishes dust in the outer disc. Notably, these phenomena occur regardless of the initial cloud core mass, size, and rotation rate. Young dynamical precursors to planet-forming discs exhibit regions with complex hydrodynamical gas features and high-temperature structures. These can play a crucial role in concentrating dust for subsequent growth into protoplanets. Dust transport, especially, from sub-au scales surrounding the protostar to the outer relatively cooler parts, offers an efficient pathway for thermal reprocessing during pre-stellar core collapse.

Facile and an efficient one-pot synthesis of 2-arylbenzoxazoles promoted by transition metal oxide nano catalyst

The advantages and an efficient path way of process for 2-arylbenzoxazole can be obtained by transition metal oxide Nano catalyst. The transition metal nano TiO2 catalysed and a tandem reaction between substituted 2-aminophenols and substituted aromatic aldehydes to produces scaffold series of 15 smoothly forming benzo heterocycles with good to excellent yields (80-94%). The synthesized benzoxazole compounds were confirmed by FT-IR, 1H, 13CNMR, and mass spectroscopy. This article describes a one-stage coupling technique that provides a unique way to access variously functionalized benzoxazole scaffolds. This methodology consists of a one-pot combination of condensation followed by oxidative addition reactions. It was shown that nano TiO2 in ethanol encouraged the formation of 2-aryl benzoxazole scaffolds and this catalyst quickly boosted the cascade reaction that produced a variety of collections of named derivatives. These protocols are atom-economic, efficient, reusable and modular means of accessing restricted named derivatives that have a substantial substrate tolerance and over ten points of diversity.

Photochemical nitrene transfer reactions of iminoiodinanes with sulfoxides

Nitrene, as an important and intriguing versatile synthon, is widely utilized for the formation of diverse nitrogenous skeletons under thermal or photochemical conditions. Typically, the N-sulfonyl nitrenes could be smoothly generated from iminoiodinanes at relatively low reaction temperatures to generate N-sulfonyl nitrenes. Herein, we described the direct immidation reaction of iminoiodinanes with sulfoxides through a blue-light-induced nitrenes transfer process. This strategy offers an efficient and gentle pathway for directly obtaining sulfoximines within a reaction time of only 10 ​min. Moreover, the reaction conditions do not necessitate the exclusion of moisture or air, rendering this photocatalytic amination reaction highly practical. A broad range of iminoiodinanes were well tolerated and reacted with sulfoxides smoothly to give the corresponding products in moderate to good yields, which provides a practical and green protocol to access N-sulfonyl architectures.

The value of a remote orthodontic assessment for children having permanent teeth extracted under general anaesthesia.

Introduction The number of children undergoing dental extractions under general anaesthetic (GA) remains high. The newly published Royal College of Surgeons guidelines in 2023 take a less prescriptive approach on balancing and compensating extractions for first permanent molars. In an effort to maintain an effective and efficient patient care pathway, an orthodontic remote assessment triage model was developed in West Dorset for the special care dentistry and community dental service.Aims The orthodontic triage form is now used across Dorset. This service evaluation assesses whether the form is still effective despite the upscaling. Furthermore, qualitative feedback was obtained from the clinicians involved in referring and triaging.Design The sample of 352 forms consisted of children aged 16 years or younger undergoing GA for dental extractions for whom orthodontic triage had been requested between March 2019 and March 2023. The clinician feedback was collected using a questionnaire.Results This service evaluation found that 53.1% of patients had their treatment plan modified following an orthodontic assessment. Positive feedback from all clinicians involved suggests there is potential to expand this model to other services.Discussion Involving the orthodontist can address orthodontic concerns which has the potential to simplify or obviate the need for future orthodontic treatment. Remote assessment reduces the need for face-to-face appointments. The clinician perspective influences willingness to further develop and expand the current pathway.Conclusion Remote triage has proved successful in Dorset. There is potential to build an initiative between primary and secondary care in the hopes of creating a universal national proforma to increase access to orthodontic opinions for children requiring dental extractions.

Audit of a Revised Pathway Aimed at Expediting Diagnosis and Treatment for Suspected Achilles Tendon Rupture

Treatment outcomes for Achilles tendon ruptures depend upon prompt diagnosis and management. A local study in 2018 highlighted inefficiencies in patient management, and a revised protocol was introduced allowing investigation and referral to be initiated by other healthcare professionals. This retrospective audit evaluates the impact of this on the timescale from presentation to treatment. It analyzes all suspected Achilles tendon ruptures within one District General Hospital from April 2021 to March 2022. Data regarding patient timelines was compared to the 2018 study. Over 12 months, 99 patients were referred to Virtual Fracture Clinic, 87.8% (n = 87) of which had a complete or partial tear on ultrasound scan (USS). In comparison to 2018, the average time from presentation to USS request reduced from 2.9 to 1.1 days (p < .01). 95% were scanned within one week of USS request and 31.3% within 48 hours (81% and 18%, previously). The average time from USS request to scan went from 6.8 to 3.2 days (p < .01). The time from presentation to treatment decision reduced from 10.9 to 6.2 days (p < .01) and the percentage of patients with a definitive treatment plan within one week increased from 34.5% to 74.2% (p < .01). Patients required 0.8 fewer appointments (p < .01) giving an estimated total saving of $10,110 ($128 per patient) during the analyzed period. The Achilles Tendon Rupture Pathway has significantly improved the proportion of patients undergoing USS within 48 hours and receiving a treatment decision within one week. This study demonstrates an efficient, cost-saving and replicable pathway for Achilles tendon ruptures.

Development of an Efficient and Effective Clinical Pathway for Cesarean Section in West Sumatra (Indonesia).

As with several countries around the world, cesarean section rates are increasing also in Indonesia, raising issues of quality and cost-effectiveness of health care, especially with the shift from a fee-for-service to a prospective payment system. For hospital services to be effective (quality control) and efficient (cost control), clinical pathways are essential. However, no studies have been done to develop a clinical pathway for cesarean sections (CS) in the INA-CBG system that is both effective and efficient. To develop clinical pathways for CS that are both effective and efficient by determining unit costs and tariffs for CS services, reviewing procedures and outcomes, and assessing performance efficiency and effectiveness. Using a sample of 110 patients undergoing cesarean sections consecutively recruited in 11 hospitals of West Sumatra (6 public hospitals and 5 private institutions), this mixed (qualitative and quantitative) study aimed at developing clinical guidelines for childbirth delivery modes responding both to criteria of efficacy and efficiency. Of 110 patients, 50 patients (45%) had efficient CS, 85 patients (77%) had effective CS, and 40 patients (36.4%) had both effective and efficient CS. A comprehensive clinical pathway for CS procedure was created by investigating 40 patients who underwent effective and efficient CS using interviews, a Delphi study, and professional advice. Hospitals can adopt the effective and efficient clinical pathwayfor CS protocol to prevent cost-related losses (efficient)while retaining the quality of the service (effective).

Additive Manufacturing of Micro‐Architected Copper based on an Ion‐Exchangeable Hydrogel

AbstractAdditive manufacturing (AM) of copper through laser‐based processes poses challenges, primarily attributed to the high thermal conductivity and low laser absorptivity of copper powder or wire as the feedstock. Although the use of copper salts in vat photopolymerization‐based AM techniques has garnered recent attention, achieving micro‐architected copper with high conductivity and density has remained elusive. In this study, we present a facile and efficient process to create complex 3D micro‐architected copper structures with superior electrical conductivity and hardness. The process entails the formulation of an ion‐exchangeable photoresin, followed by the utilization of digital light processing (DLP) printing to sculpt 3D hydrogel scaffolds, which were transformed into Cu2+‐chelated polymer frameworks (Cu‐CPFs) with a high loading of Cu2+ ions through ion exchange, followed by debinding and sintering, results in the transformation of Cu‐CPFs into miniaturized copper architectures. This methodology represents an efficient pathway for the creation of intricate micro‐architected 3D metal structures.

Additive Manufacturing of Micro-Architected Copper based on an Ion-Exchangeable Hydrogel.

Additive manufacturing (AM) of copper through laser-based processes poses challenges, primarily attributed to the high thermal conductivity and low laser absorptivity of copper powder or wire as the feedstock. Although the use of copper salts in vat photopolymerization-based AM techniques has garnered recent attention, achieving micro-architected copper with high conductivity and density has remained elusive. In this study, we present a facile and efficient process to create complex 3D micro-architected copper structures with superior electrical conductivity and hardness. The process entails the formulation of an ion-exchangeable photoresin, followed by the utilization of digital light processing (DLP) printing to sculpt 3D hydrogel scaffolds, which were transformed into Cu2+-chelated polymer frameworks (Cu-CPFs) with a high loading of Cu2+ ions through ion exchange, followed by debinding and sintering, results in the transformation of Cu-CPFs into miniaturized copper architectures. This methodology represents an efficient pathway for the creation of intricate micro-architected 3D metal structures.

Techno-economic analysis of small-scale ammonia production via sorption-enhanced gasification of biomass

Biomass gasification is a green and efficient pathway for lowering the carbon footprint of ammonia production. Decentralized, small-scale biomass gasification plants (<150 t NH3/day output) are more practical than large plants due to sustainable large-scale biomass supply constraints. Small-scale biomass gasification for ammonia production faces the challenges of high energy consumption and production costs. Process intensification through sorption-enhanced gasification (SEG) integrates steam gasification and in-situ CO2 separation using regenerable CaO sorbents, directly producing hydrogen-rich syngas (∼70 vol%), which streamlines syngas conditioning and increases cost-effectiveness. Two SEG process configurations for small-scale biomass-to-ammonia (∼45000 t of agricultural residues/year) were proposed: SEG process A, which produced low-carbon ammonia without air separation, and SEG process B, which employed an air separation unit to deliver carbon-negative ammonia by capturing CO2. The two processes were compared against a dual fluidized bed gasification (DFBG) process, which generated green ammonia without an air separation, like SEG process A. Of the three cases, SEG process B showed the lowest biomass (2.14 t biomass/t NH3) and water consumption (0.47 t H2O/t NH3) and avoided 2.8 t CO2/t NH3, making it carbon-negative. While the DFBG process and SEG process A had higher energy efficiencies, SEG process B posted the lowest net energy consumption (36.6 GJ/t NH3). Furthermore, SEG process B had the lowest ammonia production cost ($692/t NH3) and payback time (9.4 years), making it the most economically viable. Sensitivity analysis showed that favorable carbon credit policies could boost the economics of SEG process B to match large-scale plants.

Surface water oxygenation and low bioproductivity during deposition of iron formation of the Jacadigo Group (Brazil): Insights from combined cadmium – Chromium isotopes

The Banda Alta Formation (Urucum district, Mato Grosso do Sul, Brazil) comprises ∼600 Ma Fe and Mn deposits, which are among the world's youngest and largest Neoproterozoic sedimentary Fe and Mn formations (IF; MnF). These have been deposited in a redox-stratified, marine sub-basin (Jacadigo Basin), which was strongly influenced by glacial advance/retraction cycles with temporary influx of continental freshwater and upwelling of metal-enriched deep anoxic seawater. Cr and Cd isotopes measured on meticulously separated hematite mesobands from drill core samples are relatively homogenous throughout the ca. 325 m thick sequence sampled in the Banda Alta Fm., with average authigenic δ53Cr values of +0.93 ± 0.24 ‰ (2σ; n = 23) and δ114Cd values of −0.14 ± 0.14 ‰ (2σ; n = 15). The significant enrichment of Cr, in parallel with the strong enrichments of other redox sensitive elements (U, Mo), attests for effective and efficient reduction removal processes in the surface waters during cycles where upwelling Fe2+-rich waters reached the oxygenated surface layer exposed to the atmosphere during episodic glacier retreat stages. Assuming a similar quantitative and efficient removal pathway of dissolved Cd by iron oxyhydroxides, the so-inferred average δ114Cd signature of −0.14 ± 0.14 ‰ in the Jacadigo Basin surface water is significantly lower than signatures of modern ocean surface waters with a range of δ114Cd of ca. ∼0.4 to ∼1 ‰ and even lower than the signature of modern ocean deep waters with δ114Cd of ∼0.3 ‰. It possibly attests to reduced primary production levels and lower nutrient utilization rates during deposition of the Late Neoproterozoic Jacadigo Group, compared to today. This despite the inferred oxidized surface water layer that must have prevailed during this time, as implied by the strongly positively fractionated Cr isotope signatures and pronouncedly negative Ce-anomalies recorded in the seawater-like, shale-normalized Rare Earth Element and Yttrium (REY) patterns exhibited by the hematite mesobands. Data presented herein speak for: (1) a stable, isotopically heavy Cr input to the Jacadigo Basin at the time of deposition, implying high atmospheric O2 levels in the Late Neoproterozoic (2) likely quantitative, reductive incorporation / adsorption processes of dissolved Cr and Cd, respectively, into/onto precipitating iron oxyhydroxides, and (3) the prevalence of low nutrient concentrations and utilization rates in the Jacadigo Basin during glacier retreat cycles. Banded iron formations are considered suitable archives for reconstructing redox and bioproductivity levels in past marine depositional basin, including those prevalent in Neoproterozoic glacial conditions, via employing the CrCd isotope double tracer to iron-rich mesobands.

Highly thermally conductive PVDF-based composites with well-dispersed carbon nanotubes/graphene-Ag 3D interconnected frame via electrostatic self-assembly

Polyvinylidene fluoride (PVDF) is a thermoplastic polymer known for its superior chemical and thermal stability and good mechanical properties. However, the application of polymers in heat transfer is limited by their inherent poor thermal conductivity (λ). This study uses electrostatic self-assembly between negatively charged Graphene-Silver (GNs-Ag) and positively charged cetyltrimethylammonium bromide (CTAB)-functionalized multiwall carbon nanotubes (fMWCNTs) to construct a unique three-dimensional (3D) structure in PVDF. AgNPs are uniformly loaded on graphene nanosheets, and the well-dispersed fMWCNTs act as bridges connecting adjacent AgNPs and GNs, forming a more efficient heat transfer pathway, thereby obtaining polymer nanocomposites with higher λ. The λ of GNs-Ag/fMWCNTs/PVDF composites reaches 9.24 W/(m·K) with 25 wt% of GNs-Ag/fMWCNTs fillers, which is 3495 % higher than that of pure PVDF. Additionally, the mechanical properties and electrical conductivity and electromagnetic interference shielding effectiveness of the GNs-Ag/fMWCNTs/PVDF composites are also markedly enhanced.