bluuebunny/crossref_metadata_2025 huggingface dataset:
The Intrinsic Stochasticity of the 56Ni Distribution of Single-degenerate Near-Chandrasekhar-mass SN Ia
Authors: Byrohl Chris , Fisher Robert , Townsley Dean
Published: June 2019

Although Chandrasekhar-mass white dwarfs (WDs) accreting mass from non-degenerate stellar companions through the single-degenerate channel have reigned for decades as the leading explanation of SNe Ia, a comprehensive theoretical explanation has not yet emerged to explain the expected properties of the canonical near-Chandrasekhar-mass WD model. A simmering phase within the convective core of the WD leads to the ignition of one or more flame bubbles scattered across the core. Consequently, near-Chandrasekhar-mass single-degenerate SNe Ia are inherently stochastic and are expected to lead to a range of outcomes, from subluminous SN 2002cx-like events to overluminous SN 1991T-like events. However, all of the prior simulations of the single-degenerate channel carried through the detonation phase have set the ignition points as free parameters. In this work, for the first time, we place a single ignition point as predicted by ab initio models of the convective phase leading up to ignition and follow through the detonation phase in fully three-dimensional simulations. Single-degenerates in this framework are characteristically overluminous. Using a statistical approach, we determine the 56Ni mass distribution arising from stochastic ignition. While there is a total spread of ≳0.2 M
⊙ for detonating models, the distribution is strongly left-skewed and with a narrow standard deviation of ≃0.03 M
⊙. Conversely, if single-degenerates are not overluminous but primarily yield normal or failed events, then our models require fine-tuning of the ignition parameters, or otherwise require revised physics or WD models. We also discuss the implications of our findings for the modeling of single-degenerate SNe Ia.
A New Generation of Cool White Dwarf Atmosphere Models. IV. Revisiting the Spectral Evolution of Cool White Dwarfs
Authors: Blouin S. , Dufour P. , Thibeault C. , Allard N. F.
Published: June 2019

As a result of competing physical mechanisms, the atmospheric composition of white dwarfs changes throughout their evolution, a process known as spectral evolution. Because of the ambiguity of their atmospheric compositions and the difficulties inherent to the modeling of their dense atmospheres, no consensus exists regarding the spectral evolution of cool white dwarfs (T
eff < 6000 K). In the previous papers of this series, we presented and observationally validated a new generation of cool white dwarf atmosphere models that include all the necessary constitutive physics to accurately model those objects. Using these new models and a homogeneous sample of 501 cool white dwarfs, we revisit the spectral evolution of cool white dwarfs. Our sample includes all spectroscopically identified white dwarfs cooler than 8300 K for which a parallax is available in Gaia DR2 and photometric observations are available in Pan-STARRS1 and 2MASS. Except for a few cool carbon-polluted objects, our models allow an excellent fit to the spectroscopic and photometric observations of all objects included in our sample. We identify a decrease of the ratio of hydrogen- to helium-rich objects between 7500 and 6250 K, which we interpret as the signature of convective mixing. After this decrease, hydrogen-rich objects become more abundant up to 5000 K. This puzzling increase, reminiscent of the non-DA gap, has yet to be explained. At lower temperatures, below 5000 K, hydrogen-rich white dwarfs become rarer, which rules out the scenario in which the accretion of hydrogen from the interstellar medium dominates the spectral evolution of cool white dwarfs.
A Pair of Planets Likely in Mean-motion Resonance From Gravitational Microlensing
Authors: Madsen Sabrina , Zhu 祝 Wei 伟
Published: June 2019

We combine statistical arguments and dynamical analysis to study the orbital configuration of the microlensing planetary system OGLE-2012-BLG-0026L. This system is known to host two massive planets, both projected close to the Einstein ring at the time of the detection. Assuming an isotropic distribution for the orbital orientation, we find that the two planets should also be closely spaced in 3D space and that the ratio of their orbital periods is almost certainly less than two. With N-body numerical integrations, we then identify two types of stable configurations: the two planets can be in first-order mean-motion resonances (MMRs) and have significant (≳0.1) eccentricities, or they stay out of MMRs and have nearly circular orbits. The latter is disfavored, given the absence of similar planet pairs in radial velocity observations as well as the theoretical difficulties in forming such a configuration. Therefore, the two massive planets in OGLE-2012-BLG-0026L are likely in a resonance configuration. Our work shows that the microlensing technique, which usually only measures the projected configurations, can also probe the detailed dynamical state of multi-planet systems. We also discuss theoretical implications of measuring the multiplicity and the orbital architecture of cold planets.
Hypothesizing novel mating behaviours in the squaretail grouper based on direct behavioural observations
Authors: Karkarey Rucha , Zambre Amod , Isvaran Kavita , Arthur Rohan
Published: June 2019

Historically unfished, high-density spawning aggregations are vanishingly uncommon. Behavioural observations from such aggregations are rare, and may be sometimes novel and unexpected. Given the weight of evidence required to document spawning aggregations, how can we best report rare and unusual behavioural variations in spawning populations? Based on two years of in-water observations of a high-density spawning aggregation of the squaretail grouper in the Lakshadweep Archipelago, we described a previously unreported male alternative reproductive tactic (ART) and an inverse size assortment with large males courting several small females that shoaled mid-water (https://doi.org/10.1186/s12898-017-0120-5). In critiquing our manuscript, it has been suggested that our observations, methodologies and interpretation are inadequate, flawed, and do not fit within currently accepted theory (https://doi.org/10.1186/s12898-018-0206-8). While offering a detailed counter of the main methodological and theoretical criticisms we question how best to document and interpret novel behaviours in poorly known systems. Reporting novelty itself can hardly be the basis of criticism. Our report relied on direct in-water observations, conducted at peak densities over two spawning years. The critique ignores this, choosing instead to focus on a supplementary video which was not the basis of our conclusions. Like other researchers working on this species, we did not directly observe mating, but report courtship as a well-established proxy used across mating systems studies. Apart from these methodological concerns, the authors suggest that there is no theoretical support for our observations. However, sexual selection theory provides well-established frameworks showing that, at very high mating densities, a variety of tactics can emerge, that often vary considerably between populations and locations. In our original paper, we use this broader theory of sexual selection together with detailed behavioural data to propose plausible evolutionary explanations that bear testing in these novel, high-density systems. We agree with the authors that novel observations should be scrutinised carefully as they can challenge our current understanding of the range of behaviours populations display and serve as a springboard for theoretical advancement. Given their rarity, these observations should be evaluated against the rigour of their documentation and the transparency of their reporting. In this context, we hope our carefully documented observations serve as a useful addition to the fascinating and complex natural history of species like the squaretail grouper.
A History of Asylum in Kenya and Tanzania: Understanding the Drivers of Domestic Refugee Policy
Authors: Milner James
Published: June 2019

Comment comprenons-nous les moteurs de la politique intérieure en matière de réfugiés dans les États africains ? Cet article s’appuie sur les cas du Kenya et de la Tanzanie pour affirmer que les modifications apportées à la politique d’asile des deux États résultent principalement de facteurs internes, souvent sans lien avec les réfugiés. Tandis que des facteurs internationaux, comme la réaction de la communauté internationale à l’arrivée massive et à la présence prolongée de réfugiés, ont contribué aux réponses politiques, d’autres, telles que la démocratisation et la libéralisation économique, ont joué un rôle plus central. Cette analyse suggère des enseignements importants pour l’engagement futur en matière de protection et des solutions pour les réfugiés dans le contexte africain.
Documenter les pays d’origine pour les procédures d’asile à l’Ofpra, 1988-2008
Authors: Rosset Damian
Published: June 2019

À la fois type spécifique de savoir et registre particulier de pratiques, l’information sur les pays d’origine (COI/Country of Origin Information) est considérée comme un outil fondamental de la détermination du statut de réfugié. Cet article se penche sur l’institutionnalisation de la documentation sur les pays d’origine au sein de l’Ofpra entre 1988 et 2008 et montre comment cette histoire renvoie à celles de l’institution, de la communauté COI et de l’européanisation des procédures d’asile.
Une victoire opportune
Authors: Astruc Clément
Published: June 2019

En 1970, le Brésil remporte pour la troisième fois la Coupe du monde de football. Partant de l’étude de cet événement, cet article questionne le rôle de ce sport dans la construction de la visibilité et des représentations de ce pays à l’étranger. Fondée sur des archives diplomatiques et des sources de presse, cette recherche envisage également la potentielle utilisation du football comme outil de politique extérieure pendant les « années de plomb » de la dictature brésilienne.
L’illisibilité du paysage
Authors: Zhong Mengual Estelle , Morizot Baptiste
Published: June 2019

Quels liens entretiennent la crise écologique actuelle et l’esthétique environnementale ? Ce que nous nous proposons de suivre comme piste, c’est que la crise écologique constitue aussi une crise de la sensibilité – une crise de notre sensibilité à l’égard du vivant. Par crise de la sensibilité, nous entendons un appauvrissement de ce que nous pouvons sentir, percevoir, comprendre, et tisser comme relations à l’égard du vivant. Cet article tente d’esquisser la généalogie, à travers la philosophie et l’histoire de l’art, d’un motif central de cette crise, profondément ancré dans notre cosmologie et notre histoire culturelle : l’idée d’une illisibilité et insignifiance du monde vivant.
Y a-t-il une esthétique de la protection de la nature ?
Authors: Larrère Catherine
Published: June 2019

Dans le souci de protéger la nature, sa beauté a toujours joué un rôle important. Cette appréciation esthétique est-elle demeurée la même ? L’intérêt de la réflexion d’Aldo Leopold, qui a développé une éthique de la protection de la nature dirigée par des connaissances scientifiques, mais également soucieuse du beau, est d’éclairer cette esthétique de la protection de la nature et d’en montrer les changements et les enjeux. Mais si l’esthétique léopoldienne se révèle en accord avec les principes développés par la récente théorie esthétique des environnements naturels, sa convergence avec certaines formes du Land art , conduit à réexaminer la condamnation de toute esthétique paysagère portée par certains théoriciens. Ce qui est en cause, finalement, c’est l’autonomie de l’esthétique, de quelque façon qu’on la conçoive.
Esthétique de la charogne : Aristote, père de l’esthétique cognitive ?
Authors: Afeissa Hicham-Stéphane
Published: June 2019

Le propos de cet article est tout d’abord de démontrer que l’esthétique élaborée par Aristote dans la Poétique est une esthétique cognitive. Pour ce faire, nous mettrons au centre de notre attention un extrait du chapitre IV, dont nous donnerons un commentaire linéaire. Le point qui nous paraît décisif concerne le passage où il est fait mention de « formes d’animaux parfaitement ignobles et de cadavres », dont nous nous efforcerons de montrer qu’il contient in nuce les éléments principaux d’une esthétique de la charogne. C’est par ce biais que nous nous proposerons, en un second temps, de rattacher l’esthétique aristotélicienne au courant d’esthétique environnementale. Nous proposerons en conclusion de chercher chez Aristote des indications et des arguments pour l’élaboration d’une variante originale d’esthétique de l’environnement.
Consommateurs vulnérables et satisfaction associée aux services publics : le pays a-t-il une importance ?
Authors: Clifton Judith , Díaz Fuentes Daniel , Fernández-Gutiérrez Marcos
Published: June 2019

L’administration publique s’intéresse aujourd’hui davantage aux « citoyens vulnérables » qui, pour des raisons qu’ils ne maîtrisent pas, sont désavantagés par rapport aux autres citoyens lorsqu’ils consomment des services publics. Les premières recherches se sont concentrées sur la manière dont le niveau socio-économique des citoyens conditionne leur comportement et leur satisfaction. Ces derniers prennent leurs décisions dans un contexte donné mais nous savons peu de choses sur la manière dont leurs expériences varient en fonction de leur pays de résidence. Nous comparons les expériences des citoyens vulnérables sur les marchés des télécommunications et de l’énergie de trois grands pays de l’Union européenne, choisis pour représenter chacun d’eux un stade d’avancement des réformes : « pays avancé », « pays intermédiaire » et « pays en retard ». Nous établissons dans un premier temps que les caractéristiques socio-économiques expliquent des choix de dépenses et la perception de l’accessibilité financière des services. Nous montrons ensuite de quelle manière la vulnérabilité des citoyens varie en fonction du pays. Les résultats obtenus sont utiles aux praticiens cherchant à déterminer quelle réglementation peut améliorer l’expérience des citoyens vulnérables. Remarques à l’intention des praticiens Les praticiens reconnaissent que la réforme des services publics s’est accompagnée d’une complexité et d’un choix accrus et que cela pose des problèmes pour les citoyens, en particulier pour les plus vulnérables d’entre eux. Les premiers travaux empiriques ont montré que le niveau socio-économique des citoyens a une incidence sur leur degré de satisfaction. Toutefois, nous savons peu de choses sur la manière dont le pays joue un rôle dans cette vulnérabilité. Nous analysons ici les marchés de l’électricité et des télécommunications dans trois grands pays de l’Union européenne et montrons que le niveau socio-économique conditionne les dépenses des citoyens et la perception qu’ils ont de l’accessibilité financière des services, avant de montrer que le pays a lui aussi une influence sur ces expériences. Les citoyens moins formés, âgés ou sans emploi rencontrent plus souvent des difficultés avec ces services que les autres citoyens, le pays de résidence jouant à cet égard un rôle significatif.
Gouvernance mondiale des risques. Quel rôle pour les administrations publiques : le paradigme des systèmes de contrôle et d’alerte de l’U.E. en matière de sécurité alimentaire
Authors: Iurato Andrea
Published: June 2019

Cette étude traite des questions cruciales que soulève la multiplication des systèmes supranationaux de gouvernance des risques, qui recherchent un compromis entre la nécessité d’une gouvernance efficace et celle de ne pas entraver les échanges commerciaux. Dans de tels contextes, les administrations publiques nationales deviennent des modules périphériques dans des systèmes à plusieurs niveaux, dans lesquels leur organisation est modifiée et la légitimité de leur action remise en question. Nous analysons ici le paradigme des systèmes de contrôle et d’alerte rapide de l’U.E. en matière de sécurité alimentaire et tentons de répondre aux questions suivantes : comment faire en sorte que les administrations publiques aient un rôle efficace sur la scène mondiale ? Les administrations nationales sont-elles vouées purement et simplement à mettre en œuvre des règles définies à un niveau supranational ? Les résultats montrent l’efficacité de systèmes juridiques à haut niveau d’intégration, avec l’introduction d’un nouveau modèle de gouvernance mondiale où la souveraineté nationale se verrait confier un nouveau rôle, et non réduite, et où la réalisation d’objectifs fixés au niveau supranational serait garantie et l’autonomie des administrations publiques nationales préservée. Remarques à l’intention des praticiens Il n’est pas rare que les praticiens, en particulier ceux qui occupent des postes de direction, se trouvent désorientés lorsqu’ils interviennent dans un contexte à plusieurs niveaux, d’une part parce que leur autonomie est réduite et d’autre part, parce que des règles et des contrôles externes s’imposent à eux. En partant de l’analyse du paradigme choisi, les praticiens pourraient trouver que, dans un système de régulation à plusieurs niveaux qui fonctionne bien, les administrations publiques nationales sont en mesure d’utiliser la marge de manœuvre qui leur reste – même si elle est minime – pour créer des modèles organisationnels novateurs, sans aucune intervention directe des niveaux supérieurs, un modèle à reprendre et à appliquer dans tout le système.
L’émergence des initiatives post-NMP : l’évaluation d’impact intégrée comme un outil hybride d’aide à la prise de décision
Authors: Marchand Jean-Sébastien , Brunet Maude
Published: June 2019

Le Nouveau Management Public (NMP) tend à persister malgré les critiques. Les initiatives post-NMP demeurent assez théoriques et tardent à s’implanter au cœur de l’appareil gouvernemental. L’évaluation d’impact intégrée (EII), un outil d’aide à la prise de décision au niveau national, semble apporter des réponses nouvelles. L’EII s’est développé à partir des initiatives d’allègement règlementaire du NMP, mais ses objectifs et effets concordent davantage avec les principes post-NMP. Cet article vise à situer le concept de l’EII, son développement et les implications de son institutionnalisation. Une analyse comparative de la pratique de l’EII est effectuée pour quatre approches : trois au niveau national (France, Royaume-Uni et Suisse) et une au niveau supranational (Commission européenne). L’EII apparait comme un outil hybride NMP et post-NMP, dont l’utilisation permet la mise en pratique de certains principes post-NMP. L’article conclu sur des pistes de recherche futures. Remarques à l’intention des praticiens Les administrations doivent souvent composer avec les problématiques liées à la prise de décision basée sur des données probantes, la transparence et la multiplication des évaluations d’impact sectorielles statutaires. Dans un contexte de ressources limitées, l’évaluation d’impact intégrée (EII) peut représenter une réponse attrayante. Or, une meilleure compréhension de son développement permet de mieux saisir les enjeux de son institutionnalisation. La pratique de l’EII permet de systématiser la consultation des parties prenantes, mais varie en fonction des méthodes utilisées et des structures administratives en place. L’EII pourrait s’avérer un outil d’aide à la prise de décision permettant d’ajouter une composante d’intérêt public et de refléter davantage les valeurs publiques d’une situation décisionnelle.
L’influence de la communication des risques sur l’acceptation des politiques relatives aux installations à haut risque en Corée du Sud, et plus particulièrement les effets médiateurs de la perception des risques
Authors: Lee Dae-Woong , Kwon Gi-Heon
Published: June 2019

Le développement technologique continu a donné naissance à un nouveau type de risque pour la vie humaine : ce que l’on appelle aujourd’hui le « risque social ». Les idées sur le risque sont de plus en plus axées sur le risque subjectif plutôt qu’objectif. Ce changement est clairement observable dans le cas des politiques de localisation des installations d’énergie nucléaire. La population sud-coréenne se méfie souvent des nouvelles installations énergétiques ; par exemple, dans le cas de l’énergie nucléaire, elle se méfie du risque d’exposition involontaire à des rayonnements dangereux, qui ne peuvent être contrôlés efficacement. C’est pourquoi le gouvernement sud-coréen discute en permanence des moyens d’accroître l’acceptation de ces installations à haut risque en gérant la perception des risques par le public. La question de recherche était la suivante : « La stratégie de communication des risques du gouvernement coréen a-t-elle un impact positif sur la perception des risques et l’acceptation des politiques par le public ? ». Dans la présente étude, nous avons cherché à savoir si la communication des risques contribue à accroître l’acceptation du public à l’égard des installations à haut risque. Nous avons utilisé un modèle d’équation structurelle et des analyses de groupes multiples pour l’analyse empirique. Notre étude explore les perspectives gouvernementales en termes d’insécurité et de conflits causés par les progrès scientifiques et les perceptions incertaines du public à l’égard des installations à haut risque, comme les centrales nucléaires. Notre étude fournit des résultats empiriques concernant la communication des risques et les implications pour les politiques publiques qui diminuent la perception des risques et augmentent l’acceptation de ces politiques. Remarques à l’intention des praticiens Dans la présente étude, nous tentons de déterminer si la communication des risques peut résoudre le problème de la faible acceptation par le public des installations à haut risque, sur la base de sa perception des risques. Notre étude contribue dès lors aux implications stratégiques concernant la communication des risques en tant que moyen de contrôler la perception des risques et d’accroître l’acceptation des politiques. Il est plus particulièrement essentiel d’élaborer des stratégies de communication des risques dans le cadre desquelles le public partage le processus décisionnel avec les organismes gouvernementaux et les fournisseurs d’énergie.
L’ambiguïté des objectifs organisationnels et l’engagement des cadres supérieurs : le capital social organisationnel fait-il une différence ?
Authors: Andrews Rhys , Sayed Mostafa Ahmed Mohammed
Published: June 2019

Le modèle Exigences – Ressources de l’épuisement professionnel souligne que les aspects de l’environnement de travail qui imposent des exigences élevées aux employés sont des facteurs de stress au travail, ce qui peut réduire leur niveau d’engagement envers leur travail et leur organisation. En revanche, le soutien social en faveur des travailleurs est une ressource qui peut promouvoir leur engagement et leur permettre de faire face à des exigences élevées. Nous analysons les effets distincts et combinés de deux exigences professionnelles et de deux ressources clés sur l’engagement de plus de 4000 cadres supérieurs du secteur public dans 10 pays européens : l’ambiguïté des objectifs organisationnels, qui peut démotiver les travailleurs, et le capital social organisationnel, qui peut les inciter à partager les connaissances de façon constructive. Les résultats statistiques suggèrent qu’il existe une relation négative entre l’ambiguïté des objectifs et l’engagement, et une relation positive entre le capital social et l’engagement. Une analyse plus poussée révèle que le capital social organisationnel affaiblit la relation négative entre l’ambiguïté des objectifs et l’engagement. Remarques à l’intention des praticiens La présente étude met l’accent sur l’importance du capital social organisationnel pour accroître l’engagement des cadres supérieurs. Les relations positives entre collègues de travail amènent les cadres supérieurs du secteur public à se sentir plus engagés dans leur travail et leur organisation, ce qui protège cet engagement des effets néfastes de l’ambiguïté des objectifs organisationnels. Les conclusions que nous présentons constituent donc une base solide pour l’introduction de politiques et de pratiques qui appuient le développement du capital social au sein des organismes publics.
Presse écrite et événement terroriste : routines narratives et émergence de la société civile (1995-2016)
Authors: Garcin-Marrou Isabelle , Hare Isabelle
Published: June 2019

The irruption of terrorism within the States of law undermines the social bond and democracy. In these days of the crisis created by violence, the media produce stories that allow the integration the event into the history of the society affected by the violence. The semiotic and discursive analysis of the newspapers published during the 1995-1996 (Paris) and 2015-2016 (Paris and Nice) attacks makes it possible to understand the evolution of media narratives and the emergence of civil society.
A Cognitive Assistant that Uses Small Talk in Tutoring Conversation
Authors: De Medeiros Luciano Frontino , Kolbe Junior Armando , Moser Alvino
Published: June 2019

This paper presents a cognitive conversational agent for use in teaching and learning processes named THOTH (Training by Highly Ontology-oriented Tutoring Host) that is capable of formulating and enunciating a well-defined set of small talk segments in a Q&A (Question and Answer) interaction. The small talk structures are placed within the tutoring conversation by an agent designed as a cognitive assistant, in order to make communication smoother and less formal, presenting a more “concerned” behavior. Twelve small talk segments are suggested, included in conversation stages such as opening and closing the conversation, maintaining the rhythm and managing learning. We also explore some branches of the theoretical assumptions and concepts grounding THOTH, such as Dennett’s intentional stance, Bloom’s taxonomy and microlearning theory. In order to measure the perception and effects of using THOTH, we performed a quantitative and qualitative study with a group of students from a course in Applied Artificial Intelligence over one semester. The outcomes are classified into two main categories of analysis – interactivity and intentionality – informing the discussion on the potential uses of a small talk agent as a valuable resource in tutoring interaction, and also raising some points for improvement. In addition to this study, we also drew a small talk profile for this group of students revealing what structures and topics they use the most, as well as a partial performance analysis that allows identifying some effects on learning.
Multitasking in Embedded System Designs
Authors: Mavrevski Radoslav , Traykov Metodi , Trenchev Iavn
Published: June 2019

It is common knowledge in Information Technology (IT) that an embedded system is based on microprocessor and is built to control a function or a range of functions. Although, it is not designed to be programmed by the end user in the same way that a PC is, it is designed to perform one particular task with choices and different options [1-5]. Multitasking is a method by which multiple tasks, also known as processes, share common processing resources, such as CPU. The main aim of this paper is analysis of the design of the embedded systems and a focus on mid-level abstractions for concurrent programs.
An Investigation of User Privacy and Data Protection on User-Side Storage
Authors: Al-rousan Thamer
Published: June 2019

Along with the introduction of HTML5, a new user storage technologies; particularly, Web SQL Database, Web Storage, and Indexed Database API have emerged. The common goal of these storage technologies is to overcome the limitations of legacy of user-side storage mechanisms. All these technologies have many privacy and security concerns, and the main threat is user tracking. In this context, this study investigates the usage of these technologies and to find out which one of these technologies is primarily used by user trackers, and to calculate their frequency in context of 3rd-party tracking code. The result exposes that the adoption of Web Storage most commonly used amongst the three storage technologies. Motivated by the investigation results, this study examines the degree of protection which the popular web browsers supply to prevent privacy violations. The result reveals that the protection mechanisms that are provided by web browsers are almost the same, and in many occasions privacy violations do exist
JAVA : ARTS AND REPRESENTATIONS. Art historical and Archaeometric Analyses of Ancient Jewellery (7–16th C.) : The Prillwitz Collection of Javanese Gold
Authors: Tjoa-Bonatz Mai Lin , Lockhoff Nicole
Published: June 2019

The Weltkulturen Museum in Frankfurt am Main holds the collection of gold and silver jewellery from the Classical period of Java acquired in 1913 from Conrad Ernst August Prillwitz. Archaeometric analyses of rings and earrings, including chemical and technological examinations, define the composition of the raw material and contribute information on the manufacturing processes and issues related to authenticity. The art historical approach reveals that the gold ornaments cover a wide span of time and allow new interpretations of motifs, chrono-typological markers and the assigning of historical terminology. Javanese goldsmiths used motifs on coins and intaglio which had already been disseminated during the 1st millennium from South Asia as models for their images on rings, but advanced to a high level of technical knowledge and decorative innovations, so much so, that its goldsmithing diverged greatly from other Asian regions from 7th to the early 16th century.
Pangolin, Rāma, and the garden in Laṅkā in the 9th century CE : A few notes on a symbolically powerful “anteater”
Authors: Jákl Jiří
Published: June 2019

In ancient Java, pangolin was a symbolically loaded animal. Its representations in Old Javanese literature and visual art are, however, rare. The pangolin is mentioned four times in the Kakawin Rāmāyaṇa, composed between the middle of the 9th and the first quarter of the 10th century CE. A pangolin is also represented in a narrative relief of Caṇḍi Śiva, in Prambanan, and a very large skeleton of pangolin was found interred under the Caṇḍi Nandi standing in front of the Śiva temple. This article tries to make sense of this sparse evidence, interpreting the pangolin of the Javanese court imaginaire as a military, apotropaic animal and a demon slayer. The natural characteristics of the pangolin, such as its scaly skin, and especially its diet, based almost exclusively on ants and termites – insects standing for adharma and demonic qualities in pre-Islamic Java – made pangolin a powerful “consumer” of demonic śakti – and hence an apotropaic animal.
A Study of Leadership Style on Employees' Performance in some Selected Private Universities in Ghana
Authors: Andoh Juliana Serwaa , Ghansah Benjamin
Published: June 2019

Evolving structures and systems in higher education institutions require leaders who can provide direction, implement plans, and motivate people towards greater performance that meets or surpasses organizational goals. The authors in this study sought to ascertain the relationship between leadership styles and job performance among academic staff working in three (3) selected private universities in Ghana. A sample size of 114 was drawn from a total population size of 160 staff from Data Link Institute, Fountainhead University College and Presbyterian University College. Stratified random sampling method was used to gather data from respondents. Using three different hypotheses that were stated and tested with linear regression and Pearson’s Product Moment Correlation, the study revealed that leadership styles have direct effect on job performance. In particular, democratic leadership style showed a significant impact on the employee’s performance while autocratic and laissez-faire leadership styles demonstrated less or no significant impact on the employee performance. The authors proceed to discuss the implications of the study by way theory, practice and future study. Additionally, we recommended among other things that the use of autocratic and laissez-faire leadership styles should be reduced in practice since they have the proclivity of stifling the overall organization performance.
Optimization of Biodiesel Production from Used Cooking Oil: Aspen HYSYS Simulation and Experimental Validation
Authors: Giwa Abdulwahab , Umanah Kenya Samuel
Published: June 2019

Due to the awareness of adverse effects of conventional fuels to environment and the frequent rise in crude oil price, the need for sustainable and environmentally friendly alternative source of energy has gained importance in recent years. This alternative has been identified to be biofuel, one of which is biodiesel. As such, this work was carried out to contribute to the development of biodiesel. The aim was accomplished by employing Design Expert, based on the chosen operating factors (reaction temperature and methanol-to-oil ratio), to design experiments carried out for the production of biodiesel using used cooking oil and methanol in the presence of alkaline catalyst. After carrying out the experiments using the design parameters generated, the results were analysed, and a model equation was developed for the system. Furthermore, the model equation was used to optimize the process using Excel Solver to obtain a temperature, a methanol-to-oil ratio and a yield of 63.45 °C, 3 and 59.32 as the optimum values, respectively. The optimum parameters estimated were validated experimentally and with the Aspen HYSYS model of the process that was also developed. The results obtained using the design factors showed that the factors considered were having effects on the yield of biodiesel. Also, the results of the experimental validation carried out with the optimum parameters obtained with the aid of Excel Solver were found to compare very well with those obtained from the simulation of the developed Aspen HYSYS model of the biodiesel production because the errors were estimated to be less than 5%. Therefore, the developed Aspen HYSYS model of biodiesel production of this work was able to represent the process very well and can be used for further studies on the process.
Preparation for Graphene Coated Polyvinyl Alcohol Based Conductive Fiber Containing Silver Nanowires
Authors: Xiao Chao , Xiong Xi Ke , Sun Jun , Dai Li Xing
Published: June 2019

Graphene oxide (GO) coated fiber via deposition of GO sheets on polyvinyl alcohol (PVA) fiber containing silver nanowires (AgNWs) was fabricated, and chemical reduction for GO on the fiber surface was carried out to obtain reduced GO (rGO) coated PVA-AgNWs (rGO/PVA-AgNWs) fiber. The results showed that the rGO sheets were closely adhered on the surface of fiber, the electrical conductivity of the fiber increased with coating times of GO, and the conductivity was high up to 2.05×10-3 S/m when GO was coated 3 times on the fiber and reduced. The synergistic effect of rGO and AgNWs for the conductivity was also clearly indicated.
Optimum Design of Reactive Sputtering Parameters on the Mechanical Property of C-Doped TiO2 Photocatalytic Films: CO2 as Carbon Source
Authors: Wei Bo , Li Hai Guang , Cao Hua Tang , Wen Feng
Published: June 2019

In this research, CO2 gas was used as carbon and oxygen source to prepare carbon-doped TiO2 (C-TiO2) films on stainless steel by reactive magnetron sputtering. In order to grasp the relationship between sputtering process, microstructure and mechanical and photocatalysis properties of C-TiO2 thin film, a orthogonal experiment design validated by following mechanical analysis and photo-degradation experiments was employed to determine the optimal reactive sputtering parameters, including substrate temperature, sputtering power and CO2 gas flow rate. nanoindentation and nanoscratch tests were employed to analyze the hardness, modules and adhesion strength of as-deposited C-TiO2 films, respectively. Taking the hardness, modules and adhesion between the film and the substrate as a reference of integrated mechanical properties, range analysis of as-prepared C:Ti-O films were done to search the optimal combination of sputtering parameters. The photocatalytic activities of as-prepared C-TiO2 films using methyl orange (MO) as colored dye indicator were also evaluated by measuring absorbance and calculating the MO’s decolorization rate under different UV light irradiation time. The results of photocatalysis experiment compared with a blank group proved that C-TiO2 films sputtered at the optimized reactive sputtering parameters can achieve both superior photocatalysis and mechanical properties.
Effect of Carbonate Substitution on the Biomineralization of Apatite Bulk and Coating
Authors: Zhu Qing Xia , Nie Quan Yi
Published: June 2019

In-vitro experiment method was used to study biomineralization properties of carbonate apatite bulk and electrophoresis coating with different carbonate contents. The mineralization processes in SBF solution were investigated by means of XRD, SEM and so on. Research results show that the apatite with poor crystallization and small grain size induced by the carbonate substitution is beneficial to the sintering of the bulk and the formation of the bone-like hydroxyl-carbonate apatite (HCA) layer on the surface after soaking in the SBF. However, the carbonate substitution greatly reduces the pore size and porosity of coating, which is not conducive to the deposition and growth of the mineralized layer, thus weakens the biomineralization properties of the coating.
The photoperiodic response to single nights suggests a rapidly damping oscillator in Trichogramma telengai (Hymenoptera: Trichogrammatidae)
Authors: Reznik Sergey Y. , Voinovich Natalia D.
Published: June 2019

It is known that diapause-inducing effect of ultra-long (16–18 hours and longer) nights on insects with a facultative winter diapause is often weaker than that of “natural” long (usually 10–14 hours) nights. The weak diapause-inducing effect of ultra-long nights can be explained, in particular, in the frames of the external coincidence model of photoperiodic time measurement with a circadian oscillator, which damps under ultra-long nights. Based on this model, it can be expected that (1) the first ultra-long night would have the same diapause-inducing effect as natural long night because the damping of the oscillator will not manifest itself before the next light–dark cycle and (2) the diapause-inducing effect would decrease with the increase in the number of succeeding ultra-long nights. However, these hypotheses have never been tested with any insect species. We investigated progeny diapause-inducing effect of single and multiple nights of different lengths onTrichogramma telengaiSorokina (Hymenoptera: Trichogrammatidae) pupae and adult females. The results of the study support the external coincidence model with a damping circadian oscillator and suggest that inT. telengaithe oscillator damps out after one or two cycles.
Performance Comparison Between Surface-mount and Embedded Power Modules
Authors: Weis Gerald
Published: June 2019

Increasing efficiency in power electronic circuits requires innovative cooling concepts and a low impedance connection in the power path as well as low inductance driving circuits placed as close as possible to the main power switches. A direct comparison between state-of-the-art standard surface-mount build-ups and power switches embedded directly into the printed circuit board shows the high potential of integrated electronics. Measurements at defined operating point(s) verify improved thermal performance due to more heat spreading area, as well as higher achievable switching speed.

For performance benchmarking two similar versions of half bridge circuits in DC-DC buck configuration were built to be compared in measurement. The first configuration uses standard, state-of-the-art SMD packages assembled onto the module. For the second half bridge module an embedded power path was used: The power transistors (GaN HEMT devices) are mounted inside the printed circuit board (PCB) and galvanically isolated from the heat sink pad on top of the package.

Both versions use exactly the same schematic, layer stack-up and copper structure on the six layers used. A slightly different laser drill configuration was necessary because embedded parts are connected by copper filled laser drill holes. This measure was taken to optimize the modules according to their technology. Each module has an NTC thermistor mounted at the same distance to the half bridge transistors, and is used to indicate the temperature of the transistor dies during measurement.

To cover a wide range of operational conditions the devices under test (DUTs) were stressed under hard switching operation (HSW) as well as triangular current mode (TCM). HSW causes more stress because the opposite transistor is switched before the whole energy of Coss has been discharged. In TCM the current through the inductor is becoming negative for a short time period and discharges the Coss capacitors of the power transistors.

The test conditions were set as follows: 150V, 11A with 200kHz switching frequency in HSW mode. The switching behavior is similar, because both modules uses the same power transistors. Due to less parasitic impedance at the embedded module the turn-on behavior is slightly improved at the embedded module.

Embedding as a new, innovative concept is compared to standard technologies. First measurements show that the embedded DUT stays 20K below the temperature of the standard module while running at the same load current. Additionally fewer disturbances were observed at the embedded module.
Ancestral beliefs in modern cultural and religious practices – The case of the Bapedi tribe
Authors: Lebaka Morakeng E.K.
Published: June 2019

There is no consensus among scholars of myth as to how the central concept of their field should be defined. What is a ‘myth’ and how does it differ from a ‘belief’? Moreover, scholars have argued for a homological relationship between myth and ritual. Semantically, the word ‘myth’ has a connotation of disbelief in ‘superstition’, and the word ‘belief’ should be substituted when talking about religious practices. Likewise, the word ‘ritual’ may be substituted with ‘ceremonial’, which has connotations that are more positive. Earlier publications that associate ancestral veneration with the words ‘myth’ or ‘superstition’ display a judgemental view of the beliefs of other cultures. In this article, the author attempts, via recourse to the use of the word ‘myth’, to describe and interpret traditional and cultural belief systems among the Bapedi people of Limpopo Province in South Africa. It is argued that myth should not be reduced to ritual nor ritual to myth. Belief and ritual, in Bapedi religion and belief systems, complete and complement each other, thus allowing the harmonious unison of meta and paralinguistic elements in religiocultural discourse. The focus of this study is to explore and document these links within the context of the Bapedi culture.
Peripartum HIV infection in very low birth weight infants fed ‘raw’ mother’s own milk
Authors: Coetzee Melantha , Delport Suzanne D.
Published: June 2019

Background: HIV-exposed very low birth weight (VLBW) infants (≤ 1500 g) are considered at high risk of peripartum mother-to-child HIV transmission (MTCT). In the past, they received formula to prevent breast milk related HIV transmission. This denied them the benefits of breast milk, thus exposing the infant to the risk of necrotising enterocolitis (NEC). From 2010, ‘raw’ mother’s own milk (rMOM) has been recommended for term infants whose mothers’ received antenatal antiretroviral therapy (ART). At the same time, the infant received antiretroviral (ARV) prophylaxis as per the National Prevention of MTCT programme.Objectives: To determine the cumulative incidence of peripartum HIV infection by 4–6 weeks of age in HIV-exposed VLBW infants, who received rMOM and infant ARV prophylaxis.Method: A retrospective, observational audit over 3 years at a single institution was undertaken. The study population comprised HIV-exposed VLBW infants who received both nevirapine prophylaxis and rMOM from birth until discharge. A positive HIV-PCR by 4–6 weeks of life was used to confirm maternal to infant HIV transmission.Results: Of the 80 eligible infants admitted between 2010 and 2013, 63 (79%) were exposed to antenatal ART. Seventy-eight (97.5%) tested HIV-PCR negative at 4–6 weeks. Of the two infants who tested positive, both presented with features of an acute HIV infection. The absence of MTCT in the remaining 78 infants given ARV prophylaxis and rMOM suggests that rMOM is an unlikely source of infection in the two infected infants.Conclusion: rMOM, in the presence of infant prophylaxis, was a safe feeding option for HIV-exposed VLBW infants. It should be strongly considered for these infants, as rMOM likely provides additional maternal and child benefits.
Effectiveness of Occupational Therapy Interventions for Adults With Systemic Lupus Erythematosus: A Systematic Review
Authors: Poole Janet L. , Bradford Joshua D. , Siegel Patricia
Published: June 2019

OBJECTIVE. Our objective was to assess the efficacy of occupational therapy–related interventions for adults with systemic lupus erythematosus (SLE).

METHOD. We reviewed intervention studies published from 2000 to 2017. The method used for conducting the review was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PEDro scale was used to evaluate methodological quality. Risk of bias was appraised with methods described by the Cochrane Methods Group.

RESULTS. The final analysis included 20 studies (10 physical activity and 10 psychoeducational). Moderate evidence supports physical activity to improve depression, fatigue, exercise tolerance, and function without exacerbation of disease symptoms. Strong evidence supports psychoeducational interventions using cognitive–behavioral approaches to improve pain, depression, anxiety, perceived stress, quality of life, and function. Moderate evidence supports patient education and self-management interventions for pain, depression, anxiety, perceived stress, quality of life, and function.

CONCLUSION. Further research on occupation-based interventions for people with SLE is needed.
Trapping of HCl and oxidized, organic trace-gases in growing ice at temperatures relevant for cirrus clouds
Authors: Kippenberger Matthias , Schuster Gerhard , Lelieveld Jos , Crowley John N.
Published: June 2019

Abstract. The uptake of hydrochloric acid (HCl), ethanol (C2H5OH), 1-butanol (1-C4H9OH), formic acid HC(O)OH and tri-fluoro acetic (CF3C(O)OH) acid to growing ice surfaces was investigated at temperatures between 194 and 228 K. HCl displayed extensive, continuous uptake during ice growth, which was strongly dependent on the ice growth velocity, the temperature of the ice surface and the gas phase concentration of HCl. Tri-fluoro acetic acid was also observed to be trapped in growing ice, albeit approximately an order of magnitude less efficiently than HCl, whereas the adsorption and desorption kinetics of ethanol, 1-butanol, formic acid on ice was not measurably different to that for non-growing ice, even at very large ice-growth rates. We present a parameterisation of the uptake coefficient for HCl on growing ice films (gamma_trap) and compare the results to an existing framework that describes the non-equilibrium trapping of trace gases on ice. The trapping of HCl in growing ice crystals in the atmosphere is assessed and compared to the gas- and ice-phase partitioning resulting from equilibrium surface adsorption and solubility.