bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of bovine gelatin viscosity on gelatin-based edible film mechanical, physical and morphological properties
Authors: Sancakli A. , Basaran B. , Arican F. , Polat O.
Published: January 2021

This study was conducted to determine the effect of gelatin reology on mechanical, physical and morphological properties of gelatin-based edible films. The aim of this study was to better understand the variation of viscosity on the structural behaviour of gelatin-based films in the presence of glycerol and sorbitol plasticizers. Gelatin-based films were casted by using gelatins of different viscosities as 2.5, 3.0 and 3.5 centipoise with plasticisers as glycerol and sorbitol. Finally, the physical, mechanical and morphological properties of the films were investigated via pH, thickness, tensile strength and elongation, fourier transform infrared spectroscopy and scanning electron microscopy. As a result of the study, it was observed that a durable film structure could be obtained with gelatin viscosity at 3 centipoise. Furthermore 5.5% gelatin, 0.1% glycerol and 0.4% sorbitol concentration were found as the most suitable formulation for gelatin based film structure with Tukey Test. The results suggest that gelatin-plastisizer combinations can be an excellent source of biobased packaging material with further investigations.
Electrochemical determination of the levels of lead and cadmium in soil samples from Niger and Ogun States, Nigeria: remediation potential with chitosan phosphate and implications for human health and disease
Authors: Olaitan Greatness , Okiei Wesley
Published: January 2021

Lead and cadmium poisoning is common in some parts of Nigeria as a result of artisanal mining of gold. The poisoning has led to the deaths of hundreds of women and children below the age of five years. In this study, the concentrations of lead and cadmium in eight soil samples collected from selected artisanal gold mining locations in Niger State and battery dismantling site in Ogun State were electrochemically determined. Linear sweep stripping voltammetry technique was used with glassy carbon as working electrode, Ag/AgCl as reference and platinum as auxiliary electrode. The cathodic peak current for the reduction of lead was observed at − 490 mV while that of cadmium was observed at − 675 mV. The concentrations of lead in the soil samples ranged between 19 and 417 mg/kg while that of cadmium was in the range 20–182 mg/kg. The ability of chitosan phosphate to adsorb lead and cadmium in the polluted soil samples was investigated as a step towards carrying out remediation of the polluted environment. Chitosan phosphate was derived from chitosan which was prepared by the deacetylation of chitin obtained from crab. The chitosan phosphate was found to remove the lead and cadmium from all the soil samples studied.
Reducing cementitious paste volume of slipformed pavement concrete by blending aggregates
Authors: Chung Hung-Wen , Subgranon Thanachart , Tia Mang
Published: January 2021

A high cementitious paste volume (CPV) can increase the early cracking tendency of the concrete and reduce the durability of concrete pavement. This study investigated the effects of minimized CPV in slipformed pavement concrete (SPC) with blended aggregates (BA). Based on the laboratory results, the performance of pavement concrete with different CPV was evaluated. The CPV of standard SPC can be reduced to 25.0% without affecting its properties as evaluated by compressive strength, drying shrinkage and surface resistivity tests However, the CPV of SPC with optimized aggregate gradation (OAG) using BA technique can be further reduced to 22.5% with satisfactory properties. The SPC mixes with OAG was noted to have better potential performance as a pavement concrete. SPC concrete using Portland limestone cement can give similar properties as those of the conventional concrete using ordinary Portland cement.
Selected implications of a hyper-connected world on pavement engineering
Authors: Steyn Wynand Jacobus van der Merwe
Published: January 2021

The world is becoming a hyper-connected environment where an abundance of data from sensor networks can provide continuous information on the behaviour and performance of infrastructure. The last part of the 3rd Industrial Revolution (IR) and the start of the 4th IR gave rise to a world where this overabundance of sensors, and availability of wireless networks enables connections between people and infrastructure that was not practically comprehensible during the 20th century. 4IR supports the datafication of life, data science, big data, transportation evolution, optimization of logistic and supply chains and automation of various aspects of life, including vehicles and road infrastructure. The hyper-connected 4IR environment allows integration between the physical world and digital and intelligent engineering, increasingly serving as the primary lifecycle management systems for engineering practitioners. With this background, the paper evaluates a few concepts of the hyper-connected pavement environment in a 4IR Digital Twin mode, with the emphasis on selected applications, implications, benefits and limitations. The hyper-connected world can and should be managed in the pavement realm to ensure that adequate and applicable data are collected regarding infrastructure, environment and users to enable a more efficient and effective transportation system. In this regard, and planning for future scenarios where the proliferation of data is a given, it is important that pavement engineers understand what is possible, evaluate the potential benefits, conduct cost/benefit evaluations, and implement appropriate solutions to ensure longevity and safety of pavement infrastructure.
Using Heat to Trace Vertical Water Fluxes in Sediment Experiencing Concurrent Tidal Pumping and Groundwater Discharge
Authors: LeRoux N. K. , Kurylyk B. L. , Briggs M. A. , Irvine D. J. , Tamborski J. J. , Bense V. F.
Published: January 2021

Heat has been widely applied to trace groundwater‐surface water exchanges in inland environments, but it is infrequently applied in coastal sediment where head oscillations induce periodicity in water flux magnitude/direction and heat advection. This complicates interpretation of temperatures to estimate water fluxes. We investigate the convolution of thermal and hydraulic signals to assess the viability of using heat as a tracer in environments with tidal head oscillations superimposed on submarine groundwater discharge. We first generate sediment temperature and head time series for conditions ranging from no tide to mega‐tidal using a numerical model (SUTRA) forced with periodic temperature and tidal head signals. We then analyze these synthetic temperature time series using heat tracing software (VFLUX2 and 1DTempPro) to evaluate if conventional terrestrial approaches to infer fluxes from temperatures are applicable for coastal settings. We consider high‐frequency water flux variability within a tidal signal and averaged over tidal signals. Results show that VFLUX2 analytical methods reasonably estimated the mean discharge fluxes in most cases but could not reproduce the flux variability within tidal cycles. The model results further reveal that high‐frequency time series of water fluxes varying in magnitude and direction can be accurately estimated if paired temperatures and hydraulic heads are analyzed using numerical models (e.g., 1DTempPro) that consider both dynamic hydraulic gradients and thermal signals. These results point to the opportunity to incorporate pressure sensors within heat tracing instrumentation to better assess sub‐daily flux oscillations and associated reactive processes.
Nanodroplet-mediated catheter-directed sonothrombolysis of retracted blood clots
Authors: Goel Leela , Wu Huaiyu , Zhang Bohua , Kim Jinwook , Dayton Paul A. , Xu Zhen , Jiang Xiaoning
Published: January 2021

One major challenge in current microbubble (MB) and tissue plasminogen activator (tPA)-mediated sonothrombolysis techniques is effectively treating retracted blood clots, owing to the high density and low porosity of retracted clots. Nanodroplets (NDs) have the potential to enhance retracted clot lysis owing to their small size and ability to penetrate into retracted clots to enhance drug delivery. For the first time, we demonstrate that a sub-megahertz, forward-viewing intravascular (FVI) transducer can be used for ND-mediated sonothrombolysis, in vitro. In this study, we determined the minimum peak negative pressure to induce cavitation with low-boiling point phase change nanodroplets and clot lysis. We then compared nanodroplet mediated sonothrombolysis to MB and tPA mediate techniques. The clot lysis as a percent mass decrease in retracted clots was 9 ± 8%, 9 ± 5%, 16 ± 5%, 14 ± 9%, 17 ± 9%, 30 ± 8%, and 40 ± 9% for the control group, tPA alone, tPA + US, MB + US, MB + tPA + US, ND + US, and ND + tPA + US groups, respectively. In retracted blood clots, combined ND- and tPA-mediated sonothrombolysis was able to significantly enhance retracted clot lysis compared with traditional MB and tPA-mediated sonothrombolysis techniques. Combined nanodroplet with tPA-mediated sonothrombolysis may provide a feasible strategy for safely treating retracted clots.
Cardiopulmonary performance in allogeneic hematopoietic cell transplantation recipients—evaluation of pre-transplant risk assessments
Authors: Pahl Antonia , Waibel Sarah , Wehrle Anja , Ihorst Gabriele , Gollhofer Albert , Bertz Hartmut
Published: January 2021

Cardiopulmonary performance reflects how well different organ systems interact. It is inter alia influenced by body composition, determines patients’ quality of life and can also predict mortality. However, it is not yet used for risk prediction prior to allogeneic hematopoietic cell transplantations (alloHCT). Thus, we aimed to examine the predictive power of peak oxygen consumption (VO2peak) as a representative of cardiopulmonary performance and that of body composition before alloHCT to determine overall survival (OS) and non-relapse mortality (NRM) 2 years after transplantation. We also compared it with the predictive power of four commonly-used risk scores: revised Pretransplant Assessment of Mortality (rPAM), Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI), revised Disease Risk Index (rDRI), European Society for Blood and Marrow Transplantation (EBMT). Fifty-nine patients performed a cardiopulmonary exercise test and body composition assessments before alloHCT and were observed for 2 years. Sixteen patients died. VO2peak and most risk scores assessed pre-transplant revealed no association with OS or NRM. Body composition parameters only within univariable analyses. But higher rDRI and the male sex, were associated with shorter OS and higher NRM. We thus propose that the current risk assessments be reconsidered. The predictive value of VO2peak and body composition need further clarification, however.
Integrated decoding hematopoiesis and leukemogenesis using single-cell sequencing and its medical implication
Authors: Qin Pengfei , Pang Yakun , Hou Wenhong , Fu Ruiqing , Zhang Yingchi , Wang Xuefei , Meng Guofeng , Liu Qifa , Zhu Xiaofan , Hong Ni , Cheng Tao , Jin Wenfei
Published: January 2021

Single-cell RNA sequencing provides exciting opportunities to unbiasedly study hematopoiesis. However, our understanding of leukemogenesis was limited due to the high individual differences. Integrated analyses of hematopoiesis and leukemogenesis potentially provides new insights. Here we analyzed ~200,000 single-cell transcriptomes of bone marrow mononuclear cells (BMMCs) and its subsets from 23 clinical samples. We constructed a comprehensive cell atlas as hematopoietic reference. We developed counterpart composite index (CCI; available at GitHub: https://github.com/pengfeeei/cci) to search for the healthy counterpart of each leukemia cell subpopulation, by integrating multiple statistics to map leukemia cells onto reference hematopoietic cells. Interestingly, we found leukemia cell subpopulations from each patient had different healthy counterparts. Analysis showed the trajectories of leukemia cell subpopulations were similar to that of their healthy counterparts, indicating that developmental termination of leukemia initiating cells at different phases leads to different leukemia cell subpopulations thus explained the origin of leukemia heterogeneity. CCI further predicts leukemia subtypes, cellular heterogeneity, and cellular stemness of each leukemia patient. Analyses of leukemia patient at diagnosis, refractory, remission and relapse vividly presented dynamics of cell population during leukemia treatment. CCI analyses showed the healthy counterparts of relapsed leukemia cells were closer to the root of hematopoietic tree than that of other leukemia cells, although single-cell transcriptomic genetic variants and haplotype tracing analyses showed the relapsed leukemia cell were derived from an early minor leukemia cell population. In summary, this study developed a unified framework for understanding leukemogenesis with hematopoiesis reference, which provided novel biological and medical implication.
Platypus and echidna genomes reveal mammalian biology and evolution
Authors: Zhou Yang , Shearwin-Whyatt Linda , Li Jing , Song Zhenzhen , Hayakawa Takashi , Stevens David , Fenelon Jane C. , Peel Emma , Cheng Yuanyuan , Pajpach Filip , Bradley Natasha , Suzuki Hikoyu , Nikaido Masato , Damas Joana , Daish Tasman , Perry Tahlia , Zhu Zexian , Geng Yuncong , Rhie Arang , Sims Ying , Wood Jonathan , Haase Bettina , Mountcastle Jacquelyn , Fedrigo Olivier , Li Qiye , Yang Huanming , Wang Jian , Johnston Stephen D. , Phillippy Adam M. , Howe Kerstin , Jarvis Erich D. , Ryder Oliver A. , Kaessmann Henrik , Donnelly Peter , Korlach Jonas , Lewin Harris A. , Graves Jennifer , Belov Katherine , Renfree Marilyn B. , Grutzner Frank , Zhou Qi , Zhang Guojie
Published: January 2021

Egg-laying mammals (monotremes) are the only extant mammalian outgroup to therians (marsupial and eutherian animals) and provide key insights into mammalian evolution1,2. Here we generate and analyse reference genomes of the platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus), which represent the only two extant monotreme lineages. The nearly complete platypus genome assembly has anchored almost the entire genome onto chromosomes, markedly improving the genome continuity and gene annotation. Together with our echidna sequence, the genomes of the two species allow us to detect the ancestral and lineage-specific genomic changes that shape both monotreme and mammalian evolution. We provide evidence that the monotreme sex chromosome complex originated from an ancestral chromosome ring configuration. The formation of such a unique chromosome complex may have been facilitated by the unusually extensive interactions between the multi-X and multi-Y chromosomes that are shared by the autosomal homologues in humans. Further comparative genomic analyses unravel marked differences between monotremes and therians in haptoglobin genes, lactation genes and chemosensory receptor genes for smell and taste that underlie the ecological adaptation of monotremes.
Injectable nanofibrillar hydrogels based on charge-complementary peptide co-assemblies
Authors: Soto Morales Bethsymarie , Liu Renjie , Olguin Juanpablo , Ziegler Abigail M. , Herrera Stephanie M. , Backer-Kelley Kimberly L. , Kelley Karen L. , Hudalla Gregory A.
Published: January 2021

CATCH(+/−) peptide co-assemblies form injectable, biocompatible hydrogels with sequence-dependent viscoelastic properties.
Smart metal organic frameworks: focus on cancer treatment
Authors: Falsafi Monireh , Saljooghi Amir Sh. , Abnous Khalil , Taghdisi Seyed Mohammad , Ramezani Mohammad , Alibolandi Mona
Published: January 2021

Metal–organic frameworks (MOFs), as a prominent category of hybrid porous materials, have been broadly employed as controlled systems of drug delivery due to their inherent interesting properties.
In situ investigation of oxidation across a heterogeneous nanoparticle–support interface during metal support interactions
Authors: Datta Abheek , Deolka Shubham , Kumar Pawan , Ziadi Zakaria , Sasaki Toshio , Steinhauer Stephan , Singh Vidyadhar , Jian Nan , Danielson Eric , Porkovich Alexander James
Published: January 2021

This work examines oxidation across heterogenous interfaces in the context of EMSI between catalytic nanoparticles and oxide supports.
Natural abundance oxygen-17 solid-state NMR of metal organic frameworks enhanced by dynamic nuclear polarization
Authors: Carnevale Diego , Mouchaham Georges , Wang Sujing , Baudin Mathieu , Serre Christian , Bodenhausen Geoffrey , Abergel Daniel
Published: January 2021

The 17O resonances of zirconium-oxo clusters that can be found in porous Zr carboxylate metal–organic frameworks (MOFs) have been investigated by magic-angle spinning (MAS) NMR spectroscopy enhanced by dynamic nuclear polarization (DNP).
Microfluidics for the rapid and controlled preparation of organic nanotubes of bent-core based dendrimers
Authors: Castillo-Vallés Martín , Romero Pilar , Sebastián Víctor , Ros M. Blanca
Published: January 2021

Microfluidics is suitable for the self-assembly of bent-core molecules and for the first time, a range of experimental conditions allows the fabrication of different organic and gold-based hybrid nanostructures in a rapid and controlled manner.
Magnetite doped metal–organic framework nanocomposites: an efficient adsorbent for removal of bisphenol-A pollutant
Authors: Icten Okan , Ozer Demet
Published: January 2021

The removal of bisphenol-A (BPA) from the aqueous environment is a vital issue for public health due to its toxic effect.
Highly efficient fused ring electron acceptors based on a new undecacyclic core
Authors: Zhao Fuwen , He Dan , Xin Jingming , Zhang Huotian , Zhou Jixiang , Lin Baojun , He Yongju , Li Jiang , Ma Wei , Li Bao , Gao Feng , Li Yongfang , Wang Chunru
Published: January 2021

Two FREAs, IUIC-O and IUIC-T, based on a large fused ring donor core (undecacyclic unit) were developed. IUIC-T, having 2D conjugated side chains, affords a higher PCE of 13.05%.
Stabilizing decontamination foam using surface-modified silica nanoparticles containing chemical reagent: foam stability, structures, and dispersion properties
Authors: Yoon In-Ho , Yoon Suk Bon , Sihn Youngho , Choi Man-Soo , Jung Chong-Hun , Choi Wang-Kyu
Published: January 2021

The stabilization of decontamination foams containing a chemical reagent is a crucial requirement for their use in the decontamination of nuclear power plants.
Bioinspired polymeric pigments to mimic natural hair coloring
Authors: Sun Yu , Wang Congyu , Sun Min , Fan Zhen
Published: January 2021

A biocompatible eumelanin mimetic approach is proposed to achieve hair coloring under mild condition. Through optimizing the dyeing process, various colors and desired darkness could be achieved within less than 1 minutes.
Minerals in biology and medicine
Authors: Carter Oliver W. L. , Xu Yingjian , Sadler Peter J.
Published: January 2021

Minerals play important natural roles in biology and offer relatively unexplored potential for the design of novel drugs, for the diagnosis of disease, and for discovery of new biotechnological applicationsviamultisite recognition of biomolecules.
Identification of β-strand mediated protein–protein interaction inhibitors using ligand-directed fragment ligation
Authors: Hegedüs Zsófia , Hóbor Fruzsina , Shoemark Deborah K. , Celis Sergio , Lian Lu-Yun , Trinh Chi H. , Sessions Richard B. , Edwards Thomas A. , Wilson Andrew J.
Published: January 2021

Dynamic ligation screening is used to identify acylhydrazone-linked peptide-fragment hybrids which bind to the SHANK1 PDZ domain with comparable affinity to the native GKAP peptide as shown by biophysical and structural analyses.
Demonstration of green hydrogen production using solar energy at 28% efficiency and evaluation of its economic viability
Authors: Khan M. A. , Al-Shankiti I. , Ziani A. , Idriss H.
Published: January 2021

The solar to hydrogen (STH) efficiency of photovoltaic-electrolysis (PV-E) setups are a key parameter to lower the cost of green hydrogen produced.
The essence, features and prospects of homestead land use in Uzbekistan
Authors: Ashurov Abdullo , Saydaliyeva Guzal
Published: January 2021

The socio-economic role of homestead land plots and private farms is studied, definitions of their terms are given, the role of the homestead land Fund in ensuring food security of the country and increasing the export potential of fruit and vegetable products is considered. The reasons for the higher efficiency of growing agricultural products in private farms in comparison with other forms of farming, as well as the features of the use of homestead land plots, are studied.
Reuse of ground tire rubber (GTR) as a filler of TPE matrix*
Authors: Majewska-Laks Kinga , Sykutera Dariusz , Ościak Adrian
Published: January 2021

Used car tires are the type of waste that does not decompose naturally and is not recyclable in molten state. Despite many initiatives to reuse these materials on a global scale, a large part of used tires are still landfilled. The present work is an attempt to use ground powder of ground tire rubber (GTR) to filling the TPE-S thermoplastic elastomer matrix. The aim of this study was to obtain TPE-GTR compositions in standard thermoplastic processing machines. This study used rubber powder with a grain size of 0.2-0.4 mm, obtained by grinding process in a knife mill of own design. The GTR filler into the TPE matrix in the amount of 5 and 50 wt% was dosed. Specimens were produced by injection molding. The obtained molded parts were tested for tensile strength, Shore hardness and Schob elasticity. Influence of melt temperature on TPE-GTR molded parts properties was also examined. The addition of GTR to the matrix causes a significant decrease in elongation at break, while improving the stiffness, damping properties and hardness of the TPE-GTR composition. It was also found that the melting temperature above 200°C has negative effect on the properties of the TPE-GTR compounds.
Analysis of the sensitivity of the identification method of inability states of rotating systems to the conditions of the experiment
Authors: Pająk Michał , Lisjak Dragutin , Kluczyk Marcin , Kolar Davor
Published: January 2021

One of the most important subsystems of the vehicles and machines operating currently in industry and transportation are the rotating subsystems. Monitoring of its technical state is an important issue of the engineering and academic research. As a result of the research a lot of new diagnostic methods have been formulated but one of the most important characteristic of them is the ability to industrial implementation. It depends on the insensitivity to disturbance which can arise in real operational environment. In the paper the method formulated by the authors is analysed. This is the method of the identification of inability states of rotating subsystems based on the vibrations analyses in the time domain. It constitutes the system approach to the considered issue. There are three applications of the method described - research on simulation laboratory stand, research on a real technical object conducted in the laboratory and research carried out on a real technical object under the real operation conditions. In each case different accuracy of the ability and inability states identification is achieved. Analysing the differences in accuracy of the method applications the conclusion of its sensitivity to the conditions of the experiment were formulated which are presented in the end of the paper.
Frequency response function shape differences as a sign of bricks elements destruction diagnostics
Authors: Żółtowski Mariusz , Šadzevičius Raimondas
Published: January 2021

The knowledge of the dynamic state and structure of system allows describing its behavior and allows creating prognosis models of the system behavior in the function of dynamic evolution time, based on the model of the technical state symptoms growth. Most often, there are no known equations describing behaviors of the system in the function of dynamic evolution time, which accounts for the need to apply new tools to examine the dynamic state. In this article authors shows chosen problems of technical state diagnosis with the use of identification and technical diagnostics methods such as experimental modal analysis. Relations between methods of dynamic state evaluation and methods of technical state evaluation were indicated. Example modal analysis results illustrate the complexity of projecting dynamic state researches into diagnostic researches of state evaluation.
Genetic and Biochemical Predictors of Neonatal Bronchopulmonary Dysplasia
Authors: Abdellatif May A.K. , Eyada Eman , Rabie Walaa , Abdelaziz Azza , Shahin Walaa
Published: January 2021

Bronchopulmonary dysplasia (BPD) is a common complication of prematurity with a multifactorial etiology, influenced by both genetic susceptibility and environmental factors on the immature lung. Fibroblast growth factor receptor-3 and -4 (FGFR-3 and FGFR-4) are abundantly expressed in both the epithelium and mesenchyme in the developing mammalian lung. FGFR-4 may play a role in developing BPD as it is associated with airway inflammation and remodeling; studies showed a link between BPD and a polymorphism in the FGFR-4 gene. The aim of this study was to study the significance of FGFR-4 in developing BPD and to investigate the correlation between its serum level and its genetic polymorphism in relation to development of BPD in preterms. This case–control study was performed on 80 preterm neonates (<32 weeks) divided into two groups: group I included 50 preterms with respiratory distress syndrome (RDS) who developed BPD and group II included 30 preterms with RDS only. The mean serum level of FGFR-4 was significantly lower in group I than in group II (p-value < 0.05). There was no significant correlation between the serum levels of FGFR-4 and the degree of severity of BPD. Allele variation in the FGFR-4 gene was similar in both groups. The serum level of FGFR-4 was significantly lower in preterms with BPD, although the gene polymorphism was not significantly different in the studied groups.
Explaining the legitimizing function of expert knowledge: how France got away with pain in farm animals
Authors: Caby Vincent
Published: January 2021

Scholars have long investigated connections between types of knowledge use and types of policy subsystem. Yet, most of them focus on the learning function of expert information. The legitimizing function of knowledge—when expertise serves as a substitute for decision (Boswell in J Eur Public Policy 15(4):471–488, 2008)—has attracted less attention. An empirically validated explanation of this function is still missing. This article tests existing hypotheses regarding which features of the subsystem are conducive to the legitimizing function. The demonstration rests upon a case study: France’s Ministry of Agriculture’s commissioning of INRA to carry out a systematic literature review on pain in farm animals. Two types of factors are involved in the legitimizing function of knowledge: environmental mechanisms (an adversarial policy subsystem, concentration of policy authority) and relational mechanisms (coalitions displaying epistemic uncertainty and exerting pressures on the source of policy authority, a policy broker mitigating the conflict between the two coalitions).
The human (in)security trap: how European border(ing) practices condemn migrants to vulnerability
Authors: Fontana Iole
Published: January 2021

This article explores the experience of migrants at Europe’s borders and beyond building upon the notion of human security—or rather its antithesis insecurity—and looking at it afresh through the lenses of border studies. It introduces the concept of ‘human insecurity trap’ as a tool to grasp the insecurities and vulnerabilities of people-on-the-move and the different border(ing)s, barriers and confinements they stem from. The article argues that smuggling to and across Europe, as well as EU and MS policy apparatus, entraps migrants into a spiral of human insecurity which unfolds at different levels and borders: at sea, in the ongoing struggle between smugglers and EU counter-smuggling operations; at the state border, where bureaucratic limbo and the (mis)management of shipwrecked migrants and asylum-seekers variously contend and combine with populist anti-migrant discourse; and across the EU, as practices of ‘re-smuggling’ and ‘secondary movement’ compete with practices of mobility limits, returns and border closures.
Elitism in mathematics and inequality
Authors: Chang Ho-Chun Herbert , Fu Feng
Published: January 2021

The Fields Medal, often referred as the Nobel Prize of mathematics, is awarded to no more than four mathematicians under the age of 40, every 4 years. In recent years, its conferral has come under scrutiny of math historians, for rewarding the existing elite rather than its original goal of elevating under-represented mathematicians. Prior studies of elitism focus on citational practices while a characterization of the structural forces that prevent access remain unclear. Here we show the flow of elite mathematicians between countries and lingo-ethnic identity, using network analysis and natural language processing on 240,000 mathematicians and their advisor–advisee relationships. We present quantitative evidence of how the Fields Medal helped integrate Japan after WWII, through analysis of the elite circle formed around Fields Medalists. We show increases in pluralism among major countries, though Arabic, African, and East Asian identities remain under-represented at the elite level. Our results demonstrate concerted efforts by academic committees, such as prize giving, can either reinforce the existing elite or reshape its definition. We anticipate our methodology of academic genealogical analysis can serve as a useful diagnostic for equity and systemic bias within academic fields.
Propagation properties of electron cyclotron waves with helical wavefronts in magnetized plasma
Authors: Tsujimura Toru Ii , Kubo Shin
Published: January 2021

Propagation properties of an optical vortex with a helical wavefront in cold uniform magnetized plasma are theoretically investigated in an electron cyclotron range of frequencies. The effects of the helical wavefront of the optical vortex on the wave fields in magnetized plasma are described. These effects become significant as the topological charge of the optical vortex increases or the distance from the phase singularity point becomes small. The different properties of propagation are also confirmed in propagation of Laguerre–Gaussian beams by three-dimensional simulations with the finite element method.
Drop size measurement techniques for sprays: Comparison of image analysis, phase Doppler particle analysis, and laser diffraction
Authors: Sijs R. , Kooij S. , Holterman H. J. , van de Zande J. , Bonn D.
Published: January 2021

Four different methods for measuring droplet size distributions are evaluated: the Image Analysis VisiSizer technique, a stroboscopic imaging method developed in-house, phase Doppler particle analysis (PDPA), and laser diffraction (Malvern Spraytec). We find that the larger the droplets, the bigger the differences between the results obtained by the different methods. The Image Analysis VisiSizer technique yields results that are comparable with those of the stroboscopic imaging method, provided that the raw Visisizer data are used, as the VisiSizer software makes corrections that can skew the results. Our measurements confirm how the limitations of PDPA can influence its outcomes; the presence of air bubbles inside droplets will cause PDPA to mistake them for smaller droplets. The fact that PDPA reports no droplets larger than 1200 μm might be caused by large drops often not being spherical. The results of the laser diffraction technique are influenced by its fitting method to obtain the droplet size distribution and by overestimation of the number of small droplets due to their low velocity and thus higher concentration in the sample volume. Our results emphasize the need for selecting the size measurement technique to fit the physical nature and expected range of droplet parameters.
Investigation of bulk and surface minority carrier lifetimes in metamorphic InAsSb grown on GaAs and Si
Authors: Taghipour Z. , Liu A. W. K. , Fastenau J. M. , Lubyshev D. , Nelson S. A. , Krishna S.
Published: January 2021

Monolithic integration of III–V-based optoelectronic devices onto Si wafers provides enormous benefits to many device manufacturing technologies. Therefore, it is essential to understand the effect of limiting factors such as dislocations on the material properties. In this paper, we study the minority carrier lifetimes in mid-wave infrared InAsSb alloys grown on lattice-matched GaSb and lattice-mismatched semi-insulating GaAs and Ge/Si substrates. Time-resolved microwave reflection measurement has been performed to study the carrier dynamics and different recombination mechanisms over the temperature range of 20–300 K at various optical injection levels. The sample on GaAs is found to have a lower lifetime over the entire temperature region than the sample on the Ge/Si substrate. The threading dislocation density values estimated from the lifetime analysis were found to be 2.9±0.2 times larger in the sample on GaAs when averaged over the temperature range of 70–200 K. Furthermore, we studied the contribution of various recombination mechanisms, and it was shown that the lifetime in the sample on GaAs is dominated by the Shockley–Read–Hall recombination up to 140 K, above which the Auger recombination is the limiting factor. This transition temperature is 80 K and 100 K for the samples on GaSb and Ge/Si, respectively. We have also investigated the effect of the surface recombination on the total lifetime. The extracted bulk lifetime was found to be up to 2× higher when the surface effect was excluded.
Nonadiabatic couplings from a variational excited state method based on constrained DFT
Authors: Ramos Pablo , Pavanello Michele
Published: January 2021

Excited Costrained Density Functional Theory (XCDFT) [Ramos and Pavanello, J. Chem. Phys. 148, 144103 (2018)] is a variational excited state method that extends ground state DFT to the computation of low-lying excited states. It borrows much of the machinery of Constrained DFT (CDFT) with a crucial difference: the constraint imposes a population of one electron in the Hilbert space spanned by the virtuals of a reference ground state. In this work, we present theory and implementation for evaluating nonadiabatic coupling vectors (NACVs) between the first excited state computed with XCDFT and the ground state. Our NACVs are computed analytically using density functional perturbation theory with a formalism that is general enough that could be applied to CDFT diabatic states. We showcase the new method with pilot NACV calculations for the conical intersection in H3, the avoided crossing in selenoacrolein, and the NACV magnitudes in azobenzene. Despite complications from the nonorthogonality of the wavefunctions, XCDFT’s energy surfaces and NACVs reproduce benchmark values and respect known sum rules within a reasonable degree. This shows that XCDFT is a viable method for nonadiabatic dynamics simulations.
The “isothermal” compressibility of active matter
Authors: Dulaney Austin R. , Mallory Stewart A. , Brady John F.
Published: January 2021

We demonstrate that the mechanically defined “isothermal” compressibility behaves as a thermodynamic-like response function for suspensions of active Brownian particles. The compressibility computed from the active pressure—a combination of the collision and unique swim pressures—is capable of predicting the critical point for motility induced phase separation, as expected from the mechanical stability criterion. We relate this mechanical definition to the static structure factor via an active form of the thermodynamic compressibility equation and find the two to be equivalent, as would be the case for equilibrium systems. This equivalence indicates that compressibility behaves like a thermodynamic response function, even when activity is large. Finally, we discuss the importance of the phase interface when defining an active chemical potential. Previous definitions of the active chemical potential are shown to be accurate above the critical point but breakdown in the coexistence region. Inclusion of the swim pressure in the mechanical compressibility definition suggests that the interface is essential for determining phase behavior.
Out-of-plane ferroelectricity and multiferroicity in elemental bilayer phosphorene, arsenene, and antimonene
Authors: Liang Yan , Guo Rongjing , Shen Shiying , Huang Baibiao , Dai Ying , Ma Yandong
Published: January 2021

Developing out-of-plane ferroelectricity in a two-dimensional (2D) lattice is becoming increasingly important due to its high potential for miniaturized device applications. Current research efforts for 2D out-of-plane ferroelectrics mainly focus on compounds, while 2D elemental material-based ferroelectrics have been rarely explored. Herein, we show first-principles evidence of the existence of out-of-plane ferroelectricity in elemental 2D lattices, bilayer phosphorene, arsenene, and antimonene, which can be easily synthesized in a controllable manner in experiments. Our results reveal that their sizable out-of-plane polarizations are attributed to the charge redistribution caused by the unique stacking pattern. Upon doping holes, bilayer phosphorene and arsenene are shown to be multiferroic, presenting a strong coupling between ferroelectricity and ferromagnetism. Moreover, reversible spin texture induced by ferroelectric switching is achieved in all these three systems. These findings thereby not only broaden the class of 2D out-of-plane ferroelectrics but also enable future multifunctional nanodevice designs.
A Bayesian approach to the mean flow in a channel with small but arbitrarily directional system rotation
Authors: Huang Xinyi L. D. , Yang Xiang I. A.
Published: January 2021

The logarithmic law of the wall loses part of its predictive power in flows with system rotation. Previous work on the topic of mean flow scaling has mostly focused on flows with streamwise, spanwise, or wall-normal system rotation. The main objective of this work is to establish the mean flow scaling for wall-bounded flows with small but arbitrarily directional system rotation. Our approach is as follows. First, we apply dimensional analysis to the Reynolds-averaged momentum equation. We show that when a boundary-layer flow is subjected to small system rotation, the constant stress layer survives, and the mean flow U+ is a universal function of y+, Ωx+, Ωy+, and Ωz+, where U is the mean flow, y is the distance from the wall, Ωi is the system rotation speed in the ith direction (in the locally defined coordinate), and the superscript + denotes normalization by the local wall units. Second, we survey the three-dimensional parameter space of Ωx,y,z+ and determine U+(y+,Ωx+,Ωy+,Ωz+) for small Ω+. Here, we conduct direct numerical simulation (DNS) of a Reτ = 180 channel at various rotation conditions. This approach is conventionally considered as “brutal force.” However, as we will show in this work, the Bayesian approach allows us to very efficiently sample the parameter space. Four independent surveys are conducted with 146 DNSs, and the resulting Bayesian surrogate agrees well with our DNSs. Finally, we upscale to high Reynolds numbers via wall-modeled large-eddy simulation. In general, the present framework provides a path for surrogate modeling in a high-dimensional parameter space at high Reynolds numbers when sampling in a designated parameter space is possible at only a few conditions and at a low Reynolds number.
Perspective on the switching behavior of HfO2-based ferroelectrics
Authors: Wang Chenxi , Qiao Huimin , Kim Yunseok
Published: January 2021

Since ferroelectricity was first observed in 2011, HfO2-based ferroelectrics have garnered significant attention, owing to their compatibility with complementary metal–oxide–semiconductors. Moreover, their thickness scalability facilitates the miniaturization of integrated circuit systems. The ultrafast polarization switching speed in the range of sub-nanoseconds helps in the fabrication of fast-operation devices. The origins of ferroelectricity in HfO2-based ferroelectrics differ from those of conventional perovskite ferroelectrics, with more complex behaviors associated with polarization switching. In this Perspective, recent investigations on the complex behaviors pertaining to polarization switching, including wake-up, split-up, fatigue, negative capacitance, accumulative switching, and some of their relations are discussed. Furthermore, the polarization switching dynamics have also been studied. Finally, the potential applications and investigations of HfO2-based ferroelectrics are discussed.
Determination of the interface between amorphous insulator and crystalline 4H–SiC in transmission electron microscope image by using convolutional neural network
Authors: Yoshioka Hironori , Honda Tomonori
Published: January 2021

A rough interface seems to be one of the possible reasons for low channel mobility (conductivity) in SiC metal-oxide-semiconductor field-effect transistors. To evaluate the mobility by interface roughness, we drew a boundary line between an amorphous insulator and crystalline 4H–SiC in a cross-sectional image obtained by using a transmission electron microscope by using the deep learning approach of a convolutional neural network (CNN). We show that the CNN model recognizes the interface very well, even when the interface is too rough to draw the boundary line manually. The power spectral density of interface roughness was calculated and was comparable with those of Si interfaces, indicating that interface roughness cannot account for the low channel mobility of SiC interfaces.
Molecular photodissociation enabled by ultrafast plasmon decay
Authors: Torres-Sánchez José , Feist Johannes
Published: January 2021

We propose a strategy for enabling photodissociation of a normally photostable molecule through coupling to a nanoparticle plasmon. The large possible coupling on the single-molecule level combined with the highly lossy nature of plasmonic modes, with lifetimes on the order of femtoseconds, opens an ultrafast decay channel for the molecule. For plasmon mode frequencies below the vertical photoexcitation energy of the molecule, the difference between the excitation and emission energies is converted into vibrational energy on the molecular ground state in a Raman-like process. Under the correct conditions, this energy can be high enough to enable efficient photodissociation on the electronic ground state. We demonstrate the concept using numerical simulations of the Lindblad master equation for the hydrogen molecule in the vicinity of an aluminum nanoparticle and explore the photodissociation efficiency as a function of various system parameters.
Variational design principles for nonequilibrium colloidal assembly
Authors: Das Avishek , Limmer David T.
Published: January 2021

Using large deviation theory and principles of stochastic optimal control, we show that rare molecular dynamics trajectories conditioned on assembling a specific target structure encode a set of interactions and external forces that lead to enhanced stability of that structure. Such a relationship can be formulated into a variational principle, for which we have developed an associated optimization algorithm and have used it to determine optimal forces for targeted self-assembly within nonequilibrium steady-states. We illustrate this perspective on inverse design in a model of colloidal cluster assembly within linear shear flow. We find that colloidal clusters can be assembled with high yield using specific short-range interactions of tunable complexity. Shear decreases the yields of rigid clusters, while small values of shear increase the yields of nonrigid clusters. The enhancement or suppression of the yield due to shear is rationalized with a generalized linear response theory. By studying 21 unique clusters made of six, seven, or eight particles, we uncover basic design principles for targeted assembly out of equilibrium.
Phase-field simulation of magnetic microstructure and domain switching in (Tb0.27Dy0.73)Fe2 single crystal
Authors: Hu Chengchao , Zhang Zhao , Yang Tiannan , Li Wei , Chen Longqing
Published: January 2021

The morphotropic phase boundary (MPB), separating two ferroic phases with rhombohedral and tetragonal crystal symmetries, has been utilized extensively in ferroelectrics because it can lead to high-performance piezoelectricity. Recently, a parallel ferromagnetic MPB was experimentally reported and was suggested that the optimal point for magneto-mechanical applications might lies on the rhombohedral side. However, the insight of the domain structures and switching mechanism near ferromagnetic MPB is still unclear. In this work, phase-field micromagnetic microelastic modeling was employed to simulate the domain formation and magnetization switching of (Tb0.27Dy0.73)Fe2, whose composition is around the rhombohedral side of ferromagnetic MPB. The results show that four kinds of domains of the rhombohedral phase automatically form twins of {110} or {100} boundaries with 71° and 109° domain walls after a process of nucleation and growth. The rhombohedral domain evolution and phase volume fraction under the external field of 120 kA/m along different directions are investigated. In ferromagnetics subject to an alternating magnetic field, domain magnetization switches to cause a magnetization hysteresis loop and an associated butterfly magnetostriction loop with the alternating magnetic field.
Effect of coil positioning and orientation of the quadruple butterfly coil during transcranial magnetic stimulation
Authors: Afuwape Oluwaponmile Faith , Rastogi Priyam , Jiles David
Published: January 2021

Transcranial Magnetic Stimulation (TMS) is a non-invasive neuromodulation technique for treating neurological and psychiatric disorders. It is a proven technique that is safe and considered very effective when compared to conventional brain surgery or drug therapy. Researchers and clinicians are interested in understanding the distribution of the induced electric field (E-Field) during TMS and determining its effectiveness in treating neurological disorders. TMS studies are primarily focused on enhancing the focality and depth of penetration of the induced electric field in order to increase its effectiveness. Coil orientation has been confirmed to have an effect on the magnitude and direction of the induced E-Field. In this paper, we study the effect of the orientation of the novel Quadruple Butterfly Coil (QBC) on the distribution of the induced E-Field. Finite element analyses were conducted with the orientation of the QBC in steps of 15° over the vertex of two head models and about the transverse (XY –) plane and coronal (XZ –) plane of the head model. The maximum electric field intensity (E-Max) and stimulated volume of the brain (V-Half) were computed and compared to determine the optimal coil orientation.