bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein-losing enteropathy as a result of colon polyposis and colon cancer: a multidisciplinary approach to diagnosis and treatment
Authors: Kuipers Hendrien , van Westreenen Henderik L , Moll Freek C P , de Vos tot Nederveen Cappel Wouter H
Published: August 2024

A man in his 60s presented to our emergency department with severe peripheral pitting oedema, weight gain, dyspnoea and diarrhoea. Blood tests showed a hypoalbuminaemia of 15 g/L. A suspicion of protein-losing enteropathy arose after the exclusion of albuminuria, cardiac failure, protein deficiency and liver cirrhosis. An abdominal CT scan revealed a wall thickening of the colon, and a subsequent colonoscopy identified multiple large obstructive polyps in the ascending colon. The patient underwent a right hemicolectomy which revealed the presence of tubulovillous polyps and a pT2N0 colon carcinoma. Following surgery, the patient experienced clinical improvement with normalisation of serum albumin and resolution of the oedema.

Protein-losing enteropathy should be considered an underlying syndrome in patients with peripheral oedema and hypoalbuminaemia in the absence of cardiac failure, proteinuria, malnutrition and hepatic disease. This diagnostic process requires a multidisciplinary approach. For adequate treatment, the primary cause of protein-losing enteropathy needs to be investigated.
Unveiling collodion baby: confronting ectropion and respiratory drama in neonatal care
Authors: Srivastava Utkarsh , Singh Kshitij Aviraj , Sahu Animesh , Dalai Richie
Published: August 2024

A neonate presented to us with respiratory distress with diffuse involvement of skin with thickening, cracking and peeling since birth with severe ectropion and eclabium. The hospital course was complicated by polymicrobial sepsis requiring prolonged antibiotics and antifungals. The skin lesions were treated with acitretin, humidification and topical emollients. With the improvement of pneumonia and clearing of nasal debris, the neonate could be gradually weaned off respiratory support. Despite a stormy course, there was marked improvement in all skin lesions including ectropion and eclabium at discharge. This case highlights and discusses the challenges in diagnosis and underscores the need for multidisciplinary involvement of neonatology, dermatology and ophthalmology for a neonate with collodion baby syndrome.
Carpal tunnel syndrome and occupational hand exposures: a Danish nationwide cohort study
Authors: Tabatabaeifar Sorosh , Dalbøge Annett
Published: August 2024

Objectives

The aim was to examine exposure–response relations between occupational hand exposures and carpal tunnel syndrome (CTS) and to compare the relation between surgery-treated and non-surgery-treated CTS. The secondary aim was to study sex-specific differences in exposure–response relations.

Methods

We conducted a nationwide register-based cohort study of all persons born in Denmark (1945–1994). During follow-up (2010–2013), we identified first-time events of CTS. Occupational hand exposure estimates the year before each follow-up year were obtained by linking individual occupational codes with a job exposure matrix. We used multivariable logistic regression equivalent to discrete survival analysis based on sex and surgery. The excess fraction of cases was calculated.

Results

For both sexes, exposure–response relations were found for all occupational hand exposures. Among men, we found ORadjof 3.6 (95% CI 3.2 to 3.8) for hand-related force, 2.9 (95% CI 2.5 to 3.2) for repetitive hand movements, 3.8 (95% CI 2.7 to 5.2) for non-neutral hand posture and 2.5 (95% CI 2.2 to 2.7) for hand-arm vibration in the highest exposure groups. For combined exposure (hand load), ORadjwas 3.5 (95% CI 3.1 to 4.0). Slightly higher ORsadjwere generally found for surgery-treated CTS compared with non-surgery-treated CTS for both sexes. When comparing sex, somewhat higher ORsadjwere found among men. The excess fraction was 42%.

Conclusions

Occupational hand exposures carried a 3-5-fold increased risk of CTS with slightly higher risks for surgery-treated compared with non-surgery-treated CTS. Even though CTS occurs more frequently among women, somewhat higher exposure–response relations were found for men compared with women. In the general working population, a substantial fraction of first-time CTS could be related to occupational hand exposures.
Declines and shifts in morphological diversity of ciscoes (Coregonus spp.) in lakes Huron and Michigan, 1917–2019
Authors: Fedorowicz Paul W. , Kao Yu-Chun , Ackiss Amanda S. , Anweiler Katie V. , Honsey Andrew E.
Published: August 2024

Ciscoes ( Coregonus spp .) were historically abundant and ecologically important in Laurentian Great Lakes ecosystems. Despite well-documented declines in their abundance and taxonomic diversity, declines in morphological diversity remain understudied. This knowledge gap is especially pertinent for lakes Michigan and Huron, which have each lost six of eight historical species. Improved understanding of historical and contemporary morphological diversity of Great Lakes ciscoes can inform ongoing restoration efforts and further elucidate the factors that contributed to declines. Our goal was to characterize shifts in morphological diversity of ciscoes in lakes Michigan and Huron over a century (1917–2019). We analyzed size-corrected morphometric and meristic measurements from three periods: Early (1917–1923), Middle (1950–1972), and Contemporary (2015–2019). We then identified morphologically distinct clusters while remaining agnostic to species identifications. We found that morphological diversity and the number of distinct clusters declined over time. We then leveraged species identifications to highlight key species losses and examine morphological shifts among extant species. Our findings provide insights into the historical and contemporary morphological diversity of ciscoes and will inform restoration efforts.
Extreme mass-ratio inspiral around the horizonless massive object
Authors: Zi Tieguang , Ren Liangliang , Cheng Jun
Published: August 2024

In this paper, we calculated the extreme mass-ratio inspiral (EMRI) waveform radiated from a binary composed of a massive horizonless object (MHO) and a compact object (CO), where CO is spiraling on a circular equatorial orbit around the MHO. Due to the absent of horizon, there exist the ingoing and outgoing waves near the reflective surface of MHO, which have significantly influence on the evolution of orbital parameters. We observe that there indeed exist the differences of EMRI trajectories between the massive Kerr black hole and MHO cases. By calculating the mismatch of gravitational wave (GW) waveforms from massive black hole (MBH) and MHO, our result indicates that the space-borne gravitational wave detector could distinguish the modified effect of reflectivities from the BH case, which allows to put an upper constraint on the reflectivity $${\mathcal {R}}$$
R
of MHO, at the level of $${\mathcal {R}} > rsim 10^{-4}$$

R
≳

10

-
4

.
A Characterization of Polynomial Time Computable Functions from the Integers to the Reals Using Discrete Ordinary Differential Equations
Authors: Blanc Manon , Bournez Olivier
Published: August 2024

In a recent article, the class of functions from the integers to the integers computable in polynomial time has been characterized using discrete ordinary differential equations (ODE), also known as finite differences. Doing so, the authors pointed out the fundamental role of linear (discrete) ODEs and classical ODE tools such as changes of variables to capture computability and complexity measures, or as a tool for programming.

In this article, we extend the approach to a characterization of functions from the integers to the reals computable in polynomial time in the sense of computable analysis. In particular, we provide a characterization of such functions in terms of the smallest class of functions that contains some basic functions, and that is closed by composition, linear length ODEs, and a natural effective limit schema.
Optimization of English Teaching Model Based on Deep Learning Algorithm
Authors: Yun Wei , Zhu Jing , Wu Ting
Published: August 2024

With the vigorous development of artificial intelligence technology, especially in the field of deep learning, English education and teaching models are facing unprecedented opportunities and challenges. In order to enable students to master English knowledge more efficiently and align with international standards, it is particularly important to study the optimization of English teaching models. This paper uses specific deep learning algorithms and techniques, such as Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN), to model and optimize English teaching modes, aiming to solve many problems in English teaching and improve the quality of English teaching. Through deep learning algorithms, we can analyze students’ learning behavior, habits and grades, thereby providing them with personalized learning resources and teaching strategies. Deep learning technologies such as CNN and RNN are used to recognize keywords and phrases in text, as well as to process sequence data such as speech and text, helping teachers better understand students’ learning needs and interests, thereby adjusting teaching content and methods. In addition, the adaptive nature of deep learning algorithms allows automatic adjustment of teaching content and difficulty according to the actual situation of students, providing them with learning resources and support that better meet their learning needs. This study not only applies deep learning algorithms to optimize English teaching modes but also delves into how these algorithms affect the learning outcomes of students and the teaching efficiency of teachers. Through empirical research and case analysis, we hope to provide new ideas and methods for the future development of English education.
Cavitating bubbly flow of non-Newtonian second grade fluid through nozzles: Application of reduction of cavitation damage and noise
Authors: Nadeem M. S. , Zeeshan A. , Majeed A. , Sait Sadiq M. , Ellahi R.
Published: August 2024

This research is focused on studying the behavior of bubbles in one-dimensional nozzle flows. The study delves into the complex flow of cavitating bubbles within geometries of varying cross-sectional areas, using a second-grade fluid. The cavitation phenomenon poses a potential threat, as it can harm surfaces upon bubble collapse or interaction with adjacent boundaries. Thus, the proposed model unveils the intricate behavior of cavitating bubbles in response to nozzle shape and fluid properties. The governing equations are first modeled using the Rayleigh–Plesset equation along with continuity and momentum equations for bubbly liquids. They are then simplified and nondimensionalized to solve by means of the RK method. The influence of several nondimensional parameters, including the Reynolds number, fluid parameter, cavitation number and the number of bubbles, on the flow behavior of second-grade fluid through various channels is illustrated using graphs. To validate the results, the Newtonian formulation was applied in the current setting, and it was found that the obtained results matched the available literature. Also, critical values of void fractions for the radius of the bubble are presented. The non-Newtonian properties of the fluid are observed a significant outcome for the reduction of cavitation damage and noise.
New insights into transport phenomena within steady MHD two-phase nanofluid flows over a permeable elastic sheet of an uneven thickness
Authors: Awati Vishwanath B. , Muchandi Sachin S. , Kumar N. Mahesh , Muhammad Taseer , Zaydan M. , Wakif A. , Sehaqui Rachid
Published: August 2024

This paper presents the effects of various properties on nanofluid flows and heat transfer over a permeable stretching sheet of variable thickness in the presence of a transverse magnetic field. Mathematically, the leading coupled partial differential equations are transformed into a self-similar system of ordinary differential equations through similarity variables, which are solved thereafter using Keller-box and Haar’s wavelet methods. Moreover, the impacts of various flow parameters involved in the physical problem are discussed thoroughly via tables and graphs. As findings, the analysis discloses that the nanofluid flow is significantly influenced by the physical parameters. Dynamically, the nanofluid flow is accelerated prominently with the strengthening in the injection process and decelerated in other situations. Furthermore, the obtained results are compared successfully with the earlier published findings.
On Combining Instance Selection and Discretisation: A Comparative Study of Two Combination Orders
Authors: Sue Kuen-Liang , Tsai Chih-Fong , Yan Tzu-Ming
Published: August 2024

Data discretisation focuses on converting continuous attribute values to discrete ones which are closer to a knowledge-level representation that is easier to understand, use, and explain than continuous values. On the other hand, instance selection aims at filtering out noisy or unrepresentative data samples from a given training dataset before constructing a learning model. In practice, some domain datasets may require processing with both discretisation and instance selection at the same time. In such cases, the order in which discretisation and instance selection are combined will result in differences in the processed datasets. For example, discretisation can be performed first based on the original dataset, after which the instance selection algorithm is used to evaluate the discrete type of data for selection, whereas the alternative is to perform instance selection first based on the continuous type of data, then using the discretiser to transfer the attribute type of values of a reduced dataset. However, this issue has not been investigated before. The aim of this paper is to compare the performance of a classifier trained and tested over datasets processed by these combination orders. Specifically, the minimum description length principle (MDLP) and ChiMerge are used for discretisation, and IB3, DROP3 and GA for instance selection. The experimental results obtained using ten different domain datasets show that executing instance selection first and discretisation second perform the best, which can be used as the guideline for the datasets that require performing both steps. In particular, combining DROP3 and MDLP can provide classification accuracy of 0.85 and AUC of 0.8, which can be regarded as the representative baseline for future related researches.
Varying free-gas zone (FGZ) and bottom-simulating reflection (BSR) response across a deep graben off Trujillo, central Peru
Authors: Herbozo Gery , Díaz-Naveas Juan
Published: August 2024

The complexity of marine gas hydrate systems at the Peruvian convergent margin has been linked to the post-Miocene history of vertical tectonics and subduction erosion that affected the forearc. Here, multichannel seismic data and published findings reveal that such a complexity has been further extended by the occurrence of the pre-Miocene deep Morsa Norte Graben (MNG) off Trujillo (8°–9° S) in the Central Peru margin. At water depths of 650–750 m in the upper slope, directly above the MNG depocentre (which has a 4–6 km overburden thickness), continuous bottom-simulating reflections (BSRs) and concentrated sub-BSR high-amplitude reflections are confined beneath a layered basin with a low–moderate near-seafloor heat flow (7–33 mW m
−2
). A deeper BSR modelled with a thermogenic gas composition is associated with the enhanced reflections. At a water depth of 900 m, sub-BSR reflections become less frequent in an area with a layered sediment cover defined by a moderate near-seafloor heat flow (15–33 mW m
−2
). At a water depth of 1200 m, where the MNG is relatively thick (3–4 km overburden thickness), faults connect patchy BSRs with a moderate–high near-seafloor heat flow (52–110 mW m
−2
). There, sub-BSR enhanced reflections are scarce. Immediately above the top of the gas hydrate stability zone (GHSZ), the near-seafloor heat flow reaches 81 mW m
−2
. Modelling suggests a water depth-dependent transport of heat towards the seafloor with respect to the top of the GHSZ, implying that the closer the seafloor is to the top of the GHSZ, the lower the advection of heat, and vice versa. Recent seafloor-related depositional and structural features amplify such relations in agreement with near-seafloor heat-flow variability. However, towards the area outside the extent of the MNG (<3 km overburden thickness), continuous BSRs are not linked either to a deeper BSR or to sub-BSR enhanced reflections. The continuity of one of these BSRs is deflected upwards beneath a slump, suggesting an incomplete thermal re-equilibration of the GHSZ. Therefore, we conclude that the BSR responds to: (1) the confinement and thickening of the free-gas zone (FGZ) above the MNG depocentre due to the sealing effect of recent sedimentation close to the top of the GHSZ; (2) the seepage of gas-rich fluids from a thinned FGZ above the relatively thick MNG, due to the enabling effect of faults cutting the GHSZ far from the top of the GHSZ; (3) the undisturbed state of the FGZ outside the extent of the MNG; and (4) the disequilibrium state of the base of the GHSZ due to the unloading of sediments in an unstable slope environment prone to failure.
Optimists, Pessimists, and Stock Prices
Authors: Daniel Kent , Klos Alexander , Rottke Simon
Published: August 2024

We review the academic findings from psychology and economics on disagreement—specifically, the effect of disagreement on asset prices. We discuss measurement of disagreement and how disagreement, coupled with constraints on short selling, can sideline pessimistic investors and result in overpricing. We review the literature on short selling in financial markets, paying particular attention to how and why some issues become hard-to-borrow and what factors go into the determination of borrowing costs, and we discuss the evolution of borrowing costs over the last several decades. We show how an examination of the prices and borrowing costs for constrained stocks can lead to an improved understanding of how disagreement in financial markets arises and is resolved, and we discuss directions for future research.
Statistical Data Integration for Health Policy Evidence-Building
Authors: Paddock Susan M. , Franco Carolina , Breidt F. Jay , Betancourt Brenda
Published: August 2024

Health policy evidence-building requires data sources such as health care claims, electronic health records, probability and nonprobability survey data, epidemiological surveillance databases, administrative data, and more, all of which have strengths and limitations for a given policy analysis. Data integration techniques leverage the relative strengths of input sources to obtain a blended source that is richer, more informative, and more fit for use than any single input component. This review notes the expansion of opportunities to use data integration for health policy analyses, reviews key methodological approaches to expand the number of variables in a data set or to increase the precision of estimates, and provides directions for future research. As data quality improvement motivates data integration, key data quality frameworks are provided to structure assessments of candidate input data sources.
(Invited) The Role of Ligand Characteristics in Modulating the Size, Size Distribution, and Alloy Formation in Metal Nanoparticle Systems
Authors: Bhagavatula L V Prasad
Published: August 2024

The transformation of the intert noble metals into functional materials not only involves their preparation at nanometer scale but also their surface functionalization with appropriate molecules. Such surface functionalization assumes significance not just for their stability in diverse solvent media but defines the way nanoparticles interact either with themselves or with the environment/biological systems. In general, organic molecules/ligands which have at least one functional group are known to act as stabilizing agents. Apart from this ligands also play a key role in nanoparticle formation in many aspects viz. controlling their size, morphology and their dispersional stability in a given medium. This talk briefly reviews the role of molecules/ligands as tools for controlling nanoparticle size, morphology and dispersion stability in solvent media. In particular we will introduce “Digestive Ripening” (DR), a post-synthetic size modification process as a reliable and reproducible method offering great control over size and size distribution of NCs. DR is known for converting a polydisperse NC system, post synthesis to nearly monodisperse NCs with the help of surface active organic molecules/ligands. Some of the recent results that we obtained helped unravel the dependency of DR process on the final size distribution dependency on the ligand chain length, the liagnd head group-NC binding strength, the ligand-solvent compatibility etc. Based on the understanding gained from this work we also try to provide some guidelines on how DR could be effectively used to make alloy NCs from a physical mixture of NC dispersions. The specific details of the above mentioned parameters will be disussed during the talk.
(Invited) NiCo2O4/MnO2 Microsphere as Efficient Bi-functional Electrocatalyst for Zinc-air Battery
Authors: Anand Abhas , Verma Anil , Basu Suddhasatwa
Published: August 2024

Microsphere-like NiCo2O4/MnO2 composite was synthesized via hydrothermal route as an efficient electrocatalyst with dual functionality, facilitating oxygen electrocatalysis reactions and serving as an air cathode in zinc-air batteries (ZABs) applications. The as-synthesized NiCo2O4/MnO2 demonstrated adaptable kinetics for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Specifically, it displayed a half-wave potential of 0.692 V for ORR and an overpotential of 218 mV for OER at a current density of 10 mA·cm-2. The double layer capacitance for NiCo2O4/MnO2 was experimentally calculated to be 31.67 mF.cm-2, suggesting a substantial level of electrochemical activity in the synthesized composite. The ZAB device assembled with a NiCo2O4/MnO2 cathode in a 6 M KOH electrolyte achieved an open circuit voltage of 1.48 V. It demonstrated a maximum power density of 127.04 mW·cm–2 at a current density of 190.64 mA·cm-2 and exhibited a notable specific discharge capacity of 756.62 mAh·g-1 at a current density of 5 mA·cm-2. The ZAB exhibited remarkable stability over 200 hours (equivalent to 600 cycles) of charge-discharge cycling at 5 mA·cm-2, with an almost negligible decrease in voltaic efficiency (~1.58%). Moreover, the practical applicability of Zn//NiCo2O4/MnO2 battery was assessed by powering a 2 V light-emitting diode for 20 hours employing two ZAB devices connected in series. This study establishes a foundation for the feasible application of ZABs incorporating cathodes based on Ni-Co-Mn.
(Invited) Flow of Charge and Heat in Ultra-Clean Graphene
Authors: Ghosh Arindam
Published: August 2024

Over the past two decades our understanding of the charge and heat transport properties of graphene has evolved progressively as the quality of graphene devices improved. In this talk, I shall present some new experimental result on the electrical and thermal transport measurements in graphene devices of unprecedented electrical mobility (> 1 million cm2/V.s). We show that the transport in such graphene devices is limited by intrinsic acoustic phonons and their scattering with electrons, rather than charged impurities – which is the case in conventional disordered graphene devices. This manifests in a rather striking violation of the Wiedemann-Franz law and density-dependent variation of the effective Lorenz number over six orders of magnitude. We find that the transport properties of ultra-clean graphene are quantitatively consistent with that of a hydrodynamic Dirac fluid.
Multimodal X-Ray Measurements for Sulfur and Sulfide Related Electrochemical Energy Storage
Authors: Zheng Xueli
Published: August 2024

Sulfur and sulfide are very promising candidates for electrochemical energy storage in electric vehicles and grid-scale storage due to their high theoretical capacity, low cost, and abundance. Although tremendous efforts have been devoted to sulfur and sulfide related batteries in recent years, they are still facing several challenges that need to be addressed before they can be widely adopted. Challenges including polysulfide shuttling effect in metal-sulfur batteries and electrochemical/interphase stabilities in sulfide solid-state electrolytes hindered their practical applications. Various techniques and strategies have been developed to address the above-mentioned challenges. However, revealing a next-level understanding of sulfur species interactions and speciation, using multimodal X-ray measurements to study the interaction temporally and spatially is still lacking. Here, we employed multimodal X-ray measurements including in situ sulfur K-edgeX-ray absorption spectroscopy, X-ray diffraction, and transmission X-ray microscopy to reveal electronic structure, crystal structure, morphology of sulfur species during battery cycling. Specifically, using operando sulfur K-edge X-ray absorption and X-ray diffraction, we obtained real-time and chemical information of sulfur species occurring at the sulfur cathode during lithium-sulfur battery operation. In the case of sulfide solid-state electrolytes, we explored the capacity loss mechanism in LiNi0.8Mn0.1Co0.1O2 cathodes when using argyrodite Li6PS5Cl sulfide solid electrolytes. Nickel K-edge X-ray absorption spectroscopy and transmission X-ray microscopy showed the cracking formation and heterogeneity in oxidation states for LiNi0.8Mn0.1Co0.1O2 cathodes using Li6PS5Cl solid-state electrolytes. In summary, we elucidated the dynamic changes in sulfur and provide insights on designing next-generation sulfur and sulfide related batteries.
Affecting the Electropolymerization of Aniline with Permanent Magnets
Authors: McLeod William T , Sheelam Anjaiah , Kroiss Aspen K , Bell Jeffrey Gordon
Published: August 2024

As portable electronics become more ubiquitous, the demand for different electrochemical energy storage (EES) systems grows. Conductive-polymer-based supercapacitors are an emerging type of EES device promising for their rapid charging and discharging, and among these, polyaniline (PANI) is favored for the ability to deposit it electrochemically from aqueous solutions of monomer. Despite this advantage, supercapacitors fabricated with PANI exhibit poor energy density and cyclability compared to other supercapacitors. In this work, it is shown how a permanent magnet can be applied to affect this electropolymerization, increasing the capacitance of the resultant polymer film by over 70% and increasing its cyclability more than ten-fold. The use of a permanent magnet allows enhancement of the process without the use of any chemical additives or additional energy input, such as from heating, excessive overpotentials, or mechanical stirring. The magnet influences the electropolymerization primarily through the magnetohydrodynamic (MHD) effect, but this work shows that the effect of the magnetic field exceeds that of mechanical stirring. Furthermore, evidence is presented that the influence from the magnet goes beyond forced convection from the MHD effect.
Low-Cost Anode-Free Aqueous Batteries Using Permanent Magnets
Authors: McLeod William T , Boni Tyler N , Bell Jeffrey Gordon
Published: August 2024

The rise in portable electronics has created an ever growing demand for more electrochemical energy storage (EES) systems. Lithium-ion batteries have achieved widespread commercial use because of their high energy density, but concerns about their safety and the sustainability of lithium have created a search for alternatives. Aqueous batteries present a much safer option, and they are cheaper both in materials and fabrication. The zinc-ion battery is among the most researched aqueous batteries, but problems remain with the formation of zinc dendrites during plating on the anode. A number of solutions to this problem have been proposed, including the use of a permanent magnet placed behind a zinc-foil anode, which creates uniform zinc deposition via the magnetohydrodynamic (MHD) effect. Herein, we expand this concept to zinc deposition on other substrates for the so-called anode-free configuration, in which an inactive current collector is used for the zinc to plate and strip off of during cycling. This anode-free configuration is a promising way to reduce the cost and increase the energy density of batteries by removing active material and allowing a cheaper, inactive material to serve as the substrate for metal plating and stripping, and the use of a permanent magnet precludes the need for a complicated material or over-engineered solution interface to prevent dendrite growth.
(Invited) Functionalization of Metallofullerenes and Formation of Bisadduct
Authors: Zhang Jianyuan , Sun Yue , Li Yanbang
Published: August 2024

Functionalization of metallofullerenes are critical steps to turn them into practical materials. In particular, regioselective multiadduct formation has been a critical challenge and only a few precedents were achieved among the metallofullerene reactions. Recently we have developed a new multicomponent reaction that gave trimetallic nitride clusterfullerenes an unusual behavior in the crystal solid state with a fixed cluster. Building on the previous results, we have synthesized metallofullerene bisadducts of in a regioselective manner. The regioselectivity is different from the previously reported bisadducts of trimetallic nitride metallofullerenes, and we are exploring the possibility of using the new bisadduct as a stepping stone to form higher adducts, or open an orifice on the metallofullerene cage.
Quantifying Interfacial Energetics of 2D Semiconductor Electrodes Using in situ Spectroelectrochemistry and Many-Body Theory
Authors: Almarez Rafael , Sambur Justin
Published: August 2024

2D transition metal dichalcogenides (TMDs) (MX2; M = Mo, W; X = S, Se) have unique electronic properties that may lead to the next generation of photo-electrocatalysis. The fundamental problem is that the interfacial energetics of TMDs are poorly understood. It is essential that we quantify the behavior of the energy bands in monolayer TMDs to understand their electronic properties. In this work, we develop an in-situ absorbance spectroscopy approach to quantify interfacial energetics of 2D semiconductor/electrolyte interfaces using a minimal many-body model to calculate the carrier concentration (n). Our results show that band edge movement in monolayer MoS2 is significant (0.2-0.5 eV) over a narrow range of applied potentials (0.2-0.3 V). Such large band edge shifts could change kET by a factor of 10-100, which has important consequences for practical solar energy conversion applications. In addition, our results show that we can modulate n of TMDs by introducing a redox couple in the electrolyte solution. I will discuss how these findings relate to solar energy conversion in photoelectrochemical cells.
(Invited) Manipulating the Exotic Excitons of Van Der Waals Correlated Antiferromagnet with Impurities and Size
Authors: Htoon Han
Published: August 2024

A Van der Waals correlated antiferromagnet, metal phosphorus trichalcogenides (MPX3, M = Mn, Fe, Ni; X = S, Se), have emerged as promising candidates for next generation spintronics, and quantum information technologies. Nickel phosphorus trisulfide (NiPS3) is a most notable member of this family and has been extensively studied for its unique properties, including the emergence of an ultra-sharp photoluminescence (PL) peak at ~1.476 eV below Néel temperature of 150 Kelvin. While the highly anisotropic, linearly polarized emission of this PL peak has been shown to be directly correlated to the long-range spin order of NiPS3, its ultra-narrow linewidth of a few hundred meV has led to the speculation that it is originated from a coherent many-body exciton state. Observations of multiple phonon bounds states and formation of exciton-polaritons also creates more excitement as they present new possibilities for design and control of correlated electron systems.

Aiming to achieve understanding and control of this spin-correlated exciton, we conduct temperature dependent, polarization resolved, PL studies on compounds of NiPS3 doped with different concentration of Mn (Ni1-xMnxPS3) and Se (NiPS3(1-x)Se3x). We observed systematic variation in characteristics of the spin-correlated exciton revealing their sensitive dependence on disturbance in the magnetic order of NiPS3.Next, to explore the effect of nanostructuring, we developed a novel chemical synthesis for highly crystalline NiPS3 nano flakes. We observed an activation of a new exciton state that share many exciting properties of bulk spin-correlated exciton.
Mechanochemical Synthesis of Sodium-Ion Conducting Chloride NaTaCl6
Authors: Motohashi Kota , Tsukasaki Hirofumi , Sakuda Atsushi , Mori Shigeo , Hayashi Akitoshi
Published: August 2024

All-solid-state sodium batteries have been attracting attentions owing to their high energy density and safety. Solid electrolytes play a significant role in the electrochemical performances of all-solid-state batteries. Chloride-based solid electrolytes are particularly important for achieving high energy densities because of their high oxidation stability, ionic conductivity, and formability. Fewer sodium-ion conducting chlorides have been developed compared to lithium-ion conducting materials. It is necessary to discover the chlorides as the end-member of sodium-ion conductors. In this study, we report the development of a new NaTaCl6 chloride as an end-member sodium-ion conductor with high ionic conductivity.

NaTaCl6 sample was mechanically prepared using a planetary ball mill apparatus. The X-ray diffraction patterns of the obtained sample displayed a broad pattern similar to the reported NaTaCl6 (ICSD#36519), suggesting that the sample contains both amorphous and crystalline phases. The reference intensity ratio method was used to investigate the weight ratios of the amorphous phases in the sample. The ratio was approximately 45 %. Transmission electron microscopy observations suggested that the sample consisted of the amorphous matrix and crystalline with the crystallite size of approximately 20 nm. The electrical conductivities of the pelletized samples were measured using two-terminal AC electrochemical impedance spectroscopy. The sample pellets were prepared by uniaxial pressing at 360 MPa without heat treatment. The pellet sample had the relative density of 85 % (powder density: 3.32 g cm–3, pellet density: 2.83 g cm–3). The sample shows σ
25ºC of 6.2×10–5 S cm–1, and the activation energy of 0.37 eV. To determine the NaTaCl6 onset oxidation voltage (OOV), linear sweep voltammetry measurement was carried out. The OOV of the sample at 60 ºC was 3.8 V vs. Na15Sn4. To demonstrate the high oxidation stability of NaTaCl6 in all-solid-state sodium batteries, it was used in a positive electrode by mixing Na3V2(PO4)3 as the active material and the buffer layer. The cell exhibited an initial reversible capacity of 96 mAh g–1 and stable cycling after 40 cycles with the capacity retention of 99.5 %. A 3.3 V all-solid-state sodium battery without oxide solid electrolytes was successfully operated. In this study, the NaTaCl6 electrolyte was developed with a high ionic conductivity and oxidation stability.

Acknowledgement: This work was partly supported by JSPS KAKENHI (Grant Numbers: JP21H04701 and JP19H05816) and MEXT Program: Data Creation and Utilization-Type Material Research and Development Project Grant Number JPMXP1122712807.
(Invited) S. R. Narayan and the Electrochemistry Scene at the Institute of Science
Authors: Rajeshwar Krishnan
Published: August 2024

The late Prof. S. R. Narayan was trained at the prestigious Indian Institute of Science in Bangalore, India. This author had the fortune of also receiving his Ph.D. degree from the same institution, albeit not quite in the area of electrochemistry but in a closely allied topic, namely, solid state chemistry. This author also did not overlap with the symposium honoree but was quite familiar with the infrastructure and faculty that existed in the department at the time Prof. Narayn graduated. The home department went by the acronym "IPC" and stood for Inorganic and Physical Chemistry. This talk will first summarize the electrochemistry division in that department and the R&D activities in progress in the 1970s and 80s. Then my talk will briefly address the areas where my own research overlapped with Prof. Narayan's research interests in the area of fuel cells. The talk will conclude with some personal recollections and reminiscences of this very fine gentleman and electrochemist.
(Invited) Lyten’s High Energy Li-S Batteries for a Sustainable and Circular EV Economy
Authors: Mikolajczak Celina , Bugga Ratnakumar , Vanheusden Karel , Mendiratta Arjun , Favors Zach , Cook Dan
Published: August 2024

Li-ion batteries (LIB), though widely used in EV batteries will be unable to meet the demands of the rapidly expanding vehicular market, mainly due to the challenges of cost and availability of key materials globally with limited resources, complicated by geopolitical factors. Li-S batteries promise significant advantages over Li-ion batteries with potentially higher specific energy, lower cost, and enhanced safety. However, their implementation has been hampered by poor cycle life due mainly to polysulfide shuttle caused by the soluble polysulfide intermediates. Lyten, an advanced materials company, has developed a family of new 3D Graphene™ materials for various applications including lithium-sulfur batteries. The mechanically flexible and electrically conductive framework of 3D graphene and its hierarchical porous structure make it an ideal host for potentially confining sulfur intermediates and mitigate the polysulfide shuttle. Lyten 3D Graphene™ materials have already shown enhanced sulfur utilization in Li-S cells far superior to the commercial nanocarbons (Fig. 1), even while their further fine-tuning is on-going. Lyten has established environmentally friendly 3D graphene-sulfur cathode fabrication methodology with high sulfur loadings using an aqueous binder.

In parallel, Lyten has been developing new protected Li anodes, advanced stable electrolytes that can function at low quantities (electrolyte/sulfur ratio), and multi-functional separators with an ability to block polysulfide crossover. Integration of these cell components resulted in Li-S cells with specific energy comparable to current Li-ion cells (250-275 Wh/kg). The cycle life is, however, relatively modest with 300 cycles @ 100% DOD, C/3 in coin cells, and ~150 cycles@100% DOD and over one thousand cycles @ 50% DOD in multi-layer pouch cells and 18650 cylindrical cells. There is a steady growth in both these categories enabled by further tuning of 3D graphene and advances in other materials.

Recently, Lyten has set up semi-automatic assembly lines for both multi-layer pouch and 18650 cylindrical cells, targeting an annual capacity of 2.4 MWh. These cells have started showing excellent consistency in specific energy in both cell formats. Fig.2 shows the narrow variability in the performance of 35 pouch and 18650 cells made recently for a customer.

Finally, preliminary safety tests performed on the recent prototype cells have yielded surprisingly good results for the Li-S cells containing Li metal anode. Tolerance to usual abuse conditions, e.g., internal and external shorts, overcharge and overdischarge, as demonstrated in our ARC tests will be an additive advantage of Lyten Li-S cells.

Figure 1
(Invited) Tunable Chemistry of 2D Carbide Mxenes for Hydrogen Evolution Reaction
Authors: Thakur Anupma , Anasori Babak
Published: August 2024

Two-dimensional (2D) transition metal carbides and nitrides (MXenes) are a large family of earth-abundant materials with more than forty compositions synthesized since 2011, such as Ti2CT
x
, Mo2CT
x
, Nb2CT
x
, Ti3C2T
x
, Mo2TiC2Tx, and Mo2Ti2C3T
x

. MXenes have emerged as promising candidates for catalytic energy storage and conversion because their 2D surfaces are electrochemically active combined with MXenes’ hydrophilicity, high electrical conductivity, and affinity to bond to molecules and nanomaterials to form hybrid structures. MXenes electrochemical properties can be tuned by the control of multiple variables: in the MXene formula of M
n

+1X
n
T
x
, the transition metals (M) can be any of the groups 4, 5, 6 of the periodic table or their combination, X can be carbon, nitrogen, or a solid solution of both, surface terminations (T
x
) can be any of the group 16 and 17, and the ‘n’ (MXene 2D flake thicknesses) can be 1 to 4. In this talk, we will discuss the control of MXene transition metals, their thicknesses, and surfaces to tune their electrocatalytic behavior. Specifically, we present a systematic study of 20 different MXenes, including novel compositions such as W2TiC2T
x
and Mo2Nb2C3T
x
and high-entropy MXenes, and discuss how we achieve low overpotential for hydron evolution reaction (as low as ~160 mV).
Engineered 2-D Heterostructures for Electrocatalysis
Authors: Nadarajan Renjith , Rajbongshi Bhargav , Shaijumon Manikoth
Published: August 2024

Atomically thin layered transition metal dichalcogenides (TMDs) such as MoS2, WS2, MoSe2 and WSe2 have been emerging as the cutting edge in materials science and engineering, due to their interesting electronic properties.1 These materials open up new opportunities for a variety of applications, including optoelectronics, energy conversion, and catalysis. To realize their potential device applications, it is highly desirable to achieve controllable growth of these layered nanomaterials, with tunable structure and morphology. TMDs exhibit promising catalytic properties for hydrogen generation and several approaches including defect engineering have been shown to increase the active catalytic sites.2,32D heterostructures based on various 2D layered materials with distinct properties have been demonstrated to exhibit novel physicochemical properties for their potential application in electrocatalytic hydrogen production. Here we present some of our efforts on morphological and photo/electrocatalytic studies of engineered 2D nanomaterials and their heterostructures.4-6 A seed-assisted chemical vapor transport (CVT) growth of ultra-thin triangular flakes of highly crystalline trigonal selenium (t-Se) oriented in (0001) direction, with lateral size >30 μm is demonstrated.[5,6] To study their promising photo-electrocatalytic properties and further realize the device applications, we employed a single-step CVT approach to grow selenene/WSe2 heterostructures. Vertical heterostructures of bi-layer selenene and monolayer WSe2 domains obtained via the CVT method are characterized by optical microscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The micro electrocatalytic reactor fabricated with Se/WSe2 heterostructure shows significantly improved HER activities upon shining the light. The work further extends to explore strain-engineered TMDs and their heterostructures towards efficient electrocatalytic hydrogen evolution reaction.

References

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P.V. Sarma, T.V.Vineesh, R.Kumar, V.Sreepal, R.Prasannachandran, A.K. Singh, and M.M. Shaijumon, ACS Catalysis(2020), 10,6753–6762

P. V. Sarma, A. Kayal, C. H. Sarma, M. Thalakulam, J. Mitra, and M. M. Shaijumon, ACS Nano, 13, 10448-10455 (2019).

R. Prasannachandran, T. V. Vineesh, A. Anil, B. M. Krishna and M. M. Shaijumon, ACS Nano, 12, 11511–11519 (2018).

R. Prasannachandran, T. V. Vineesh, M.B.Lithin, R. Nandakishore, M. M. Shaijumon, Chem. Commun., 56, 8623-8626 (2020).

P.V. Sarma, N. Renjith et al., 2D Mater., 9, 045004 (2022)
(Invited) Stabilizing the Electrodes and Interfaces in Lithium-Sulfur Batteries
Authors: Manthiram Arumugam
Published: August 2024

As the electrification of transportation sector and grid storage of electricity produced from renewable sources like solar and wind are rapidly evolving, cost, sustainability, and supply chain challenges will become the dominant issue. Lithium-sulfur batteries offer significant sustainability and cost advantages compared to the currently used lithium-ion batteries as sulfur is abundant and inexpensive and offers an order of magnitude higher capacity than the oxide cathodes. However, the commercialization of lithium-sulfur batteries is met with a few challenges, such as poor cycle life in practical cells. These challenges originate from the poor electronic and ionic conduction in sulfur and its discharged products, polysulfide shuttle, and poor cyclability of lithium-metal anode. To overcome some of these difficulties, generally a large amount of conductive carbon and liquid electrolyte are added to the cell; they enhance the cycle life, but drastically lower the practical energy density and make the lithium-sulfur batteries uncompetitive with lithium-ion batteries. To overcome the above challenges, this presentation will focus on optimizing sulfur and lithium sulfide cathodes, incorporation of electrocatalysts into the cathode to enhance sulfur redox, development of advanced electrolytes, incorporation of additives into the cathode and electrolyte to stabilize the cathode-electrolyte and anode-electrolyte interfaces, anode-free cells that eliminate the handling of thin lithium-metal foils, while keeping the sulfur loading and electrolyte/sulfur ratio at a practically accepted level. The improvements achieved and the mechanisms involved in the performance improvement will be discussed based on in-depth characterization data obtained with time-of-flight secondary ion spectrometry (TOF-SIMS), x-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR) spectroscopy, etc.
(Invited) Research and Development Trends in Sodium-Ion Batteries
Authors: Belharouak Ilias , Essehli Rachid , Dixit Marm , Li Mengya , Amin Ruhul
Published: August 2024

Lithium-ion batteries (LIBs) are the most used energy storage technology for electronic devices and electric vehicles. However, the increasing demand for lithium may make it difficult to support the widespread use of LIBs in electric vehicles, utility grids, and other applications. Therefore, developing alternative technologies to LIBs is critical for large-scale energy storage. Studies suggest that using sodium-ion batteries with renewable energies can significantly reduce the cost of electricity. Despite the lower energy density, sodium-ion batteries are appealing for several reasons: (1) sodium is abundant, (2) less critical components are used, and (3) the manufacturing knowledge of LIBs can be used. Herein, we report for the first time a hydrothermal synthesis of a new class of sodium-rich cathode material with the formula Na3+xNixV2-x(PO4)2F2O that could enable the compensation of the irreversible sodium loss in the first charge in a full cell with hard carbon. Trends in sodium-ion batteries will be discussed, considering the new developments in layered oxides, oxy-fluoro-phosphates, and Prussian blue cathodes.
(Invited) Element-Inserted Perylene Bisimides
Authors: Fukui Norihito
Published: August 2024

I report the synthesis and properties of element-inserted perylene bisimides.