bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mesoscale numerical study on the evolution of borehole breakout in heterogeneous rocks
Authors: Li Yingchun , Qu Yaodong , He Qiangyuan , Tang Chunan 
Published: February 2020

SummaryInherent heterogeneity of a rock strongly affects its mechanical behavior. We numerically study the mechanisms governing the initiation, propagation, and ultimate pattern of borehole breakouts in heterogeneous rocks. A two‐dimensional finite element model incorporating material heterogeneity is established to systematically examine the effects of several key factors on borehole failure, including borehole diameter, far‐field stress, and rock heterogeneity. The inherent heterogeneity of a rock is explicitly characterized by prescribing the rock mechanical properties of mesoscale elements statistically obeying the Weibull distribution. Elastic damage mechanics is used to represent the constitutive law of the mesoscale element. We find that borehole diameter reduction remarkably changes the crack failure from tensile to shear and elevates the critical hydrostatic pressure. Far‐field stress anisotropy strongly affects the shape of the borehole breakout. Rock heterogeneity dictates the location of the preferred crack under the hydrostatic stress, which leads to local stress concentration, and determines the types of breakouts around the borehole. Our findings facilitate in‐depth understanding of the classic borehole stability problems in heterogeneous rocks.
Linear and nonlinear topology optimization design with projection‐based ground structure method (P‐GSM)
Authors: Deng Hao , To Albert C. 
Published: February 2020

SummaryA new topology optimization scheme called the projection‐based ground structure method (P‐GSM) is proposed for linear and nonlinear topology optimization designs. For linear design, compared to traditional GSM which are limited to designing slender members, the P‐GSM can effectively resolve this limitation and generate functionally graded lattice structures. For additive manufacturing‐oriented design, the manufacturing abilities are the key factors to constrain the feasible design space, for example, minimum length and geometry complexity. Conventional density‐based method, where each element works as a variable, always results in complex geometry with large number of small intricate features, while these small features are often not manufacturable even by 3D printing and lose its geometric accuracy after postprocessing. The proposed P‐GSM is an effective method for controlling geometric complexity and minimum length for optimal design, while it is capable of designing self‐supporting structures naturally. In optimization progress, some bars may be disconnected from each other (floating in the air). For buckling‐induced design, this issue becomes critical due to severe mesh distortion in the void space caused by disconnection between members, while P‐GSM has ability to overcome this issue. To demonstrate the effectiveness of proposed method, three different design problems ranging from compliance optimization to buckling‐induced mechanism design are presented and discussed in details.
Global stabilizability of an anaerobic biodegradation process via piecewise constant feedback
Authors: Borisov Milen K. , Dimitrova Neli S. , Krastanov Mikhail I. 
Published: February 2020

SummaryWe consider a nonlinear model of an anaerobic digestion process with methane production. We propose a stabilizing control law involving piecewise constant feedback and study the asymptotic stability of the obtained closed‐loop system. An extremum seeking algorithm is applied to maximize the output. Numerical simulation results are also presented to illustrate the theoretical investigations.
Optimal‐switched extended H∞ filter for nonlinear systems with stochastic uncertainties
Authors: Li Yuankai , Ding Liang , Jing Zhongliang 
Published: February 2020

SummaryThe extended H∞ filter (EH∞F) is a conservative solution with infinite‐horizon robustness for the state estimation problem regarding nonlinear systems with stochastic uncertainties, which leads to excessive costs in terms of filtering optimality and reduces the estimation precision, particularly when uncertainties related to external disturbances and noise appear intermittently. In order to restore the filtering optimality lost due to the conservativeness of the EH∞F design, we developed an optimal‐switched (OS) filtering mechanism based on the standard EH∞F to obtain an optimal‐switched extended H∞ filter (OS‐EH∞F). The OS mechanism has an error‐tolerant switched (ETS) structure, which switches the filtering mode between optimal and H∞ robust by setting a switching threshold with redundancy to uncertainties, and a robustness‐optimality cost function (ROCF) is introduced to determine the threshold and optimize the ETS structure online. The ROCF is the weighted sum of the quantified filtering robustness and optimality. When a weight is given, the proposed OS‐EH∞F can obtain the optimal state estimates while maintaining the filtering robustness at an invariant ratio. A simulation example of space target tracking has demonstrated the superior estimation performance of the OS‐EH∞F compared with some other typical filters, thereby verifying the effectiveness of using the weight to evaluate the estimation result of the filters.
Variation in soil lignin protection mechanisms in five successional gradients of mixed broadleaf–pine forests
Authors: Feng Yue , Han Shijie , Chen Wei , Gu Yue , Stewart Catherine E. , Zhang Junhui , Geng Shicong , Chen Zhijie , Setälä Heikki 
Published: February 2020

AbstractOver 200 yr of ecosystem succession in northeastern China, conifers have replaced broadleaf trees. Vegetation changes during forest succession may affect soil organic C (SOC) stability, which is associated with altered protection mechanisms. Lignin phenol composition, a predictor of soil organic matter variation, was assessed for macroaggregates, microaggregates, and silt–clay (SC) fractions from successional gradients in five forests aged 19 to 239 yr in the Changbai Mountains nature reserve. The large macroaggregates (4.00–8.00 and 2.00–4.00 mm) comprised 45.17 to 59.87% of bulk dry weight and 40.22 to 60.89% of SOC in the 19‐, 32‐, and 48‐yr‐old pioneer forests. However, we detected increased mass proportions and SOC contents in small macroaggregates (1.00–2.00 and 0.25–1.00 mm) in the mixed broadleaf–Korean pine (Pinus koraiensis Siebold & Zucc.) forest after 122 yr. Lignin in bulk soil and aggregates in the 122‐yr‐old stand had lower acid/aldehyde ratios for the vanillyl and syringyl types than other stands, indicating less lignin decomposition. The highest C (198.20 g kg−1 soil) and lignin concentrations (6.14 mg 100 mg−1 C) were detected in the bulk soil from the 239‐yr‐old stand, where SC fraction occupied 56.18% of the C and 84.17% of the lignin content in bulk soil. Forest succession from broadleaf to a broadleaf–pine mixture shifted SOC sequestration and lignin protection from aggregates to SC fractions, along with the development of plant litter composition, fine‐root biomass and turnover, and microorganism biomass, which prompted effective long‐term SOC accumulation in successional forest communities.
Non‐targeted metabolomics approach to assess the brown marine macroalga Dictyota dichotoma as a functional food using liquid chromatography with mass spectrometry
Authors: Dixit Dhara , Reddy C.R.K. , Trivedi M.H. , Gadhavi Devesh K. 
Published: February 2020

AbstractThe study elucidates presence of 16 potential putative metabolites in Dictyota dichotoma through non‐targeted secondary metabolite profile analysis using electrospray ionization negative mode of liquid chromatography with time‐of‐flight mass spectrometry. Two fatty acyl glycosides viz; 5‐megastigmen‐7‐yne‐3,9‐diol 9‐glucoside (biomarker for food consumption) and (3S,7E,9S)‐9‐hydroxy‐4,7‐megastigmadien‐3‐one 9‐glucoside (nutrient, emulsifier, surfactant), an o‐glycosyl compound 5‐megastigmen‐7‐yne‐3,9‐diol 3‐glucoside (biomarker for food consumption), all with m/z value 370.19 were detected. An acyclic monoterpenoid and diterpenoid viz; isodigeranyl and digeranyl (both with m/z 274.26; food biomarkers) were detected. Additionally, (3′x,5′a,9′x,10′b)‐O‐(3‐hydroxy‐6‐oxo‐7‐drimen‐11‐yl) umbelliferone (m/z 396.19; nutrient, emulsifier, surfactant) and kamolonol (m/z 398.2; antibacterial, anti‐tumor) were observed. Two angular pyranocoumarins: mammea C/AB cyclo D (m/z 398.2; food consumption biomarker) and 5‐hydroxy‐8, 8‐dimethyl‐6‐(3‐methyl‐1‐oxobutyl)‐4‐pentyl‐2H,8H‐benzo[1,2‐b:3,4‐b']dipyran‐2‐one (m/z 398.2; fruit constituent) were present. Two terpene lactones ‐ galbanic acid (m/z 398.2; antimicrobial, anticoagulant, antiviral, anti‐inflammatory, anti‐cancer) and asacoumarin A (m/z 398.2; antiprotozoal, antiglycation activity) were detected. Armillaribin (m/z 398.2; food biomarker) along with glycinoeclepin B (m/z 558.28; nutrient, emulsifier, surfactant) was noted. Two flavonoids; (S)‐(E)‐2′‐(3,6‐dimethyl‐2‐heptenyl)‐3′,4′,7‐trihydroxyflavanone and (S)‐(E)‐8‐(3,6‐dimethyl‐2‐heptenyl)‐4′,5,7‐trihydroxyflavanone (m/z 396.19) and a drug triclofos (m/z 227.89; sedative) were detected. This study highlights the metabolic makeup of D. dichotoma collected from Kachchh coast thereby, accentuating the probability of its inclusion as a promising ingredient in functional foods from algal origin.
Influence of basalt fibers on the mechanical behavior of concrete—A review
Authors: John Vinotha Jenifer , Dharmar Brindha 
Published: February 2020

AbstractThe natural fibers are evolving in the construction industry in many forms due to its dominant characteristics since decades. This paper delivers a review of the behavior of basalt fiber reinforced concrete under static and dynamic loading conditions. The main aim of the paper is to signify the influence of basalt fibers in concrete as chopped fibers, minibars, rebars, and meshes by showcasing the physical and mechanical properties of the concrete. The proposed review paper furnishes a summary of obtainable evidence about the incorporation of basalt fibers in concrete under various loading conditions. The effect of size and volume fraction of the fibers in concrete subjected to static loading and dynamic loading is discussed and reviewed. Additionally, the optimum length, diameter, and aspect ratio of the fibers with its volume fraction depending on the constituents in concrete is exhibited. Basalt fibers, can operate as an exceptional reinforcing material which can replace the conventional reinforcement with appropriate implementation.Highlights
Application of basalt fibers in concrete based on different loading conditions has been reviewed.
Properties and applications of basalt fibers in various forms were assessed.
Static and dynamic behavior of basalt fiber reinforced concrete has been summarized based on the studied literature.
Addition of suitable forms and size of basalt fibers in concrete were examined.
Parameters such as volume fraction, aspect ratio of basalt fibers has been highlighted.
A review of nonrevenue water assessment software tools
Authors: AL‐Washali Taha M. , Elkhider Mohamed E. , Sharma Saroj K. , Kennedy Maria D. 
Published: February 2020

AbstractSeveral software tools are available that can assess the performance of nonrevenue water (NRW) in water distribution networks and plan for reduction measures. Of the 21 tools that have been reported in the literature, 12 are freely available. The creation of these many tools and different versions of each individual tool indicates the promising future of NRW software development. This review comprises 12 freely available tools for water balance establishment, NRW performance assessment, and NRW reduction planning. Most of the tools have been developed to establish standard annual water balances and recommended performance indicators (PIs) for the entire network. Some tools have been developed to intervene and reduce the leakage in a district metered area. Key features increasingly being included in NRW software include uncertainty analysis, recognition of supply intermittency, and accommodation of a guidance matrix and benchmarks. Leakage assessment is fully recognized, and leakage reduction analyses are increasingly growing in the software tools. However, much less attention has been paid to assessing and options for reducing apparent losses. Although a comprehensive NRW management tool for monitoring, planning, and intervention is not currently available, developing a comprehensive tool is worthwhile, in the form of one package or a kit of smaller tools. Toward this goal, the article provides insights and recommendations addressing topics of intermittency, normalization, multi‐method assessment, planning for the reduction of apparent and real losses, and estimation of the economic level of water loss.This article is categorized under:
Engineering Water > Planning Water
Engineering Water > Methods
A survey and taxonomy of adversarial neural networks for text‐to‐image synthesis
Authors: Agnese Jorge , Herrera Jonathan , Tao Haicheng , Zhu Xingquan 
Published: February 2020

AbstractText‐to‐image synthesis refers to computational methods which translate human written textual descriptions, in the form of keywords or sentences, into images with similar semantic meaning to the text. In earlier research, image synthesis relied mainly on word to image correlation analysis combined with supervised methods to find best alignment of the visual content matching to the text. Recent progress in deep learning (DL) has brought a new set of unsupervised DL methods, particularly deep generative models which are able to generate realistic visual images using suitably trained neural network models. The change of direction from the computer vision‐based approaches to artificial intelligence (AI)‐driven methods ignited the intense interest in industry, such as virtual reality, recreational & professional (eSports) gaming, and computer‐aided design, and so on, to automatically generate compelling images from text‐based natural language descriptions. In this paper, we review the most recent development in the text‐to‐image synthesis research domain. Our goal is to provide value by delivering a comparative review of the state‐of‐the‐art models in terms of their architecture and design. The survey first introduces image synthesis and its challenges, and then reviews key concepts such as generative adversarial networks (GANs) and deep convolutional encoder‐decoder neural networks (DCNNs). After that, we propose a taxonomy to summarize GAN‐based text‐to‐image synthesis into four major categories: semantic enhancement GANs, resolution enhancement GANs, diversity enhancement GANS, and motion enhancement GANs. We elaborate on the main objective of each group, and further review typical GAN architectures in each group. The taxonomy and the review outline the techniques and the evolution of different approaches, and eventually provide a roadmap to summarize the list of contemporaneous solutions that utilize GANs and DCNNs to generate enthralling results in categories such as human faces, birds, flowers, room interiors, object reconstruction from edge maps (games), and so on. The survey concludes with a comparison of the proposed solutions, challenges that remain unresolved, and future developments in the text‐to‐image synthesis domain.This article is categorized under:

Algorithmic Development > Multimedia
Technologies > Machine Learning
The geometry of SUSY enhancement
Authors: Carta Federico , Giacomelli Simone , Hayashi Hirotaka , Savelli Raffaele 
Published: February 2020

Abstract
We provide a precise geometric picture that demystifies the phenomenon of supersymmetry enhancement along certain RG flows of four-dimensional field theories, recently discovered by Maruyoshi and Song. It applies to theories of arbitrary rank and it is based on a hyperkähler-structure restoration on the moduli space of solutions of (twisted) Hitchin systems, which underly the class-$$ \mathcal{S} $$
S
construction we use as an engineering tool. Along the way, we formulate a necessary algebraic condition for supersymmetry enhancement, and, when enhancement occurs, we are able to derive the Seiberg-Witten geometry and all conformal dimensions of Coulomb-branch operators for the infrared theory, without using a-maximization.
The Mixed Degree of Families of Lattice Polytopes
Authors: Nill Benjamin 
Published: February 2020

AbstractThe degree of a lattice polytope is a notion in Ehrhart theory that was studied quite intensively over previous years. It is well known that a lattice polytope has normalized volume one if and only if its degree is zero. Recently, Esterov and Gusev gave a complete classification result for families of n lattice polytopes in $${\mathbb {R}}^n$$Rn whose mixed volume equals one. Here, we give a reformulation of their result involving the novel notion of mixed degree that generalizes the degree similar to how the mixed volume generalizes the volume. We discuss and motivate this terminology, also from an algebro-geometric viewpoint, and explain why it extends a previous definition of Soprunov. We also remark how a recent combinatorial result due to Bihan solves a related problem posed by Soprunov.
Spectroscopy and diode-pumped continuous-wave laser operation of Tm:Y2O3 transparent ceramic at cryogenic temperatures
Authors: Yue Fangxin , Jambunathan Venkatesan , Paul David Samuel , Mateos Xavier , Aguiló Magdalena , Díaz Francesc , Šulc Jan , Lucianetti Antonio , Mocek Tomáš 
Published: February 2020

AbstractWe present the spectroscopic and laser characteristics of a 3 at.% Tm:Y2O3 transparent ceramic at cryogenic temperatures. An absorption cross section of 4.7 × 10−21 cm2 with a bandwidth of 0.7 nm centered at 793.3 nm and an emission cross section of 29.0 × 10−21 cm2 centered at 1930.9 nm were estimated at 80 K. Continuous-wave laser operation was achieved using broadband and VBG stabilized laser diodes emitting around 793 nm as pump sources. With the VBG pump diode, a maximum output power of 6.4 W was achieved at 80 K corresponding to a slope efficiency of 52.0% with respect to absorbed power.
Decoding a highly mixed Kazakh genome
Authors: Seidualy Madina , Blazyte Asta , Jeon Sungwon , Bhak Youngjune , Jeon Yeonsu , Kim Jungeun , Eriksson Anders , Bolser Dan , Yoon Changhan , Manica Andrea , Lee Semin , Bhak Jong 
Published: February 2020

AbstractWe provide a Kazakh whole genome sequence (MJS) and analyses with the largest comparative Kazakh genomic data available to date. We found 102,240 novel SNVs and a high level of heterozygosity. ADMIXTURE analysis confirmed a significant proportion of variations in this individual coming from all continents except Africa and Oceania. A principal component analysis showed neighboring Kalmyk, Uzbek, and Kyrgyz populations to have the strongest resemblance to the MJS genome which reflects fairly recent Kazakh history. MJS’s mitochondrial haplogroup, J1c2, probably represents an early European and Near Eastern influence to Central Asia. This was also supported by the heterozygous SNPs associated with European phenotypic features and strikingly similar Kazakh ancestral composition inferred by ADMIXTURE. Admixture (f3) analysis showed that MJS’s genomic signature is best described as a cross between the Neolithic East Asian (Devil’s Gate1) and the Bronze Age European (Halberstadt_LBA1) components rather than a contemporary admixture.
Mitochondrial genome variation between different accessions of Matricaria chamomilla L. (Asteraceae) based on SNP mutation analysis
Authors: Ruzicka Joana , Novak Johannes 
Published: February 2020

AbstractMatricaria chamomilla L. (chamomile, Asteraceae) (GRIN, The Plant List 2013) has a long history of usage in traditional herbal medicine and is still today amongst the most important medicinal plants. Despite this importance, genetic diversity of cultivated and wild germplasm of M. chamomilla was rarely investigated so far. The objective of this study was to estimate the mitochondrial (mt) diversity of various cultivated M. chamomilla genotypes by determining point mutations in the mt genome. 89 SNPs (single nucleotide polymorphisms) were identified in the next generation sequencing data of 33 genotypes from 11 di- and tetraploid chamomile accessions representing a sequence diversity of 0.32 SNPs/kb. Based on the SNP analysis 19 mitochondrial haplotypes (mitotypes) could be specified with genetic distances ranging between 0.011 and 0.851. The examined mt variability within the accessions was higher than expected; only one monomorphic accession (variety ‘Camoflora’) was identified. Diploid accessions exhibited with 1.9 mitotypes per accession a higher variability than tetraploid accessions with a ratio of 1.3. Although some of the mitotypes were distributed over different accessions, identical mitotypes within di- and tetraploid accessions could not be determined. Furthermore, the mitotypes did not correspond to the geographical origin of the accessions. Although not the whole mt genome could be assembled in this study, the substitutions identified represent a valuable tool for further investigations of maternal phylogenetic relationships within M. chamomilla.
Four Distinct Pathways to the Element Abundances in Solar Energetic Particles
Authors: Reames Donald V. 
Published: February 2020

AbstractBased upon recent evidence from abundance patterns of chemical elements in solar energetic particles (SEPs), and, ironically, the belated inclusion of H and He, we can distinguish four basic SEP populations: (1) SEP1—pure “impulsive” SEPs are produced by magnetic reconnection in solar jets showing steep power-law enhancements of $1\leq Z \leq 56$1≤Z≤56 ions versus charge-to-mass ratio $A/Q$A/Q from a $\approx 3$≈3 MK plasma. (2) SEP2—ambient ions, mostly protons, plus SEP1 ions reaccelerated by the shock wave driven by the narrow coronal mass ejection (CME) from the same jet. (3) SEP3—a “gradual” SEP event is produced when a moderately fast, wide CME-driven shock wave barely accelerates ambient protons while preferentially accelerating accumulated remnant SEP1 ions from an active region fed by multiple jets. (4) SEP4—a gradual SEP event is produced when a very fast, wide CME-driven shock wave is completely dominated by ambient coronal seed population of 0.8–1.8 MK plasma usually producing a full power law vs. $A/Q$A/Q for $1\leq Z \leq 56$1≤Z≤56 ions. We begin with element abundances in the photosphere that are fractionated during transport up to the corona based upon their first ionization potential (FIP); this important “FIP effect” for SEPs provides our reference abundances and is different for SEPs from that for the solar wind. We then show evidence for each of the processes of acceleration, reacceleration, and transport that conspire to produce the four abundances patterns we distinguish.