bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of the finite‐difference and finite‐volume methods for a numerical solution of a hyperbolic thermoelasticity problem utilizing the implicit and explicit schemes
Authors: Matias Dmitrii V. , Vitokhin Evgeniy Yu. 
Published: February 2019

AbstractA numerical solution for a coupled hyperbolic thermoelasticity problem of the Lord‐Shulman type is presented. An infinite layer with free boundaries that are kept at a constant temperature is irradiated by a short laser impulse. In this case the problem can be studied in the one‐dimensional formulation. An impact of the laser impulse on a medium is modeled by an internal heat source. The laser impulse intensity decays with a distance from an irradiated surface according to the Bouguer law. The layer is in an unperturbed state at the initial moment of time. The material properties of copper are taken to be the thermo‐mechanical properties of the layer.Two approaches for the boundary value problem are considered: the finite‐difference method (FDM) and the finite‐volume method (FVM). In the first case the system of two second‐order PDE is investigated, in the second case a system of integral balance equations and an integral thermal conductivity equation are composed. To integrate these equations both the explicit and implicit schemes are used. The obtained results are compared with each other and with an analytical solution. A numerical error is estimated for different time and space step sizes. The features inherent in various ways of integration of the coupled hyperbolic thermoelastic problem with the thermal excitation are found.
Solving partial differential equations in computational mechanics via nonlocal numerical approaches
Authors: Martowicz Adam , Roemer Jakub , Staszewski Wieslaw J. , Ruzzene Massimo , Uhl Tadeusz 
Published: February 2019

AbstractThe work addresses solving partial differential equations (PDE)s for a continuum solid body using a nonlocal formulation. Second order spatial derivatives are of concern as they enable to deal with many dynamic problems in physics. The authors introduce a nonlocal finite difference (FD) scheme to show its applicability to computational mechanics. In the theoretical part of the work exemplary solutions of the second order ordinary derivatives are discussed. The capability of numerical dispersion reduction, which is identified for the proposed approach, is demonstrated for the crude spatial domain discretization. Based on the provided nonlocal FD scheme, discrete forms for the two types of PDEs are derived to indicate potential areas of practical applications for the presented method. Elastic wave equation and thermal diffusion equation are taken into account. Moreover, for the former case, the peridynamics – which is also a nonlocal approach – is also used to derive an alternative discrete formulation. The stability conditions for the provided numerical schemes are determined using von Neumann stability analysis. The limits for the allowed simulation time steps are found. The second part of the paper is devoted to the practical applications of the elaborated nonlocal formulations. There are studied selected thermal and mechanical properties of a gas foil bearing (GFB) component. A rod‐like structural part of GFB made of superalloy Inconel 625 is analyzed. A one‐dimensional model is built to determine temperature and displacement distributions via transient simulations. Again, reduced numerical dispersion is confirmed for the model with a crude mesh.
Landscape Response to Climate and Human Impact in Western China During the Han Dynasty
Authors: Mischke Steffen , Zhang Chengjun , Liu Chenglin , Zhang Jiafu , Lai Zhongping , Long Hao 
Published: February 2019

AbstractThe Chinese empire experienced a large expansion to the arid regions in the west during the Han Dynasty (206 BCE–220 CE). The Hexi Corridor, the Yanqi Basin, the southeastern part of the Junggar Basin and the Tarim Basin became part of the empire. The expansion of the Han Dynasty was accompanied by the significant intensification of irrigation farming along rivers draining the Qilian, Tianshan and Kunlun Mountains. Sedimentological and geochemical analyses and dating of lake sediments and shorelines revealed that four large lakes in the region experienced falling levels, or were almost or completely desiccating. The level of Zhuyeze Lake was falling rapidly ca. 2100 years before present (a BP), and the accumulation of lake sediments was replaced by an alluvial fan setting in large parts of the basin. Lake Eastern Juyan desiccated ca. 1700 a BP. Lake Bosten experienced low levels and increasing salinities at ca. 2200 a BP. Lake sediments in the Lop Nur region were mostly replaced by aeolian sands during a period of near-desiccation at 1800 a BP. In contrast, records from fifteen lakes farther in the west, north or south of the Han Dynasty realm indicate relatively wet climate conditions ca. 2000 years ago. Thus, dramatic landscape changes including the near and complete desiccation of large lakes in the arid western part of today’s China probably resulted from the withdrawal of water from tributaries during the Han Dynasty. These changes likely represent the earliest man-made environmental disasters comparable to the recent Aral-Sea crisis.
Quantitative Evaluation of the Impact on Aral Sea Levels by Anthropogenic Water Withdrawal and Syr Darya Course Diversion During the Medieval Period (1.0–0.8 ka BP)
Authors: Sala Renato 
Published: February 2019

AbstractPaleo-climatic, environmental, archaeological studies and historical accounts concerning the behavior of the Aral Sea during the last 2000 years point to a number of water level regressions similar or deeper than the modern one. This article is focused on the causes of such regressions, which are variously attributed to climatic change, diversion of river courses and anthropogenic water withdrawal. The first factor has been researched by several geo-specialists and its potential impact has been preliminarily evaluated. The second factor has been considered only in the case of the Amu Darya river. The third factor—water withdrawal for irrigation purposes—has been hypothesized, though never deserved specific analysis. The article provides a quantitative evaluation of the total hectares covered by the medieval urban systems of the Syr Darya and Amu Darya river basins, and of the coefficient of water use per hectare of walled towns during the X-XII centuries AD. Estimates of annual volumes of anthropogenic water withdrawal allow the investigation of the complex interaction of the three factors above in determining the hydrological conditions of the Aral Sea. On the basis of the calculation of possible scenarios of water mass balance, the occurrence of transmission losses by medieval diversions of the Syr Darya course has been suspected as the main cause of lake regressions, which is supported by geological considerations, archaeological data and historical accounts.
Evaluation of the Operationalisation of the TATA-BOX Process
Authors: Taverne Marie , Clément Sarah , Prost Lorène , Barcellini Flore 
Published: February 2019

AbstractThe chapter evaluates how the TATA-BOX process supported the collective design of an agroecological transition. In order to carry out this evaluation, we interviewed a panel of 24 participants about their experience of the process and their opinions on it. In this chapter we set out the results in relation to three questions: How did the workshops go? What characterised the outputs? What effects were identified? On these bases, we discuss some possible improvements in the TATA-BOX process and the ways in which this process supported the design of an agroecological transition. We show in particular that the TATA-BOX process successfully initiated a collective design process as it allowed the participants to establish a common ground, define a range of goals to meet, and identify actionable means that could help to reach these goals. The process will nevertheless have to be continued through actual implementation. Various actors will most likely take responsibility for limited actions, rather than for the territorial agricultural transition project in its entirety. They will select the design solutions they need and might revise them. The TATA-BOX participatory process thus appears to be one step in the process of designing the territory’s transition.
Holographic Weyl anomaly for GJMS operators: one Laplacian to rule them all
Authors: Bugini F. , Diaz D. E. 
Published: February 2019

Abstract

The holographic Weyl anomaly for GJMS operators (or conformal powers of the Laplacian) are obtained in four and six dimensions. In the context of AdS/CFT correspondence, free conformal scalars with higher-derivative kinetic operators are induced by an ordinary second-derivative massive bulk scalar. At one-loop quantum level, the duality dictionary for partition functions entails an equality between the functional determinants of the corresponding kinetic operators and, in particular, it provides a holographic route to their Weyl anomalies. The heat kernel of a single bulk massive scalar field encodes the Weyl anomaly (type-A and type-B) coefficients for the whole tower of GJMS operators whenever they exist, as in the case of Einstein manifolds where they factorize into product of Laplacians.
While a holographic derivation of the type-A Weyl anomaly was already worked out some years back, in this note we compute holographically (for the first time to the best of our knowledge) the type-B Weyl anomaly for the whole family of GJMS operators in four and six dimensions. There are two key ingredients that enable this novel holographic derivation that would be quite a daunting task otherwise: (i) a simple prescription for obtaining the holographic Weyl anomaly for higher-curvature gravities, previously found by the authors, that allows to read off directly the anomaly coefficients from the bulk action; and (ii) an implied WKB-exactness, after resummation, of the heat kernel for the massive scalar on a Poincaré-Einstein bulk metric with an Einstein metric on its conformal infinity.
The holographically computed Weyl anomaly coefficients are explicitly verified on the boundary by exploiting the factorization of GJMS operators on Einstein manifolds and working out the relevant heat kernel coefficient.
Silica-silk fibroin hybrid (bio)aerogels: two-step versus one-step hybridization
Authors: Maleki Hajar , Huesing Nicola 
Published: February 2019

AbstractIn this study, silk fibroin as a highly promising naturally occurring biopolymer extracted from silkworm cocoon is applied to mechanically reinforce silica aerogels. To this aim, two different approaches for the incorporation of silk fibroin into the silica network are compared: (1) a one-step acid catalyzed and (2) a two-step acid-base catalyzed sol–gel reaction. The total organosilane concentration, as well as the SF to silane mass fractions, regulated the hybridization process to proceed either through a one-step or two-step sol–gel reaction. In both processes, for an efficient chemical mixing the silk fibroin components with the silane phase, a silane coupling agent, 5-(trimethoxysilyl) pentanoic acid (TMSPA), comprising carboxylic acid groups and a pentyl hydrocarbon chain has been used. For a low organosilane content (3.4 mmol) along with a high SF to silane mass ratio (15–30%), the gelation of the silane and silk fibroin phases took place in a one-pot/one-step process in the presence of an acid catalyst in an entirely aqueous system. In the two-step synthesis approach, which was applied for high initial silane contents (17 mmol), and low SF to silane mass ratios (1–4%), first, the gelation of the silk fibroin phase was triggered by addition of an acid catalyst followed by a more pronounced condensation of the silane catalyzed by the addition of the base. Both synthesis approaches led to materials with promising mechanical properties—being 1) the one-step process resulting in gels with much better compressibility (up to 70% of strain), low density (0.17–0.22 g cm−3) and three orders of magnitude improvement in the Young’s modulus (13.5 MPa) compared to that of the pristine silica aerogel but with rather high shrinkage (30–40%). The two-step process in principle could result in the hybrid aerogel with interesting bulk density (0.17–0.28 g cm−3) with lower shrinkage (10%), but the resultant aerogel was stiff and fragile. Also, both approaches led to a significant reduction in the time required to prepare strong hybrid aerogels compared to conventional hybrid polymer-silica aerogels with the utilization of an entirely aqueous synthesis approach for a wide range of applications.
Outcome of Pregnancies with Isolated Absent Fetal Nasal Bone in the Second Trimester
Authors: Desai Purvi , Chauhan Binodini , Jhawar Manisha 
Published: February 2019

AbstractAbsent nasal bone is associated with 58 genetic syndromes, Trisomy 18 and trisomy 21. It increases the sensitivity of second trimester scan for aneuploidy from 83 to 90%. Since 2003, absent or unossified nasal bone is therefore an integral part of the second trimester scan. The present study aimed at confirming the sensitivity of isolated absent NB in the second trimester USG, by reviewing the karyotypes and/or postnatal outcomes of such pregnancies up till at least 6 months of postnatal life. Facial profile was seen in 2D and 3D reconstructed view in all the cases to avoid missing the unilateral absence of nasal bone. Complete detailed scan and FISH on amniotic fluid cells was advised for all the cases with absent nasal bone. The present study concluded that isolated absence of NB in the second trimester may not be an effective marker for diagnosis of Down’s syndrome. Amniocentesis should be advised only if absent nasal bone is associated with any other structural abnormality or additional soft marker.
Benefit-Cost Analysis of a Package of Early Childhood Interventions to Improve Nutrition in Haiti
Authors: Wong Brad , Radin Mark 
Published: February 2019

We conduct a benefit-cost analysis of a package of early childhood interventions that can improve nutrition outcomes in Haiti. Using the Lives Saved Tool, we expect that this package can prevent approximately 55,000 cases of child stunting, 7,600 low-weight births and 28,000 cases of maternal anemia annually, if coverage reaches 90% of the target population. In addition, we expect these nutrition improvements will avoid 1,830 under-five deaths, 80 maternal deaths and 900,000 episodes of child illness every year. Those who avoid stunting will experience lifetime productivity benefits equivalent to five times gross national income per capita in present value terms, at a 5% discount rate. While previous benefit-cost analyses of this specific package have only estimated the lifetime productivity benefits of avoided stunting, this paper also accounts for reductions in fatal and non-fatal health risks. In the base case scenario, the annualized net benefits of the intervention equal Haitian gourdes 13.4 billion (USD 211 million) and the benefit-cost ratio (BCR) is 5.2. Despite these substantial benefits, the package may not be the most efficient use of a marginal dollar, with alternative interventions to improve human capital yielding BCRs approximately three to four times higher than the base estimate.
Cholinergic Neurons in Nucleus Subputaminalis in Primary Progressive Aphasia
Authors: Hamodat Hayam , Fisk John D. , Darvesh Sultan 
Published: February 2019

ABSTRACT:Background: Primary Progressive Aphasia (PPA) is a syndrome characterized by an isolated impairment of language function at disease onset. The cholinergic system is implicated in language function and cholinergic deficits are seen in the brains of individuals with PPA. One major source of cholinergic innervation of the cerebral cortex is the nucleus basalis of Meynert (NBM) within which lies the nucleus subputaminalis (NSP). This nucleus is postulated to be involved in language function. We compared the abundance of cholinergic neurons in the NBM and NSP of controls and individuals with PPA. Also explored was whether the individuals presenting with PPA, who subsequently developed different clinical and neuropathological profiles, showed similar cholinergic deficits in the NSP. Methods: Cytoarchitecture of the basal forebrain was studied using Nissl staining in control (n = 5) and PPA (n = 5) brains. Choline acetyltransferase (ChAT) immunohistochemical staining labeled cholinergic neurons were quantified using Neurolucida software. Results: In comparison to matched controls, PPA showed reduction of cholinergic neurons in the NBM (t(8) = 4.04, p = 0.0037; Cohen’s effect size value d = 2.62) and the NSP (t(6) = 4.62, p = 0.0042; Cohen’s d effect size d = 2.92). The average percent of cholinergic neuronal loss was relatively higher in the NSP (64.7%) compared to the NBM (47.7%). Conclusion: Regardless of underlying pathology, all cases presenting with PPA showed a marked loss of cholinergic neurons in the NSP, providing further evidence for the importance of this nucleus in language function.
Subjective morbidity following radial free flap reconstruction in head and neck tumour patients
Authors: Minkara A , Simmons M R , Goodale A , Patil Y J 
Published: February 2019

AbstractObjectiveEvaluation of post-operative donor site disability remains unaddressed in radial forearm free flap cases. This study aimed to assess donor site dysfunction following radial forearm free flap harvest using validated general, disease-specific and site-specific disability questionnaires.MethodsIn this retrospective case series of 24 patients at a tertiary academic medical centre, patients were assessed using the Short Form 36 Health Survey, Short Musculoskeletal Function Assessment questionnaire, and Disabilities of the Arm, Shoulder and Hand questionnaire. One-sample z-tests were performed, comparing means of the cohort to controls.ResultsCompared to population controls, the cohort had higher mean scores for the Disabilities of the Arm, Shoulder and Hand questionnaire (18.22vs10.1,p&lt; 0.01), and Short Musculoskeletal Function Assessment questionnaire bothersome index (21.44vs13.77,p= 0.04), and a lower mean score for the Short Form 36 Health Survey physical component (38.88vs50,p&lt; 0.01), indicating a greater disability for the cohort compared to controls.ConclusionRadial forearm free flap harvest causes significant long-term donor site disability in head and neck tumour patients. The Disabilities of the Arm, Shoulder and Hand questionnaire is a concise tool for measuring this dysfunction.
Factors influencing local attitudes towards the conservation of leopard cats Prionailurus bengalensis in rural Taiwan
Authors: Best Ian , Pei Kurtis Jai-Chyi 
Published: February 2019

AbstractUnderstanding the human dimension is critical for effective conservation management of species involved in human–carnivore conflict. There is also a need to recognize who among the local human population is supportive of wildlife conservation. We investigated how local people's attitudes and knowledge of the leopard cat Prionailurus bengalensis are influenced by socio-demographic variables, encounter rates and the nature of encounters with the felid in Taiwan. During June–August 2014 we interviewed 150 residents in Miaoli County in northern Taiwan, where the leopard cat is known to occur. More than half of the participants indicated they were supportive of leopard cat conservation. The majority of those who expressed positive attitudes towards protection of the leopard cat belonged to younger, more educated socio-demographic groups. Negative attitudes towards leopard cat conservation were most prevalent among farmers, who also reported the highest incidence of negative experiences, mainly involving predation of poultry. We provide recommendations to mitigate human–felid conflict, including changes to animal husbandry practices. We also describe how conservation efforts for this species and wildlife in general in Taiwan could be improved, for example through incentive and awareness-raising programmes.
Shoring up divine simplicity against modal collapse: a powers account
Authors: LENOW JOSEPH E. 
Published: February 2019

AbstractThis article defends a broadly Thomist understanding of the doctrine of divine simplicity from the objection that such a position inevitably leads to a modal collapse. To do so, it draws upon Barbara Vetter's recent dispositionalist account of modality, in which irreducibly modal multi-track powers are the truthmakers of modal claims. Conceiving of God's power on the analogy of these dispositional properties enables us to hold that the divine life is itself the truthmaker of modal truths, without requiring a real distinction between what is necessary and contingent in God that would compromise divine simplicity.
Grammatical thomism
Authors: HEWITT SIMON 
Published: February 2019

AbstractCentred on figures like Herbert McCabe, David Burrell, and Brian Davies the loose tradition known as grammatical thomism is undervalued within analytic philosophy of religion. This is particularly unfortunate, since a grammatical thomist approach offers the prospect of both a reorientation towards a more apophatic conception of God, consonant with the theology and practice of many religious traditions, and of moving beyond certain debates in the philosophy of religion. In this article, a grammatical thomist approach to the word ‘God’ is laid out: the conditions for introducing the word constrain its grammar, such that it cannot be understood as designating anything within our world. Accordingly inferential moves which we might otherwise find tempting are blocked. The result is an apophatic theology grounded in linguistic considerations. Objections against linguistic approaches to philosophy and theology, owing to Williamson and Murphy respectively, are considered and counter-arguments presented. The potential for therapeutic approaches to both the problem of evil and questions around theology and politics is then flagged.
Asymmetry and Non-Identity
Authors: Algander Per , Berndt Rasmussen Katharina 
Published: February 2019

AbstractIn this article we distinguish two versions of the non-identity problem: one involving positive well-being and one involving negative well-being. Intuitively, there seems to be a difference between the two versions of the problem. In the negative case it is clear that one ought to cause the better-off person to exist. However, it has recently been suggested that this is not so in the positive case. We argue that such an asymmetrical treatment of the two versions should be rejected and that this is evidence against views according to which it is permissible to cause the less well-off person to exist in the positive non-identity case.
Characterizing polynomial Ramsey quantifiers
Authors: de Haan Ronald , Szymanik Jakub 
Published: February 2019

AbstractRamsey quantifiers are a natural object of study not only for logic and computer science but also for the formal semantics of natural language. Restricting attention to finite models leads to the natural question whether all Ramsey quantifiers are either polynomial-time computable or NP-hard, and whether we can give a natural characterization of the polynomial-time computable quantifiers. In this paper, we first show that there exist intermediate Ramsey quantifiers and then we prove a dichotomy result for a large and natural class of Ramsey quantifiers, based on a reasonable and widely believed complexity assumption. We show that the polynomial-time computable quantifiers in this class are exactly the constant-log-bounded Ramsey quantifiers.