bluuebunny/crossref_metadata_2025 huggingface dataset:
On the transport limit of singularly perturbed convection–diffusion problems on networks
Authors: Egger Herbert , Philippi Nora
Published: December 2020

We consider singularly perturbed convection–diffusion equations on one‐dimensional networks (metric graphs) as well as the transport problems arising in the vanishing diffusion limit. Suitable coupling conditions at inner vertices are derived that guarantee conservation of mass and dissipation of a mathematical energy which allows us to prove stability and well‐posedness. For single intervals and appropriately specified initial conditions, it is well‐known that the solutions of the convection–diffusion problem converge to that of the transport problem with order
in the L∞(L2)‐norm with diffusion ϵ → 0. In this paper, we prove a corresponding result for problems on one‐dimensional networks. The main difficulty in the analysis is that the number and type of coupling conditions changes in the singular limit which gives rise to additional boundary layers at the interior vertices of the network. Since the values of the solution at these network junctions are not known a priori, the asymptotic analysis requires a delicate choice of boundary layer functions that allows to handle these interior layers.
Accuracy of dose‐volume metric calculation for small‐volume radiosurgery targets
Authors: Stanley Dennis N. , Covington Elizabeth L. , Liu Haisong , Alexandrian Ara N. , Cardan Rex A. , Bridges Daniel S. , Thomas Evan M. , Fiveash John B. , Popple Richard A.
Published: December 2020

Purpose

For stereotactic radiosurgery (SRS), accurate evaluation of dose‐volume metrics for small structures is necessary. The purpose of this study was to compare the DVH metric capabilities of five commercially available SRS DVH analysis tools (Eclipse, Elements, Raystation, MIM, and Velocity).

Methods

DICOM RTdose and RTstructure set files created using MATLAB were imported and evaluated in each of the tools. Each structure set consisted of 50 randomly placed spherical targets. The dose distributions were created on a 1‐mm grid using an analytic model such that the dose‐volume metrics of the spheres were known. Structure sets were created for 3, 5, 7, 10, 15, and 20 mm diameter spheres. The reported structure volume, V100% [cc], and V50% [cc], and the RTOG conformity index and Paddick Gradient Index, were compared with the analytical values.

Results

The average difference and range across all evaluated target sizes for the reported structure volume was − 4.73%[−33.2,0.2], 0.11%[−10.9, 9.5], −0.39%[−12.1, 7.0], −2.24%[−21.0, 1.3], and 1.15%[−15.1,0.8], for TPS‐A through TPS‐E, respectively. The average difference and range for the V100%[cc] (V20Gy[cc]) was − 0.4[−24.5,9.8], −2.73[−23.6, 1.1], −3.01[−23.6, 0.6], −3.79[−27.3, 1.3], and 0.26[−6.1,2.6] for TPS‐A through TPS‐E, respectively. For V50%[cc](V10Gy[cc]) in TPS‐A through TPS‐E the average and ranger were − 0.05[−0.8,0.4], −0.18[−1.2, 0.5], −0.44[−1.4, 0.3], −0.26[−1.8, 2.6], and 0.09[−1.4,2.7].

Conclusion

This study expanded on the previously published literature to quantitatively compare the DVH analysis capabilities of software commonly used for SRS plan evaluation and provides freely available and downloadable analytically derived set of ground truth DICOM dose and structure files for the use of radiotherapy clinics. The differences between systems highlight the need for standardization and/or transparency between systems, especially when evaluating plan quality for multi‐institutional clinical trials.
A time‐discontinuous peridynamic method for transient problems involving crack propagation
Authors: Liu Zhenhai , Ye Hongfei , Qian Dong , Zhang Hongwu , Zheng Yonggang
Published: December 2020

A time‐discontinuous peridynamic method (TDPD) for modeling transient problems of wave and crack propagation in solids is presented in this article. The main features of the TDPD are that the displacement field and the velocity field are independently interpolated in the temporal domain by using cubic and linear functions, respectively. Jump terms representing discontinuities of the variables are introduced between the adjacent time steps. The weak form and a new time integration scheme are derived by combining the peridynamic governing equations with the time‐discontinuous method. The displacement field is continuous while discontinuous jumps are introduced into the velocity field. Those characteristics enable the TDPD to accurately capture the sharp gradient in stress and effectively control the spurious numerical oscillation. The effectiveness of the TDPD is first demonstrated through two representative numerical examples of wave propagation. Three additional examples are presented to show the advantages of the TDPD in the simulation of dynamic crack propagation problems. It is shown that TDPD provides more accurate and satisfactory results when compared with the traditional time integration scheme.
Environmentally Benign Solution‐Based Procedure for the Fabrication of Metal Oxide Coatings on Metallic Pigments
Authors: Bies Thorsten , Hoffmann Rudolf C. , Stöter Matthias , Huber Adalbert , Schneider Jörg J.
Published: December 2020

Aluminum pigments were coated with Fe2O3and CuO by solution‐based thermal decomposition of the urea nitrate compounds hexakisureairon(III)nitrate and tetrakisureacopper(II)nitrate. The deposition process was optimized to obtain homogeneously coated aluminum pigments. The growth of the surface coatings was controlled by investigation with scanning electron microscopy, energy dispersive X‐ray spectroscopy and static light scattering as well as infrared, X‐ray diffraction and thermogravimetric analysis. The iron precursor showed an incomplete decomposition in solution, incorporating traces of urea molecules inside the coatings while the copper precursor showed complete dissociation accompanied by in situ formation of amine complexes. The amount of organic residues resulting from ligand fragments in the final oxide coatings could be reduced to 22 % for the iron oxide and 12 % for the copper oxide by further temperature treatment in solution (259 °C). Colorimetric investigations of the obtained pigments revealed an excellent hiding power, outperforming the pigments used in current state‐of‐the‐art formulations.
Maternal employment and children's health in India: An exploratory analysis
Authors: Shajan Jince , Sumalatha Bevinje Subbyamoola
Published: December 2020

This study explores the relationship between maternal employment and health status of children aged under 60 months in India. The study uses data from the nationally representative National Family Health Survey‐4 (2015–2016) of India, and the health status of children was measured using anthropometric indicators, mainly height‐for‐age Z‐score and weight‐for‐age Z‐score. The econometric analysis was performed using ordinary least squares, endogenous treatment effects, and logistic regression models. In general, the findings reveal that children whose mothers are employed have poorer health status compared to children whose mothers are unemployed. To deal with the diversified employment of working mothers, the relationship between maternal employment and children's health was analysed based on various occupational categories. The findings show that children whose mothers are employed in professional jobs have better health status, while children whose mothers are employed in agricultural and manual (skilled and unskilled) jobs have poor health status. Maternal education is found to be one of the important determinants of better child health. The study confirms that investment in female education will bring progress not only for women and their children but also for society as a whole.
Squaring small and medium businesses and branding post Covid‐19 in Nigeria: Tripartite imperatives for performance
Authors: Ogunsanya Akintayo Adesoji
Published: December 2020

Since the Corona virus is expected to create a paradigm shift of so called new normal, contemplation of imperatives needed to adapt to the post Covid‐19 world is in order. In the case of Nigeria, the already troubled small and medium business (SME) sector and branding of small businesses require attention. Departing from the strict marketing perspective it is typically understood, branding is construed as a function of the overall state of a society in this article. As such, three foundational requirements, namely, technological, socio‐economic, and educational imperatives, are identified as society wide policies that must be re‐imagined and implemented consistently for SMEs in Nigeria to have strong basis for their branding as well as their emergence as competitive brands post Covid‐19. A wide range of secondary sources such as reports, articles in the field of marketing, branding and small business branding, and contemporary global and national developments are integrated in advancing the position of this article.
UNPACKING COMPLEX MEDIATION MECHANISMS AND THEIR HETEROGENEITY BETWEEN SITES IN A JOB CORPS EVALUATION
Authors: Qin Xu , Deutsch Jonah , Hong Guanglei
Published: December 2020

This study aims to test the theory underlying Job Corps, one of the largest education and training programs in the U.S. serving disadvantaged youth. Central to the program are vocational training and general education that serve as two concurrent mediators transmitting the program impact on earnings. To distinguish the relative contribution of each, we develop methods for decomposing the Job Corps impact on earnings into an indirect effect transmitted through vocational training, an indirect effect transmitted through general education, and a direct effect attributable to supplementary services. We further ask whether general education and vocational training reinforce each other and produce a joint impact greater than the sum of the two separate pathways. Moreover, we examine the heterogeneity of each causal effect across all the Job Corps centers. This article presents concepts and methods for defining, identifying, and estimating not only the population averages but also the between‐site variance of these causal effects. Our analytic procedure incorporates a series of weighting strategies to enhance the internal and external validity of the results and assesses the sensitivity to potential violations of the identification assumptions.
Policy issue interdependency and the formation of collaborative networks
Authors: Hedlund Johanna , Bodin Örjan , Nohrstedt Daniel
Published: December 2020

Environmental problems often span a set of challenges that each may engage different policy actors across different policy domains. These challenges, orpolicy issues, nonetheless exhibit interdependencies that may constrain the ability of actors to work together towards joint solutions.

Still, we have limited knowledge about whether and how policy issue interdependencies actually shape how actors collaborate.

Using data derived from two venues for collaborative water governance in the Norrström basin, Sweden, we investigate whether and how policy issues and policy issue interdependencies influence actors' selection of collaborative partners. We test two alternative sets of propositions; one set assumes that partner selection is driven by actors' engagement in policy issues and their interdependencies, while the other set emphasises social positions and actor attributes.

Our results show that in one venue, actors' choices of collaborative partner were associated with factors from both sets, but not with policy issue interdependencies specifically. In the other venue, only actor and relational attributes shaped social tie formation. These results suggest that how actors interact does not necessarily align with the policy issues and the policy issue interdependencies defined by the environmental problem they are to address.

Our results provide an important step towards arriving at evidence‐based recommendations for more effective collaborative efforts in addressing complex environmental problems that no actor can address alone.

A freePlain Language Summarycan be found within the Supporting Information of this article.
Investigation of electric field‐aligned edge‐oxidized graphene oxide nanoplatelets in polyethersulfone matrix in terms of pure water permeation and dye rejection
Authors: Besharat Farzaneh , Manteghian Mehrdad , Russo Francesca , Galiano Francesco , Figoli Alberto , Abdollahi Mahdi , Lazzeri Andrea
Published: December 2020

Herein, we have evaluated the impact of orientated edge‐oxidized graphene oxide nanoplatelets (EOGO) in polyether sulfone (PES) membrane on the pure water permeability (PWP) and organic dye molecule rejection values. Aligned PES/EOGO nanocomposite films were prepared through electric field induction. Morphological, structural, and chemical‐physical characterizations including atomic force microscopy, thermogravimetric analysis (TGA), contact angle, zeta potential, porosity, and PWP measurements were carried out. The results revealed successful aligned/oriented PES/EOGO nanocomposite formation at low‐to‐moderate EOGO loadings. Membrane function tests demonstrated an increase in water permeability at higher EOGO contents, up to 0.5 wt%, followed by a decrease at 1 wt% nanoplatelets due to nanoparticles agglomeration. The horizontal electric field (1000 Hz) processed samples indicated lower PWP in comparison with their vertical‐field (34% decrement) and No‐field (29% increment) counterparts as well as a better dye molecule rejection at 0.1 wt%, referring to nanoplatelets successful alignment at this loading level.
Transnational lives on the move: Looking beyond binational sedentarism
Authors: Mavrommatis George
Published: December 2020

Transnationalism and the mobilities paradigm are important theoretical contributions to have emerged during the last three decades in social sciences. However, they have not been meaningfully integrated within migration studies. Rather, analysis of transnational phenomena has focused on two distinct places (country, society, city etc.); back and forth movement between them; and the flows that create the social fields that link them. This article attempts to disrupt that binational/bilocal view by understanding transnational lives as part of a continuous yet fragmented mobility. It does so through an ethnography conducted in 2016 of refugees at a camp at the Port of Piraeus in Athens, Greece, during the so‐called European refugee crisis. The findings show that although spatially stranded in Greece, the refugees maintained dreams of getting farther into Europe while relying on, and being aided by, information and communication technology. Theirs were transnational lives not between just two places but on the move.
Investigation of Field‐Effect Passivation Created by Hydrogen Plasma Etching of Radio Corporation of America Formed Chemical Oxides on Crystalline Silicon Wafers
Authors: Jia Haitian , Tang Muzhi , Ge Jia
Published: December 2020

This work investigates the interface properties of intrinsic hydrogenated amorphous silicon film passivated wafers that underwent hydrogen plasma cleaning. A high level of interface band bending of nearly −0.6 eV, which corresponds to a fixed charge of −2.2 × 1012 cm−2, is found to be responsible for an effective minority carrier lifetime of over 6 ms on the 4.5 Ω cm n‐type wafer, while such field‐effect passivation is missing in hydrofluoric acid (HF) cleaned wafers. Further study indicates a positive correlation between the extent of surface band bending and doping concentration, together with an inverted U‐shape with respect to the increased annealing condition. The fixed charge on p‐type wafer is found to have a higher “formation energy” compared with the n‐type case, which renders its field‐effect passivation much less effective due to H effusion at high annealing temperatures. With reference to the theory on donor/acceptor‐H complex upon H plasma treatment, the origin and observed properties of the surface band bending on both dopant types are discussed. The unique presence of field effect on hydrogen plasma cleaned n‐type wafers can provide new insights into passivation material selection and structural design of heterojunction silicon wafer solar cells.
Climate‐linked freshwater habitat change will have cost implications: Pest blackfly outbreaks in two linked South African rivers
Authors: Rivers‐Moore Nicholas A. , de Moor Ferdy C.
Published: December 2020

Calls for implementation of environmental flows have been growing over the past 20 years, and their implementation is now being recognized. The need for such assessments to occur in conjunction with maintenance of environmental water temperatures has also been emphasized. When the costs of departures from natural thermal regimes are considered, this moves from being an academic exercise to a tangible management imperative. Pest outbreaks of aquatic macroinvertebrates typically occur when environmental conditions disproportionately and overwhelmingly favor a particular species. This has been the case for at least three major river systems of economic importance in South Africa, namely, the Orange River and its major tributary (Vaal River) as well as the Great Fish River. In these rivers, two species of pest blackfly, Simulium chutteri and S. damnosum (Diptera: Simuliidae), have become problematic following on from changes in natural flows through either impoundment or interbasin transfers. In this study, a statistically robust reference thermal condition was defined and exceedances assessed (based on a 2°C increase in water temperatures). The implications of these assessments were then applied to future possible pest blackfly outbreaks, factoring in changes in flows in response to global climate change. Results show that the current seasonal variation in the likelihood of pest outbreaks is replaced by high perpetual outbreak probabilities. Interactions between major environmental variables become synergistic, with major cost implications to regional economies. Lessons from this study can be generalized and used as a means of predicting similar synergistic effects in other aquatic macroinvertebrate disease vectors (such as bilharzia vector snails and mosquitoes) in response to global climate change.
Study of Spin Crossover Property of a Series of X‐OMe‐SalEen (X=6, 5 and 4) Based Fe(III) Complexes
Authors: Dey Bijoy , Gupta Arindam , Kapurwan Sandhya , Konar Sanjit
Published: December 2020

Three complexes bearing the molecular formula [Fe(X‐OMe‐SalEen)2]NCY⋅nH2O; X=6, Y=S, n=0 (1); X=5, Y=S, n=1.5 H2O (2) and X=4, Y=Se, n=0 (3), where 6‐OMe‐SalEen=2‐((E)‐(2‐(ethylamino)ethylimino)methyl)‐6‐methoxyphenol, 5‐OMe‐SalEen=2‐((E)‐(2‐(ethylamino)ethylimino)methyl)‐5‐methoxyphenol, and 4‐OMe‐SalEen=2‐((E)‐(2‐(ethylamino)ethylimino)methyl)‐4‐methoxyphenol, have been synthesized, characterized and their spin crossover behavior has been studied. The ligands differ in the position of the methoxy group (ortho, meta, and para) of the phenoxide ring directly bonded to the Fe center. Complex 1 and 3 comprise FeIII centers, whereas rare crystallographically independent high‐spin and low‐spin FeIII centers are present in complex 2. Complex 1 shows a sharp and hysteric spin crossover behavior with a hysteresis loop having 4 K width. Complex 2 shows spin crossover for the FeIIILS in solvated form which after desolvation becomes stable at the high spin. Complex 3 shows abrupt and incomplete spin crossover above room temperature. Magneto‐structural correlation and UV‐Vis spectroscopy have been done to study spin‐crossover behavior and the spin transition temperature of the complexes.
Pyrrole‐Based Schiff‐Base Sensor for Copper Ions
Authors: Sidana Nancy , Kaur Manpreet , Kaur Harminder , Devi Pooja
Published: December 2020

A new, simple, and reversible Schiff base, (E)‐N′‐((1H‐pyrrol‐2‐yl) methylene) isonicotinohydrazide (L), has been designed, synthesized, and characterized for its optical and elemental properties. The synthesized sensor, L is then successfully investigated for selective and sensitive detection of Cu+2 ions by the colorimetric and spectroscopic method in an aqueous organic solvent. The sensor L showed high selectivity toward Cu+2 ions over other possible interfering ions (Na+, K+, Ca+2, Mg+2,Co+2, Ni+2, Zn+2, Cd+2, Pb+2, Cr+3, Ag+, Al+3 and Mn+2) and in a wide pH range. The detection limit reaches up to 17.6 μM, which is lower than the WHO recommended guidelines for drinking water, while the limit of quantification was found to be 58 μM. The binding mode of complexation between Cu+2 and L was found to be 1 : 1 using Job's plot. For practical usage, the designed sensor (L) is transferred onto paper strips and demonstrated for real sample analysis through naked eye color change.
Approach to the Core Structure of Schweinfurthin B
Authors: Roos Dominika , Maier Martin E.
Published: December 2020

We investigated approaches to the xanthene part of schweinfurthin B. Starting from an exo‐methylene cyclohexanone, an organocuprate addition led to a cyclohexanone featuring a functionalized benzyl substituent in the 2‐position. Ring‐closing reactions to the tetrahydroxanthene core (formation of the central ring) were possible in moderate yield by attack of a phenolic oxygen function on the keto group. More effective was the cyclization to the xanthene core structure after conversion of the cyclohexanone to the exo‐methylene cyclohexane derivative and Lewis acid mediated addition of the phenolic OH to the double bond. In addition, we tried to form the xanthene ring system in a model study by cycloaddition reaction of a silyl enol ether with an ortho‐quinone methide.
Heterogeneous Photo‐Fenton Catalytic Oxidation of Ciprofloxacin Using LaFeO3/Diatomite Composite Photocatalysts under Visible Light
Authors: Liu Ying , Wu Min , Ren Lili , Wang Chuanchuan , Li Zhihao , Ling Liwei , Guo Yuting
Published: December 2020

LaFeO3/Diatomite porous disk composites have been successfully prepared by sol‐gel method for the photocatalytic oxidative degradation of ciprofloxacin (CIP) compounds. The structure of the porous disc plays an important role in improving the photocatalytic activity by increasing the contact area between the photocatalyst and CIP to enhance CIP molecule adsorption. Meanwhile, the porous disk composite photocatalysts can effectively prevent the recombination of light‐induced electron‐hole pairs. A photo‐Fenton‐like reaction is triggered by addition of H2O2, which further remarkably improves the photocatalytic activity of LaFeO3/Diatomite. Then, the factors like catalyst concentration, H2O2 dosage, initial pH and CIP concentration of the solution responsible for the enhanced photocatalytic performance of the reaction system are investigated. The optimal degradation rate of ciprofloxacin by the LaFeO3/Diatomite catalyst is 99.02 % after visible light irradiation for 150 min, which is 1.22 times of the pure LaFeO3. The catalysts have a much high stability which can be recycled for many times and the degradation rate of four cycles is still about 98 %. The excellent performance and high photocatalytic efficiency of the LaFeO3/Diatomite photocatalyst make it have potential application foreground in the treatment of pharmaceutical wastewater.
A Novel Annealing‐Free Amorphous Inorganic Metal Oxyhydroxide Cathode Interlayer for Efficient and Stable Inverted Perovskite Solar Cells
Authors: Feng Wenhuai , Liao Jin-Feng , Yang Meifang , Zhong Jun-Xing , Lei Bing-Xin , Ding Liming , Wu Wu-Qiang
Published: December 2020

The state‐of‐the‐art high‐performance perovskite solar cells (PSCs) with inverted p‐i‐n device structure normally use crystalline metal oxide materials or organic small molecules as the cathode interlayer between the fullerene layer and metal electrode. However, these interlayers are made by either high‐temperature or complicated vacuum‐assisted fabrication process, and in many cases, they are not efficient and effective enough to simultaneously extract the electrons and suppress the interfacial charge recombination. Herein, for the first time, a facile low‐temperature solution‐processed strategy is demonstrated to fabricate an amorphous metal oxyhydroxide (a‐MOH) thin film, which is used as a robust cathode interlayer in inverted PSCs. The a‐MOH interlayer not only facilitates electron extraction and collection via “energy‐favorable” electron tunneling, but also suppresses the interfacial charge recombination via effective hole blocking and electron backflow inhibition. As a result, the PSCs based on a‐MOH interlayer achieve a stabilized power conversion efficiency (PCE) of 21.1% and retain 93% of initial PCE after continuous one‐sun illumination for 500 hours.
Dual‐grained representation for hand, foot, and mouth disease prediction within public health cyber‐physical systems
Authors: Wang Zhijin , Huang Yaohui , He Bingyan
Published: December 2020

The prediction model is a major component within public health cyber‐physical systems, which supports decisions on prevention and control of diseases. Hand, foot, and mouth disease (HFMD) is one of the most common global infectious diseases with the highest incidence rate. Previous HFMD prediction models are mainly based on the time series that counted in equal‐grained time intervals. However, there are details in the time series counted in fine‐grained time intervals. To benefit from both equal‐grained and fine‐grained data, we proposed a dual‐grained representation (DGR) model. The DGR first represents inputted data to temporal patterns. Then, the represented patterns are consolidated to generate predictions. Experimental comparisons of the short‐term prediction performance are figured out by using real outpatient collections in Xiamen, China.
Microstructure Evolution during Controlled Rolling of an Nb–Ti Microalloyed Steel
Authors: Rezayat Mohammad , Mohebbi Mohammad Sadegh , Parsa Mohammad Habibi , Nagy Stefan , Nosko Martin
Published: December 2020

The microstructural evolution of an Nb–Ti microalloyed steel with the application of coiled tubing is studied in detail during hot rolling followed by accelerated cooling and simulated coiling by means of optical microscopy complemented with electron backscattered diffraction and transmission electron microscopy. It is found that the main microstructural characteristics, i.e., grain size, grain morphology, and texture, vary during different thermomechanical steps, largely in finish rolling. Finish rolling at 850 °C, in the nonrecrystallization region, activates the deformation‐induced ferrite transformation (DIFT) mechanism and leads to the appearance of γ‐fiber, and {332}<113> and {113}<110> components. Decreasing the finish rolling temperature to 750 °C promotes this mechanism and results in finer final microstructure consisting of low angle grain boundaries. However, it is found that to obtain a homogenous microstructure with γ‐fiber texture, the final rolling temperature should be high enough for the sufficient occurrence of static recrystallization in ferrite just after finish rolling. More deformation in the nonrecrystallization region, especially for the last rolling steps, strongly affects the DIFT mechanism and leads to fine‐grained microstructure. Refining of ferrite to the grain size of 3.5 ± 0.5 μm results in 65% enhancement of yield strength and reduction of strain hardening by 25%.
Effect of Annealing Process on Microstructure and Mechanical Properties in Microalloyed Medium Manganese Steel
Authors: Qin Dongyang , Gao Xiuhua , Liu Tao , Wu Hongyan , Zhang Mei , Du Linxiu
Published: December 2020

The effects of annealing conditions on microstructure evolution and strengthening mechanisms are investigated based on microalloyed medium manganese steel. The diffusion of C and Mn atoms is altered with increase in annealing temperatures or annealing time. Microstructure and mechanical properties are studied. It is found that the retained austenite generated by the reverse transformation of martensite is used to improve the strength and ductility during the intercritical temperature region. The total elongation (TE) is related to the fraction and stability of retained austenite. High strength is also obtained when there is almost no retained austenite below Ac1 temperature.
On the Influence of Vanadium on Air‐Hardening Medium Manganese Steels for Sustainable Forging Products
Authors: Gramlich Alexander , Middleton Aaron , Schmidt Rolf , Krupp Ulrich
Published: December 2020

A new alloy for drive‐train applications with a significant addition of vanadium is presented. The influence of vanadium addition to air‐hardening forging steels is investigated and discussed. For the investigations, a laboratory melt is casted and forged into a rod. The mechanical properties and the microstructure of the new alloy are described and compared with a vanadium‐free reference alloy from a previous study. The forged component shows high strength and hardness in the as‐forged state (YS: 892 MPa, UTS: 1366 MPa, hardness: 430 HV30) distributed equally over the full cross‐section. In addition, the strength does not decrease during subsequent heat treatments enabling the application as a material for surface treatments such as nitriding or plasma nitriding. Although strength, ductility, and hardness change as expected with increasing tempering, toughness acts different than in vanadium‐free alloys during intercritical annealing which hints at the interaction of vanadium with the fracture mechanism.
Predicting lifespan of Drosophila melanogaster: A novel application of convolutional neural networks and zero‐inflated autoregressive conditional Poisson model
Authors: Zhang Yi , Samaranayake V.A. , Olbricht Gayla R. , Thimgan Matthew
Published: December 2020

A model to classify the lifespan of Drosophila, the fruit fly, into short‐ and long‐lived categories based on a sleep characteristic, extracted from activity data, is developed using a two‐stage process. Stage 1 models the per‐minute activity counts of each fly using a zero‐inflated autoregressive conditional Poisson model. These probabilities are allowed to vary hourly, reflecting the circadian and other cycles present in a fly's sleep architecture. A 5‐day moving window is used to model data allowing the model parameters to vary over the course of the fly's life. The resulting probabilities capture information about changes in sleep patterns with age and are hypothesized to contain features that help categorize flies into short‐ and long‐lived groups. The resulting hourly zero‐inflation probabilities over a 24‐day period are utilized to create a ‘heat map’ containing information on the 24‐hour daily sleep cycle and its changes across the 24‐day observation period. In Stage 2, the heat maps for individual flies are used as inputs to a convolutional neural network to build a classification model. The estimated model provides a reasonably accurate way to group flies into lifespan categories. Grouping flies into such categories would facilitate the discovery of biochemical markers of aging.
Experimental and numerical research on the bond‐slip behavior of square‐rebar reinforced concrete during the republic of China (1912–1949)
Authors: Zhang Chengwen , Chun Qing , Jin Hui , Zhang Shiqi , Lin Yijie
Published: December 2020

Square‐rebar reinforced concrete structures during the republic of China (ROC) (1912–1949) have special material properties and structural characteristics. To perform nonlinear finite element simulations of this special type of structure more accurately, a specialized bond‐slip constitutive model is built. Eighteen central pullout specimens were designed based on the ROC concrete mix proportions and the square‐rebar. Then, the test data were fitted with the universal global optimization method and the minimum Euclidean distance point method was chosen to calculate the inflection point matrix of the bond‐slip constitutive model. Finally, the main factors influencing the bond‐slip behavior of the ROC square‐rebar reinforced concrete were analyzed. The research results show that the corrosion of the square‐rebar produces a negative effect on the whole structure and a modified bond‐slip regression curve considering the size effect is obtained. The research results can provide a scientific basis for the nonlinear calculation of ROC square‐rebar reinforced concrete structures considering the bond‐slip behaviors.
Applications and regulatory of nanotechnology‐based innovative in vitro diagnostics
Authors: Chen Kuan , Han Houyu , Tuguntaev Ruslan G. , Wang Peirong , Guo Weisheng , Huang Jiayu , Gong Xiaoqun , Liang Xing‐Jie
Published: December 2020

Nanotechnology‐basedin vitro diagnostics (nanoIVDs) are widely studied for disease diagnostics with promising sensitivity, specificity, and convenience. However, it is still a major challenge for both regulatory authorities and scientific researchers to accelerate the clinical translation of such an innovative technology. Herein, this perspective discussed the benefits and challenges of nanoIVDs as well as the administration considerations on the distinguish features of nanoIVDs by regulatory authorities, so as to further achieve the evaluation, translation, and application of nanoIVD products.
Culture, Freedom, and the Spread of Covid‐19: Do Some Societies and Political Systems Have National Anti‐Bodies?
Authors: Mayer Jeremy D. , Schintler Laurie A. , Bledsoe Scott
Published: December 2020

Public health scholars have previously explored the impact of culture upon various aspects of infectious disease policy. Similarly, regime type, while less studied, has been suggested as a possible explanation for varying rates of efficacy in infection vulnerability, mitigation, and abatement. The COVID‐19 pandemic offers an intriguing opportunity to test whether culture or level of societal freedom affects how different societies manage a serious pandemic challenge. We examine whether societies that are more free or have different cultures are more or less effective at managing the spread of COVID‐19. To examine possible correlational pathways, we conduct a country‐level regression analysis. After controlling for population size, income, stringency of government policies, population density, and age dispersion, we find that the level of freedom in a political system is unrelated to rates of COVID‐19 infection, at least in the time period under study. By contrast, two cultural families seemed to show at least temporary superiority in disease response: Confucian and South Asian culturally affiliated nations. While our results may be artifacts of aspects of the disease not yet revealed by science, if they are sustained by future research, they potentially offer insights into unusual intersections of culture and public health.
Measurement of L subshell fluorescence yield ratios of some high Z elements by selective excitation method
Authors: Hiremath G. B. , Bennal A. S. , Hosamani M. M. , Badiger N. M. , Trivedi A. , Tiwari M. K.
Published: December 2020

The L1, L2 and L3 subshells of Hf, Ta and Re atoms have been excited selectively by using microprobe XRF beam line, Indus‐2, RRCAT, India. The consequent characteristic L X‐ray photons, emitted from the targets due to creations of vacancies in L subshells, are measured using silicon drift detector (X‐123) spectrometer. As the energy of synchrotron radiation increases, the contribution of characteristic L X‐ray intensity increases. The advantage of the increase in the intensity of the characteristic L X‐ray photons with an increase in the energy of synchrotron radiation has been used to determine the L subshell fluorescence yield ratios of Hf, Ta and Re atoms by adopting the selective excitation method. The measured ratios of L subshell fluorescence yield have been compared with theoretical and other experimental values.
Marginal operators and supersymmetry enhancement in 3d S-fold SCFTs
Authors: Maduli Emanuele , Mekareeya Noppadol , Sacchi Matteo
Published: December 2020

Abstract

The study of exactly marginal deformations of superconformal field theories is a topic that has received considerable attention due to their rich properties. We investigate the $$ \mathcal{N} $$
N
= 2 preserving exactly marginal operators of 3d S-fold SCFTs. Two families of such theories are considered: one is constructed by gauging the diagonal flavour symmetry of the T(U(2)) and T(U(3)) theories, and the other by gauging the diagonal flavour symmetry of the $$ {T}_{\left[2,{1}^2\right]}^{\left[2,{1}^2\right]}\left( SU(4)\right) $$

T

2

1
2

2

1
2

SU

4

theory. In both families, it is possible to turn on a Chern-Simons level for each gauge group and to couple to each theory various numbers of hypermultiplets. The detailed analysis of the exactly marginal operators, along with the superconformal indices, allows us to determine whether supersymmetry gets enhanced in the infrared and to deduce the amount of supersymmetry of the corresponding SCFT.
Holo-ween
Authors: Simidzija Petar , Van Raamsdonk Mark
Published: December 2020

Abstract

We argue that given holographic CFT1 in some state with a dual spacetime geometry M, and given some other holographic CFT2, we can find states of CFT2 whose dual geometries closely approximate arbitrarily large causal patches of M, provided that CFT1 and CFT2 can be non-trivially coupled at an interface. Our CFT2 states are “dressed up as” states of CFT1: they are obtained from the original CFT1 state by a regularized quench operator defined using a Euclidean path-integral with an interface between CFT2 and CFT1. Our results are consistent with the idea that the precise microscopic degrees of freedom and Hamiltonian of a holographic CFT are only important in fixing the asymptotic behavior of a dual spacetime, while the interior spacetime of a region spacelike separated from a boundary time slice is determined by more universal properties (such as entanglement structure) of the quantum state at this time slice. Our picture requires that low-energy gravitational theories related to CFTs that can be non-trivially coupled at an interface are part of the same non-perturbative theory of quantum gravity.
Physical observers, T-vacuum and Unruh like effect in the radiation dominated early universe
Authors: Modak Sujoy K.
Published: December 2020

Abstract

We report the existence of an Unruh like effect, for physical observers (cosmo- logical and comoving observers) in the radiation dominated early universe, which is possible due to the discovery of a new vacuum state (referred here as the T−vacuum). Both the comoving and the cosmological observers, who are crucial in our understanding of cosmology, observe this T−vacuum as a particle excited state and are able to detect radiation due to particle creation. We draw a robust analogy with the Unruh effect, whereby — (i) the physical observers here are closely analogous to the accelerated (Rindler) observers in the flat spacetime, and (ii) the T−vacuum plays the role of the Minkowski vacuum state which contains particles when viewed from the physical observers frame. Our analogy is further supported by a proof of well-defined (hadamard) behavior of the T−vacuum in the entire spacetime. All our analysis of the particle creation process is done here within a two dimensional set up.
Building bulk geometry from the tensor Radon transform
Authors: Cao ChunJun , Qi Xiao-Liang , Swingle Brian , Tang Eugene
Published: December 2020

Abstract

Using the tensor Radon transform and related numerical methods, we study how bulk geometries can be explicitly reconstructed from boundary entanglement entropies in the specific case of AdS3/CFT2. We find that, given the boundary entanglement entropies of a 2d CFT, this framework provides a quantitative measure that detects whether the bulk dual is geometric in the perturbative (near AdS) limit. In the case where a well-defined bulk geometry exists, we explicitly reconstruct the unique bulk metric tensor once a gauge choice is made. We then examine the emergent bulk geometries for static and dynamical scenarios in holography and in many-body systems. Apart from the physics results, our work demonstrates that numerical methods are feasible and effective in the study of bulk reconstruction in AdS/CFT.
Gravitational waves from fundamental axion dynamics
Authors: Ghoshal Anish , Salvio Alberto
Published: December 2020

Abstract

A totally asymptotically free QCD axion model, where all couplings flow to zero in the infinite energy limit, was recently formulated. A very interesting feature of this fundamental theory is the ability to predict some low-energy observables, like the masses of the extra fermions and scalars. Here we find and investigate a region of the parameter space where the Peccei-Quinn (PQ) symmetry is broken quantum mechanically through the Coleman-Weinberg mechanism. This results in an even more predictive framework: the axion sector features only two independent parameters (the PQ symmetry breaking scale and the QCD gauge coupling). In particular, we show that the PQ phase transition is strongly first order and can produce gravitational waves within the reach of future detectors. The predictivity of the model leads to a rigid dependence of the phase transition (like its duration and the nucleation temperature) and the gravitational wave spectrum on the PQ symmetry breaking scale and the QCD gauge coupling.
IBP reduction coefficients made simple
Authors: Boehm Janko , Wittmann Marcel , Wu Zihao , Xu Yingxuan , Zhang Yang
Published: December 2020

Abstract

We present an efficient method to shorten the analytic integration-by-parts (IBP) reduction coefficients of multi-loop Feynman integrals. For our approach, we develop an improved version of Leinartas’ multivariate partial fraction algorithm, and provide a modern implementation based on the computer algebra system Singular. Furthermore, we observe that for an integral basis with uniform transcendental (UT) weights, the denominators of IBP reduction coefficients with respect to the UT basis are either symbol letters or polynomials purely in the spacetime dimensionD. With a UT basis, the partial fraction algorithm is more efficient both with respect to its performance and the size reduction. We show that in complicated examples with existence of a UT basis, the IBP reduction coefficients size can be reduced by a factor of as large as ∼ 100. We observe that our algorithm also works well for settings without a UT basis.
Investigation into the surface quality and stress corrosion cracking resistance of AISI 316L stainless steel via precision end-milling operation
Authors: Yasir Muhammad , Danish Mohd , Mia Mozammel , Gupta Munish Kumar , Sarikaya Murat
Published: December 2020

This study presents a two-fold investigation on precision end-milling of stainless steel (AISI 316L). First, the impact of end-milling variables (cutting speed and feed rate) on the surface quality (surface roughness, microhardness, and surface morphology) was analyzed. The best surface quality with surface roughness (Ra) 0.65 ± 0.02 μm was observed for cutting speed of 140 m/min and 0.025 mm/tooth of feed rate. Microhardness was increased with increment in cutting speed. Second, the impact of surface roughness (Ra) on the stress corrosion cracking under two different mediums, i.e., body solutions (Hank’s solution) and 1 M hydrochloric acid solution, was studied. The investigations showed that the samples with higher surface roughness values were more prone to stress corrosion cracking.
Better together? How intergroup associations affect energy balance and feeding behavior in wild bonobos
Authors: Lucchesi Stefano , Cheng Leveda , Deschner Tobias , Mundry Roger , Wessling Erin G. , Surbeck Martin
Published: December 2020

When the benefits of interacting with out-group members exceed the associated costs, social groups may be expected to be tolerant towards each other. However, in many species exhibiting intergroup tolerance, the nature of benefits gained from intergroup encounters remains unclear. We investigated the potential costs and benefits associated with intergroup associations in bonobos, a species with varying degrees of intergroup tolerance, by testing whether these associations conferred energetic benefits to participants under different socioecological contexts and whether the consequences of these associations substantially differed from within-group competition. We used measures of socioecological factors (fruit abundance and group size), feeding and ranging behaviors, and a physiological marker of energy balance (urinary c-peptide of insulin) collected over a 19-month period from two neighboring wild communities in the Kokolopori Bonobo Reserve, Democratic Republic of the Congo. We found that intergroup associations were not related to individuals’ energy balance, but they were related to variations in individuals’ ranging and feeding behavior. Specifically, bonobos traveled longer distances, visited larger fruit patches, and increased the time spent feeding on fruits on days they associated with the neighboring group. These adaptations in feeding behavior may be strategies to offset the energetic costs of increased travel distances. In the absence of obvious energetic benefits and with clear strategies employed to offset energetic costs, it is likely that intergroup associations in bonobos provide benefits unrelated to energy acquisition, such as social benefits. Our study sheds light on the potential incentives promoting social networks to extend beyond and across groups in a tolerant species.

Significance statement

Intergroup encounters can be energetically costly due to increased competition over resources. Yet, some species associate with out-group individuals for extended periods of time when the benefits of participating in these associations exceed the potential costs. Bonobos, a species exhibiting intergroup tolerance, modified their feeding behavior during intergroup associations by feeding on larger fruit patches and increasing their time spent feeding on fruits, likely to offset energetic costs of increased travel distances. As results, individuals’ energy balance was not related with intergroup associations. The employment of such strategies in addition to the absence of clear energetic benefits suggests that intergroup associations in bonobos provide social rather than ecological benefits.
Treatment and outcomes of primary mediastinal B cell lymphoma: a three-decade monocentric experience with 151 patients
Authors: Casadei Beatrice , Argnani Lisa , Morigi Alice , Lolli Ginevra , Broccoli Alessandro , Pellegrini Cinzia , Nanni Laura , Stefoni Vittorio , Coppola Paolo Elia , Carella Matteo , Cavo Michele , Zinzani Pier Luigi
Published: December 2020

Primary mediastinal B cell lymphoma is a rare entity and often should be promptly treated as a hematological emergency: The initial treatment decision is crucial for the management of this disease. An observational retrospective study was conducted with the aim to improve information on treatment and outcomes of primary mediastinal B cell lymphoma in real practice. After 12 cycles of MACOP-B regimen (methotrexate, doxorubicin, cyclophosphamide, vincristine, bleomycin, and prednisone) with or without rituximab, 120 patients out of 151 (79.5%) achieved a complete response and 12 (7.9%) a partial response leading to a global response of 87.4%. The 21-year overall survival is 82.6%; progression-free and disease-free survivals are 69.3% and 86.4%, respectively. Regarding the role of radiotherapy (RT), patients with a negative PET scan after MACOP-B did not undergo RT: One out of these 48 (2.1%) showed a relapse at 11 months. All relapsed/refractory patients who achieved a response with checkpoint inhibitors are still in continuous complete response with a median follow-up of 14 months. Data that we have gathered over a 30-year experience in the treatment of primary mediastinal B cell lymphoma patients clearly indicate that a third-generation chemotherapy regimen such as MACOP-B is feasible and easily deliverable on an outpatient basis. Regarding the unmet medical need of relapsed/refractory patients, new encouraging results occurred with the advent of the checkpoint inhibitors.