bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving the Rheological and Mechanical Properties of Oil Well Cement Slurries Using Multiple Chemical Admixtures for Enhancing Zonal Isolation: A Laboratory Evaluation
Authors: Elahifar Behzad , Hosseini Erfan
Published: April 2022

The study uses chemical and mineral admixtures to understand the critical processes affecting the cement slurry characteristics, including rheological properties, free water, compressive strength, and thickening time. Using alternate mineral admixtures to replace cement slurry partially has environmental and economic benefits. The mechanisms behind the effects of chemical admixtures on the parameters of cement slurry were investigated at different temperatures using cutting-edge experimental equipment. The binder's compatibility and reactions with chemical admixtures were examined. When temperature and chemical admixtures are combined, it has a major effect on the flow characteristics of slurries. The results suggested that present technical data for chemical admixtures must be confirmed for use in oil well cementing; admixtures that are efficient at raised temperatures in conventional cementing work may become ineffective at elevated temperatures in oil well cementing. Finally, the new mixture can be employed in the desired oil field due to this new material generation (4200–6900 feet and pressure and temperature range of 4100–4800psi and 140–170 °F, respectively). Because this mixture enhances the rheological properties of cement slurry, the end product will be better than the current version. After all, the plastic viscosity, apparent viscosity, and yield stress diagrams of mixture #3*-A are lower than the desired oil field. The other mixtures in this study lead to a decrease in cement slurry viscosity and have the highest compressive strength. Finally, mixture #3*-A was the optimal blend.
Leakage Characteristics of a Novel Hole-Pattern Damping Seal With Dovetail-Like Diversion Grooves: Numerical Simulation and Experiment
Authors: Jiang Jinbo , Zhang Xuan , Zhao Wenjing , Ma Yi , Peng Xudong
Published: April 2022

Reasonable design of the cavity shape of the damping hole effectively reduces the leakage rate of the hole-pattern damping seal (HPDS). A novel HPDS with dovetail-like diversion grooves was proposed, and the geometry outline of the dovetail-like diversion groove was described by using the hyperelliptic curve. Computational fluid dynamics commercial software was used to simulate the three-dimensional flow field of the dovetail-like hole-pattern damping seal (D-HPDS). The leakage characteristics of the damping seals with a typical circular hole, leaf-like hole, and dovetail-like hole were compared numerically and experimentally. The three-velocity zone model of HPDS was proposed to reveal the mechanism of leakage reduction effect of the D-HPDS compared with typical circular hole-pattern damping seal (C-HPDS). The influence of operating parameters and key geometric parameters on leakage characteristics of the D-HPDS was studied. The results show that the leakage rate of the D-HPDS can be reduced significantly in a wide range of operating conditions and seal clearance compared with the typical C-HPDS, and the maximum reduction amplitude of leakage rate reaches up to 25% at a relatively small pressure ratio. The main reasons for the leakage reduction of the D-HPDS can be explained by the fact that the change of outflow direction from the cavity induced by the interaction effect of adjacent cavities, further resulting in the formation of turbulent vortex in the cavity and the low-speed flow zone in the sealing gap. For the design goal of low leakage rate, the inclined angle of the dovetail-like diversion groove is appropriate between 45 deg and 55 deg, the tip extension ratio is appropriate between 0.8 and 0.95.
Enhancing binaural rendering of head-worn microphone arrays through the use of adaptive spatial covariance matching
Authors: Fernandez Janani , McCormack Leo , Hyvärinen Petteri , Politis Archontis , Pulkki Ville
Published: April 2022

In this article, the application of spatial covariance matching is investigated for the task of producing spatially enhanced binaural signals using head-worn microphone arrays. A two-step processing paradigm is followed, whereby an initial estimate of the binaural signals is first produced using one of three suggested binaural rendering approaches. The proposed spatial covariance matching enhancement is then applied to these estimated binaural signals with the intention of producing refined binaural signals that more closely exhibit the correct spatial cues as dictated by the employed sound-field model and associated spatial parameters. It is demonstrated, through objective and subjective evaluations, that the proposed enhancements in the majority of cases produce binaural signals that more closely resemble the spatial characteristics of simulated reference signals when the enhancement is applied to and compared against the three suggested starting binaural rendering approaches. Furthermore, it is shown that the enhancement produces spatially similar output binaural signals when using these three different approaches, thus indicating that the enhancement is general in nature and could, therefore, be employed to enhance the outputs of other similar binaural rendering algorithms.
Characterizing core–shell nanostructures through photoacoustic response based on theoretical model in the frequency domain
Authors: Shen Si-Si , Yao Jie , Zhang Wei-Xuan , Wu Da-Jian
Published: April 2022

Core–shell nanostructures are widely used, and their photoacoustic (PA) properties are important for applications. However, the relations between their structural parameters and the properties of the PA spectrum are indirect because most theoretical models have been reported for them in the time domain. In this study, we develop a complete model in the frequency domain to analyze the PA response of core–shell particles. As in the case of solid spheres, the core-shell particles have pronounced resonant modes. The PA mode varies with the thickness of the shell and the radius of the core. Under single-pulse irradiation, PA signals of gold–silica nanospheres obtained by our theory agreed with those of the theory in the time domain and experiments. Under multi-pulse irradiation, the magnitude of the PA signals peaked whether the repeated excitation itself or its harmonic was equal to the PA mode. The structure could thus be monitored by the PA signals. These findings enrich PA theory and may inspire new techniques for the noninvasive characterization of nanoparticles.
Class C β-Lactamases: Molecular Characteristics
Authors: Philippon Alain , Arlet Guillaume , Labia Roger , Iorga Bogdan I.
Published: April 2022

Class C β-lactamases or cephalosporinases can be classified into two functional groups (1, 1e) with considerable molecular variability (≤20% sequence identity). These enzymes are mostly encoded by chromosomal and inducible genes and are widespread among bacteria, including Proteobacteria in particular.
High-Resolution Structure of the Nuclease Domain of the Human Parvovirus B19 Main Replication Protein NS1
Authors: Sanchez Jonathan L. , Ghadirian Niloofar , Horton Nancy C.
Published: April 2022

The high-resolution structure of the DNA binding and cleavage domain of the main replicative protein, NS1, from the human-pathogenic virus human parvovirus B19 is presented here. Included also are predictions of how the protein recognizes important sequences in the viral DNA which are required for viral replication.
Microbes and Climate Change: a Research Prospectus for the Future
Authors: Tiedje James M. , Bruns Mary Ann , Casadevall Arturo , Criddle Craig S. , Eloe-Fadrosh Emiley , Karl David M. , Nguyen Nguyen K. , Zhou Jizhong
Published: April 2022

Climate change is the most serious challenge facing humanity. Microbes produce and consume three major greenhouse gases—carbon dioxide, methane, and nitrous oxide—and some microbes cause human, animal, and plant diseases that can be exacerbated by climate change.
An E3 Ubiquitin Ligase Scaffolding Protein Is Proviral during Chikungunya Virus Infection in Aedes aegypti
Authors: Dubey Sunil Kumar , Mehta Divya , Chaudhary Sakshi , Hasan Abdul , Sunil Sujatha
Published: April 2022

Arboviruses cause several diseases in humans and livestock. Vector control is the main strategy for controlling diseases transmitted by mosquitoes.
Interaction of Bartonella henselae with Fibronectin Represents the Molecular Basis for Adhesion to Host Cells
Authors: Vaca Diana J. , Thibau Arno , Leisegang Matthias S. , Malmström Johan , Linke Dirk , Eble Johannes A. , Ballhorn Wibke , Schaller Martin , Happonen Lotta , Kempf Volkhard A. J.
Published: April 2022

Deciphering the mechanisms of bacterial host cell adhesion is a clue for preventing infections. We describe the underestimated role that the extracellular matrix protein fibronectin plays in the adhesion of human-pathogenic
Bartonella henselae
to host cells.
Spermidine Is an Intercellular Signal Modulating T3SS Expression in Pseudomonas aeruginosa
Authors: Lin Qiqi , Wang Huishan , Huang Jiahui , Liu Zhiqing , Chen Qunyi , Yu Guohui , Xu Zeling , Cheng Ping , Liang Zhibin , Zhang Lian-Hui
Published: April 2022

Type III secretion system (T3SS) is one of the pivotal virulence factors of
Pseudomonas aeruginosa
responsible for evading phagocytosis, and secreting and translocating effectors into host cells. Previous studies underline the complicated and elaborate regulatory mechanisms of T3SS for the accurate, fast, and malicious pathogenicity of
P. aeruginosa
. Among these regulatory mechanisms, our previous study indicated that the spermidine from the host was vital to the host-pathogen interaction.
Paleoproterozoic–Paleozoic tectonic evolution of the Longshou Shan, western North China craton
Authors: Wu Chen , Li Jie , Zuza Andrew V. , Haproff Peter J. , Yin An , Ding Lin
Published: April 2022

The Longshou Shan of western China is the northern backstop of the Cenozoic Himalayan-Tibetan orogen and occupies a key linkage between the Tarim continent and North China craton which separate the pre-Cenozoic Tethyan orogenic system and Central Asian orogenic system. Therefore, the Paleoproterozoic–Paleozoic evolution of this region is critical to understanding the extent of overprinting Cenozoic deformation, construction of the Eurasian continent, and relationships between the pre-Cenozoic Tethyan orogenic system and Central Asian orogenic system. Here we present detailed field observations and results of geochronological and major and trace element and Sr-Nd isotope geochemical analyses of samples from the Longshou Shan to decipher its complex Paleoproterozoic–Paleozoic tectonic history. Our results show that the Paleoproterozoic basement rocks of the Longshou Shan were part of the North China craton and involved in Paleoproterozoic northern North China orogeny. A ca. 965 Ma granitoid in the Longshou Shan provides key evidence for a spatial linkage between northern Tibetan continents, the North Tarim continent, and the North China craton in the early Neoproterozoic. The presence of Early Ordovician granitoids and arc volcanic rocks in the Longshou Shan suggest that bivergent subduction of Qilian oceanic lithosphere occurred during the early Paleozoic. Crustal shortening and thickening during Ordovician–Carboniferous orogenesis are evidenced by the presence of several unconformities in the Longshou Shan. Late Carboniferous arc granites exposed in the study area are likely associated with the southward subduction of the Paleo-Asian Ocean to the north and with Permian siliciclastic strata sourced from a proximal arc-subduction system, based on detrital zircon ages. Although the tectonic history of the Longshou Shan can be traced back to Neoproterozoic time, most of the recorded deformation and uplift of the region occurred during the early Paleozoic Qilian orogeny and late Paleozoic Central Asian orogeny. Furthermore, we interpret that the several orogenic events recorded in the Longshou Shan (i.e., northern North China, Qilian, and Central Asian orogenies) are spatially and temporally correlative along strike with those recorded in the Tarim and North China cratons.
How often should percutaneous gastrostomy feeding tubes be replaced? A single-institute retrospective study
Authors: Cha Byung Hyo , Park Min Jung , Baeg Joo Yeong , Lee Sunpyo , Jeon Eui Yong , Alsalami Wafaa Salem Obaid , Idris Osama Mohamed Ibrahim , Ahn Young Joon
Published: April 2022

Objective

Percutaneous gastrostomy (PG) is a common procedure that enables long-term enteral nutrition. However, data on the durability of individual tube types are insufficient. We conducted this study to compare the longevities and features of different PG tube types.

Design

We performed a 5-year retrospective analysis of patients who underwent endoscopic and radiologic PG-related feeding tube procedures. The primary and secondary outcomes were tube exchange intervals and revenue costs, respectively. Demographic factors, underlying diseases, operator expertise, materials used, and complication profiles were assessed.

Results

A total of 599 PG-related procedures for inserting pull-type PG (PGP), balloon-type PG (PGB), PG jejunal MIC* (PGJM; gastrojejunostomy type), and PG jejunal Levin (PGJL) tubes were assessed. On univariate Kaplan-Meier analysis, PGP tubes showed longer median exchange intervals than PGB tubes (405 days (95% CI: 315 to 537) vs 210 days (95% CI: 188 to 238); p<0.001). Larger PGB tubes diameters were associated with longer durations than smaller counterparts (24 Fr: 262 days (95% CI: 201 to NA), 20 Fr: 216 days (95% CI: 189 to 239), and 18 Fr: 148 days (95% CI: 100 to 245)). The PGJL tubes lasted longer than PGJM counterparts (median durations: 168 days (95% CI: 72 to 372) vs 13 days (95% CI: 23 to 65); p<0.001). Multivariate Cox proportional regression analysis revealed that PGJL tubes had significantly lower failure rates than PGJM tubes (OR 2.97 (95% CI: 1.17 to 7.53); p=0.022). PGB tube insertion by general practitioners was the least costly, while PGP tube insertion by endoscopists was 2.9-fold more expensive; endoscopic PGJM tubes were the most expensive at two times the cost of PGJL tubes.

Conclusion

PGP tubes require replacement less often than PGB tubes, but the latter are more cost-effective. Moreover, PGJL tubes last longer than PGJM counterparts and, owing to lower failure rates, may be more suitable for high-risk patients.
Altered attentive bias towards interpersonal communication information across phases of schizophrenia: an eye-tracking study
Authors: Zhu Yikang , Xu Lihua , Guo Qian , Zhang Tianhong , Hu Xiaochen , Enck Paul , Wang Jijun , Li Chunbo
Published: April 2022

Background

Eye movement abnormality in schizophrenia has been studied for several decades. However, patient differences in eye movements across phases of schizophrenia from eye-tracking studies have not been well documented.

Aims

This pilot study used eye-tracking technology to investigate attentive bias towards interpersonal communication information across different clinical phases of schizophrenia.

Methods

This study included 78 persons at clinical high risk (CHR) for schizophrenia, 68 first-episode (FEZ) patients, and 39 chronically ill patients from the Shanghai At Risk for Psychosis Extending Project (SHARP Extending cohort) as well as 74 healthy controls (HCs). The experiment was an unguided-viewing task composed of 24 trials showing three types of pictures which varied in the degree of interpersonal communication. Type 1 was a scenery picture without people, type 2 was a picture with four people not communicating, and type 3 was a picture with four people communicating. We used two measures: (1) initial fixation duration and (2) total fixation duration.

Results

A ratio for both measures was calculated between measures for pictures with more or less interpersonal communication. The ratio of initial fixation duration for pictures with people communicating versus pictures with people not communicating was lowest in chronically ill patients (0.13 (0.34))compared with HCs (0.31 (0.36)), FEZ patients (0.31 (0.46)), and CHR patients (0.36 (0.42)). The difference in the ratios of initial fixation duration for type 2 and type 3 pictures was also significant for female participants (HCs vs chronically ill patients, t=2.706, p=0.009; CHR patients vs chronically ill patients, t=4.079, p<0.001). In addition, the ratio of initial fixation duration on pictures with people not communicating versus pictures without people negatively correlated with participants’ high-risk symptoms (r=−0.35, p=0.002) among the CHR group and also correlated with the negative symptom subscore on the Positive and Negative Syndrome Scale (PANSS) among chronically ill patients (r=−0.33, p=0.037). The ratio of initial fixation duration between type 1 and type 3 pictures was associated with PANSS negative symptoms only in female patients with schizophrenia (r=−0.46, p=0.004).

Conclusions

These findings suggest an altered attentive bias towards pictures with a high degree of interpersonal communication information across different clinical phases in schizophrenia. The ratio of initial attentive orienting was associated with negative symptoms in female patients.
The influence of ultrasound image depth and gain on skeletal muscle echo intensity
Authors: Girts Ryan M. , Harmon Kylie K. , Pagan Jason I. , Alberto Ariel , Hernandez Manuel G. , Stock Matt S.
Published: April 2022

Echo intensity may associate with indicators of skeletal muscle quality, but investigators often use different methodological approaches that may alter echo intensity when acquiring B-mode ultrasound images. We examined the influence of image depth and gain settings on the interpretation of echo intensity. Thirty-six college-aged males and females participated. Ultrasound images of the vastus lateralis were captured in the sagittal plane. Images were captured at depths of 3.0, 3.5, 4.0, 4.5, 5.0, 6.0, and 7.0 cm and gain settings of 50 and 60 dB in random order. For both gain settings, echo intensity values were similar between 4.0 and 6.0 cm. At a gain of 50 dB, 7.0 cm demonstrated greater values than all other depths. At a gain of 60 dB, 7.0 cm displayed greater values compared to all other depths, but 3.0 cm displayed lower echo intensity values than other depths. Echo intensity was substantially higher when using a gain of 60 dB compared to 50 dB (mean difference ≥ 21.7 arbitrary units, d ≥ 3.47). When planning investigations in new research areas, researchers should carefully consider their study-specific image depth. Echo intensity values are stable between depths of 4.0 and 6.0 cm, suggesting that changing image depth may not be problematic. Image gain must be kept constant.

Novelty:

Optimal approaches for B-mode ultrasound image acquisition of skeletal muscles remain unclear. Echo intensity is similar between depths of 4.0 and 6.0 cm, regardless of image gain. Investigators should seek to utilize a constant depth setting, but small deviations may be acceptable.
T-duality, vertical holonomy line bundles and loop Hori formulae
Authors: Han Fei , Mathai Varghese
Published: April 2022

This paper is a step towards realizing T-duality and Hori formulae for loop spaces. Here, we prove T-duality and Hori formulae for winding [Formula: see text]-loop spaces, which are infinite dimensional subspaces of loop spaces.
An overview of MEMS S&A device and its application in the micro-detonated system
Authors: Kan Wenxing , Chu Enyi , Qu Ping , Ren Wei , Hu Tengjiang , Liu Wei , Zhao Yulong
Published: April 2022

The integration of fuzes and initiators has been promoted by the development requirements of the miniaturized and intelligent ammunition, and the micro-detonated system integrated with S&A device is the key development direction. Initiators are considered the first component of the weapon system, and the safety and reliability of the initiators directly affect the safety and reliability of the weapon system. With the development of micro-electromechanical system (MEMS) initiators and the integration of fuze, in order to further improve the safety of the weapon system in the miniaturized and intelligent ammunition system, it is necessary to integrate the MEMS S&A device with the initiators, which is an important technical feature, to form a MEMS initiator with functional integration, high safety and reliability. MEMS S&A device is the key technology of the MEMS initiators’ devices with safety-isolation function. This paper summarizes the development of MEMS S&A devices in micro-fuzes and the micro-detonated systems in recent years. Combined with comparative analysis, it analyzes and summarizes the driving principles, application platforms, process technologies, structural material characteristics and other aspects, and proposes a suitable structure for the MEMS initiators integrated with S&A devices, which provides a reference for the research on the design of MEMS initiators with safety-isolation function.
Univariate and bivariate zeta functions of unipotent group schemes of type G
Authors: Zordan Michele
Published: April 2022

We compute the representation and class counting zeta functions for a family of torsion-free finitely generated nilpotent groups of nilpotency class 2. These groups arise from a generalization of one the families of unipotent groups schemes treated by Stasinski and Voll in [18], [19] and Lins in [10]. The univariate zeta functions are obtained by specializing the respective bivariate zeta functions defined by Lins in [9]. These are also used to deduce a formula for a joint distribution on Weyl groups of type B.
The power-law dependence between the matter-radiation and Hubble anisotropies
Authors: Dias F. S. , Santos G. B. , Gomes L. G. , Mello L. F.
Published: April 2022

In this paper, we investigate the cosmological evolution of the Hubble and the matter-radiation anisotropies, characterized by [Formula: see text] and [Formula: see text], respectively, under the power-law condition [Formula: see text]. This is a suitable choice in order to understand how different [Formula: see text] and [Formula: see text] would behave in the expanding universe if they had distinct orders of magnitude. Hence, their early and late-time behaviors are examined, and in particular, the dependence of their qualitative features on [Formula: see text]. This includes some nontrivial aspects in their long-time dynamics, which goes beyond the reach of the linear perturbations of the homogeneous and isotropic models. Besides those cosmological concerns, the concept of anisotropy in general relativity and its counterpart in Einstein’s equations is clarified and interpreted, and the general notion of the Kasner plane, the arena where its dynamics takes place, is extended beyond the reach of the spatially homogeneous models.
Study of cluster emissions from heavy nuclei using an empirical formula and the Coulomb and Proximity potential model for deformed nuclei
Authors: Prathapan K. , Preethi Rajan M. K. , Biju R. K.
Published: April 2022

The decay characteristics of various clusters and neutron halo nuclei from heavy elements [Formula: see text] are studied within the framework of the Coulomb and Proximity Potential Model for Deformed Nuclei (CPPMDN) and using a new empirical formula proposed by us. The predictive power of our formula is verified by comparing the predictions with the available experimental data and with the predictions of other models such as CPPM, Universal Decay Law of Qi et al. (UDL), Unified Description formula (UD) of Ni et al. Using the present formula and CPPMDN, decay half-lives of various light clusters from heavy elements are calculated, and the results are compared with the predictions of UDL, UD, and predictions made by Santhosh et al. based on the Modified Generalized Liquid Drop Model (MGLDM). The decay half-lives of halo nuclei from heavy elements are also calculated using the new formula and CPPMDN and compared with the predictions of UDL, UD, and the predictions made by Santhosh et al. based on the Coulomb and Proximity Potential Model (CPPM).
ARTIFICIAL INTELLIGENCE AND STOCHASTIC OPTIMIZATION ALGORITHMS FOR THE CHAOTIC DATASETS
Authors: WANG FUZHANG , SOHAIL AYESHA , WONG WING-KEUNG , UL AIN AZIM QURAT , FARWA SHABIEH , SAJAD MARIA
Published: April 2022

Almost every natural process is stochastic due to the basic consequences of nature’s existence and the dynamical behavior of each process that is not stationary but evolves with the passage of time. These stochastic processes not only exist and appear in the fields of biological sciences but are also evident in industrial, agricultural and economical research datasets. Stochastic processes are challenging to model and to solve as well. The stochastic patterns when repeated result into random fractals and are very common in natural processes. These processes are usually simulated with the aid of smart computational and optimization tools. With the progress in the field of artificial intelligence, smart tools are developed that can model the stochastic processes by generalization and genetic optimization. Based on the basic theoretical description of the stochastic optimization algorithms, the stochastic learning tools, stochastic modeling, stochastic approximation and stochastic fractals, a comparative analysis is presented with the aid of the stochastic fractal search, multi-objective stochastic fractal search and pattern search algorithms.
A note on the infinite-dimensional quantum Strassen’s theorem
Authors: Accardi Luigi , Dhahri Abdallah , Lu Yun Gang
Published: April 2022

In Ref. 3, the quantum Strassen’s theorem has been extended to the infinite-dimensional case. This theorem consists in the solution of the coupling problem for two states on the algebra of bounded operators on two Hilbert spaces [Formula: see text], [Formula: see text] with the additional constraint that the coupling state has support in a pre-assigned sub-space of [Formula: see text]. In this paper, we give an alternative proof of the main theorem in Ref. 3 that allows such extension.
Four-dimensional generalized Ricci flows with nilpotent symmetry
Authors: Gindi Steven , Streets Jeffrey
Published: April 2022

We study solutions to generalized Ricci flow on four-manifolds with a nilpotent, codimension 1 symmetry. We show that all such flows are immortal, and satisfy type III curvature and diameter estimates. Using a new kind of monotone energy adapted to this setting, we show that blowdown limits lie in a canonical finite-dimensional family of solutions. The results are new for Ricci flow.
Smoothness of the diffusion coefficients for particle systems in continuous space
Authors: Giunti Arianna , Gu Chenlin , Mourrat Jean-Christophe , Nitzschner Maximilian
Published: April 2022

For a class of particle systems in continuous space with local interactions, we show that the asymptotic diffusion matrix is an infinitely differentiable function of the density of particles. Our method allows us to identify relatively explicit descriptions of the derivatives of the diffusion matrix in terms of correctors.
A Class of Unconditionally Stable Shooting Methods with Application to Radiative Darcy–Forchheimer Flow
Authors: Nawaz Yasir , Arif Muhammad Shoaib , Ashraf Muhammad Usman , Abodayeh Kamaleldin
Published: April 2022

Since there are shooting methods in the literature to solve ordinary differential equations (ODEs), those are mainly based on Runge–Kutta explicit methods. It is a proven fact that explicit Runge–Kutta methods are conditionally stable. The present contribution consists of constructing a class of shooting methods based on implicit methods that are unconditionally stable with their application to solving the problem of Darcy–Forchheimer’s flow over the stretching sheet under the influence of thermal radiations. Governing equations of the flow phenomena are presented in the form of partial differential equations (PDEs). Further, these PDEs are reduced into ODEs which are tackled by the present constructing shooting methods based on the class of Adam Moulton’s techniques with the Gauss–Siedel iterative method. The stability and convergence for the system of differential equations are also given. Thus, the main advantage of the presented methods is to turn the implicit methods into explicit methods using the shooting approach. Also, the impact of inertia coefficient, porosity parameter, radiation parameter, and Prandtl number on velocity and temperature profiles is given graphically. It is seen that the increment of the porosity parameter escalates the temperature profile. A computational code for the proposed model scheme may be made available to readers upon request for convenience.
Lost in translation: The Abelian affine connection (in the coincident gauge)
Authors: Beltrán Jiménez Jose , Koivisto Tomi S.
Published: April 2022

The simplest, i.e. the Abelian, i.e. the commutative, i.e. the integrable, i.e. the flat and torsion-free, i.e. the symmetric teleparallel affine connection has been considered in many recent works in the literature. Such an affine connection is characterized by the property that it can be vanished by a general coordinate transformation, by fixing the so-called coincident gauge. This paper focuses on the subtleties involved in the applications of the coincident gauge.
Complexity aspects of restrained Roman domination in graphs
Authors: Chakradhar Padamutham
Published: April 2022

For a simple, undirected graph [Formula: see text], a restrained Roman dominating function (rRDF) [Formula: see text] has the property that, every vertex [Formula: see text] with [Formula: see text] is adjacent to at least one vertex v for which [Formula: see text] and at least one vertex [Formula: see text] for which [Formula: see text]. The weight of an rRDF is the sum [Formula: see text]. The minimum weight of an rRDF is called the restrained Roman domination number (rRDN) and is denoted by [Formula: see text]. We show that restrained Roman domination and domination problems are not equivalent in computational complexity aspects. Next, we show that the problem of deciding if G has an rRDF of weight at most l for chordal and bipartite graphs is NP-complete. Finally, we show that rRDN is determined in linear time for bounded treewidth graphs and threshold graphs.
An instance-based algorithm for deciding the bias of a coin
Authors: Schultz Xavier da Silveira Luís Fernando , Smid Michiel
Published: April 2022

Let [Formula: see text] and [Formula: see text] be real numbers, and let C be a coin that comes up heads with an unknown probability p, such that [Formula: see text]. We present an algorithm that, on input C, q, and [Formula: see text], decides, with probability at least [Formula: see text], whether [Formula: see text] or [Formula: see text]. The expected number of coin flips made by this algorithm is [Formula: see text], where [Formula: see text].
Fast Active Fault-Tolerant Control for a Quadrotor UAV Against Multiple Actuator Faults
Authors: Xing Zhou , Jia Jindou , Guo Kexin , Jia Wei , Yu Xiang
Published: April 2022

This paper proposes a fast adaptive fault estimator-based active fault-tolerant control strategy for a quadrotor UAV against multiple actuator faults. A fast adaptive fault estimation algorithm is designed to estimate the unknown actuator fault parameters. By synthesizing the fast adaptive fault estimator with the embedded control law, an active fault-tolerant control mechanism is established to compensate the adverse effects of multiple actuator faults. The effectiveness of the proposed strategy is validated through both numerical simulations and experimental tests.
Magma–rock interactions: a review of their influence on magma rising processes with emphasis on short-timescale assimilation of carbonate rocks
Authors: Knuever M. , Sulpizio R. , Mele D. , Costa A.
Published: April 2022

The interaction of magma and wall-rocks is inevitable when magma is moving through Earth's crust. These interactions happen on different timescales and especially the short-term interactions (seconds to days) during the final ascent of the magma can induce changes in eruption dynamics. However, information on this matter is scarce and scattered in different scientific fields. We conducted this review in order to present a full picture of the state of the art for short-timescale magma–wall-rock interactions. According to the three existing studies on short-term magma–carbonate interactions, magma viscosity is the most important controlling factor for carbonate assimilation. Lower viscosity magmas enhance CO
2
-bubble migration away from the reaction site, resulting in a higher carbonate assimilation rate. The released CO
2
plays an important role regarding eruption dynamics since a higher CO
2
release rate would result in accelerated magma ascent and may increase eruption intensity. Despite the importance for hazard assessment, important factors (pressure, magma composition, vapour phase solubilities, carbonate clast properties) for carbonate assimilation in general and CO
2
release rate in particular are not or only poorly constrained. This review presents the present-day knowledge of short-term magma–carbonate interaction that is relevant to establish the basis for future work concerning magma–wall-rock interactions.
In the Black Mirror: Youth Investigations into Artificial Intelligence
Authors: Lee Clifford H. , Gobir Nimah , Gurn Alex , Soep Elisabeth
Published: April 2022

Over the past two decades, innovations powered by artificial intelligence (AI) have extended into nearly all facets of human experience. Our ethnographic research suggests that while young people sense they can't “trust” AI, many are not sure how it works or how much control they have over its growing role in their lives. In this study, we attempt to answer the following questions: (1) What can we learn about young people's understanding of AI when they produce media with and about it? and (2) What are the design features of an ethics-centered pedagogy that promotes STEM engagement via AI? To answer these questions, we co-developed and documented three projects at YR Media, a national network of youth journalists and artists who create multimedia for public distribution. Participants are predominantly youth of color and those contending with economic and other barriers to full participation in STEM fields. Findings showed that by creating a learning ecology that centered the cultures and experiences of its learners while leveraging familiar tools for critical analysis, youth deepened their understanding of AI. Our study also showed that providing opportunities for youth to produce ethics-centered interactive stories interrogating invisibilized AI functionalities, and to release those stories to the public, empowered them to creatively express their understandings and apprehensions about AI.
The Affordable Care Act After a Decade: Industrial Organization of the Insurance Exchanges
Authors: Handel Benjamin , Kolstad Jonathan
Published: April 2022

The regulated insurance exchanges set up in the Affordable Care Act (ACA) were designed to deliver affordable, efficient health coverage through private insurers. It is crucial to study the complex industrial organization (IO) of these exchanges in order to assess their impacts during the first decade of the ACA and to project their effects going forward. We revisit the inherent market failures in health care markets that necessitate key ACA exchange regulations and investigate whether they have succeeded in their goals of expanding coverage, creating robust marketplaces, providing product variety, and generating innovation in health care delivery. We discuss empirical IO research to date and also highlight shortcomings in the existing research that can be addressed moving forward. We conclude with a discussion of IO research-based policy lessons for the ACA exchanges and, more generally, for managed competition of private insurance in health care.
Recognition and Response in Plant–Nematode Interactions
Authors: Siddique Shahid , Coomer Alison , Baum Thomas , Williamson Valerie Moroz
Published: April 2022

Plant-parasitic nematodes spend much of their lives inside or in contact with host tissue, and molecular interactions constantly occur and shape the outcome of parasitism. Eggs of these parasites generally hatch in the soil, and the juveniles must locate and infect an appropriate host before their stored energy is exhausted. Components of host exudate are evaluated by the nematode and direct its migration to its infection site. Host plants recognize approaching nematodes before physical contact through molecules released by the nematodes and launch a defense response. In turn, nematodes deploy numerous mechanisms to counteract plant defenses. This review focuses on these early stages of the interaction between plants and nematodes. We discuss how nematodes perceive and find suitable hosts, how plants perceive and mount a defense response against the approaching parasites, and how nematodes fight back against host defenses.
Tuning Fluorination of Linear Carbonate for Lithium-Ion Batteries
Authors: Yu Zhiao , Yu Weilai , Chen Yuelang , Mondonico Luca , Xiao Xin , Zheng Yu , Liu Fang , Hung Samantha T. , Cui Yi , Bao Zhenan
Published: April 2022

Liquid electrolyte engineering plays a critical role in modern lithium-ion batteries. However, the existing electrolytes fall short when used with some trending battery chemistries such as high-voltage and high-energy-density electrodes. Fluorination of electrolyte solvents has been identified as an effective approach for improved cyclability, but few works systematically studied the effects of fluorination extent of carbonate solvents on battery performance. Here we design and synthesize a family of fluorinated ethyl methyl carbonates. Different numbers of F atoms are finely tuned to yield monofluoroethyl methyl carbonate (F1EMC), difluoroethyl methyl carbonate (F2EMC) and trifluoroethyl methyl carbonate (F3EMC). The cycling behavior of several types of lithium-ion pouch cells, including graphite (Gr)/single-crystalline LiNi0.8Mn0.1Co0.1O2 (SC-NMC811), Gr-SiOx/LiNi0.6Mn0.2Co0.2O2 (NMC622), high-voltage Gr/LiNi0.5Mn1.5O4 (LNMO), Gr/layered Li-rich Mn-based oxide (LLMO) and fast-charging Gr/NMC622, were systematically investigated to understand the impact of fluorination degree. Compared to the commercially available F3EMC, we found that the partially-fluorinated F1EMC and F2EMC in some cases showed improved cycling stability, which we attribute to their locally-polar –CH2F and –CHF2 groups and thus fast ion conduction than –CF3. This work suggests that highly or fully fluorinated solvents are not necessarily desirable; instead, fluorination degree needs to be rationally and finely tuned for optimized lithium-ion cell performance.
First Electrochemical Approach to Voltammetric Behavior and Sensing of Anticancer Drug Ponatinib
Authors: Koszelska Kamila , Ciesielski Witold , Smarzewska Sylwia
Published: April 2022

This study investigated for the first time the electrochemical behavior of the anticancer drug ponatinib (Pon). All voltammetric experiments were conducted using square-wave voltammetry (SWV) and cyclic voltammetry (CV), with a boron-doped diamond electrode (BDDE) as a working electrode. The recorded voltammograms showed a well-defined oxidation peak for Pon at a positive potential value of around +1.35 V (vs Ag/AgCl) in hydrochloric acid of pH 1.3. The study also analyzed the influence of experimental conditions, such as pH and composition of supporting electrolyte, as well as the parameters of the square-wave voltammetric technique. A rapid, simple, and sensitive SWV methodology was established for the determination of ponatinib in the concentration range of 1.0 × 10−6–2.0 × 10−5 mol l−1, with a detection limit of 2.5 × 10−7 mol l−1. The biological significance of the developed SWV procedure was demonstrated by a quantitative analysis of ponatinib in spiked urine samples with a highly satisfactory rate of recovery. In addition, the effect of some interfering agents coexisting in the human urine on the peak current of Pon was evaluated. Cyclic voltammetry was used to study the electrochemical behavior of the analyte. The obtained results indicated that the oxidation of ponatinib was an irreversible process and was controlled by diffusion. The number of electrons and protons involved in the oxidation process was also estimated.
How to Minimise Hydrogen Evolution on Carbon Based Materials?
Authors: Oates Rose P. , Murawski James , Hor Carys , Shen Xuyang , Weber Daniel J. , Oezaslan Mehtap , Shaffer Milo S. P. , Stephens Ifan E. L.
Published: April 2022

In many electrochemical systems, such as carbon dioxide reduction, batteries and supercapacitors, hydrogen evolution reaction is an undesired competing reaction. Herein, we investigate the factors controlling the hydrogen evolution reaction (HER) on seven different commercial carbon materials commonly found in many of these systems. The electrochemical HER response was determined by rotating disk electrode potential hold measurements in acidic media, and correlated with the physical characteristics of the carbon materials determined nitrogen adsorption/desorption, as well as previous experiments on the same materials. An on-chip electrochemical mass spectrometer was used to probe the gaseous products produced at the electrode in situ, which allowed HER to be distinguished from other competing reaction and the onset of the reaction was established to be −0.38 V vs RHE. The results indicate that carbons with low amount of metal impurities have the lowest H2 evolution rates.
Assessment of Core-Shell and Agglomerate Particle Design for All-Solid-State Batteries
Authors: Cistjakov Walter , Laue Vincent , Röder Fridolin , Krewer Ulrike
Published: April 2022

All-solid state lithium polymer batteries are promising next-generation batteries with high safety and energy density. Their success depends on an improved design with a tailored cathode manufacturing process. To facilitate a knowledge-driven optimal design of cathode, a model-based analysis on the impact of the cathode particle structure on the electrochemical cell performance is conducted. During production of solid-state cathodes, small active material particles such as lithium-iron phosphate tend to form large agglomerates with inner electrolyte-filled pores which have significant effect on transport properties within a secondary particle. Therefore, a battery cell model with secondary particles and optionally with a core-shell structure is developed and evaluated. Discharge performance is shown to be stronger impacted by changing the electrolyte fraction inside the particle than by changing the size of the electrolyte core within the secondary particle. A core-shell structure has a positive impact on the discharge performance and should be preferred for high power application. In contrast, cells with homogeneous agglomerate particles show better performance at low discharge rates. Thus, they are recommended for high energy and low power applications. The results of this study highlight the potentials of tailored production process for next-generation batteries.
Parameter Identification of Lithium-Ion Batteries by Coupling Electrochemical Impedance Spectroscopy with a Physics-Based Model
Authors: Duan Xiting , Liu Fuqiang , Agar Ertan , Jin Xinfang
Published: April 2022

Nondestructive, quick, and accurate diagnosis of Lithium-ion batteries are critical tools to extend battery lifetime and ensure safe operation under complicated real-time power demand conditions. In this study, an electrochemical characterization approach coupling impedance spectroscopy with a physics-based model (EIS-Physical) has been demonstrated to accurately identify key transport and kinetic parameters for an in-house assembled Li(Ni0.5Mn0.3Co0.2)O2/Li-metal half-cell. The parameter identification process has been realized by a nonlinear optimization algorithm, along with proper sensitivity and dependence analyses on initial guesses. The parameters obtained using this approach have been compared with those determined from the benchmark Galvanostatic Intermittent Titration Technique (GITT). Equivalent circuit method as an important state-of-the-art modeling approach to interpret EIS has also been compared against the proposed method. The results show that: i) cathode Li-ion diffusivity and cathode/electrolyte exchange current density are quadratic functions of x
Li, which indicates cathode is the capacity limiting electrode and operates in a wide SOC range. Therefore, cathode must be simulated using the concentrated solution theory. ii) EIS-Physical method can provide consistent and unique parameters with clear physical meanings compared to its equivalent circuit counterpart. iii) EIS-Physical method is as precise as GITT but less time consuming (i.e., <2.5 h vs > 200 h). Consequently, the proposed method is found to be more practical to implement as a Lithium-ion battery diagnostic tool.
First Principles Study of Layered CrGeTe3 as Lithium Intercalation Compound
Authors: Ahmed Sheraz , Alkhedher Mohammad , Isa Muhammad , Majid Abdul
Published: April 2022

There have been unprecedented research efforts to produce efficient and sustainable electrode materials for lithium-ion batteries (LIB). The research efforts to increase energy density, life cycle, safety, and rate-capability are still in progress. This work is carried out to explore the prospects of a new anode material CrGeTe3 for use in LIB studied via first-principles predictions. The investigation of Li: CrGeTe3 system and lithiation mechanism in the proposed material pointed out its suitability for lithium intercalation compound. The energy-profiling at highly symmetry points in the host structure revealed that BGe-Cr is most favorable energy site for lithiation in the material. The maximum value of the lithium insertion voltage is 3.41 V and the storage capacity is 620.60 mAh g−1. The diffusion barrier faced by lithium atom is 0.27 eV which is the minimum value, while moving along the x-axis within the top and middle hexagonal rings. The steric interaction of Li with Ge and Te atoms pointed structural reliability and hence stable operation of the anode to address capacity fading problems in LIB.
Anhydrous LiNbO3 Synthesis and Its Application for Surface Modification of Garnet Type Li-Ion Conductors
Authors: Mann Markus , Schwab Christian , Ihrig Martin , Finsterbusch Martin , Martin Manfred , Guillon Olivier , Fattakhova-Rohlfing Dina
Published: April 2022

In our work we demonstrate a facile, water-free synthesis of amorphous lithium niobate (LiNbO3) layers. Our developed method also enables the coating of substrates in inert atmosphere with simple, industrial scalable methods. As verification, a 120 nm thin LiNbO3 layer was deposited on the garnet type lithium ion conductor Li6.45Al0.05La3Zr1.6Ta0.4O12 (LLZTO) to improve its interface to lithium metal and reduce dendrite formation. The application of the thin film reduced the interface resistance between LLZTO and lithium metal to 1.02(13) Ω∙cm2 and increased the critical current density for dendrite formation to at least 0.5 mA cm−2. The chemical stability of the LiNbO3 thin film in contact with Li-metal was verified by SEM, XPS and ToF-SIMS.