bluuebunny/crossref_metadata_2025_split huggingface dataset:
Timing and Distribution of Single‐Layered Ejecta Craters Imply Sporadic Preservation of Tropical Subsurface Ice on Mars
Authors: Kirchoff Michelle R. , Grimm Robert E. 
Published: December 2017

AbstractDetermining the evolution of tropical subsurface ice is a key component to understanding Mars's climate and geologic history. Study of an intriguing crater type on Mars—layered ejecta craters, which likely form by tapping subsurface ice—may provide constraints on this evolution. Layered ejecta craters have a continuous ejecta deposit with a fluidized‐flow appearance. Single‐layered ejecta (SLE) craters are the most common and dominate at tropical latitudes and therefore offer the best opportunity to derive new constraints on the temporal evolution of low‐latitude subsurface ice. We estimate model formation ages of 54 SLE craters with diameter (D) ≥ 5 km using the density of small, superposed craters with D < 1 km on their continuous ejecta deposits. These model ages indicate that SLE craters have formed throughout the Amazonian and at a similar rate expected for all Martian craters. This suggests that tropical ice has remained at relatively shallow depths at least where these craters formed. In particular, the presence of equatorial SLE craters with D ~ 1 km indicates that ice could be preserved as shallow as ~100 m or less at those locations. Finally, there is a striking spatial mixing in an area of highlands near the equator of layered and radial (lunar‐like ballistic) ejecta craters; the latter form where there are insufficient concentrations of subsurface ice. This implies strong spatial heterogeneity in the concentration of tropical subsurface ice.
Longitudinal and Temporal Evolution of the Tectonic Style Along the Cyprus Arc System, Assessed Through 2‐D Reflection Seismic Interpretation
Authors: Symeou Vasilis , Homberg Catherine , Nader Fadi H. , Darnault Romain , Lecomte Jean‐Claude , Papadimitriou Nikolaos 
Published: December 2017

AbstractThe Cyprus Arc system constitutes a major active plate boundary in the eastern Mediterranean region. This structure is directly linked with the northward convergence of the African and Eurasian plates since the Late Cretaceous. Two‐dimensional reflection seismic data were utilized, which image the main plate structures and their lateral evolution south of the island of Cyprus. Interpretation of these data allowed the identification of nine tectono‐sedimentary packages in three different crustal domains south of the Cyprus Arc system: (1) the Levant Basin (attenuated continental crust), (2) the Eratosthenes microcontinent (continental crust), and (3) the Herodotus Basin (oceanic crust). Within these domains, numerous tectonic structures were documented and analyzed in order to understand the mechanism and timing of deformation. In the north, south verging thrusting commenced in early Miocene along the Larnaca and Margat ridges, whereas no activity was identified before middle Miocene along the Latakia Ridge. Thus, the deformation front migrated southward and was accompanied by the development of flexural basins and stratigraphic onlaps as in the Cyprus Basin. The acme of deformation occurred in mid‐late Miocene. A regional unconformity of Pliocene age marks the end of the first deformation sequence. In Plio‐Pleistocene time, the westward escape of the Anatolian microplate resulted in the reactivation of existing structures. The evolution of deformation along the plate boundary is identified from the creation of positive flower structures revealing transpressive movements along the Larnaca and Latakia Ridges (eastern domains), whereas in the Eratosthenes domain a flexural basin highlights a compressive regime.
Fundamentals: Introduction and Survey
Authors: Stein Erwin 
Published: December 2017

Abstract
This chapter first provides a motivation and the scope of the whole encyclopedia, especially the mathematically oriented fundamentals with rapidly developing generalizations of classical FEMs and new strategies. Then, the stages of historical developments and features of computational mechanics are outlined for four essential development stages. The main third section presents the reviews and appreciations of the 28 articles in Volume 1, among them 6 new contributions. The last section What We Do Expect presents expected trends of future scientific and applied developments that become necessary of multiconnected challenges from natural and engineering sciences as well as planning, developing, and production of systems of products in industry and their maintenance.
Interpolation and Quasi‐Interpolation inh‐ andhp‐Version Finite Element Spaces
Authors: Apel Thomas , Melenk Jens M. 
Published: December 2017

AbstractInterpolation operators map a function to an element of a finite element space. Unlike more general approximation operators, interpolants are defined locally. Estimates of theinterpolation error, that is, the difference , are of utmost importance in numerical analysis. These estimates depend on the size of the finite elements, the polynomial degree employed, and the regularity of . In contrast to interpolation the term quasi‐interpolation is used when the regularity is so low that interpolation has to be combined with regularization. This chapter gives an overview of different interpolation operators and their error estimates. The discussion includes the ‐version and the ‐version of the finite element method, interpolation on the basis of triangular/tetrahedral and quadrilateral/hexahedral meshes, affine and nonaffine elements, isotropic and anisotropic elements, and Lagrangian and other elements.
Thep‐Version of the Finite Element and Finite Cell Methods
Authors: Düster Alexander , Rank Ernst , Szabó Barna 
Published: December 2017

AbstractIn the first part of this chapter, the basic algorithmic structure and performance characteristics of thep‐version of the finite element method (FEM) are surveyed with reference to elliptic problems in solid mechanics. For this class of problems, the theoretical basis of thep‐version is fully established, and a very substantial amount of engineering experience covering linear and nonlinear applications is available. It is shown thatp‐extensions on properly designed meshes make realization of exponential rates of convergence in practical computations possible and provide for the estimation and control of relative errors in terms of any quantity of interest. In the second part, thep‐version of the FEM is extended to a high‐order fictitious domain approach, the finite cell method (FCM). While the FCM inherits the advantages of thep‐version with respect to accuracy and robustness, it relieves analysts from the necessity of generating finite element meshes. Thus, it strongly supports the analysis of problems with highly complicated geometry, for which meshing with finite elements would be very difficult. Given the growing demand for verified numerical solutions, thep‐version of the finite element and FCMs are expected to play an increasingly important role.
Spectral Methods
Authors: Canuto Claudio , Quarteroni Alfio 
Published: December 2017

AbstractSpectral methods represent a family of methods for the numerical approximation of partial differential equations. Their common denominator is to rely on high‐order polynomial expansions, notably trigonometric polynomials for periodic problems, and orthogonal Jacobi polynomials for nonperiodic boundary‐value problems. They have the potential to provide a high rate of convergence when applied to problems with regular data. They can be regarded as members of the broad family of (generalized) Galerkin methods with numerical evaluation of integrals based on Gaussian nodes. In the first part, we introduce the methods on a computational domain of simple shape and analyze their approximation properties as well as their algorithmic features. Next, we address the issue of how these methods can be extended to more complex geometrical domains by retaining their distinctive approximation properties.
Meshfree Methods
Authors: Huerta Antonio , Belytschko Ted , Fernández‐Méndez Sonia , Rabczuk Timon , Zhuang Xiaoying , Arroyo Marino 
Published: December 2017

AbstractThe aim of this chapter is to provide an in‐depth presentation and survey of meshfree particle methods. Several particle approximations are reviewed; the SPH method, corrected gradient methods, the moving least‐squares (MLS) approximation, and maximum‐entropy approximations. The discrete equations are derived from a collocation scheme or a Galerkin method. Special attention is paid to the treatment of essential boundary conditions. Finally, different approaches for modeling discontinuities in meshfree methods are described, including peridynamics and phase‐fields.
Boundary Element Methods: Foundation and Error Analysis
Authors: Hsiao George C. , Steinbach O. , Wendland W. L. 
Published: December 2017

AbstractThis chapter gives an expository introduction to the Galerkin‐BEM for the elliptic boundary value problems from the mathematical point of view. Emphasis will be placed on the variational formulations of the boundary integral equations (BIEs) and the general error estimates for the approximate solution in appropriate Sobolev spaces. A classification of BIEs will be given on the basis of the Sobolev index. The simple relations between the variational formulations of the BIEs and the corresponding partial differential equations under consideration will be indicated. Basic concepts such as stability, consistency, and convergence as well as the condition numbers and ill‐posedness, will be discussed by using elementary examples.This is the second edition of this chapter. The first edition was published in 2004. In this edition, additional topics have been included and discussed. These additional topics are concerned with the BIE‐method for a higher‐order elliptic equation, trace theorem and boundary spaces as well as numerical experiments for standard and fast multipole BEMs.
Coupling of Boundary Element Methods and Finite Element Methods
Authors: Stephan Ernst P. 
Published: December 2017

Abstract

For the numerical treatment of elliptic boundary value problems, the coupling of boundary element methods (BEM) and finite element methods (FEM) is widely used. Usually, the FEM is applied in a bounded subdomain, whereas the BEM subdomain may be unbounded, but without inhomogeneous or nonlinear material behavior. This article gives a survey of FE/BE coupling for elliptic interface problems from a mathematical perspective. We concentrate on the symmetric coupling method because of its general applicability and give
a priori
and
a posteriori
error estimates. Further, we address implementational aspects such as suitable preconditioning for appropriate solvers of the Galerkin equations. As new developments, we consider a least squares coupling method with first‐order systems in the FEM domain and consider both primal and dual FE/BE coupling methods for interface problems with Signorini contact condition. Besides standard formulations, mixed FEM formulations are also considered. Applications in elasticity are discussed. We present proofs of essential theorems because we feel that these proofs are essential for understanding the mathematical aspects. We also present illustrative numerical examples and provide a list of references to the current literature. The new version contains sections on convergence of an adaptive coupling algorithm and on nonsymmetric coupling methods
Multigrid Methods forFEMandBEMApplications
Authors: Hackbusch Wolfgang 
Published: December 2017

AbstractAfter discretizing the partial differential equations from mechanics, one usually obtains large systems of (non)linear equations. Their efficient solution requires the use of fast iterative methods. Multigrid iterations are able to solve linear and nonlinear systems with a rather fast rate of convergence, provided the problem is of elliptic type. This contribution describes the basic construction of multigrid methods, their ingredients, related methods, and their application to various problem classes. Although most of the applications concern FEM (finite element method) discretizations of partial differential equations, there are also applications to integral equations as they occur in boundary element methods (BEMs).
Computational Fracture Mechanics
Authors: Ingraffea Anthony R. , de Borst René 
Published: December 2017

AbstractThe purpose of this article is to survey examples of historical and state‐of‐the‐art approaches of computational fracture mechanics (CFM). Approaches are described and compared for their use in both the traditional role of CFM – calculation of crack‐front fields – and the emerging role of prediction of material‐damage evolution and toughness.
Computational Geomechanics Including Consolidation
Authors: Carter John P. , Small John C. 
Published: December 2017

AbstractA review is presented of the role of computational mechanics in geotechnical engineering. Discussions of the conventional deterministic techniques used for numerical modeling in geomechanics and a brief discussion of the stochastic techniques for dealing with the uncertainties encountered in geotechnical practice are included. Considerable emphasis is given to the methods commonly used for the solution of boundary and initial value problems. Significantly, the chapter also includes a discussion of the limitations of the various numerical modeling techniques. Constitutive modeling of soil and rock mass behavior and material interfaces is an essential component of this type of computing, and so a review of recent developments and capabilities of constitutive models for geomaterials is also included. Problems involving the interaction of the ground with other engineering structures are also addressed. Some of the concepts described in the paper are illustrated with examples taken from research and practice. Emphasis has been placed on the mechanical behavior of soil, but it is noted that many of the models and techniques described also have application in rock mechanics and rock engineering.
Industrial Aerodynamics
Authors: Chalot Frédéric L. 
Published: December 2017

AbstractThis chapter describes the use of computational fluid mechanics at Dassault Aviation. A historical perspective gives a measure of the successive giant steps that have been made over the past 30 years. A rather detailed description of industrial codes leads to a good understanding of the key numerical concepts assembled to create a powerful tool for computational aerodynamics. The fundamental issue of turbulence modeling is addressed in detail. A large range of complex applications is described to illustrate the variety of problems solved. The status of the development and application of shape optimization techniques and multidisciplinary design are finally illustrated.
Investigation of DNA‐Binding Activities of Zinc(II) and Cobalt(II) Phthalocyanine Compounds with 3,4,5‐Trimethoxybenzyloxy Substituents
Authors: Arslantas Ali , Agirtas Mehmet Salih 
Published: December 2017

AbstractIn this study, DNA‐binding activities of previously synthesized tetrakis(3,4,5‐trimethoxybenzyloxy)‐substituted Zn(II) and Co(II) phthalocyanines (Pc4 and Pc5) have been chosen for the study. The interaction of synthesized tetrakis(3,4,5‐trimethoxybenzyloxy)‐substituted Zn(II) and Co(II) phthalocyanine compounds with CT‐DNA was investigated by using UV/Vis titrimetric method, fluorescence spectroscopy, cyclic voltammetry, thermal denaturation profile, gel electrophoresis and viscosty measurement in a Tris‐HCI buffer at pH 7.0. The results indicated that tetrakis(3,4,5‐trimethoxybenzyloxy)‐substituted Zn(II) and Co(II) phthalocyanines (Pc4 and Pc5) can interact with CT‐DNA via intercalation binding mode.
Polycystic ovary syndrome
Authors: Kayemba-Kay's Simon , Pambou Armelle , Heron Anne , Benosman Sidi Mohammed 
Published: December 2017

Background:
Polycystic ovary syndrome (PCOS) is a common reproductive endocrinopathy in women of childbearing age, affecting 5–15% women in this age group. Suggestive cardinal features comprise hyperandrogenism, ovulatory dysfunction and/or polycystic ovary appearance. The gold standard radiological tool is the pelvic ultrasound (PUS) whose yield may be limited in overweight and obese adolescent girls.

Objective and hypotheses:
To evaluate the contribution of pelvic MRI to the diagnosis of PCOS in a specific group of virginal overweight and obese adolescent girls.

Method:
Eight adolescent girls seen for menstrual irregularities or amenorrhea, with features of hyperandrogenism were biochemically screened (LH, FSH, testosterone, S-DHEA, delta-4 androstenedi- one, 17 (OH) P, SHBG, TSH, free T4, prolactin and lipid profile, fasting blood sugar and HOMA-IR and HOMA-B). Each had PUS and/or pelvic MRI (PMRI) performed. Other causes of hyperandrogenism were excluded.

Imaging:
PUS with the trans-abdominal transducer was attempted in only one patient Acuson© scanner, using 3.5–7.5 MHz transducer; PMRI was performed in all patients with phased array coil of 1.5 T Siemens MRI scanner, with T1 and T2-weighted axial and coronal images. PCOS was defined according to the Rotterdam PCOS consensus Workshop.

Results:
Eight girls (mean age 14,6 ± 1.47 years) are reported, one was overweight (BMI Z-score > 1 SDS), seven others were obese (BMI Z-score > 2 SDS). Mean age at menarche was 11.58 ± 1.11 years, except for one who had not yet entered menarche. All had menstrual irregularities, acanthosis nigricans, acne, hirsutism, and biochemical characteristics of PCOS (high plasma androgens, insulin resistance, glucose/ insulin ratio <4.5, decreased SHBG).
PUS was not contributive to the diagnosis of PCOS, whereas PMRI showed typical aspect (well delineated peripheral ovarian cysts), with increased ovarian volume and stroma.

Conclusion:
Although PUS remains the gold standard for the diagnosis of PCOS in most cases, its limitations in overweight and obese girls are real and must be considered.
If utilization of endovaginal transducer not being feasible in young virginal girls, PMRI could be a useful alternative, allowing greater delineation of structural components of the ovary and better appreciation of both its volume and structural alterations.
Preparation of ultra-broadband antireflective coatings for amplifier blast shields by a sol–gel method
Authors: Xiong Huai , Shen Bin , Chen Zhiya , Zhang Xu , Li Haiyuan , Tang Yongxing , Hu Lili 
Published: December 2017

A type of $\unicode[STIX]{x1D706}/4$–$\unicode[STIX]{x1D706}/4$ ultra-broadband antireflective coating has been developed using modified low refractive silica and high refractive silica layers by a sol–gel dip coating method for amplifier blast shields of the Shen Guang II high power laser facility (SG-II facility). Deposition of the first layer (high refractive index silica) involves baking at $200\,^{\circ }\text{C}$ in the post-treatment step. The second layer (low refractive index, $n=1.20$) uses low refractive index silica sol modified by acid catalysis. Thermal baking at temperatures no less than $500\,^{\circ }\text{C}$ for 60 min offers chemical stability, ethanol scratch resistance, and resistance to washing with water. The average residual reflection of dual-side-coated fused silica glass was less than 1% in the spectral range from 450 to 950 nm. Transmission gain has been evaluated by taking into account angular light, and the results show that the transmission gain increases with increasing light incidence. Even at $60^{\circ }$, the transmission spectrum of the broadband antireflective coating effectively covered the main absorption peak of Nd:glass.
Israeli National Policy for Carbapenem-Resistant Enterobacteriaceae Screening, Carrier Isolation and Discontinuation of Isolation
Authors: Solter Ester , Adler Amos , Rubinovitch Bina , Temkin Elizabeth , Schwartz David , Ben-David Debby , Masarwa Samira , Carmeli Yehuda , Schwaber Mitchell J. 
Published: December 2017

AbstractSince 2006, Israel has been confronting an outbreak of carbapenem-resistant Enterobacteriaceae (CRE), and in 2007 Israel implemented a national strategy to contain spread. The intervention was initially directed toward acute-care hospitals and later expanded to include an established reservoir of carriage in long-term-care hospitals. It included regular reporting of CRE cases to a central registry and daily oversight of management of the outbreak at the institutional level. Microbiological methodologies were standardized in clinical laboratories nationwide. Uniform requirements for carrier screening and isolation were established, and a protocol for discontinuation of carrier status was formulated. In response to the evolving epidemiology of CRE in Israel and the continued need for uniform guidelines for carrier detection and isolation, the Ministry of Health in 2016 issued a regulatory circular updating the requirements for CRE screening, laboratory diagnosis, molecular characterization, and carrier isolation, as well as reporting and discontinuation of isolation in healthcare institutions nationwide. The principal elements of the circular are contained herein.Infect Control Hosp Epidemiol 2018;39:85–89
100 % Fruit juice and measures of glucose control and insulin sensitivity: a systematic review and meta-analysis of randomised controlled trials
Authors: Murphy Mary M. , Barrett Erin C. , Bresnahan Kara A. , Barraj Leila M. 
Published: December 2017

AbstractStudies on the effects of consuming 100 % fruit juice on measures of glycaemic control are conflicting. The purpose of the present study was to systematically review and quantitatively summarise results from randomised controlled trials (RCT) examining effects of 100 % fruit juice on glucose–insulin homeostasis. Eligible studies were identified from a systematic review of PubMed and EMBASE and hand searches of reference lists from reviews and relevant papers. Using data from eighteen RCT, meta-analyses evaluated the mean difference in fasting blood glucose (sixteen studies), fasting blood insulin (eleven studies), the homeostatic model assessment of insulin resistance (HOMA-IR; seven studies) and glycosylated Hb (HbA1c; three studies) between the 100 % fruit juice intervention and control groups using a random-effects model. Compared with the control group, 100 % fruit juice had no significant effect on fasting blood glucose (−0·13 (95 % CI −0·28, 0·01) mmol/l;P = 0·07), fasting blood insulin (−0·24 (95 % CI −3·54, 3·05) pmol/l;P = 0·89), HOMA-IR (−0·22 (95 % CI −0·50, 0·06);P = 0·13) or HbA1c (−0·001 (95 % CI −0·38, 0·38) %;P = 0·28). Results from stratified analyses and univariate meta-regressions also largely showed no significant associations between 100 % fruit juice and the measures of glucose control. Overall, findings from this meta-analysis of RCT suggest a neutral effect of 100 % fruit juice on glycaemic control. These findings are consistent with findings from some observational studies suggesting that consumption of 100 % fruit juice is not associated with increased risk of diabetes.