bluuebunny/crossref_metadata_2025 huggingface dataset:
ALMA hints at the presence of turbulent disk galaxies at z > 5
Authors: Parlanti E. , Carniani S. , Pallottini A. , Cignoni M. , Cresci G. , Kohandel M. , Mannucci F. , Marconi A.
Published: April 2023

Context. High-redshift galaxies are expected to be more turbulent than local galaxies because of their smaller size and higher star formation and thus stronger feedback from star formation, frequent mergers events, and gravitational instabilities. However, this scenario has recently been questioned by the observational evidence of a few galaxies at z ∼ 4 − 5 with a gas velocity dispersion similar to what is observed in the local population.

Aims. Our goal is to determine whether galaxies in the first billion years of the Universe have already formed a dynamically cold rotating disk similar to the local counterparts.

Methods. We studied the gas kinematic of 22 main-sequence star-forming galaxies at z > 5 and determined their dynamical state by estimating the ratio of the rotational velocity and of the gas velocity dispersion. We mined the ALMA public archive and exploited the [C II] and [O III] observations to perform a kinematic analysis of the cold and warm gas of z > 5 main-sequence galaxies. We compared our results with what was found in the local and distant Universe and investigated the evolution of the gas velocity dispersion with redshift. We also compared the observations with theoretical expectations to assess the main driver of the gas turbulence at z > 5.

Results. The gas kinematics of the high-z galaxy population observed with ALMA is consistent within the errors with rotating but turbulent disks. We indeed infer a velocity dispersion that is systematically higher by 4–5 times than the local galaxy population and the z ∼ 5 dust-obscured galaxies reported in the literature. The difference between our results and those reported at similar redshift can be ascribed to the systematic difference in the galaxy properties in the two samples: the disks of massive dusty galaxies are dynamically colder than the disks of dust-poor galaxies. The comparison with the theoretical predictions suggests that the main driver of the velocity dispersion in high-redshift galaxies is the gravitational energy that is released by the transport of mass within the disk. Finally, we stress that future deeper ALMA high-angular resolution observations are crucial to constrain the kinematic properties of high-z galaxies and to distinguish rotating disks from kiloparsec-scale mergers.
Rational methods of geodetic control of technogenic consequences of the development of oil and gas fields
Authors: Volkov Victor , Volkov Nikita , Volkova Tatiana
Published: April 2023

The methods of controlling the consequences of the influence of manmade geomechanical processes caused by the extraction of hydrocarbons from the subsurface in the fields under development are considered. The possibilities of methods from the standpoint of separate determination of spatial and temporal quantitative parameters characterizing the deformed state of the skeletons of reservoirs and host rocks, the entire thickness of the rock mass above the deposit in an uneven field of compressive stresses and deformations of the earth’s surface are shown. The inconsistency of methods of classical repeated leveling, geodetic positioning and traditional radar interferometry in connection with the low level of representativeness of their results is noted. scientific novelty lies in the development of ways to improve the effectiveness of the method of radar satellite interferometry. As a result, the conditions for the effective use of radar satellite interferometry on the basis of a network of stationary points which coincide with the points of the leveling network method of spot geodetic sounding of deformation processes in the oil and gas fields under development have been determined and characterized.
Reducing harmful air emissions from vehicles, ships and stationary facilities operating in the Arctic
Authors: Antipov Boris , Shotidi Konstantin , Novikov Denis
Published: April 2023

The paper proposes a method for reducing harmful emissions into the Arctic atmosphere during the operation of diesel engines using electromagnetic waves of ultra-high frequency (UHF) and ultrasound. Experimental studies were conducted, which confirmed the reduction of NOx emissions by 50%. In order to implement the method, a multipurpose fuel unit is being developed.
Study of water purification reactor operating modes
Authors: Chuikov Alexander , Volkov Andrey , Barskii Igor , Shabanov Dmitrii
Published: April 2023

Wastewater treatment is one of the main problems of development and urbanization of the Arctic regions. This article is devoted to the development of a method for assessing the degree of water purification in order to determine the optimum operating parameters of treatment reactors for water treatment by ferrates from industrial and household waste resulting from the development of Arctic regions. Experiments reflecting the influence of the amount of air supplied to the purification plant on the processes of mixing and distribution of water were carried out and analyzed. Based on the experimental data, a method for determining the optimum operating parameters of a new mobile water purification plant has been developed and applied. The operation of the plant is based on the use of the ferrate method. equations and dependencies describing the relationship between the reactor volume, liquid flow rate and the degree of water purification are given. The degree of water pollution is estimated as its fraction which has left the reactor before the time required for complete treatment of the liquid from the moment it enters i the reactor. Optimal parameters of the ferrate reactor, such as volume and air supply, for a mobile water treatment plant were determined.
Thermodynamic modeling of the reaction of simultaneous interaction of nickel (II), cobalt (II) and iron (III) oxides with carbon
Authors: Kolesnikova Olga , Nurbaeva Farida , Sabyrbayeva Guizhan , Nurshakhanova Lazzat
Published: April 2023

This paper considers thermodynamic modeling of electric smelting of Allarechenskoye deposit dumps for nickel, cobalt, and iron extraction. Thermochemical transformations in the reaction of interaction of carbon with oxides of nickel (II), cobalt (II) and iron (III) are considered. The investigations of thermochemical transformations of the chemical-phase composition of the system were carried out using the software complex “Astra-4” developed by a team of scientists at the Bauman Moscow State Technical University. Thermochemical transformations and chemical-phase composition of the system as a function of T (temperature) and P (pressure) were studied. In particular, the temperature was in the range from 973K to 1773K and the pressure range was taken from 0.001 MPa to 0.1 MPa. According to the results, it was found that iron in the system transitions to condensed iron, with the degree of transition (αFe) from 29.0% at T = 1173K to 99.1% at 1773K, the degree of transitions of nickel to condensed nickel is 100% before T = 1273K, and with an increase in temperature from 1273K to 1773K decreases to 99,98%; the transition of cobalt to the gas phase is distributed similarly to nickel.
Variability of the ice area and the possibility of achieving an ice-free regime in the Barents Sea
Authors: Istomin Eugene , Petrov Yaroslav , Martyn Irma , Abramov Valery , Yagotinceva Natalia
Published: April 2023

The results of the analysis of the interannual variability of the Barents Sea ice area, including trends in the area of sea ice distribution for the period 1979-2018 based on remote sensing data, are presented. The analysis of trends is based on a dimensionless trend index, which allows comparing different areas of sea ice distribution. Estimates of the Barents Sea ice-free regime in January and August are presented on the basis of extrapolation of trends for the period 1979-2018. The ice-free regime of the Barents Sea in January is expected in 2055, in August - 2026.
Efficiency of sorption-biological treatment of oil-polluted coastal areas in the Euro-Arctic region
Authors: Myazin Vladimir
Published: April 2023

A biotechnology based on sorption-biological treatment for the restoration of the Arctic coastal areas after oil spills was proposed. A hydrocarbon-oxidizing microbial preparation based on microfungi (Penicillium janthinellum, Penicillium simplicissimum) and bacteria (Pseudomonas fluorescens, Pseudomonas putida) was created. Granular activated carbon, thermoactivated vermiculite, and peat were used as sorbents. The sorbents are concentration centers for microorganisms, prevent the spread of hydrocarbons, and improve the condition of the polluted substrate by optimizing the water-air regime. After treatment, sorbents are not removed from the soil. As a result of laboratory studies at +10°C, the hydrocarbon content in the polluted coastal sand was reduced by 44-60%, and in the coastal soil by 25-68% after three months. This technology can be used at the final stage of coastal areas cleaning, as well as the only method of cleaning in highly sensitive areas. The use of aboriginal hydrocarbon-oxidizing microorganisms, typical of most coastal substrates of the Euro-Arctic region, excludes changes in the structure of the microbial community in these areas. The adaptation of these microorganisms to extreme climatic conditions allows biological treatment to be carried out with high efficiency in the Subarctic and Arctic.
Problems of Environmental and Technogenic Safety Regulation in the Arctic Region: Oil Spills
Authors: Yakovlev Sergey , Shemyakin Alexey
Published: April 2023

The article analyzes the changes in the regulatory and legal framework related to the development of the main document on oil spill response planning. the key points of the regulatory and methodological framework applied until January 1, 2021, which should have been given special attention, are highlighted. The second part of the article analyzes the updated regulatory and legal framework for preventing and responding to spills. the third part provides a comparative analysis of the old and new legislation governing the development of oil and petroleum product spill prevention and response plan, and also discusses some methodological aspects. The results of the analysis are formulated in the conclusion. It is noted that despite innovations, scientific and methodological support of development remains insufficient.
Permafrost degradation and devastating floods of the 20th – 21st centuries for the Livelihoods of Yakut Arctic villages
Authors: Suleymanov Alexander
Published: April 2023

The article uses the example of the Argakhtakh village of the Srednekolymsky ulus of the Republic of Sakha (Yakutia) located in the middle course of the Alazeya river basin to analyse the consequences of floods during the period of a relatively stable state of the environment and in recent decades, characterized by its imbalance due to global climate transformation, based on analysis of archival data, published literature and own field materials. Due to this, the causes, history and consequences of h floods of 1977-1978 were examined. It is shown that it caused significant damage to agriculture, specifically to the fodder supply of bovine cattle and horses. At the same time the materials found confirm that the territory of the village itself was not significantly affected. A different situation occurred during the floods of 1997, 2007-2008 and 2017-2018. In the first case, not only the farmlands were flooded, but the new streambed of the Alazea River appeared next to Argakhtakh and the local farm zoo was deprived of its stable land connection to the village. The flood rises of the 21st century, apart from disastrous consequences for cattle ranges and meadows, caused damage to the housing stock of Argakhtakh, household outbuildings and infrastructure objects. all this led to a radical reduction in the scale of involvement of the local population in traditional sectors of economic activity (cattle and horse breeding), the elimination of fur farming, the degradation of transport accessibility of the village and the costs of the population to restore the economy.
Problems of entrepreneurship development in the Arctic: Russian and foreign experience of observing the principles of green economy
Authors: Kuchumov Artur , Pecheritsa Elena , Blazhenkova Natalia
Published: April 2023

In recent years, interest in the Arctic regions has grown. Global corporations, policymakers, and research scientists became interested in the Arctic, as the climate in the Arctic regions changes and as the consequences in the global world directly or indirectly extend to all countries. The desire to understand and manage the new economic opportunities associated with the vast natural resources of the Arctic regions is common among all interested parties. However, the achievement of economic goals depends on many factors. It should be noted that among the factors facilitating economic development, we should consider important the factors of development of local communities and local entrepreneurship, and observation of the principles of green economy. In recent years, Russian and foreign Arctic research scientists have published a significant number of articles on the study of the Arctic regions and the development of entrepreneurship. The purpose of this work is to study entrepreneurship in the Arctic regions by analyzing Russian and foreign scientific publications. A common negative demographic factor for the Arctic regions is the change in the structure of the population, so the development of entrepreneurship can be considered important for the development of the Arctic regions, capable of providing livelihoods for local residents. The article considers the current conditions for entrepreneurial activity in the Arctic to determine the problems and prospects for the development of entrepreneurship in the Arctic regions from the point of view of green economy. In the article, the authors offer advice on engaging in entrepreneurial activities in the Arctic, following the principles of sustainable development and adhering to the principles of a green economy.
Problems and prospects of economic growth in the context of the environmental component of sustainable development in the Arctic zone of the Russian Federation
Authors: Kuchumov Artur , Pecheritsa Elena , Blazhenkova Natalia , Chaikovskaya Alexandra
Published: April 2023

The article examines the perceived drivers of economic growth and the corresponding implications for proactive, evidence-based policies, discusses national issues and shapes a shared vision for the future among key interested parties. The authors highlight the main drivers of change and economic growth in the Arctic, including energy security, climate change, and transportation development, which have a huge direct impact on the Arctic region across all three dimensions of sustainable development: economic, social, and environmental. The authors consider the following as the problems facing the creation of conditions for economic growth in the Arctic region of the Russian Federation, in terms of sustainable development: environment, problems of the Arctic population, management problems in the changing Arctic, and the adaptation of technologies and production processes to the Arctic climate. In conclusion, the authors deduce that the creation of a joint group consisting of relevant private, public, governmental and non-governmental organizations would be the best strategy for considering effective mechanisms for multinational and multilateral governance of sustainable development in the Russian Arctic zone. The authors also believe that in order to create conditions for economic growth in the Arctic zone of the Russian Federation and to facilitate further transition to sustainable development, the authorities at the first stage should provide economic support measures for doing business, especially in two key areas for the Arctic: the development of animal husbandry and the development of various types of tourism.
A paradigm shift in the agricultural system in the Arctic zone of the Russian Federation
Authors: Ingiri Andrey , Ageeva Polina , Ikko Natalia , Yashkina Anna
Published: April 2023

The article presents an overview of the environmental and economic consequences of chemicalization in crop production of the Murmansk region. Proposed is a way to overcome the current situation in the industry through alternative biological sources of increasing soil fertility. Three original varieties of lupines inoculated with a highly effective strain of nodule bacteria Rhizobium lupini were studied in a production experiment. The fodder value of green mass was calculated. Microbiological and agrochemical analyzes of soil in areas with alternative and traditional agricultural technologies were carried out.
Prospective industrial complexes in the Russian Arctic: focus on rare-earth metals
Authors: Solovyova Victoria , Cherepovitsyna Alina
Published: April 2023

At present, issues related to the development of rare-earth metal industrial complexes are becoming particularly relevant for Russia. Rare-earth metals (REMs) play a vital role in high technology. Therefore, success in technological progress largely depends on the availability of these metals. However, the country’s position remains uncertain – on the one hand, Russia possesses huge REM reserves, on the other hand, they are not exploited, and the existing level of import dependence of metals on supplies from foreign countries exceeds 80%. The main national REM reserves are in the Arctic region. Nevertheless, even rich deposits are still not exploited. This study aims to investigate the prospects for the development of REM industrial complexes in the Russian Arctic, taking into account both opportunities and constraints. The resource potential of REMs in the Russian Arctic is investigated, a comparative analysis of the characteristics of foreign and national REM objects is provided. The factors influencing the prospects of development of REM industrial raw material complexes are determined. Data on the main REM projects are systematized. The study makes it possible to draw some important conclusions about the current prospects for the development of rare-earth metal industrial raw materials complexes in the Russian Arctic.
Environmental tourism potential of the Arctic regions of Russia
Authors: Roslyakova Natalia , Dorofeyeva Ludmila
Published: April 2023

Tourism is an important field for international cooperation. The Arctic zone has a potential for the tourism activities development, the question remains on what policy principles should forming this industry be carried out. The goal of the work is to determine the advantages of the Arctic territories as a network cluster that takes into account modern security requirements and creates conditions for the development of territories based on tourist attractions. The work considers the best practices in the field of tourism clusters development in the world, Russian legislation aimed at activating the process of cluster formation in the field of tourism, key factors that determine the unique characteristics of the tourism sector of the Arctic. The main methods used were analytical generalization, comparative analysis, retrospective analysis of the legislative framework in the tourism sector of Russia. As a result, stating certain successes in the field of tourism development in the Arctic, the authors note the need for the development of the environment to attract the local population to forming cultural code of territory and note the key areas of digitalization that could contribute to improving the processes of tourist cluster formation in the Arctic territories.
Dépeindre la finance comme une « force pour le bien » : analyse de discours du Global Impact Investing Network (GIIN)
Authors: Burnier Daniel , Balsiger Philip , Kabouche Noé
Published: April 2023

Cet article s’intéresse au discours de l’industrie de l’investissement d’impact à travers le cas du Global Impact Investing Network (GIIN), l’une des plus importantes organisations à faire la promotion de cette approche à travers le monde. À partir d’une analyse documentaire, nous décrivons le concept flou d’« investissement d’impact » qui se trouve au cœur de ce discours. Afin de favoriser la diffusion de ce concept et de son discours, le GIIN fait appel à deux techniques de « concrétisation » qui le rendent plus tangible : l’objectivation de l’impact social ou environnemental d’un investissement qui fait exister ce dernier à travers des mesures quantifiables et son exemplification, qui se focalise avant tout sur les investisseurs et leurs intentions plutôt que sur les entreprises bénéficiaires ou les populations et environnements visés in fine par ces investissements. Nous montrons enfin que ce concept est porté par un discours plus général qui est construit autour d’une logique dite « gagnant-gagnant ».
Single-Incision Laparoscopic Cholecystectomy Using the Marionette Transumbilical Approach Is Safe and Efficient with Careful Patient Selection: A Comparative Analysis with Conventional Multiport Laparoscopic Cholecystectomy
Authors: Sohail Amir H. , Silverstein Jeffrey , Hakmi Hazim , Pacheco Tulio Brasileiro Silva , Hadi Yousaf B. , Gangwani Manesh Kumar , Aziz Muhammad , Ajouz Hana , Shin David
Published: April 2023

Objectives The “marionette technique” for transumbilical laparoscopic cholecystectomy (m-TLC) offers improved cosmesis and possibly shorter postoperative recovery for patient undergoing laparoscopic cholecystectomy versus the four-port conventional laparoscopic cholecystectomy (CLC). We compared the outcomes of m-TLC and CLC at a tertiary care facility in New York.

Methods A retrospective chart review was conducted and data on patients who underwent m-TLC and CLC were retrieved. Hospital length of stay (LOS), operative time, and complications were compared between the two groups using linear and logistic regression, as appropriate.

Results M-TLC group patients were significantly younger, predominantly females with lower body mass index. They were less likely to have previous abdominal surgery and more likely to have noninflammatory pathology (p < 0.05 for all). Nonadjusted LOS (1 vs. 3 days, p-value < 0.0001) and operative time (50 vs. 56 minutes, p-value = 0.007) were significantly lower among patients who underwent m-TLC; however, there was no significant difference on multivariate analysis. In multivariate analysis, there was no difference in the overall complication rate (odds ratio: 1.63; 95% confidence interval 0.02–2.39).

Conclusion With careful patient selection, m-TLC offers better cosmesis with comparable safety outcomes.

Level of evidence Level III.
Operative Management of Extensor Carpi Ulnaris Instability: A Systematic Review
Authors: Lari Ali , Burhamah Waleed , Alherz Mohammad , Prada Carlos
Published: April 2023

Background Posttraumatic extensor carpi ulnaris (ECU) instability is an increasingly recognized cause of ulnar-sided wrist pain that occurs when the ECU subsheath is disrupted.

Purpose The purpose of this systematic review was to assess outcomes of operatively treated posttraumatic ECU instability.

Methods A systematic search of Medline, Embase, Web of Science, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases was performed using “extensor carpi ulnaris” as the keyword. Studies were systematically screened and data extracted independently by two reviewers.

Results Eight retrospective studies met the inclusion criteria with a total of 97 wrists. The mean age was 32 years (13–61). Patients underwent either primary repair (40%) using sutures and anchors, or reconstruction (60%) using extensor retinaculum flaps. One study performed deepening of the osseous ulnar groove. Two studies compared preoperative and postoperative values. They both reported a significant improvement in pain scores, functional scoring instruments, satisfaction, and grip strength. The rest of the studies reported similarly favorable outcomes across the same outcomes. Concomitant pathologies were identified in 66% of the study population. Complications occurred in 9% of the sample size, including ECU tendinitis, ulnar sensory nerve irritation, and reintervention for concomitant pathology. None of the studies reported recurrence or reruptures. However, five patients (6.7%) did not return to their previous activity level.

Conclusion Patients can expect favorable outcomes with a potentially low complication rate. Nevertheless, the heterogeneity of the sample population, operative techniques, and outcome measures warrant further standardized studies.

Level of Evidence IV.
Surgical Management of Craniosynostosis—Between the Past and the Future: A Comprehensive Review of the Literature
Authors: Fouda Mohammed A
Published: April 2023

Cranial sutures are fibrous joints between the bones of the cranial vault, acting as centers of osteogenesis of the embryonic mesenchyme. Skull growth is a strictly regulated process, controlled by several genetic pathways. A minor perturbation of these pathways may lead to premature fusion of the cranial sutures. Craniosynostosis occurs as a result of the premature fusion of the cranial sutures. The incidence of craniosynostosis is approximately 1 in 2,500 live births. Syndromic craniosynostoses such as Apert, Crouzon, and Pfeiffer comprise 15% of patients, while nonsyndromic craniosynostosis represents 85% of all patients. By the late 1800s, Lannelongue (Paris, 1890) and Lane (San Francisco, 1892) attempted the first surgical intervention (strip craniectomy) for the management of craniosynostosis. The inadequacy of simple suturectomies and strip craniectomies in the management of craniosynostosis led to the innovation of more complex procedures such as frontoorbital advancement and posterior cranial vault distraction. However, these extensive surgical interventions are lengthy procedures and associated with more blood volume loss which requires blood transfusion. These limitations led to the modern era of minimally invasive endoscopic techniques. In this paper, we reviewed the body of the literature on the evolution of surgical management of craniosynostosis over the last century and the possible future directions.
Definitive Surgery after Neoadjuvant Chemotherapy for Locally Advanced Oral Cavity Cancers: Experience from a Tertiary Care Center
Authors: Agrawal Mansi , Konduru Vidya , Riju Jeyashanth , Singh Ashish , Joel Anjana , Karuppusami Reka , Tirkey Amit Jiwan
Published: April 2023

Background Oral cavity cancers require definitive surgical resection as the primary treatment, but with advanced T stage, complete resection with pathologically negative margins might be difficult to achieve. Induction chemotherapy helps achieve the balance between resection and morbidity in locally advanced technically unresectable tumors. The aim of this study was to analyze the impact of surgery in locally advanced, technically unresectable oral cavity cancers after neoadjuvant chemotherapy (NACT).

Materials and Methods A retrospective analysis of patients with borderline resectable, locally advanced oral cavity cancers who were given NACT between February 2017 and December 2021 was conducted. Data regarding clinical and pathological characteristics, NACT, surgery, adjuvant therapy, and recurrences was analyzed.

Results Of the 69 patients in the study, 69.6% had tongue cancer, rest were gingivobuccal complex cancers. All tumors were resected based on the post-NACT tumor volume and clear margins were achieved in 42% of cases. About 85.4% of the tongue cancers required a lesser resection than anticipated, thereby following the concept of organ and functional preservation post-NACT as proposed by Licitra et al. About 30.4% had ypT0 and 17.4% had ypN0. Recurrence and survival rates noted in our study were comparable to those reported in literature. Lymph node density of more than or equal to 0.07 was found in all recurrent cases.

Conclusions Induction chemotherapy offers a chance of achieving adequate surgical resection while reducing morbidity and improving functional outcomes for patients with technically unresectable oral cavity cancers. Nodal disease may not respond to chemotherapy as well as the primary tumor. There is a need for comprehensive evaluation of prognostic factors, which could help identify the patients who will most benefit with NACT.
Spinal Epidural Collection following Lumbar Puncture in a Patient with Idiopathic Intracranial Hypertension
Authors: Krothapalli Neeharika , Hersh David , Yorns William , Acsadi Gyula , DiMario Francis J.
Published: April 2023

Epidural cerebrospinal fluid (CSF) collections after lumbar puncture are a rare and underdiagnosed entity in the pediatric population. Physicians should maintain vigilance about warning signs of severe progressive back pain extending beyond the puncture site and new neurological symptoms after lumbar puncture. Extensive symptomatic epidural collections, which may be dorsal and compromise the thecal sac, can be secondary to CSF leakage. Early diagnosis with spinal magnetic resonance imaging and prompt treatment is vital in reducing morbidity and mortality. These collections typically resolve with conservative management and no serious sequelae. We report a rare case of spinal epidural collection following a lumbar puncture in a patient with idiopathic intracranial hypertension that was successfully treated with a blood patch and surgical decompression in the setting of significant neurological deterioration.
Scaling up superconducting nanowire-based electronics
Authors: Patrick Chris
Published: April 2023

Nanocryotrons produce a shift register capable of coupling with compatible photon detectors and withstanding strong magnetic fields.
A spatially resolved optical method to measure thermal diffusivity
Authors: Sun F. , Mishra S. , McGuinness P. H. , Filipiak Z. H. , Marković I. , Sokolov D. A. , Kikugawa N. , Orenstein J. W. , Hartnoll S. A. , Mackenzie A. P. , Sunko V.
Published: April 2023

We describe an optical method to directly measure the position-dependent thermal diffusivity of reflective single crystal samples across a broad range of temperatures for condensed matter physics research. Two laser beams are used, one as a source to locally modulate the sample temperature, and the other as a probe of sample reflectivity, which is a function of the modulated temperature. Thermal diffusivity is obtained from the phase delay between source and probe signals. We combine this technique with a microscope setup in an optical cryostat, in which the sample is placed on a three-axis piezo-stage, allowing for spatially resolved measurements. Furthermore, we demonstrate experimentally and mathematically that isotropic in-plane diffusivity can be obtained when overlapping the two laser beams instead of separating them in the traditional way, which further enhances the spatial resolution to a micron scale, especially valuable when studying inhomogeneous or multidomain samples. We discuss in detail the experimental conditions under which this technique is valuable and demonstrate its performance on two stoichiometric bilayer ruthenates: Sr3Ru2O7 and Ca3Ru2O7. The spatial resolution allowed us to study the diffusivity in single domains of the latter, and we uncovered a temperature-dependent in-plane diffusivity anisotropy. Finally, we used the enhanced spatial resolution enabled by overlapping the two beams to measure the temperature-dependent diffusivity of Ti-doped Ca3Ru2O7, which exhibits a metal–insulator transition. We observed large variations of transition temperature over the same sample, originating from doping inhomogeneity and pointing to the power of spatially resolved techniques in accessing inherent properties.
Microneedle arrays integrated with microfluidic systems: Emerging
applications and fluid flow modeling
Authors: Ahmadpour Abdollah , Isgor Pelin Kubra , Ural Berk , Eren Busra Nimet , Sarabi Misagh Rezapour , Muradoglu Metin , Tasoglu Savas
Published: April 2023

Microneedle arrays are patches of needles at micro- and nano-scale, which are competent and versatile technologies that have been merged with microfluidic systems to construct more capable devices for biomedical applications, such as drug delivery, wound healing, biosensing, and sampling body fluids. In this paper, several designs and applications are reviewed. In addition, modeling approaches used in microneedle designs for fluid flow and mass transfer are discussed, and the challenges are highlighted.
On the potentially transformative role of auxiliary-field quantum Monte Carlo in quantum chemistry: A highly accurate method for transition metals and beyond
Authors: Shee James , Weber John L. , Reichman David R. , Friesner Richard A. , Zhang Shiwei
Published: April 2023

Approximate solutions to the ab initio electronic structure problem have been a focus of theoretical and computational chemistry research for much of the past century, with the goal of predicting relevant energy differences to within “chemical accuracy” (1 kcal/mol). For small organic molecules, or in general, for weakly correlated main group chemistry, a hierarchy of single-reference wave function methods has been rigorously established, spanning perturbation theory and the coupled cluster (CC) formalism. For these systems, CC with singles, doubles, and perturbative triples is known to achieve chemical accuracy, albeit at O(N7) computational cost. In addition, a hierarchy of density functional approximations of increasing formal sophistication, known as Jacob’s ladder, has been shown to systematically reduce average errors over large datasets representing weakly correlated chemistry. However, the accuracy of such computational models is less clear in the increasingly important frontiers of chemical space including transition metals and f-block compounds, in which strong correlation can play an important role in reactivity. A stochastic method, phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC), has been shown to be capable of producing chemically accurate predictions even for challenging molecular systems beyond the main group, with relatively low O(N3 − N4) cost and near-perfect parallel efficiency. Herein, we present our perspectives on the past, present, and future of the ph-AFQMC method. We focus on its potential in transition metal quantum chemistry to be a highly accurate, systematically improvable method that can reliably probe strongly correlated systems in biology and chemical catalysis and provide reference thermochemical values (for future development of density functionals or interatomic potentials) when experiments are either noisy or absent. Finally, we discuss the present limitations of the method and where we expect near-term development to be most fruitful.
Capillary rise behavior of lubricant in micropores with spiral bulge structures
Authors: Zhang Guotao , Ma Liangliang , Tong Baohong , Yin Yanguo , Hu Enzhu , Dearn Karl
Published: April 2023

The highly efficient exudation of lubricant in porous self-lubricating materials significantly influences the formation of self-lubricating films. In this paper, micropores with inner spiral bulge structures are considered, and their influence on the capillary behaviors of the lubricant is discussed to reveal the capillary rising mechanism. The results show that the Taylor capillary lift phenomenon is produced in the spiral bulge structure of the micropore, and the capillary lift force is enhanced. The spiral structure decreases the effective diameter of micropores. The magnitudes of the pressure and velocity in the spiral structure pores are larger than those in smooth pores. The liquid in the upper part of the micropores forms a velocity vortex during its upward rotation along the spiral channel, which promotes the capillary rising behavior. For smaller pitches, the velocity vortex increases, and the rising speed of the lubricant grows. The inner spiral bulge structure gives the micropores an excellent capillary rising ability. The quantitative characterization and mechanism reveal that the capillary rising behavior can be used to guide the bionic designs of pores in self-lubricating materials.
Effect of a niobium-doped PZT interfacial layer thickness on the properties of epitaxial PMN-PT thin films
Authors: Boota M. , Houwman E. P. , Lanzara G. , Rijnders G.
Published: April 2023

We are reporting on high quality epitaxial thin films of [Pb(Mg1/3Nb2/3)O3]0.67-(PbTiO3)0.33 [PMN-PT (67/33)]. These films were deposited on (001) oriented, vicinal SrTiO3 single crystal substrates, using 1 mol. % niobium-doped Pb(Zr0.52,Ti0.48)O3 (Nb-PZT) as an interfacial layer. The functional properties of the epitaxial PMN-PT (67/33) thin films were investigated as a function of the layer thickness of the Nb-PZT layer. The deposited hetero-structures are perovskite phase pure and fully (001)-oriented. The variation in Nb-PZT interfacial layer thickness results in an increasing trend change of the in-plane lattice parameter of that layer, which in turn causes a decrease in the c/a ratio of the PMN-PT film on top. The most noticeable effect related to this is a decrease in built-in-bias (imprint) voltage. Thus, the built-in bias can be tuned by changing the interfacial layer thickness. The ferroelectric capacitor properties are found to be most stable for the thinnest interfacial layers under a high number (108) of switching cycles.
High-accuracy thermophysical property measurement technique based on Labview-3ω method
Authors: Qiu L. , Ma Y. , Wang S. , Ouyang Y. , Feng Y.
Published: April 2023

High-accuracy thermophysical property measurement technique plays a significant role in the development of new materials and structures. Especially with the emerging nanomaterials, techniques that can provide thermophysical property measurement for nanoscale structures become urgent needed. Here, a Labview-3ω technique with automatic data acquisition and thermal measurement functions on the basis of the conventional 3ω technique is developed, which greatly improves the measurement speed, accuracy, and uncertainty for a wide range of nanomaterials. This high-speed, automatic, and intelligent measurement method provides great application potential for a thermophysical property measurement of various materials.
Focusing enhancement of terahertz surface plasmon polaritons
Authors: Tan Bowen , Xiang Xingcheng , Feng Longcheng , Yang Shengxin , Zhang Wei , Zhang Caihong , Wu Jingbo , Fan Kebin , Jin Biaobing , Chen Jian , Wang Huabing , Wu Peiheng
Published: April 2023

Subwavelength-sized metallic structures exhibit extraordinary responses to electromagnetic waves due to their geometry, generating surface plasmon polaritons (SPPs) at the metal–dielectric interface. The development and application of terahertz (THz) science, which is an emerging science, can be advanced by studying SPPs in the THz band. Because the field strength of SPPs gradually weakens in the propagation direction, a coherent phase-matched THz SPP enhancement structure was designed. Here, we demonstrated an asymmetrical circular groove structure. And using this structure, THz SPPs can be excited and can be focused and enhanced under the illumination of linearly polarized THz pulses, generating a subwavelength-sized focal spot. These functions are achieved via phase matching. Furthermore, the original structure was modified by controlling the propagation phase of the THz SPPs and a periodic enhancement structure was designed. Compared to the original structure, the periodic enhancement structure has a stronger focusing effect on THz SPPs. Moreover, we imaged the THz SPPs by using a THz real-time near-field spectral imaging system and verified the feasibility of the designed structure by comparing with the simulation results. The study results are of great significance to the application of THz SPPs and the fabrication of related devices.
Strain effects on the electronic and magnetic properties of Cr2TaC2 and Cr2TaC2O2 monolayers
Authors: Bilican Fuat , Ozdemir Kart Sevgi , Vatansever Erol , Ersan Fatih , Demir Vatansever Zeynep
Published: April 2023

Double transition metal MXene materials, such as Cr2TiAlC2, were successfully synthesized recently in addition to the synthesized mono transition metal MXenes. The physical and chemical properties of the MXenes can be tuned by varying the middle metal layer composition by other metal atoms. Thus, the desired mechanical, electronic, thermal, or magnetic properties can be revealed in that MXene material. The other method to tune material properties is by applying external strain on the structure. In this study, we systematically investigate the physical properties, such as dynamical, thermal, mechanical stability, electronic, and magnetic properties of the Cr2TaC2 and the Cr2TaC2O2 MXene monolayers for equilibrium and under biaxial strain. We find that both of MXene monolayers are energetically, thermally, and dynamically stable for certain compressive and tensile strain values. The Cr2TaC2 and the Cr2TaC2O2 MXene monolayers have a ferromagnetic ground state and show a metallic character in an equilibrium state and preserve it up to high tensile strain (ε = 0.10) value. The robust ferromagnetism above room temperature is demonstrated for the Cr2TaC2 with a Curie temperature of 714 K for the strain-free case. This value reduces to 234 K for the Cr2TaC2O2 monolayer. Moreover, our detailed Monte Carlo simulations reveal that the magnetic transition temperature of the system and also hysteresis properties can be controlled by moving from compressive to tensile strain ratios.
Temperature-modulated switching behaviors of diffusive memristor for biorealistic emulation of synaptic plasticity
Authors: Tian Qiaoling , Chen Xiaoting , Zhao Xiaoning , Wang Zhongqiang , Lin Ya , Tao Ye , Xu Haiyang , Liu Yichun
Published: April 2023

Temperature is known as an important factor in biological synaptic transmission. In this study, temperature-modulated switching behaviors are reported in an amorphous carbon (a-C) diffusive memristor device to emulate biorealistic synaptic plasticity. The devices exhibit memory switching and threshold switching behaviors depending on the compliance current and ambient temperature. As confirmed by conducting atomic force microscopy, the thermal effect can promote the electrochemical formation of a stable metallic conductive filament. A series of timing-controlled pulse experiments are carried out to study the temperature effect on the switching characteristics, and the device shows second-order memristive behaviors. Frequency-dependent synaptic plasticity and timing-controlled spike-time-dependent plasticity are demonstrated in the device, which are analogous to the synaptic strength in a biological synapse at elevated temperatures. As a proof of concept, the forgetting behavior of numerical images learned at different temperatures and different pulse durations is conceptually emulated with synaptic device arrays. It is expected the present device with second order memristive behaviors provides alternatives for biorealistic synaptic applications.
A superconducting nanowire binary shift register
Authors: Foster Reed A. , Castellani Matteo , Buzzi Alessandro , Medeiros Owen , Colangelo Marco , Berggren Karl K.
Published: April 2023

We present a design for a superconducting nanowire binary shift register, which stores digital states in the form of circulating supercurrents in high-kinetic-inductance loops. Adjacent superconducting loops are connected with nanocryotrons, three-terminal electrothermal switches, and fed with an alternating two-phase clock to synchronously transfer the digital state between the loops. A two-loop serial-input shift register was fabricated with thin-film NbN and a bit error rate of less than 10−4 was achieved, when operated at a maximum clock frequency of 83   MHz and in an out-of-plane magnetic field of up to 6   mT. A shift register based on this technology offers an integrated solution for low-power readout of superconducting nanowire single photon detector arrays and is capable of interfacing directly with room-temperature electronics and operating unshielded in high magnetic field environments.
Visualization of photonic band structures via far-field measurements in SiNx photonic crystal slabs
Authors: Lan Wenze , Fu Peng , Ji Chang-Yin , Wang Gang , Yao Yugui , Gu Changzhi , Liu Baoli
Published: April 2023

Band structures of the photonic crystal slabs play a significant role in manipulating the flow of light and predicting exotic physics in photonics. In this Letter, we show that the key features of photonic band structures can be achieved experimentally by the polarization- and momentum-resolved photoluminescence spectroscopy utilizing the light emission properties of SiNx. The two-dimensional spectra clearly reveal the energy-momentum dispersion of band structures, which is in perfect agreement with the simulation results. The isofrequency contours can be measured easily by adding a bandpass filter with a desired photon energy. Furthermore, it is convenient to observe clearly and directly the optical singularity—the optical bound states in the continuum featured by dark point in three-dimensional photoluminescence spectra. The polarization-resolved isofrequency contours clearly show that this dark point is the center of an azimuthally polarized vortex. Finally, the helical topological edge states can be easily observed in photonic topological insulators with deformed hexagonal lattices. Our work provides a simple and effective approach for exploring topological photonics and other intriguing phenomena hidden in the photonic crystal slabs.
Tracking the global application of conservation translocation and social attraction to reverse seabird declines
Authors: Spatz Dena R. , Young Lindsay C. , Holmes Nick D. , Jones Holly P. , VanderWerf Eric A. , Lyons Donald E. , Kress Stephen , Miskelly Colin M. , Taylor Graeme A.
Published: April 2023

The global loss of biodiversity has inspired actions to restore nature across the planet. Translocation and social attraction actions deliberately move or lure a target species to a restoration site to reintroduce or augment populations and enhance biodiversity and ecosystem resilience. Given limited conservation funding and rapidly accelerating extinction trajectories, tracking progress of these interventions can inform best practices and advance management outcomes. Seabirds are globally threatened and commonly targeted for translocation and social attraction (“active seabird restoration”), yet no framework exists for tracking these efforts nor informing best practices. This study addresses this gap for conservation decision makers responsible for seabirds and coastal management. We systematically reviewed active seabird restoration projects worldwide and collated results into a publicly accessible Seabird Restoration Database. We describe global restoration trends, apply a systematic process to measure success rates and response times since implementation, and examine global factors influencing outcomes. The database contains 851 active restoration events in 551 locations targeting 138 seabird species; 16% of events targeted globally threatened taxa. Visitation occurred in 80% of events and breeding occurred in 76%, on average 2 y after implementation began (SD = 3.2 y). Outcomes varied by taxonomy, with the highest and quickest breeding response rates for Charadriiformes (terns, gulls, and auks), primarily with social attraction. Given delayed and variable response times to active restoration, 5 y is appropriate before evaluating outcomes. The database and results serve as a model for tracking and evaluating restoration outcomes, and is applicable to measuring conservation interventions for additional threatened taxa.