bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the link between frailty and outcomes in geriatric patients with isolated rib fractures
Authors: Mohseni Shahin , Forssten Maximilian Peter , Mohammad Ismail Ahmad , Cao Yang , Hildebrand Frank , Sarani Babak , Ribeiro Marcelo AF
Published: February 2024

Background

Studies have shown an increased risk of morbidity in elderly patients suffering rib fractures from blunt trauma. The association between frailty and rib fractures on adverse outcomes is still ill-defined. In the current investigation, we sought to delineate the association between frailty, measured using the Orthopedic Frailty Score (OFS), and outcomes in geriatric patients with isolated rib fractures.

Methods

All geriatric (aged 65 years or older) patients registered in the 2013–2019 Trauma Quality Improvement database with a conservatively managed isolated rib fracture were considered for inclusion. An isolated rib fracture was defined as the presence of ≥1 rib fracture, a thorax Abbreviated Injury Scale (AIS) between 1 and 5, an AIS ≤1 in all other regions, as well as the absence of pneumothorax, hemothorax, or pulmonary contusion. Based on patients’ OFS, patients were classified as non-frail (OFS 0), pre-frail (OFS 1), or frail (OFS ≥2). The prevalence ratio (PR) of composite complications, in-hospital mortality, failure-to-rescue (FTR), and intensive care unit (ICU) admission between the OFS groups was determined using Poisson regression models to adjust for potential confounding.

Results

A total of 65 375 patients met the study’s inclusion criteria of whom 60% were non-frail, 29% were pre-frail, and 11% were frail. There was a stepwise increased risk of complications, in-hospital mortality, and FTR from non-frail to pre-frail and frail. Compared with non-frail patients, frail patients exhibited a 87% increased risk of in-hospital mortality [adjusted PR (95% CI): 1.87 (1.52-2.31), p<0.001], a 44% increased risk of complications [adjusted PR (95% CI): 1.44 (1.23-1.67), p<0.001], a doubling in the risk of FTR [adjusted PR (95% CI): 2.08 (1.45-2.98), p<0.001], and a 17% increased risk of ICU admission [adjusted PR (95% CI): 1.17 (1.11-1.23), p<0.001].

Conclusion

There is a strong association between frailty, measured using the OFS, and adverse outcomes in geriatric patients managed conservatively for rib fractures.
Failure after operative repair is higher for ballistic femoral neck fractures than for closed, blunt-injury fractures: a multicenter retrospective cohort study
Authors: Shu Henry Tout , Ghanem Diane , Rogers Davis L. , Covarrubias Oscar , Izard Paul , Hacquebord Jacques , Lim Philip , Gupta Ranjan , Osgood Greg M. , Shafiq Babar
Published: February 2024

Introduction

The purpose of this study was to describe the outcomes after operative repair of ballistic femoral neck fractures. To better highlight the devastating nature of these injuries, we compared a cohort of ballistic femoral neck fractures to a cohort of young, closed, blunt-injury femoral neck fractures treated with open reduction and internal fixation (ORIF).

Methods

Retrospective chart review identified all patients presenting with ballistic femoral neck fractures treated at three academic trauma centers between January 2016 and December 2021, as well as patients aged ≤50 with closed, blunt-injury femoral neck fractures who received ORIF. The primary outcome was failure of ORIF, which includes the diagnosis of non-union, avascular necrosis, conversion to total hip arthroplasty, and conversion to Girdlestone procedure. Additional outcomes included deep infection, postoperative osteoarthritis, and ambulatory status at last follow-up.

Results

Fourteen ballistic femoral neck fractures and 29 closed blunt injury fractures were identified. Of the ballistic fractures, 7 (50%) patients had a minimum of 1-year follow-up or met the failure criteria. Of the closed fractures, 16 (55%) patients had a minimum of 1-year follow-up or met the failure criteria. Median follow-up was 21 months. 58% of patients with ballistic fractures were active tobacco users. Five of 7 (71%) ballistic fractures failed, all of which involved non-union, whereas 8 of 16 (50%) closed fractures failed (p=0.340). No outcomes were significantly different between cohorts.

Conclusion

Our results demonstrate that ballistic femoral neck fractures are associated with high rates of non-union. Large-scale multicenter studies are necessary to better determine optimal treatment techniques for these fractures.

Level of evidence

Level III. Retrospective cohort study.
Timing and volume of transfusion for adult major trauma patients with hemorrhagic shock: a registry-based cohort study
Authors: Mitra Biswadev , Singh Bivekjeet , Mathew Joseph , Stewart Cara , Koolstra Christine , Hendel Simon , Fitzgerald Mark
Published: February 2024

Introduction

Transfusion of blood components is vital for the resuscitation of injured patients in hemorrhagic shock. Delays in initiating transfusion have been associated with harm, as has excess transfusion. The aim of this study was to evaluate variables associated with hospital mortality, with a focus on the two modifiable risk factors— time to initiate transfusion and volume of blood components—with hospital mortality.

Methods

This was a registry-based cohort study, including all consecutive adult patients presenting with hemorrhagic shock (systolic blood pressure (SBP) ≤90 mm Hg and transfusion of blood components) to a level 1 adult trauma center during a 5-year period (January 1, 2017–December 31, 2021). Associations with hospital mortality were assessed using multivariable logistic regression analysis, with final models developed using backward elimination.

Results

There were 195 patients included and there were 49 (25.1%) in-hospital deaths. The median time to first transfusion was 10 (IQR 6–16) minutes. Age (adjusted OR (aOR) 1.06; 95% CI: 1.03 to 1.08), initial SBP (aOR 0.96; 95% CI: 0.3 to 0.98), intracranial bleeding or diffuse axonal injury (aOR 2.63; 95% CI: 1.11 to 6.23), and the volume of blood components in the first 4 hours (aOR 1.08; 95% CI: 1.03 to 1.13) were associated with mortality. Time to transfusion was not associated with in-hospital mortality (aOR 0.99; 95% CI: 0.95 to 1.03). Among the 90 patients who underwent urgent transfer to the operating room or angiography suite, the median time to transfer was 2.38 hours (IQR 1.5–3.7). In this subgroup, age (aOR 1.11; 95% CI: 1.05 to 1.18) and volume of blood components (aOR 1.20; 95% CI: 1.08 to 1.34) were associated with mortality.

Discussion

In this setting where times to transfusion are short, further reductions in the time to transfusion are unlikely to improve outcome. In our population, for every unit of blood component transfused, the adjusted odds of death increased by 8%. These findings suggest investigation into strategies to achieve earlier control of hemorrhage.

Level of evidence

III.
Complications associated with the use of resuscitative endovascular balloon occlusion of the aorta (REBOA): an updated review
Authors: Fontenelle Ribeiro Junior Marcelo Augusto , Salman Salman M , Al-Qaraghuli Sally M , Makki Farah , Abu Affan Riham A , Mohseni Shahin Reza , Brenner Megan
Published: February 2024

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has become part of the arsenal to temporize patients in shock from severe hemorrhage. REBOA is used in trauma to prevent cardiovascular collapse by preserving heart and brain perfusion and minimizing distal hemorrhage until definitive hemorrhage control can be achieved. Significant side effects, including death, ischemia and reperfusion injuries, severe renal and lung damage, limb ischemia and amputations have all been reported. The aim of this article is to provide an update on complications related to REBOA. REBOA has emerged as a critical intervention for managing severe hemorrhagic shock, aiming to temporize patients and prevent cardiovascular collapse until definitive hemorrhage control can be achieved. However, this life-saving procedure is not without its challenges, with significant reported side effects. This review provides an updated overview of complications associated with REBOA. The most prevalent procedure-related complication is distal embolization and lower limb ischemia, with an incidence of 16% (range: 4–52.6%). Vascular and access site complications are also noteworthy, documented in studies with incidence rates varying from 1.2% to 11.1%. Conversely, bleeding-related complications exhibit lower documentation, with incidence rates ranging from 1.4% to 28.6%. Pseudoaneurysms are less likely, with rates ranging from 2% to 14%. A notable incidence of complications arises from lower limb compartment syndrome and lower limb amputation associated with the REBOA procedure. Systemic complications include acute kidney failure, consistently reported across various studies, with incidence rates ranging from 5.6% to 46%, representing one of the most frequently documented systemic complications. Infection and sepsis are also described, with rates ranging from 2% to 36%. Pulmonary-related complications, including acute respiratory distress syndrome and multisystem organ failure, occur in this population at rates ranging from 7.1% to 17.5%. This comprehensive overview underscores the diverse spectrum of complications associated with REBOA.
Berberine Alleviates Ischemic Brain Injury by Enhancing Autophagic Flux via Facilitation of TFEB Nuclear Translocation
Authors: Liu Yi-Li , Guo Tao , Zhang Yong-Jie , Tang Shun-Cong , Zhao Xiao-Ming , He Hong-Yun , Yu Chun-Lei , Deng Yi-Hao
Published: February 2024

Berberine has been demonstrated to alleviate cerebral ischemia/reperfusion injury, but its neuroprotective mechanism has yet to be understood. Studies have indicated that ischemic neuronal damage was frequently driven by autophagic/lysosomal dysfunction, which could be restored by boosting transcription factor EB (TFEB) nuclear translocation. Therefore, this study investigated the pharmacological effects of berberine on TFEB-regulated autophagic/lysosomal signaling in neurons after cerebral stroke. A rat model of ischemic stroke and a neuronal ischemia model in HT22 cells were prepared using middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation (OGD), respectively. Berberine was pre-administered at a dose of 100[Formula: see text]mg/kg/d for three days in rats and 90[Formula: see text][Formula: see text]M in HT22 neurons for 12[Formula: see text]h. 24[Formula: see text]h after MCAO and 2[Formula: see text]h after OGD, the penumbral tissues and OGD neurons were obtained to detect nuclear and cytoplasmic TFEB, and the key proteins in the autophagic/lysosomal pathway were examined using western blot and immunofluorescence, respectively. Meanwhile, neuron survival, infarct volume, and neurological deficits were assessed to evaluate the therapeutic efficacy. The results showed that berberine prominently facilitated TFEB nuclear translocation, as indicated by increased nuclear expression in penumbral neurons as well as in OGD HT22 cells. Consequently, both autophagic activity and lysosomal capacity were simultaneously augmented to alleviate the ischemic injury. However, berberine-conferred neuroprotection could be greatly counteracted by lysosomal inhibitor Bafilomycin A1 (Baf-A1). Meanwhile, autophagy inhibitor 3-Methyladenine (3-MA) also slightly neutralized the pharmacological effect of berberine on ameliorating autophagic/lysosomal dysfunction. Our study suggests that berberine-induced neuroprotection against ischemic stroke is elicited by enhancing autophagic flux via facilitation of TFEB nuclear translocation in neurons.
Numerical computations for Darcy–Forchheimer-based dual convection reactive flow considering Casson nanomaterial by convected permeable surface
Authors: Kausar M. S. , Waqas M. , Shehzad S. A. , Hosseinzadeh Kh. , Hejazi Hala A. , Mtaouaa Wafa
Published: February 2024

The use of nanoparticles in heat transmission is an interesting research subject and many scholars have shown an interest in this topic. In accordance with the motivating relevance of nanomaterials, the current research advocates for an evaluation of Casson nanofluid using porous medium thermal analysis in conjunction with vibrant implementations of mixed convection through a chemical reaction. Additionally, a nonlinear suction/injection phenomenon is taken into consideration. A consistent flow pattern is created by the stretched porous structure. The extended Casson nanofluid model is used to identify the heat production of non-Newtonian fluids. The essential incentives for choosing the Casson nanofluid model are validated as it simultaneously achieves Casson fluid, nanofluid and porous medium outcomes. The convective transport of nanofluid has been addressed using convective temperature boundary conditions and convective flow. A dimensionless form with similarity variables is used to simplify the fundamental equations for the provided flow model. The fourth-order Runge–Kutta (RK) strategy is deployed to arrive at a numerical solution for simulated flow. The physical conveyance of flow variables is accessed visually. It is calculated from engineering quantities (i.e., skin friction, Nusselt number and Sherwood number) to generate the numerical values. The velocity declines with increasing porosity and material factors while opposite outcomes are witnessed for buoyancy factors (mixed convection and buoyancy ratio) and injection factor.
An exact solution for the entropy base flow of electroosmotic magneto-nanofluid through microparallel channel
Authors: Bilal M. , Lone Showkat Ahmad , Anwar Sadia , Shahab Sana , Fatima Seerat , Ramzan M. , Nadeem M.
Published: February 2024

An exact solution of steady state, electroosmotic, transient magnetohydrodynamic (MHD) flow, and heat transfer of a viscous and incompressible electrically conducting nanofluid consists of water and Cu metal, through a microparallel channel under the combined effect of pressure and vertically acting magnetic field is found. An exact solution is calculated through Laplace transform using the software of Mathematica to find the steady velocity and temperature field depending on many dimensionless parameters. The electromagnetic couple effect, the volumetric generation of heat caused by the Joule heating effect, and viscous dissipation are considered to analyze the thermally fully formed heat flow problem based on the steady part of the velocity field. The exact result of the temperature field is obtained by taking the uniform boundary heat flux. The significant parameter of heat flow known as the Nusselt number, depending on the height of the microtube, is defined. At last, the entropy generation of MHD temperature flow is analyzed. The interpretation of variations that occurred in internal and external entropy generations is given and consequences are explained.
Study of several probability distribution functions for the Klein–Kramers equation
Authors: Li Yaxi , Kai Yue
Published: February 2024

In this paper, we take variable separation method to study Klein–Kramers (KK) equation. By choosing different eigenvalues and noise functions, we can get different probability density functions (PDFs) of KK equation. These PDFs contain not only normal distributions but also other distributions that correspond to anomalous diffusion phenomena. For example, power-law distribution, truncated Cauchy–Lorentz distribution, Weibull distribution, log-logistic distribution, Gamma distribution. We also show the 3D and 2D profiles of these PDFs to analyze the corresponding dynamic properties and illustrate the possible practical applications of these results. In addition, we also find some exact solutions that are not PDFs. They are also listed to ensure the completeness of the results and to illustrate the potential applications of these exact solutions.
Natural hybrid composites for built environment and engineering applications
Authors: Amuthan Tamilselvan , Nagaprasad Nagaraj , Somurajan Vijayan , Kumar Ramakrishnan Kulasekaran Sathish , Kumar Ashish , Kumar M Sunil , Krishnaraj Ramaswamy
Published: February 2024

Most of the automobile industries use natural fiber composites for the manufacturing of components since they serve as a better choice for composites reinforced with glass. This research focuses on the usage of natural fiber composites such as Achyranthes, Aspera, and Bagasse owing to their low weight, low cost, availability, eco-friendly, and also natural fiber composites are replace- ments for metal matrix composites due to their high stiffness and high strength-to-weight ratio characteristics. Synthesis of various natural fiber composites using reinforcements such as Achyranthes aspera and bagasse fibers, as well as glass fibers, utilizing a polyester-based matrix resin. The characterization of mechanical properties such as hardness, impact strength, tensile strength, and flexural strength has been carried out for these materials in dry and wet conditions. And also, the thermal stability of the composite has been investigated using a heat deflection test.
sGuard+: Machine Learning Guided Rule-Based Automated Vulnerability Repair on Smart Contracts
Authors: Gao Cuifeng , Yang Wenzhang , Ye Jiaming , Xue Yinxing , Sun Jun
Published: February 2024

Smart contracts are becoming appealing targets for hackers because of the vast amount of cryptocurrencies under their control. Asset loss due to the exploitation of smart contract codes has increased significantly in recent years. To guarantee that smart contracts are vulnerability-free, there are many works to detect the vulnerabilities of smart contracts, but only a few vulnerability repair works have been proposed. Repairing smart contract vulnerabilities at the source code level is attractive as it is transparent to users, whereas existing repair tools, such as
SCRepair
and
sGuard
, suffer from many limitations: (1) ignoring the code of vulnerability prevention; (2) possibly applying the repair to the wrong statements and changing the original business logic of smart contracts; and (3) showing poor performance in terms of time and gas overhead.

In this work, we propose machine learning guided rule-based automated vulnerability repair on smart contracts to improve the effectiveness and efficiency of
sGuard
. To address the limitations mentioned above, we design the features that characterize both the symptoms of vulnerabilities and the methods of vulnerability prevention to learn various vulnerability patterns and reduce false positives. Additionally, a fine-grained localization algorithm is designed by traversing the nodes of the abstract syntax tree, and we refine and extend the repair rules of
sGuard
to preserve the original business logic of smart contracts and support new vulnerability types. Our tool, named
sGuard+
, reduces time overhead based on machine learning models, and reduces gas overhead by fewer code changes and precise patching.

In our experiment, we collect a publicly available vulnerability dataset from CVE, SWC, and SmartBugs Curated as a ground truth for evaluations. Overall,
sGuard+
repairs more vulnerabilities with less time and gas overhead than state-of-the-art tools. Furthermore, we reproduce about 9,000 historical transactions for regression testing. It is shown that
sGuard+
has no impact on the original business logic of smart contracts.
A Survey and an Empirical Evaluation of Multi-View Clustering Approaches
Authors: Zhou Lihua , Du Guowang , Lü Kevin , Wang Lizheng , Du Jingwei
Published: February 2024

Multi-view clustering (MVC) holds a significant role in domains like machine learning, data mining, and pattern recognition. Despite the development of numerous new MVC approaches employing various techniques, there remains a gap in comprehensive studies evaluating the characteristics and performance of these approaches. This gap hinders the in-depth understanding and rational utilization of the recently developed MVC techniques. This study formalizes the basic concepts of MVC and analyzes their techniques. It then introduces a novel taxonomy for MVC approaches and presents the working mechanisms and characteristics of representative MVC approaches developed in recent years. Moreover, it summarizes representative datasets and performance metrics commonly employed for evaluating MVC approaches. Furthermore, we have meticulously chosen 35 representative MVC approaches to conduct an empirical evaluation across seven real-world benchmark datasets, offering valuable insights into the realm of MVC approaches.
SPIMulator: A Spintronic Processing-in-memory Simulator for Racetracks
Authors: Bera Pavia , Cahoon Stephen , Bhanja Sanjukta , Jones Alex
Published: February 2024

In-memory processing is becoming a popular method to alleviate the memory bottleneck of the Von Neumann computing model. With the goal of improving both latency and energy cost associated with such in-memory processing, emerging non-volatile memory technologies, such as Spintronic magnetic memory, are of particular interest, as they can provide a near-SRAM read/write performance and eliminate nearly all static energy without experiencing any endurance limitations. Spintronic Racetrack Memory (RM) further addresses density concerns of spin-transfer torque memory (STT-MRAM). Moreover, it has recently been demonstrated that portions of RM nanowires can function as a polymorphic gate, which can be leveraged to implement multi-operand bulk bitwise operations. With more complex control, they can also be leveraged to build arithmetic integer and floating point processing in memory (PIM) primitives. This article proposes SPIMulator, a Spintronic PIM sim
ulator
that can simulate the storage and PIM architecture of executing PIM commands in Racetrack memory. SPIMulator functionally models the polymorphic gate properties recently proposed for Racetrack memory, which allows
transverse access
that determines the number of “1”s in a segment of each Racetrack nanowire. From this simulation, SPIMulator can report real-time performance statistics such as cycle count and energy. Thus, SPIMulator simulates the multi-operand bit-wise logic operations recently proposed and can be easily extended to implement new PIM operations as they are developed. Due to the functional nature of SPIMulator, it can serve as a programming environment that allows development of PIM-based codes for verification of new acceleration algorithms. We demonstrate the value of SPIMulator through the modeling and estimations of performance and energy consumption of a variety of example applications, including the Advanced Encryption Standard (AES) for encryption primarily based on logical and look-up operations; multiplication of matrices, a frequent requirement in scientific, signal processing, and machine learning algorithms; and bitmap indices, a common search table employed for database lookups.
Charge–Discharge Performances and Mechanisms of Zn-Ion Batteries with β-MnO2, γ-MnO2, and Mn2O3 Positive Electrodes
Authors: Fujimoto Hiroyuki , Okada Masaki , Yoshikawa Masaaki , Shimoda Keiji , Fujinami So , Morita Masayuki , Ogumi Zempachi , Abe Takeshi
Published: February 2024

In the present study, the charge–discharge characteristics of zinc-ion batteries fabricated with β-MnO2,
γ-MnO2, or Mn2O3 as the positive-electrode material were evaluated. MnOOH is widely believed to be formed in the discharge reaction of γ-MnO2. However, when β-MnO2 was used as the positive-electrode material, we observed the formation of Mn2O3 and Mn3O4 instead of MnOOH in the first discharge reaction, and no reformation of β-MnO2 upon charging occurred. Furthermore, during the charge–discharge process, zinc was dissolved from the negative electrode, and basic zinc compounds were observed as byproducts at both the positive and negative electrodes. For the second cycle onwards, the amounts of Mn2O3 and Mn3O4 increased during discharging and decreased during charging. The process showed a stable discharge capacity of 200 Ahkg−1 until ∼30 cycles, thereafter decreasing to 105 Ahkg–1 by the 100th cycle.
Method—Setups and Protocols for Operando Batteries Experiments at Variable Temperatures Applied to CaxTiS2 and Na3−xV2(PO4)3
Authors: Houdeville R. G. , Missyul A. , Fuentes V. , Moline M. M. Prieto , Farre F. , Gonzalez J. B. , Palacin M. R. , Fauth Francois
Published: February 2024

In this paper, we present two thermalized setups for in situ operando X-ray diffraction data collection in temperature ranging from 0° to 100 °C: a modified Leriche cell and a coin cell chamber. Both setups proved proper thermalization and representative electrochemistry. While the coin cell chamber may only be used in transmission mode, the modified Leriche cell can also be used in reflection mode. Two case studies are presented as example of operation: calcium insertion in TiS2 and sodium (de-)insertion in Na3−xV2(PO4)3. For the former, heating at 60 °C enables faster kinetics to form a solvent co-intercalated phase upon reduction, a process which is reversible upon reoxidation. For the later, Na3−xV2(PO4)3 is known to form a low temperature phase at ca 12 °C. Thanks to the thermalized setups, operando X-ray diffraction patterns were collected while cycling on the low temperature phase.
Passive Film Formed on Si-Mn Steel in Boric Acid-Borate Buffer at 6.5
Authors: Fushimi Koji , Higa Kanta , Fujimura Akihiro , Shoji Sunao , Kitagawa Yuichi , Hasegawa Yasuchika , Katayama Hideki
Published: February 2024

Passivity-maintaining current of high-strength (Si-Mn) steel in boric acid-borate buffer at pH 6.5 was larger than that of ferrite/pearlite (F/P) steel. Charge transfer resistance of the Si-Mn steel surface passivated at 1.10 V vs SHE in pH 6.5 buffer was smaller than that of F/P steel surface. Nano-analyses using AES and STEM revealed the details of the structure and components of the passive film on the Si-Mn steel. The inferiorities of passivity of Si-Mn steel were suggested to be due to the alloying components and metallurgical structure to increase the strength of the steel.
Nanoscale Carbon Allotrope at Zero-Dimension: From Small Carbon Nanoparticles to Carbon Dots and Their Organic Hybrids
Authors: Sun Ya-Ping
Published: February 2024

In the vast research field on carbon nanostructures, a seemingly broadly accepted family configuration of nanoscale carbon allotropes is such that fullerenes take the zero-dimensional dot spot, in perfect harmony with one-dimensional carbon nanotubes and two-dimensional graphene nanosheets. More recently, however, a threat to the nice “family value” has been the emergence of small carbon nanoparticles, which are carbon particles of a few nanometers in size without any defined crystal structures or largely amorphous and populated with abundant surface and other defects. The growing experimental evidence has revealed the unique and/or advantageous optical and photoexcited state properties and photoinduced redox characteristics of the small carbon nanoparticles, especially the spectacular performance enhancements upon their being effectively surface passivated by organic species for the hard-core/soft-shell nanostructures defined as carbon dots. Thus, the ugly and dirty dot-like carbon particles have been elevated to the position of being able to compete with pretty and perfect fullerenes, which by the way are nano-sized molecules strictly speaking, for the title of nanoscale carbon allotrope at the zero-dimension. Nevertheless, carbon dots are not short of controversies, which are due largely to the fact that samples sold or labeled as “carbon dots” in store or literature reports, respectively, are often not what they are advertized, but complex mixtures of varying structures and compositions. Some of these will be discussed in the presentation, so are challenges and opportunities in this seemingly rapid expanding research field.

Figure 1
3D Printing of Conversion Cathodes for Enhanced Custom-Form Lithium Batteries
Authors: Cardenas Jorge Antonio , Bullivant John Paul , Wygant Bryan R , Merrill Laura C , Kolesnichenko Igor V. , Lapp Aliya S. , Lambert Timothy N. , Whetten Shaun R. , Allcorn Eric , Talin Albert Alec , Cook Adam , Harrison Katharine L
Published: February 2024

Additive manufacturing techniques can enable the fabrication of batteries in nonconventional form factors, enabling higher practical energy densities due to improved power source packing efficiency. Furthermore, energy density can be improved by transitioning from conventional Li-ion materials to lithium metal anodes and conversion cathodes. Iron disulfide (FeS2) and iron trifluoride (FeF3) are two promising conversion cathodes of commercial and academic interest, but the 3D printing of inks made from these materials for custom-form battery applications has yet to be demonstrated. In this work, the deposition of FeS2 and FeF3 inks are investigated and optimized using direct-ink-write (DIW) 3D printing, in addition to the development of printable separators and packages to produce custom-form batteries. Two distinct custom form-factors, one on wave-shaped current collectors and the other on cylindrical rod current collectors, are demonstrated and shown to exhibit performance similar to coin cells when conventional Celgard separators are used. Additionally, FeF3 cells were integrated with a DIW printed separator consisting of an electrolyte exchanged PVDF-HFP based ionogel [1]. In the case of FeS2, it was found that cathodes with a ridged surface, produced from the filamentary extrusion of highly concentrated inks (60-70% solids w/w%) exhibited optimal power, uniformity, and stability [2]. Finally, progress toward fully-printing custom-form batteries using metal powder bed printed cases and stereolithographically printed gaskets is demonstrated. Overall, the additive manufacturing of conversion electrodes, separators, and battery packaging is shown to be a viable path toward the making of custom-form cells. More broadly, electrode ridging is found to optimize rate capability, a finding that may have broad impact beyond FeS2, FeF3 and additive manufacturing.

[1] A.S. Lapp, L.C. Merrill, B.R. Wygant, D.S. Ashby, A.S. Bhandarkar, A. Zhang, E.J. Fuller, K.L. Harrison, T.N. Lambert, and A.A. Talin. Room Temperature Pseudo-Solid State Iron Fluoride Conversion Battery with High Ionic Conductivity. ACS Applied Materials & Interfaces 15, 893-902, 2022.

[2] J.A. Cardenas, J.P. Bullivant, I.V. Kolesnichenko, D.J. Roach, M.A. Gallegos, E.N. Coker, T.N. Lambert, E. Allcorn, A.A. Talin, A.W. Cook, and K.L. Harrison. 3D Printing of Ridged FeS2 Cathodes for Improved Rate Capability and Custom-Form Lithium Batteries. ACS Applied Materials & Interfaces 14, 45342-45351. 2022.
Corrosion Properties of Quenching and Partitioning-Processed Martensitic Stainless Steels
Authors: Li Gaojie , Kwakernaak Kees , Muratori Marta , Smith Ali , Santofimia Maria , Gonzalez-Garcia Yaiza
Published: February 2024

The increasing demand for lightweight and energy-efficient automobile materials has prompted consideration of the Quenching and Partitioning (Q&P) process for developing martensitic stainless steels with enhanced combinations of strength and ductility. The microstructures of Q&P-processed martensitic stainless steels primarily consist of a matrix of carbon-depleted martensite and films of retained austenite, although some high-carbon fresh martensite may be present.

This research aimed to elucidate the influence of chemical composition (manganese content), heat treatment, and phase fractions (martensite and retained austenite) on the corrosion properties of Q&P-processed martensitic stainless steels.

The microstructures were investigated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), electron probe microanalysis (EPMA), and transmission electron microscopy (TEM). Corrosion properties were evaluated through electrochemical measurements in a 3.5% NaCl solution, which included open-circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Scanning Kelvin probe force microscopy (SKPFM) measurements were also conducted.

Q&P process ideally minimizes carbide formation, as all carbon atoms are partitioned into austenite. Nevertheless, our research demonstrates that this condition is not always met. Depending on the alloy's chemical composition and the partitioning temperature, carbides and inclusions may still form, favoring localized corrosion such as pitting and intergranular corrosion.
Effect of Selenium on Dissolution of Manganese Sulfide Inclusions in Stainless Steel
Authors: Nishimoto Masashi , Katsuyama Tomoki , Muto Izumi , Sugawara Yu
Published: February 2024

The pit initiation sites for commercial stainless steels have been attributed to sulfide inclusions such as MnS. The chemical composition of the inclusions affects the pitting corrosion resistance of stainless steels.1,2 It is known that the inclusion solubility in aqueous solutions affects pitting corrosion resistance. The dissolution of sulfide inclusions produces S species and exposes the bare surface of the steel matrix, resulting in high pitting susceptibility near the inclusions. Selenium is known to improve the machinability of stainless steels. However, the effect of selenium on the dissolution and pit initiation of MnS inclusions in stainless steels remains unclear. In this study, a microelectrochemical technique was applied to analyze the effect of Se on the dissolution and pit initiation of MnS inclusions in stainless steels.

Two re-sulfurized stainless steels were prepared by vacuum induction melting: one was Se-free, and the other was Se-added. The specimens were heat-treated at 1373 K for 30 min and quenched in water. After heat treatment, the specimens were polished with 1 µm diamond paste. Polarization curves were measured in 0.1 M NaCl and 0.1 M Na2SO4. An optical microscope and a scanning electron microscope equipped with an energy dispersive X-ray spectroscopy system were used to capture images of the specimen surfaces.

References:

M. Nishimoto, I. Muto, Y. Sugawara, and N. Hara, Corros. Sci., 176, 109060 (2020).

M. Nishimoto, I. Muto, Y. Sugawara, and N. Hara, Corros. Sci., 180, 109222 (2021).
Corrosion Resistance of Stainless Steel Containing Mo-Rich Areas
Authors: Saito Haruka , Muto Izumi , Nishimoto Masashi , Sugawara Yu
Published: February 2024

Stainless steels are widely used because of their high corrosion resistance. It is well known that Mo improves the pitting corrosion resistance of stainless steels1, 2), and the transpassive dissolution of pure Mo occurs in the passive region of stainless steels. In this study, a stainless steel that releases Mo-species in chloride solutions and exhibits self-healing properties was fabricated by spark plasma sintering (SPS) of type 304L gas atomized powder and 2.5 mass% of Mo powder. Sintering temperature was 1100℃ and it kept for 20 min. The specimen surface was polished down to 1 μm using a diamond paste.

The as-polished and etched surfaces of the samples were observed by an optical microscope. A field emission scanning electron microscope equipped with an energy-dispersive X-ray spectroscopy system was also used to observe the surface of the specimens. From the observations, the formation of Mo-rich areas was confirmed, and the Mo-rich area was found to be consisted of three phases: inner, middle, and outer phases. Inner phase was rich in Mo, and middle and outer phases contains other elements such as Cr, Ni, and Fe.

To assess the corrosion resistance, potentiodynamic polarization curves were measured in 0.1 M NaCl (pH 6.0). The size of electrode area was 300 µm × 300 µm or 5 mm × 5 mm. The stainless steel with Mo-rich areas showed higher pitting corrosion resistance compared with sintered type 316L stainless steel fabricated by SPS. After polarization, inner phase of Mo-rich area dissolved, while middle and outer phase did not dissolve. Pitting corrosion resistance was concluded to be improved by dissolved Mo-species from Mo-rich areas.

References;

Saito, I. Muto, and Y. Sugawara, Mater. Trans., 61 (2020), 2248-2251.

Saito, I. Muto, M. Nishimoto, and Y. Sugawara, Mater. Today Commun., 33 (2022) 104211.
Effect of Fe Doped Electrolyte on Advanced Alkaline Water Electrolysis
Authors: Demnitz Maximilian , Lira Garcia Barros Rodrigo , de Groot Thijs Theodorus , van der Schaaf John
Published: February 2024

Within alkaline water electrolysis, Fe is an omnipresent ion, that is frequently encountered. It may originate from steel pipes, electrolyser components, and KOH impurities. The impact of dissolved Fe in KOH electrolyte on the electrolyser performance is, however, not yet well researched and understood.

We performed studies at near industrial conditions, with varying concentrations of added Fe ([Fe] = 0 μM; 25 μM; 50 μM; 500 μM) in 30 wt.% KOH electrolyte and its effect on the cell performance in a single mixed flow cell at different temperatures (T = 20 °C; 50 °C; 85 °C) using perforated Ni plates as electrodes. The [Fe] in the electrolyte was monitored pre and post electrolysis using ICP-OES, while Fe deposition on cathode and anode was analyzed using SEM/EDX and XPS. For electrochemical characterization, chronopotentiometry and electrochemical impedance spectroscopy were conducted to obtain IV and Nyquist plots, respectively. From the obtained data we were then able to determine the internal resistance corrected IV plots and combined Tafel slopes for cathode and anode.

From the internal resistance corrected cell potential we are able to observe that an increasing [Fe] leads to a decrease in cell potential throughout all current densities (see Figure). This effect can be seen even at [Fe] = 500 μM, which is above the solubility limit of Fe in the electrolyte. The enhancement above the solubility limit could be due the formation of mobile Fe hydroxide colloids in the electrolyte. We have further conducted 3-electrode measurements in a steady state cell under the same conditions to show how Fe deposition on cathode and anode changes their respective overpotentials for OER and HER. Our studies results suggest that Fe doped electrolyte can significantly decrease the cell potential in close to industrial conditions by improving reaction kinetics.

Figure 1
Electrochemical Behavior of Mg and Zn-Substituted HA Composite Coating on Titanium Produced By Plasma Electrolytic Oxidation
Authors: Valizade Nima , Sabour Rouh Aghdam Alireza , Jarjoura George
Published: February 2024

The aim of this study is to develop a long-term corrosion-resistant, antibacterial, and bioactive TiO2/hydroxyapatite (HA) coating using a one-step plasma electrolytic oxidation (PEO) method. Magnesium and zinc-substituted HA particles were synthesized and utilized to create a composite coating that is corrosion-resistant, bioactive, and antibacterial. Prior to their use in the coating, the synthesized particles were characterized by XRD and FESEM. The results of polarization and electrochemical impedance spectroscopy (EIS) tests showed a significant increase in corrosion resistance. Moreover, the EIS results indicated an improvement in corrosion behavior after 168h, which was attributed to the formation of apatite in simulated body fluid (SBF). Additionally, a significant improvement in the bioactivity and antibacterial activity of the composite coatings was observed. Hence, the use of Mg, Zn-doped HA/TiO2 composite coatings could be a promising approach for developing bio-corrosion-resistant coatings for titanium biomaterials.

Keywords: Plasma electrolytic oxidation, Hydroxyapatite, Corrosion, Electrochemical impedance spectroscopy, Biomaterials
Characterisation of Molten Lithium Carbonate Corrosion on SiC Heating Elements Using Raman Spectroscopy
Authors: Zhang Shuoshuo , Irvine John Thomas Sirr
Published: February 2024

The synthesis of lithium battery materials involves the use of muffle furnaces operating with SiC type heating elements. Usually, the industrial SiC heating element is protected by passive oxidation forming a protective silica film on the surface of the element. However, this strategy is not suitable for heating elements that operate in a Li-rich environment. A preliminary study has recently been completed to develop an understanding on the degradation of silicon carbide heating elements under the exposure to lithia. After basic characterisation of the SiC rod and its oxidation in air, its reaction products in the presence of Li was studied. The SiC rod was reacted with a likely Li source, Li2CO3, in three different % Li concentration environments through vapour-phase, wetting and full-immersion studies, particularly at the temperature just above the Li2CO3 melting point in delivering accelerated ageing. The characterisation was achieved via an integrative data analysis through the coordination of Raman, XRD, and Energy dispersive X-ray analysis (EDX) techniques. We found that molten Li2CO3 reacts with the silica surface layer of the element forming three main lithium silicates (LixSiyOx/2+2y). The degradation of surface silica into non-adherent lithium silicate leads to a speeding-up of the SiC oxidation process. Both processes eventually lead to a complete structural failure of the SiC rod. We performed a long-term vapour phase lithium attack experiment characterising the SiC after regular time intervals solely by Raman spectroscopy. Initially, a library of Raman spectra for the commonly encountered compounds in the Si-Li-O system was obtained from specifically synthesised stoichiometric compounds. In doing so, the reaction products at different reaction time intervals can be clearly identified, demonstrating the utility of Raman characterisation in corrosion studies.
Understanding and Modeling the Stochastic Nature of Corrosion Reactions in Atmospheric Conditions
Authors: Katona Ryan Michael , Maestas Demitri , Wilson Mark , Montes de Oca Zapiain David , Melia Michael Anthony , Noell Philip James , Schaller Rebecca Filardo
Published: February 2024

Corrosion is a detrimental materials degradation mechanism to many in-service alloys and alloy systems. The stochastic nature of corrosion processes makes prediction and identification of degradation a monumental task. Additionally, the wide range of materials utilized in complex systems, coupled with variable environments, further complicates this process. Here, we utilize Finite Element Method (FEM) models coupled with statistical software (Dakota), and machine learning techniques to build a generalized framework to evaluate the probability of corrosion occurring. The ability to input defined, statistically distributed model parameters allows for the identification of corrosion probability and provides for the discovery of important parameters for future experimental efforts. In addition to the statistical predictions of corrosion, machine learning (ML) techniques allow for accelerated predictions from models, potentially reducing both time and computation effort for corrosion predictions (i.e., rate and extent of corrosion). The framework for corrosion modeling will be discussed and applied to various models, including reactive transport models.

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. This document is SAND2023-02444C.
Corrosion and Mechanical Properties of Multi Principal Element Alloys Designed By Using Diffusion Couples
Authors: Yesilcicek Yasemin , Wetzel Anncia , Ozcan Ozlem , Witt Julia , Dimper Matthias
Published: February 2024

The efficient exploration of novel alloy chemistries is crucial for advancing the development of new materials. Diffusion-controlled synthesis of gradient alloys is an intelligent approach for creating phase diagrams and to effectively identify potential material combinations with tailored properties.

This project focusses on the design of quaternary multi-principle-element alloys (MPEAs) using diffusion couples. Our diffusion system contains an equimolar ternary alloy (FeNiCr) and additional single diffusing elements e.g. Mn and Mo. We determined the optimal temperature ranges for the diffusion thermal treatment by means of ThermoCalc simulations with the aim to form single-phase MPEAs. Microstructure and chemical characterization of the diffusion couples were performed by means of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). For most alloy couples, the diffusion zone contained a single-phase alloy matrix with diffusion-induced compositional gradient as well as precipitation phases. This heterogeneity makes the diffusion couples interesting materials to investigate local mechanical and corrosion properties. Thus, local corrosion properties were examined using Atomic Force Microscopy (AFM) and Scanning Electrochemical Microscopy (SECM). Nanoindentation was used for the analysis of local mechanical properties.

Based on the results of the local corrosion analysis, we have selected single-phase alloy chemistries along the diffusion zone and reproducibly synthesized these alloys in bulk for detailed corrosion studies by means of potentiodynamic polarization and SECM.

The presentation will briefly summarize our methodology and motivation for using diffusion couples as an efficient tool for exploring phase diagrams of MPEAs in the search for new alloy chemistries and the results of our correlative study on the mechanical and corrosion properties of these materials.
(Corrosion Division H. H. Uhlig Award) A Journey From Ice-Breakers to Biomedical Implants: Multifacets of Corrosion
Authors: Virtanen Sannakaisa
Published: February 2024

Understanding of corrosion mechanisms enables safe, durable and sustainable application of metallic materials in various fields. The presentation will shortly summarize a personal selection of most important lessons learned in the last 30 years of corrosion research, and then highlights some recent developments for methodologies to study atmospheric and immersion corrosion by respirometry. The approach is based on monitoring the rate of cathodic reactions with help of different types of sensors; this enables a real-time, simultaneous quantification of the rate of the O2 reduction reaction (OER) and the H2 evolution reaction (HER). The respirometric setups can be coupled with electrochemistry, enlarging the corrosion cases to be studied from open-circuit conditions to potential-controlled systems. Examples will be presented, to illustrate the potential of these techniques to reveal insights on corrosion mechanisms of active (e.g. Mg and Zn) and passive metals and alloys (e.g. stainless steels). For passive metals and alloys, special focus in this presentation will be on transpassive dissolution. In essence, three processes can take place in this potential regime: metal dissolution, oxide film formation, and oxygen evolution from water oxidation. In this case, respirometric determination of the oxygen evolution reaction (ORR) helps to distinguish the current (charge) consumed for metal oxidation reactions vs. water oxidation. Most recent developments to enable high-resolution respirometric measurements – and hence to study corrosion in the passive state and its localized breakdown – will be presented.
Insights into Corrosion of Current Collectors for Magnesium Batteries
Authors: Rademacher Laurin , Häcker Joachim , Wagner Norbert , Nojabaee Maryam , Friedrich K. Andreas
Published: February 2024

To enable the shift towards renewable energy, the use of low-cost energy storage systems is necessary. Magnesium (Mg) is an abundant and safer raw material than lithium for electrochemical energy storage systems such as batteries, due to its reduced sensitivity to air. Promising intercalation materials for cathodes include Chevrel phase Mo6S8 and Prussian green FeFe(CN)6. Although magnesium perchlorate-based electrolytes are practical for early-stage cathode research, they are not compatible with Mg metal due to corrosion. The organo-metallic all phenyl complex (APC) based electrolyte is a potential candidate for magnesium full cells, but both systems contain reactive chloride species that cause severe corrosion of the current collector.

This study utilizes linear sweep voltammetry, chronoamperometry, and electrochemical impedance spectroscopy to identify suitable materials for current collectors, including carbon-coated Al and Ni. The selected materials must withstand a polarization potential of 2 V vs. Mg/Mg2+. A Graphite-based current collector is shown to be the most promising candidate due to its low areal density, which can increase the energy density of practical Mg batteries.