bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Sr Modifier Additions on Double Oxide Film Defects in 2L99 Alloy Castings
Authors: Chen Qi , Griffiths W. D. 
Published: September 2017

Abstract
In this paper, Sr modifier (300 ppm) was added to 2L99 alloy sand castings to investigate its effect on bifilm defects in the castings. Two different sand molds were used in this study, with good and bad running system designs, to introduce different amounts of bifilm defects into the castings. The mechanical properties of the modified 2L99 castings were compared to the properties of unmodified castings and showed that with high bifilm defect contents (H) the Sr addition reduced the Weibull modulus of the UTS by 67 pct and the Position Parameter by 5 pct, and introduced a bimodal distribution into the Weibull plot of the pct Elongation. However, for castings with low bifilm defect content (L), the Weibull moduli of both the UTS and pct Elongation were significantly improved (by 78 and 73 pct, respectively) with the addition of Sr. The Position Parameter of the pct Elongation was improved by 135 pct. The results suggested that a desirable modification effect can only be achieved while the bifilm defect content in a casting was low.
Widening of Laths in Bainite
Authors: Yin Jiaqing , Hillert Mats , Borgenstam Annika 
Published: September 2017

Abstract
Units of bainite in Fe-C alloys from the upper temperature range inherit their shape from Widmanstätten plates of ferrite, which are lathlike. The thickness increases by long-range diffusion of carbon and the length by short-range diffusion of carbon from the advancing edge of the tip. Both have been studied extensively and are fairly well understood. Widening growth seems to have been much neglected, but a study of some aspects of widening is now presented. The present report is the last one in a series of four morphological studies of bainite, isothermally formed in Fe-C alloys with 0.3 or 0.7 mass pct carbon, mainly in the upper temperature range. It contains a number of morphological observations made on cross sections of packets of bainite, and it elucidated a number of interesting questions about bainite and resulted in some proposals. The ferrite plates in a packet are nucleated as a group on a grain boundary, not each one separately on the side of a prior plate. Lengthening occurs by advancement of a short edge that is formed in close contact to the grain boundary. Widening of laths does not start spontaneously. It is initiated by a modification of the structure of the long edge of the lath. When it then moves, the lattice of the new ferrite is rotated relative to the ferrite formed by lengthening and the habit plane is different. In a section through the length direction, it is difficult to recognize what part of ferrite has formed by widening growth. Furthermore, it is proposed that the individual plates in a microstructure, previously used to illustrate subunits formed by repeated nucleation, were nucleated on a hidden grain boundary.
Metabolic pathway databases and model repositories
Authors: Labena Abraham A. , Gao Yi‐Zhou , Dong Chuan , Hua Hong‐li , Guo Feng‐Biao 
Published: September 2017

BackgroundThe number of biological Knowledge bases/databases storing metabolic pathway information and models has been growing rapidly. These resources are diverse in the type of information/data, the analytical tools, and objectives. Here we present a review of the most popular metabolic pathway databases and model repositories, focusing on their scope, content including reactions, enzymes, compounds, and genes, and applicability. The review aims to help researchers choose a suitable database or model repository according to the information and data required, by providing an insight look of each pathway resource.ResultsFour pathways databases and three model repositories were selected on the basis of popularity and diversity. Our review showed that the pathway resources vary in many aspects, such as their scope, content, access to data and the tools. In addition, inconsistencies have been observed in nomenclature and representation of database entities. The three model repositories reviewed do not offer a brief description of the models’ characteristics such as simulation conditions.ConclusionsThe inconsistencies among the databases in representing their contents may hamper the maximal use of the knowledge accumulated in these databases in particular and the area of systems biology at large. Therefore, it is strongly recommended that the database creators and the metabolic network models developers should follow international standards for the nomenclature of reactions and metabolites. Besides, computationally generated models that could be obtained from model repositories should be utilized with manual curations as they lack some important components that are necessary for full functionality of the models.
Knowledge‐driven computational modeling in Alzheimer's disease research: Current state and future trends
Authors: Geerts Hugo , Hofmann‐Apitius Martin , Anastasio Thomas J. ,   Brain Health Modeling Initiative
Published: September 2017

AbstractNeurodegenerative diseases such as Alzheimer's disease (AD) follow a slowly progressing dysfunctional trajectory, with a large presymptomatic component and many comorbidities. Using preclinical models and large‐scale omics studies ranging from genetics to imaging, a large number of processes that might be involved in AD pathology at different stages and levels have been identified. The sheer number of putative hypotheses makes it almost impossible to estimate their contribution to the clinical outcome and to develop a comprehensive view on the pathological processes driving the clinical phenotype. Traditionally, bioinformatics approaches have provided correlations and associations between processes and phenotypes. Focusing on causality, a new breed of advanced and more quantitative modeling approaches that use formalized domain expertise offer new opportunities to integrate these different modalities and outline possible paths toward new therapeutic interventions. This article reviews three different computational approaches and their possible complementarities. Process algebras, implemented using declarative programming languages such as Maude, facilitate simulation and analysis of complicated biological processes on a comprehensive but coarse‐grained level. A model‐driven Integration of Data and Knowledge, based on the OpenBEL platform and using reverse causative reasoning and network jump analysis, can generate mechanistic knowledge and a new, mechanism‐based taxonomy of disease. Finally, Quantitative Systems Pharmacology is based on formalized implementation of domain expertise in a more fine‐grained, mechanism‐driven, quantitative, and predictive humanized computer model. We propose a strategy to combine the strengths of these individual approaches for developing powerful modeling methodologies that can provide actionable knowledge for rational development of preventive and therapeutic interventions. Development of these computational approaches is likely to be required for further progress in understanding and treating AD.
Accelerated Return to Sport After Anterior Cruciate Ligament Reconstruction and Early Knee Osteoarthritis Features at 1 Year: An Exploratory Study
Authors: Culvenor Adam G. , Patterson Brooke E. , Guermazi Ali , Morris Hayden G. , Whitehead Timothy S. , Crossley Kay M. 
Published: September 2017

AbstractBackgroundA timely return to competitive sport is a primary goal of anterior cruciate ligament reconstruction (ACLR). It is not known whether an accelerated return to sport increases the risk of early‐onset knee osteoarthritis (KOA).ObjectiveTo determine whether an accelerated return to sport post‐ACLR (ie, <10 months) is associated with increased odds of early KOA features on magnetic resonance imaging (MRI) 1 year after surgery and to evaluate the relationship between an accelerated return to sport and early KOA features stratified by type of ACL injury (isolated or concurrent chondral/meniscal injury) and lower limb function (good or poor).DesignCross‐sectional study.SettingPrivate radiology clinic and university laboratory.ParticipantsA total of 111 participants (71 male; mean age 30 ± 8 years) 1‐year post‐ACLR.MethodsParticipants completed a self‐report questionnaire regarding postoperative return‐to‐sport data (specific sport, postoperative month first returned), and isotropic 3‐T MRI scans were obtained.Outcome MeasuresEarly KOA features (bone marrow, cartilage and meniscal lesions, and osteophytes) assessed with the MRI OA Knee Score. Logistic regression analyses evaluated the odds of early KOA features with an accelerated return to sport (<10 months post‐ACLR versus ≥10 months or no return to sport) in the total cohort and stratified by type of ACL injury and lower limb function.ResultsForty‐six (41%) participants returned to competitive sport <10 months post‐ACLR. An early return to sport was associated with significantly increased odds of bone marrow lesions (odds ratio [OR] 2.7, 95% confidence interval [CI] 1.3‐6.0) but not cartilage (OR 1.2, 95% CI 0.5‐2.6) or meniscal lesions (OR 0.8, 95% CI 0.4‐1.8) or osteophytes (OR 0.6, 95% CI 0.3‐1.4). In those with poor lower limb function, early return to sport exacerbated the odds of bone marrow lesions (OR 4.6, 95% CI 1.6‐13.5), whereas stratified analyses for type of ACL injury did not reach statistical significance.ConclusionAn accelerated return to sport, particularly in the presence of poor lower limb function, may be implicated in posttraumatic KOA development.Level of evidenceIV
Stability of three-dimensional columnar convection in a porous medium
Authors: Hewitt Duncan R. , Lister John R. 
Published: September 2017

The stability of steady convective exchange flow with a rectangular planform in an unbounded three-dimensional porous medium is explored. The base flow comprises a balance between vertical advection with amplitude $A$ in interleaving rectangular columns with aspect ratio $\unicode[STIX]{x1D709}\leqslant 1$ and horizontal diffusion between the columns. Columnar flow with a square planform ($\unicode[STIX]{x1D709}=1$) is found to be weakly unstable to a large-scale perturbation of the background temperature gradient, irrespective of $A$, but to have no stronger instability on the scale of the columns. This result provides a stark contrast to two-dimensional columnar flow (Hewitt et al., J. Fluid Mech., vol. 737, 2013, pp. 205–231), which, as $A$ is increased, is increasingly unstable to a perturbation on the scale of the columnar wavelength. For rectangular planforms with $\unicode[STIX]{x1D709}<1$, a critical aspect ratio is identified, below which a perturbation on the scale of the columns is the fastest growing mode, as in two dimensions. Scalings for the growth rate and the structure of this mode are identified, and are explained by means of an asymptotic expansion in the limit $\unicode[STIX]{x1D709}\rightarrow 0$. The difference between the stabilities of two-dimensional and three-dimensional exchange flow provides a potential explanation for the apparent difference in dominant horizontal scale observed in direct numerical simulations of two-dimensional and three-dimensional statistically steady ‘Rayleigh–Darcy’ convection at high Rayleigh numbers.
A Lagrangian fluctuation–dissipation relation for scalar turbulence. Part I. Flows with no bounding walls
Authors: Drivas Theodore D. , Eyink Gregory L. 
Published: September 2017

An exact relation is derived between scalar dissipation due to molecular diffusivity and the randomness of stochastic Lagrangian trajectories for flows without bounding walls. This ‘Lagrangian fluctuation–dissipation relation’ equates the scalar dissipation for either passive or active scalars to the variance of scalar inputs associated with initial scalar values and internal scalar sources, as these are sampled backward in time by the stochastic Lagrangian trajectories. As an important application, we reconsider the phenomenon of ‘Lagrangian spontaneous stochasticity’ or persistent non-determinism of Lagrangian particle trajectories in the limit of vanishing viscosity and diffusivity. Previous work on the Kraichnan (Phys. Fluids, 1968, vol. 11, pp. 945–953) model of turbulent scalar advection has shown that anomalous scalar dissipation is associated in that model with Lagrangian spontaneous stochasticity. There has been controversy, however, regarding the validity of this mechanism for scalars advected by an actual turbulent flow. We here completely resolve this controversy by exploiting the fluctuation–dissipation relation. For either a passive or an active scalar advected by any divergence-free velocity field, including solutions of the incompressible Navier–Stokes equation, and away from walls, we prove that anomalous scalar dissipation requires Lagrangian spontaneous stochasticity. For passive scalars, we prove furthermore that spontaneous stochasticity yields anomalous dissipation for suitable initial scalar fields, so that the two phenomena are there completely equivalent. These points are illustrated by numerical results from a database of homogeneous isotropic turbulence, which provide both additional support to the results and physical insight into the representation of diffusive effects by stochastic Lagrangian particle trajectories.
A Lagrangian fluctuation–dissipation relation for scalar turbulence. Part II. Wall-bounded flows
Authors: Drivas Theodore D. , Eyink Gregory L. 
Published: September 2017

We derive here Lagrangian fluctuation–dissipation relations for advected scalars in wall-bounded flows. The relations equate the dissipation rate for either passive or active scalars to the variance of scalar inputs from the initial values, boundary values and internal sources, as those are sampled backward in time by stochastic Lagrangian trajectories. New probabilistic concepts are required to represent scalar boundary conditions at the walls: the boundary local-time density at points on the wall where scalar fluxes are imposed and the boundary first hitting time at points where scalar values are imposed. These concepts are illustrated both by analytical results for the problem of pure heat conduction and by numerical results from a database of channel-flow turbulence, which also demonstrate the scalar mixing properties of near-wall turbulence. As an application of the fluctuation–dissipation relation, we examine for wall-bounded flows the relation between anomalous scalar dissipation and Lagrangian spontaneous stochasticity, i.e. the persistent non-determinism of Lagrangian particle trajectories in the limit of vanishing viscosity and diffusivity. In Part I of this series, we showed that spontaneous stochasticity is the only possible mechanism for anomalous dissipation of passive or active scalars, away from walls. Here it is shown that this remains true when there are no scalar fluxes through walls. Simple examples show, on the other hand, that a distinct mechanism of non-vanishing scalar dissipation can be thin scalar boundary layers near the walls. Nevertheless, we prove for general wall-bounded flows that spontaneous stochasticity is another possible mechanism of anomalous scalar dissipation.
Nonlinear stability in three-layer channel flows
Authors: Papaefthymiou E. S. , Papageorgiou D. T. 
Published: September 2017

The nonlinear stability of viscous, immiscible multilayer flows in plane channels driven both by a pressure gradient and gravity is studied. Three fluid phases are present with two interfaces. Weakly nonlinear models of coupled evolution equations for the interfacial positions are derived and studied for inertialess, stably stratified flows in channels at small inclination angles. Interfacial tension is demoted and high-wavenumber stabilisation enters due to density stratification through second-order dissipation terms rather than the fourth-order ones found for strong interfacial tension. An asymptotic analysis is carried out to demonstrate how these models arise. The governing equations are $2\times 2$ systems of second-order semi-linear parabolic partial differential equations (PDEs) that can exhibit inertialess instabilities due to interaction between the interfaces. Mathematically this takes place due to a transition of the nonlinear flux function from hyperbolic to elliptic behaviour. The concept of hyperbolic invariant regions, found in nonlinear parabolic systems, is used to analyse this inertialess mechanism and to derive a transition criterion to predict the large-time nonlinear state of the system. The criterion is shown to predict nonlinear stability or instability of flows that are stable initially, i.e. the initial nonlinear fluxes are hyperbolic. Stability requires the hyperbolicity to persist at large times, whereas instability sets in when ellipticity is encountered as the system evolves. In the former case the solution decays asymptotically to its uniform base state, while in the latter case nonlinear travelling waves can emerge that could not be predicted by a linear stability analysis. The nonlinear analysis predicts threshold initial disturbances above which instability emerges.
The role of conservators in facilitating the theft and trafficking of cultural objects: the case of a seized Libyan statue
Authors: Brodie Neil 
Published: September 2017

AbstractA 2015 court judgment in the United Kingdom ruled that a seized Libyan statue should be returned to the ownership of the State of Libya. The judgment prompts a critical discussion of the involvement of professional conservators in the trafficking of cultural objects. Higher standards of due diligence are recommended for conservators and other professional experts engaging with cultural objects that might have been stolen and trafficked. Stronger professional due diligence is but one component of a broader policy of demand reduction that will be necessary to control the theft and trafficking of cultural objects, and to offer protection to cultural sites around the world.
Preliminary Radiocarbon Results for Late Bronze Age Strata at Tel Azekah and Their Implications
Authors: Webster Lyndelle C , Sergi Omer , Kleiman Sabine , Lipschits Oded , Hua Quan , Jacobsen Geraldine E , Tristant Yann , Gadot Yuval 
Published: September 2017

AbstractThis article presents the first radiocarbon (14C) results from the Late Bronze Age levels of Tel Azekah (Israel). The results testify to the long and prosperous occupation of the site during this period, commencing at least in LB IIA and ending with a severe destruction at the close of LB III. In the extra-mural quarter (Area S2), a pre-monumental building phase (S2-6) dates to the 14th or early 13th century BCE. Two sub-phases of a public building constructed above this yielded dates in the second half of the 13th century and first two-thirds of the 12th century BCE, suggesting that occupation persisted through the “Crisis Years” of the eastern Mediterranean region. On the top of the mound, in Area T2, the destruction of the final LB III level (T2-3) most likely occurred near the end of the 12th century BCE. The preliminary Azekah results are in good agreement with existing data from Lachish and Megiddo, but seem at odds with results from nearby Tel es-Safi/Gath.
A TWO-ECHELON SPARE PARTS NETWORK WITH LATERAL AND EMERGENCY SHIPMENTS: A PRODUCT-FORM APPROXIMATION
Authors: Boucherie Richard J. , van Houtum Geert-Jan , Timmer Judith , van Ommeren Jan-Kees 
Published: September 2017

We consider a single-item, two-echelon spare parts inventory model for repairable parts for capital goods with high downtime costs. The inventory system consists of multiple local warehouses, a central warehouse, and a central repair facility. When a part at a customer fails, if possible his request for a ready-for-use part is fulfilled by his local warehouse. Also, the failed part is sent to the central repair facility for repair. If the local warehouse is out of stock, then, via an emergency shipment, a ready-for-use part is sent from the central warehouse if it has a part in stock. Otherwise, it is sent via a lateral transshipment from another local warehouse, or via an emergency shipment from the external supplier. We assume Poisson demand processes, generally distributed leadtimes for replenishments, repairs, and emergency shipments, and a basestock policy for the inventory control.Our inventory system is too complex to solve for a steady-state distribution in closed form. We approximate it by a network of Erlang loss queues with hierarchical jump-over blocking. We show that this network has a product-form steady-state distribution. This enables an efficient heuristic for the optimization of basestock levels, resulting in good approximations of the optimal costs.
Measurement of Fall Prevention Awareness and Behaviours among Older Adults at Home
Authors: Russell Katherine , Taing Darcie , Roy Jacqueline 
Published: September 2017

ABSTRACTThis study surveyed awareness of, and adherence to, six national fall prevention recommendations among community-dwelling older adults (n= 1050) in Ottawa. Although 76 per cent of respondents agreed falling is a concern and preventable, fewer perceived susceptibility to falling (63%). Respondents had high awareness that home modifications and physical activity can prevent falls. Reported modifications included grab bars (50%), night lights (44%), and raised toilet seats (19%). Half met aerobic activity recommendations; 38 per cent met strength recommendations. Respondents had lower awareness that an annual medication review, annual eye and physical examination, and daily vitamin D supplementation could reduce fall risk. However, reported annual medication review (79%) and eye examination (75%) was high. Nearly half met recommendations for vitamin D intake. These findings suggest a gap in knowledge of awareness and adherence to national recommendations, highlighting the ones that may require attention from those who work to prevent falls.
Introduction to quantitative engineering design methods via controls engineering
Authors: Lucero Briana M. , Adams Matthew J. , Turner Cameron J. 
Published: September 2017

AbstractFunctional modeling is an effective method of depicting products in the design process. Using this approach, product architecture, concept generation, and physical modeling all contribute to the design process to generate a result full of quality and functionality. The functional basis approach provides taxonomy of uniform vocabulary to produce function structures with consistent functions (verbs) and flows (nouns). Material and energy flows dominate function structures in the mechanical engineering domain with only a small percentage including signal flows. Research suggests that the signal flow gap is due to the requirement of “carrier” flows of either material or energy to transport the signals between functions. This research suggests that incorporating controls engineering methodologies may increase the number of signal flows in function structures. We show correlations between the functional modeling and controls engineering in four facets: schematic similarities, performance matching through flows, mathematical function creation using bond graphs, and isomorphic matching of the aforementioned characteristics allows for analogical solutions. Controls systems use block diagrams to represent the sequential steps of the system. These block diagrams parallel the function structures of engineering design. Performance metrics between the two domains can be complimentary when decomposed down to nondimensional engineering units. Mathematical functions of the actions in controls systems can resemble the functional basis functions with bond graphs by identifying characteristic behavior of the functions on the flows. Isomorphic matching, using the schematic diagrams, produces analogies based upon similar functionality and target performance metrics. These four similarities bridge the mechanical and electrical domains via the controls domain. We provide concepts and contextualization for the methodology using domain-agnostic examples. We conclude with suggestion of pathways forward for this preliminary research.