bluuebunny/crossref_metadata_2025 huggingface dataset:
À quoi sert le droit de l'environnement ? Plaidoyer pour les droits de la nature
Authors: Bourg Dominique
Published: December 2019

Quel est le bilan d'un demi-siècle de protection de l'environnement ? Telle est la question dont part cet article. Or ce bilan, que l'on se tourne vers les rapports du GIEC (Groupe d'experts sur l'évolution du climat) ou ceux de l'IPBES (Plate-forme sur la biodiversité et les écosystèmes) ou encore vers l'état planétaire des ressources, est catastrophique. Il y a donc un problème. La réponse proposée est de changer de paradigme et de construire un droit de la nature. Sont exposées des raisons philosophiques fondamentales, en lien avec l'entrée dans l'Anthropocène, en faveur d'un tel changement.
Des procès pour renforcer l'effectivité du droit de l'environnement
Authors: Hautereau-Boutonnet Mathilde , Truilhé Eve
Published: December 2019

Le droit de l'environnement fait l'objet de critiques régulières quant à son effectivité. Si, pour y remédier, il est souvent prôné d'opérer des réformes concernant le droit substantiel, il convient aussi d'observer de plus près les règles processuelles, tant elles peuvent jouer un rôle dans l'ouverture et le déroulement du procès et, in fine , contribuer à l'application du droit de l'environnement. Ce sont ces dernières règles qu'un groupe de recherche, avec le soutien de la Mission de recherche Droit et Justice, ont observé de plus près. S'intitulant « Le procès environnemental : du procès sur l'environnement au procès pour l'environnement », la recherche a conduit à l'élaboration d'un rapport contenant certaines propositions ( http://www.gip-recherche-justice.fr/publication/le-proces-environnemental-du-proces-sur-lenvironnement-au-proces-pour-lenvironnement/ ). Cette contribution propose de mettre en évidence la méthodologie qui sous-tend ces propositions, fruit d'un équilibre entre le "techniquement possible", "juridiquement réalisable" et "politiquement souhaitable".
Procès climatiques : le magistrat (à nouveau) au cœur du droit
Authors: Papaux Alain
Published: December 2019

Les procès climatiques se fondent souvent sur les Principes généraux, lesquels, de par leur nature vague, délèguent de facto la substance du droit de l'environnement au magistrat dont la parole devient alors quasi existentielle. Pareille gravité s'entend déjà dans « pollution » désignant, à l'origine, la profanation du sacré ; dans sa parole résonne alors toute une anthropologie des droits humains menacée par les « actions par omission » de l'homme lui-même. Elle ravive aussi le ressort sacré du politique : l'auto-fondation des institutions, à la J.-J. Rousseau. Mais l'entrée en Anthropocène l'oblige à reconfigurer la liberté.
Un tribunal pour juger les crimes de Daech ?
Authors: Karopkin Martin
Published: December 2019

Cet article propose une solution pour juger les crimes de Daech inspirée des chambres extraordinaires des tribunaux cambodgiens dont l'auteur a fait partie en tant que magistrat. Il évoque les différents points de cette participation internationale (accusation, défense, financement...) mais aussi les obstacles qui s'y opposent, en particulier, l'existence de la peine de mort dans la législation irakienne actuelle applicable aux crimes de terrorisme.
L'indépendance de la justice au Sénégal
Authors: Teliko Souleymane
Published: December 2019

Malgré la constitution sénégalaise de 1963 qui consacre le principe de l'indépendance du « pouvoir judicaire », force est de constater qu'en réalité il n'en est rien. Le pouvoir exécutif domine le Conseil supérieur de la magistrature et reste le chef du parquet d'un double point de vue fonctionnel et statutaire. Cet article fait des propositions afin de renforcer l'indépendance de la justice : autonomie plus grande du CSM, statut du parquet rénové, gestion des juridictions mieux adaptées à leurs besoins sont ses thèmes principaux de réforme.
Introduction. Les catégorisations des publics minorisés en questions
Authors: Laplanche-Servigne Soline , Sa Vilas Boas Marie-Hélène
Published: December 2019

Cet article a pour objectif de faire dialoguer les travaux relatifs à la démocratie participative et délibérative avec la sociologie de la catégorisation. Il se centre sur l’étude d’espaces participatifs réunissant des groupes minorisés sur la base du genre, de l’ethnicité, de la classe ou de la sexualité. Il examine d’abord la circulation des catégorisations de minorisés entre différentes scènes et leurs usages en situation dans les espaces participatifs. Il interroge ensuite les modalités de la représentation des minorisés induites par ces catégorisations de la participation. Il s’achève par l’évocation de la nature des revendications et des publics parvenant à émerger des expériences participatives des minorisés.
(Faire) participer en tant qu’indigènes. Gouvernement et contestation dans les usages de la consultation en Amazonie – Pérou
Authors: Buu-Sao Doris
Published: December 2019

À partir d’une ethnographie de la « consultation préalable » au Pérou, cet article interroge l’ambivalente ethnicisation de dispositifs participatifs destinés aux groupes « indigènes ». Il analyse dans un premier temps le rôle joué par la consultation préalable dans le système péruvien de gestion des conflits sociaux ciblant les groupes indigènes, à travers la production de catégories ethno-raciales neutralisées. Dans un second temps, il souligne la capacité des participant·e·s à repolitiser ces catégories, en fonction des socialisations à l’action contestataire qui les caractérisent. Mais celles-ci restent inégales d’une personne à l’autre, conduisant à mieux saisir la force pacificatrice de la consultation préalable, qui a finalement marginalisé les plus réfractaires aux catégories prescrites par le format consultatif.
Les freins à la participation des populations précaires. Comment une association façonne les identifications collectives
Authors: Arnal Caroline , Haegel Florence
Published: December 2019

Cet article questionne les ressorts et les freins à la participation des personnes précaires. Il s’appuie sur une enquête de terrain menée dans une association de solidarité et se centre sur la construction des identifications collectives des personnes accompagnées. Il souligne le rôle de l’association dans le façonnage de ces identifications ainsi que leur fragmentation. Ensemble, ces deux mécanismes rendent difficile une prise de parole collective. Il insiste enfin sur la manière dont émerge rarement une parole collective en posant la question des responsables de la pauvreté.
Hypnose, activation de conscience et nouvelles solutions thérapeutiques des addictions : aspects neurobiologiques
Authors: Suarez Bruno
Published: December 2019

Dans cet article, nous verrons comme le cerveau des adolescents, encore en cours de développement, présente une vulnérabilité accrue lors de la prise de drogue. Cependant, nous ne sommes pas tous égaux face aux addictions. Le mécanisme de dépendance repose sur des modifications subtiles du connectome cérébral et de la plasticité synaptique de certains neurones que nous détaillerons. Nous verrons également l’implication du cervelet dans les conduites addictives. L’hypnose peut permettre de remettre de la souplesse dans les neurones et de remettre le corps en mouvement. Il nous a paru intéressant de simplifier et de moderniser l’hypnose eriksonienne pour la rendre conforme aux données de la neuroscience. Enfin, nous verrons que de nouvelles solutions thérapeutiques se basent aujourd’hui sur des programmes sportifs, éducatifs et nutritionnels et montrent de bons résultats dans le domaine des addictions.
Prescription de cannabis à usage thérapeutique pour les personnes âgées atteintes de démence : l’engouement des proches aidants
Authors: Revol Aurélie
Published: December 2019

Fin 2017, au sein d’un Établissement Médico-Social (EMS) genevois spécialisé dans l’accueil de personnes âgées atteintes de troubles cognitifs sévères, débute une étude clinique pilote. Cette étude inclut douze résidents pour lesquels du cannabis thérapeutique est prescrit. Au-delà de l’observation des effets médicaux, un volet sociologique vise à comprendre la manière dont les proches aidants perçoivent ce nouveau traitement. Dans un contexte de souffrance de l’accompagnement, l’espoir d’un mieux-être suscite une grande adhésion de la part des familles. Les attentes positives à l’endroit du cannabis thérapeutique reposent aussi bien sur la familiarité avec le produit, son côté naturel par opposition aux médicaments synthétiques, que sur l’encadrement médical et la confiance accordée à l’institution.
Research and industrialisation ofHermetia illucens L. in China
Authors: Zhang J.B. , Tomberlin J.K. , Cai M.M. , Xiao X.P. , Zheng L.Y. , Yu Z.N.
Published: December 2019

The larvae of the black soldier fly (BSF),Hermetia illucens L., are commonly associated with decaying organic wastes. Over the past 15 years, investigators in China have conducted extensive research exploring the use of BSF larvae to recycle organic materials as a means to protect the environment, while producing products of value, such as protein and bioenergy. Initial efforts were based on a BSF strain from the USA. However, since then,H. illucens strains from specimens collected in Hubei and Guangdong Provinces have been established and used as models to explore the use of this species in sustainable agriculture. China has played an instrumental role in developing an in-door breeding method using a quartz-iodine lamp rather than depend on natural sunlight. This discovery has allowed the establishment of in-door BSF colonies in regions throughout the world where abiotic conditions (i.e. cold temperatures) are preventative. Researchers in China paved the way for using microbes as a means to enhance BSF production including, enhancing BSF egg-laying as well as waste reduction. Furthermore, bacteria from BSF gut or waste can be cultured and used to promote BSF growth, shorten conversion time, and enhanced conversion efficacy. Recent efforts have demonstrated BSF larvae can degrade antibiotics as well as suppress noxious odours in livestock manure. Due to the efforts of research on BSF in China, numerous companies that recycle organic waste at a large scale (>20 tonnes waste digested/day), have been established. Resulting products include insect powder, and live BSFL that can be used as animal feed ingredients for livestock (e.g. eels and frogs), while protecting the environment. Future work will decipher the mechanisms regulating BSF larval conversion of organic waste so that the system can be optimised. However, efforts are still needed at the government level to establish quality assurance standards if this process is truly to become established as an industry in China.
The proof is in the cricket: engaging with edible insects through action research
Authors: Seekings T.B.W. , Wong K.C.
Published: December 2019

This paper describes an ongoing research project conducted at the College of Environmental Studies at National Dong Hwa University, Taiwan. It discusses the merits of action research for conducting interdisciplinary research on edible insects and advancing the edible insects sector in Taiwan. In this study, action research has facilitated the growth and continuous improvement of a cricket farm and exploratory studies on feeding crickets using food waste and snails as well as application of turtle vine for water provision. Furthermore, action research facilitated the emergence of actions during which the farmed crickets were prepared as food in educational contexts, together with participants. Initially this occurred in informal settings. Subsequently, as the scope of actions expanded and the number of involved people increased, participants were instrumental in conceiving larger-scale and more formal interventions such as classes, workshops, and food stalls. The findings suggest that public participation can be a strong driver for advancing the edible insects sector. While there are barriers towards acceptance of edible insects in Taiwan that are comparable to those faced in Western countries, there are also unique opportunities. For example, whole insects might be more acceptable in Taiwan than in Western countries. In addition, the value of increasing acceptance through active engagement of participants in preparing crickets as food in a social context was highlighted. In the absence of an engaged local scholarly network, an existing community of practice, or well-funded and proactive research institutions, action research offers a useful paradigm for individual researchers to explore multiple aspects of edible insects research and thereby aid in advancing the edible insects sector.
The Role of Social, Economic, and Physical Environmental Factors in Care Planning for Home Health Care Recipients
Authors: Irani Elliane , Hirschman Karen B. , Cacchione Pamela Z. , Bowles Kathryn H.
Published: December 2019

Social, economic, and environmental factors contribute to patients' recovery following hospitalization. However, little is known about how home health nurses make decisions based on their assessment of these factors. The purpose of the current study was to explore the nonclinical factors that home health nurses evaluate and describe how these factors influence care planning decisions. Semi-structured interviews conducted with 20 visiting nurses from three home health agencies were analyzed using conventional content analysis. Three nonclinical factor themes emerged:
Social Support
,
Home Environment and Neighborhood
, and
Finances and Insurance Barriers
. Nurses' assessments guided them to include family caregivers in the plan of care, evaluate their own safety to complete home visits, and refer patients to useful resources. Findings highlight the role of home health nurses in supporting older adults with limited resources and the need to address the social determinants of health across the care continuum. [
Research in Gerontological Nursing, 13
(3), 130–137.]
Feasibility of Diabetes Self-Management Telehealth Education for Older Adults During Transitions in Care
Authors: Whitehouse Christina R. , Long Judith A. , Maloney Lori McLeer , Daniels Kimberly , Horowitz David A. , Bowles Kathryn H.
Published: December 2019

The current study investigated the feasibility of telehealth-delivered diabetes self-management education and support (DSMES) for older adults with type 2 diabetes mellitus following hospital discharge. The intervention included one in-person home visit and follow-up weekly virtual DSMES for 4 additional weeks. Diabetes knowledge was measured at baseline and completion of the program. The Telehealth Usability Questionnaire was completed following the final session. Hemoglobin A1C (A1C) level was abstracted from the electronic health record at baseline and 3 months post hospital discharge. Hospital re-admissions were measured at 30 days post index hospital stay. Of the 20 patients enrolled, 12 completed the intervention. The most common reason for attrition was discharge to a skilled nursing facility (3/20). Participants who completed the intervention increased their diabetes knowledge scores. A1C values decreased by 1.1%, and there were no hospital readmissions for any patient who completed the program. Participants described the program as useful and were satisfied with the program. These results suggest that it is feasible to identify and enroll patients in a telehealth education program for diabetes during hospital admission. [
Research in Gerontological Nursing, 13
(3), 138–145.]
La movilidad social de las naciones extranjeras en las ciudades andaluzas bajomedievales: los Adorno y la sociedad política de Jerez de la Frontera (1470-1520)
Authors: Ruiz Pilares Enrique José , Mingorance Ruiz José Antonio
Published: December 2019

Andalucía contaba a finales del medievo con una posición estratégica en las rutas de navegación entre el Atlántico y el Mediterráneo que estimuló el asentamiento de importantes comunidades mercantiles foráneas. Aunque la historiografía ha puesto de relieve que estos contactos produjeron transformaciones de índole social en estos espacios, son escasos los estudios dedicados a la incorporación de estos colectivos en el seno de las instituciones de poder municipal. En este trabajo profundizamos en esta cuestión a través del estudio de Jerez de la Frontera y la familia genovesa de los Adorno. Tomando como fuente principal los fondos de su Archivo Municipal, se han reconstruido el origen y las bases de su poder socioeconómico y político, así como detalles relevantes sobre su integración a través de la construcción de suntuosos enterramientos y políticas matrimoniales. Hemos corroborado cómo una rica familia de mercaderes podía llegar a la cúspide del poder municipal si invertía adecuadamente los beneficios de sus actividades en la compra de oficios de gobierno, propiedades rústicas e inmobiliarias y, sobre todo, rentables enlaces con las antiguas familias dirigentes.
Justicia popular: el castigo de la comunidad en España, 1895-1923
Authors: Bascuñán Añover Óscar
Published: December 2019

El artículo analiza las numerosas tentativas de linchamiento popular que tuvieron lugar en la España de la Restauración. El principal objetivo reside en esclarecer las causas, lógicas y procesos históricos de este fenómeno de violencia colectiva. Para ello, se examinan los comportamientos sociales que suscitaron este tipo de reacción popular, las prácticas sociales, significados culturales y usos políticos que se manifestaban en estas expresiones de violencia y su relación con los procesos y estructuras políticas del Estado. Consideradas en el pasado como estallidos de ira y venganza propios de una sociedad atrasada, estas formas de violencia revelan el propósito de castigar una infracción que rebasaba los límites de lo tolerado por la comunidad, formas propias de entender la justicia y una preocupación compartida por mantener normas de conducta que preservasen ciertos modos de convivencia e integridad de la población. A su vez, estas acciones descubren la existencia de otras prácticas de castigo en la sociedad muy diferentes a los procedimientos liberales, que pudieron persistir o alimentarse en un contexto de desconfianza y descrédito de los representantes públicos e instituciones del Estado. La investigación se funda en la exploración de la prensa nacional y provincial, las fuentes gubernamentales, judiciales y bibliográficas
Conectando un territorio: simulación de rutas de movilidad entre cazadores-recolectores y primeros cultivadores. El caso del Cauca medio (Macizo Volcánico, Colombia)
Authors: Aceituno Bocanegra Francisco Javier , Uriarte González Antonio
Published: December 2019

La movilidad es una de las principales características de los grupos cazadores-recolectores e incipientes cultivadores. A partir de los años 90 y a nivel global, los estudios sobre movilidad experimentan un fuerte avance gracias a la aplicación de los Sistemas de Información Geográfica (SIG), con los análisis de los costes de desplazamiento y el modelado de rutas, así como la relación de estos elementos con el acceso a los recursos, la interacción entre grupos y la territorialidad. El presente artículo se basa en la simulación de rutas de movilidad en el Cauca medio, región andina localizada en el Macizo Volcánico colombiano (Cordillera Central), donde se cuenta con una secuencia muy completa de ocupaciones precerámicas entre el Pleistoceno final y el Holoceno medio. Esta tarea se ha abordado, en el marco de los SIG, mediante herramientas de análisis de costes, concretamente el análisis Modelo de Acumulación del Desplazamiento Óptimo desde un origen (MADO) y la generación de caminos óptimos. Los resultados muestran una asociación significativa entre yacimientos arqueológicos y rutas potenciales, así como una red de movilidad coherente y articulada.
Dos tumbas individuales calcolíticas en las inmediaciones de los dólmenes de Osorno y Simancas: estudio bioantropológico, ofrenda de perros y ‘postvida’ megalítica en el valle medio del Duero
Authors: Delibes de Castro Germán , Esparza Arroyo Ángel , Velasco Vázquez Javier , Zapatero Magdaleno Pilar , Fernández Rodríguez Carlos , Carbajo Arana María , Palomo Díez Sara , Misiego Tejeda Jesús
Published: December 2019

Con motivo de presentar dos tumbas individuales en fosa inéditas, se aborda un estudio de conjunto sobre las prácticas funerarias del Calcolítico Precampaniforme en la submeseta norte española. Pese a su carácter mayoritario en el registro arqueológico, se discute la representatividad como norma de este tipo de sepulturas; se rastrean comportamientos propios de rituales de enterramiento en dos tiempos, preludio de los documentados en este mismo espacio en la Edad del Bronce; se aporta información sobre el ADN mitocondrial y sexo molecular de uno de los difuntos, y se pone el énfasis, por vez primera en el Calcolítico de la cuenca del Duero, en el protagonismo de los perros en el mundo funerario. Por último, la proximidad de las dos nuevas sepulturas a sendos dólmenes –Los Zumacales (Valladolid) y La Velilla (Palencia)? da pie a debatir sobre el inicio de la ‘postvida’ megalítica en el valle medio del Duero.
Las “cabezas cortadas” del poblado ibérico del Puig Castellar (Santa Coloma de Gramenet, Barcelona). Datos para una reinterpretación
Authors: Eulàlia Subirà M. , Rovira Hortalà M. Carme
Published: December 2019

En 1904 se realizaron los primeros hallazgos de “cabezas cortadas” en el oppidum ibérico de El Puig Castellar de Santa Coloma de Gramenet (Barcelona) y se interpretaron como trofeos bélicos, sin embargo, solo una mínima parte de los mismos había sido dada a conocer sucintamente hasta ahora. Este estudio presenta los resultados del estudio antropológico basado en su descripción, determinación de edad y sexo, estudio patológico y de marcas. Los resultados amplían el número de individuos inicial de 5 a 12. Se trata de dos cráneos enclavados, tres con signos de desollamiento y diversos fragmentos craneales y mandibulares con evidencias de lesiones por arma blanca. Finalmente se valora el tratamiento que sufrieron dichos cráneos para su exhibición aportando nuevos resultados significativos que contribuyen a caracterizar, desde el punto de vista físico, a las tan desconocidas poblaciones iberas, además se cuestiona la teoría que asigna las “cabezas cortadas” exclusivamente a guerreros vencidos en batalla sobre la base de episodios del ámbito céltico descritos por las fuentes escritas grecolatinas (Posidonio de Apamea).
Radiografía de un castro de la Edad del Hierro: arqueología no invasiva en el asentamiento de Villasviejas del Tamuja (Botija, Cáceres)
Authors: Mayoral Herrera Victorino , Charro Lobato Cristina , Salgado Carmona José Ángel , Pro Muñoz Carmen , De Tena Rey María Teresa , Chapa Brunet Teresa , Vallés Iriso Javier , Terrón López José María , Quirós Rosado Elia
Published: December 2019

El objetivo de este trabajo es proporcionar un primer avance del estudio del castro de Villasviejas del Tamuja (Botija, provincia de Cáceres) a partir de la combinación de técnicas no destructivas. La posibilidad de cruzar los resultados obtenidos con diversos métodos geofísicos (magnetometría, georradar y tomografía eléctrica) plantea la oportunidad de formular un diagnóstico fiable sobre la organización espacial de este enclave.Se describen los resultados más relevantes, y se valora su aportación para una interpretación general de la estructura urbana y la morfología de los espacios domésticos. Esta información es contrastada con los datos de excavación previamente disponibles, y se analiza su encuadre dentro del conocimiento actualmente existente sobre este tipo de asentamientos. Asimismo, se añaden elementos de interés acerca de la evolución diacrónica del sitio, que son relevantes en relación con las hipótesis formuladas acerca del impacto de la conquista romana.En última instancia se pondera el potencial de este tipo de estrategias de investigación para el estudio y revalorización de zonas arqueológicas grandes y complejas.
Nuevas intervenciones en la Cova Gran y la Cova Freda de Montserrat (Collbató, Barcelona) casi 100 años después
Authors: Oms F. Xavier , Morales Juan I. , Cebrià Artur , Mestres Josep , Fullola Josep M.
Published: December 2019

En este trabajo se presentan los primeros datos estratigráficos, radiocarbónicos y de cultura material de las recientes excavaciones en las Coves de Montserrat (Cova Gran y Cova Freda). Estos emblemáticos yacimientos fueron excavados el año 1922 y proporcionaron uno de los primeros conjuntos cardiales de la península ibérica. Desde entonces, no volvieron a ser intervenidos de forma oficial y quedaron abandonados. En el año 2018 se han reiniciado los trabajos con sondeos en ambas cuevas, determinando la preservación de depósitos arqueológicos estratificados en algunos de ellos. En la Cova Freda se ha reconocido la existencia de un tramo de la cavidad probablemente usado como redil durante el Neolítico Antiguo Cardial y, en la Cova Gran, se han documentado un nivel y una estructura negativa de esa misma cronología, así como un potente nivel finipaleolítico.
New Public Administration Understanding and Reform Effects as Products of Neolibal Management Concept
Authors: Acar Eray
Published: December 2019

Globalization has been a process that has deeply and continuously influenced societies and states in the late period of historical development. With neoliberalism, the ideological thought system of the process, all social organizations, especially state apparatus and public administrations, are affected by this process and continue to be affected. This transformation process, supported by its international organizations, has led to the preparation and implementation of reforms in order to adopt a new approach to public administration. This change in public administration has affected both public service understanding and public service delivery. It is a process that aims to provide the citizens/customers satisfaction by offering a faster, more efficient, and high-quality public service along with the new public management understanding. Current practices are questioned and improvements are tried.
Is Turkey a Favorable Environment for FDIs?
Authors: Demir Memduh Alper
Published: December 2019

The aim of this chapter is to measure the impact of institutional variables such as economic freedom and democracy on foreign direct investment from the European Union to Turkey. In this framework, the author models institutional factors affecting foreign direct investments. The model includes economic freedom index, political rights, civil liberties of Turkey, and Gross Domestic Products of selected European countries. In theoretical part, the perspective of institutional economics on economic freedoms and democracy is discussed. A brief literature about the relationship between foreign direct investments and economic freedoms and democracy is revealed. Stochastic frontier analysis was used in the implementation to show the relationship between variables and efficiency of European countries' foreign direct investments to Turkey. Proposals for policy implication have been made in the conclusion part. This chapter shows civil liberties and economic freedom index have positive effect on foreign direct investments that supports institutionalists.
Classes and Development
Authors: Eser Zekeriya Eray
Published: December 2019

Classes forming the social division of labor have changed with the capitalist mode of production. The inheritance from the feudal system is not suitable for the capitalist system. For this reason, the class structure which is suitable for capitalism over time has taken place in many societies. This transformation has become more difficult, especially in the late capitalist countries. This chapter examines class structures of some late-capitalist countries outside Europe and North America. Latin America, Japan, South Korea, and Turkey have historically been studied before and after periods of capitalism. While some countries have successfully completed and managed to develop their class transformations under difficult conditions, some countries have failed. Along with an unsuccessful transformation, new classes have emerged which have preventive effects on the development target. It is difficult for the countries that cannot make their class structure compatible with the capitalist system and the development target.
Damage of Solid Phase due to Explosion Effect Using Uzawa’s Algorithm
Authors: Prochazka Petr-Pavel
Published: December 2019

The paper deals with the impact of explosion on the damage development in the structure that forms a boundary of closed or semi-closed space – tunnel - the explosion in which is initiated. In the previous publications of the author the penalty formulation of the problem was used; now Uzawa’s algorithm is applied, which appears to be more promising algorithm accelerating the iterative process of damage development in the structure. Shock waves propagating in the airspace can be described by non-linear conservation equations starting with Euler’s equations which are used to be solved by forward differences of the system of pseudo-linear equations, using Arbitrary Lagrangian-Euler Method (ALE). Conservation equations are formulated for two phases: air and solid. In the solid phase, concrete lining, the time-dependent elasticity of free rectangular elements undergoing the damage, is solved by uniformly distributed boundary elements. The paper is focused on damage to the concrete lining due to impact of the explosion in the tunnel.
Modelling the Strength of Cellulose Nanofiber-Filled Rigid Low-Density PU Foams
Authors: Andersons Janis , Kirpluks Mikelis , Cabulis Ugis
Published: December 2019

Rigid low-density closed-cell polyurethane (PU) foams are used primarily as a thermal insulation material. The foams have to possess a sufficient strength and stiffness in order to ensure their mechanical integrity and dimensional stability in service. The mechanical characteristics of foams are enhanced by adding cellulose nanofibers to the polyol system, which both modify the foaming process and act as a reinforcement of cell struts and walls. A model of composite foam strength is developed based on a regular unit cell and assuming the onset of strut failure as the foam fracture criterion. The load-bearing capacity of foam struts is estimated by the modified Fukuda and Chou model considering the orientation of nanofibers along the strut axis. The model developed is shown to provide a reasonably accurate prediction for the nanofiber loading effect on the strength of composite foams.
Effect of Air Oxidation Treatment of CNT on Tensile Strength of CNT / Polyamide 6 Nanofibres and their Dispersion
Authors: Tanaka Kazuto , Kamada Masaki , Katayama Tsutao
Published: December 2019

Carbon nanotube (CNT) is excellent in mechanical and thermal characteristics, and are expected to be used in various fields such as nanoelectronic devices and reinforcing nanofillers for composites. It is expected that mechanical properties can be improved by adding CNT into the polymer. However, since CNT exists in a state of aggregation due to van der Waals forces, it is necessary to uniformly disperse CNT in order to fully extract the properties of CNT. In this study, CNT/polyamide 6 (PA6) composite nanofibres were fabricated by the electrospinning method. In order to disperse CNT in the CNT/PA6 nanofibres, CNT were subjected to air oxidation treatment. As a result of evaluating the dispersibility of CNT by sedimentation test, the dispersibility in pure water and HFIP is improved by oxidizing the surface of CNT. By conducting tensile tests and SEM observation of the nanofibre non-woven fabric, the influence of the surface treatment on the tensile strength of CNT/PA6 nanofibres and the dispersion of CNT was clarified. Although the addition of untreated CNT to PA6 nanofibres reduces the displacement at break, air oxidized CNT/PA6 suppressed the formation of CNT aggregates, and showed higher tensile strength and larger displacement at break than untreated CNT/PA6.
Fracture Toughness Evaluation of a Cracked Au Thin Film by Applying a Finite Element Analysis and Bulge Test
Authors: Tinoco Hector A. , Hutař Pavel , Merle Benoit , Göken Mathias , Kruml Tomáš
Published: December 2019

This paper presents a finite element analysis of a pre-cracked freestanding gold thin film subjected to bulge test. These tests were conducted in order to determine the elasto-plastic properties and fracture toughness of the gold films. For the experimental tests, a pre-crack was introduced in the center of the film by focused ion beam (FIB) milling with a length of 10 and a width of 100nm. For the numerical fracture analysis, the problem was divided into two stages; the first stage was the development of the numerical model on the whole film without pre-crack (elasto-plastic analysis) and the second one was performed on a film portion that included the pre-crack (sub-modeling stage). Three different notches (rounded, sharp and V-sharp) were applied to calculate the stress intensity factor around the crack tip using path independent J-integral. The obtained results show that the load-deflection curves for non-cracked and pre-cracked film reproduced the experiments using the calculated elasto-plastic properties. This indicates that the proposed models presented a good correlation and robustness. Additionally, fracture toughness values were calculated between 0.288 and 0.303with J-integral values 1.037 J/m2 (elastic) and 1.136 J/m2 (elasto-plastic) which correspond with other calculations available in the literature.
A Combined Numerical and Experimental Approach to Evaluate the Hardness of AA Aluminum 6063 T6 with A Ni-P Coating
Authors: León B. Juan S. , Pertuz Alberto , Martínez M.
Published: December 2019

The need to improve the surface properties of materials, has led to the development of parts coated with hard materials deposited on substrates. In this work, by using the finite element method the AA Aluminium 6063 T6 hardness with an error less of the 5 % of the Brinell hardness (HBN), in comparison with the experimental data supplied, was determined. For this, the modelling of a spherical indentation test was carried out, in which the indentation loads and the projected contact radius are obtained from several potential adjustments. Then, using the Lessage-Pertúz model the hardness of the Ni-P coating was determined, obtaining a value of 4.86 GPa.
Prediction of the Ceramic Foam Structure Failure Using a Detailed Finite Element Model
Authors: Ševeček Oldřich , Hanák Jiří , Majer Zdeněk , Drdlík Daniel , Chlup Zdeněk , Kotoul Michal
Published: December 2019

The contribution deals with modelling and prediction of failure of mechanically loaded open cell ceramic foam structures by using 3D volume FE models constructed from CT scans of real foam specimens. The condition for crack initiation in particular struts comes from the coupled stress-energy criterion which combines two fracture-mechanics parameters of the investigated material – tensile strength and its fracture toughness. By combining of both stress and energy condition one obtains information about the crack initiation length which is later used (together with the tensile strength) for determination of the strut failure in the complex 3D FE model of the ceramic foam structure. The crack onset is considered in the critical location at the moment when the (tensile) principal stress under the strut surface (in a depth corresponding to the crack initiation length) exceeded the tensile strength of the strut. Such approach enables us to define failure also on relatively coarse meshes of the FE models where potential stress concentrations are not described precisely and therefore it is not possible to decide about the failure just based upon the value of tensile stress on the strut surface.
A Comparison of the Fracture Behaviour of Various Concrete Grades under Mixed Mode I/II Loading
Authors: Miarka Petr , Janssen Robin , Seitl Stanislav , de Corte Wouter
Published: December 2019

The Brazilian disc test with central notch is widely used to evaluate mixed mode I/II fracture resistance of brittle materials such as rocks and concrete. An analytical evaluation is used based on the maximum tangential stress (MTS) criterion and the generalised maximum tangential stress (GMTS) criterion. In this contribution two concrete types, a C 50/60 and a high strength concrete, were compared using the GMTS criterion. Also, the influence of critical distance rC on the fracture resistance under the mixed mode I/II was studied.
On the Strength Weakening Effect of Stiffening Ribs in the Design of Machine Components
Authors: Strozzi Antonio , Bertocchi E. , Mangeruga V.
Published: December 2019

The bending stress in beams may often be reduced by adding material to the cross section. In some paradoxical cases, however, the bending stress increases by adding material from zones far away, or close to, the neutral axis. Similarly, the bending stress of rectilinear or curved beams may often be reduced by adding ribs to the initial beam section. However, such ribs may sometimes cause a both undesired and unexpected stress increase, although they still produce a beneficial stiffening effect. The aim of this paper is twofold: a) to examine this unexpected result within the context of the paradoxical behaviour of some known beam sections, and especially of a recently noted paradox; b) to provide a preliminary rule of thumb for the mechanical design of ribs sometimes added to the outer surface of an eye, with particular regard to the small end of a connecting rod.
Finite Element Modelling of Delamination Onset in Polymeric Composite Material
Authors: Ferrari Andrea , Fanelli Sergio , Parlamento Matteo
Published: December 2019

Delamination is a well-known issue in polymeric composite materials. Interlaminar Shear Stress (ILSS) plays an important role in delamination initiation and thus its value needs to be monitored when designing a composite component. In this paper a Short Beam Shear experimental test of a carbon/epoxy specimen reproducing a Formula 1 component laminate is represented through a Finite Element analysis of two different models, one featuring 2D shell elements and the other 3D elements. ILSS results from both models are compared to experimental data in order to assess whether a 2D shell model can be used instead of its 3D counterpart, in favour of design versatility.
Computational Multi-Scale Modelling of Fiber-Reinforced Composite Materials
Authors: Eleftherios Tsivolas , Gergidis Leonidas N. , Paipetis Alkiviadis S.
Published: December 2019

A cross-ply fiber-reinforced composite in uniaxial tension is modelled using a mesoscale and a micro-scale approach comparing the results from both the analyses. The use of multi-scale modelling gives directly the macroscopic constitutive behaviour of the structures based on its microscopically heterogeneous representative volume element (RVE). In the meso-scale approach the material of each layer is modelled as a homogeneous transversely isotropic material whose properties resulted from a numerical homogenization analysis. One of the main advantages of micro-scale modelling is the ability to simulate damage mechanisms such as matrix cracking, delaminations of the matrix-fiber interface and fibre-damage. In the first part of this study, analytical and numerical homogenization schemes are compared. RVEs of continuous fibre and short-fibre reinforced composites are created, homogenized numerically and compared with the widespread analytical scheme of Mori-Tanaka based on Eshelby’s solution of the single inclusion problem. In the second part, results’ comparison between the simulations of both scales is performed. In the meso-scale model stochasticity has been introduced, assigning interfacial strength following a normal distribution, in order to predict cracking initiation, propagation and saturation at the matrix material. The stresses at the crack tips are compared with the stress fields around the cracks from the micro-scale analysis and the results are in good agreement.
Evaluation of Quasi-Static and Dynamic Fracture Toughness on the Low-Alloy Reactor Pressure Vessel Steel JRQ in the Transition Region
Authors: Spätig Philippe , Mazánová Veronika , Suman S. , Seifert Hans Peter
Published: December 2019

Three point bending and impact tests with sub-sized Charpy specimens were performed on the JRQ reference steel for reactor pressure vessels. Quasi-static and dynamic fracture toughness data were calculated and the fracture behavior in the ductile to brittle transition region was evaluated within the frame of the master curve method (ASTM E1921). Specimens with shallow and deep cracks were studied and the respective influence of crack length and loading rate on the reference transition temperature was determined. The force-time curves of specimens with shallow cracks presented significantly smaller oscillations with respect to the absolute force, making the fracture toughness evaluation more accurate.
Photoelastic Analysis of the Stressed State of a Flat Element with Geometrical Stress Concentrators (Cutout and Cuts)
Authors: Tabanyukhova Marina
Published: December 2019

The investigation of the stressed state of flat element with the geometrical stress concentrators was performed. The sample was made of piezo optic material. The oval-shape cutout and linear cuts were issued as the stress concentrators. On the symmetrical axles was cut out an oval. Linear cuts were made one by one under the different angles. Each time after appearing of the new cut, we fixed the stress fields in the model. Issue was performed using the axial compression at the elastic linear stage of loading. We used the method of photoelasticity. We estimated the quality and quantity of the influence of the size and the angle of cuts on the element stressed state, and received the stress fields during the different loadings. Also we estimated the stress coefficients near the tops of the cuts.
Numerical Simulation of Volcanic Ash Infiltration into Thermal Barrier Coatings
Authors: Arai Masayuki , Fukushima Yuta , Ito Kiyohiro
Published: December 2019

CMAS attack is known to occur owing to the deposition of volcanic ash onto thermal barrier coating (TBC) surface at a high-temperature environment. The serious problem is TBC spallation resulting from the infiltration of molten volcanic ash into the porous microstructure of TBC. The infiltration induces inner stress and phase transformation, which directly results in those serious problems. In this study, the diffusional equation for expressing the infiltrating process of the molten ash into the porous structure of TBC and the associated constitutive equation considered regarding phase transformation are formulated. The equations are installed into commercial finite element (FE) code (MARC) using the user subroutine. The numerical simulation results are compared with the cross-sectional SEM observation for the volcanic-ash-deposited TBC sample exposed at a high-temperature to confirm verification of the model proposed herein.
Crack Initiation Mechanism of Hydrogen Induced Cracking in Nickel
Authors: Takano Noriyuki , Yamamoto Hiroki
Published: December 2019

Cracks are induced during hydrogen charging in Nickel. We have reported that the cracks initiate near the boundary between nickel matrix and nickel hydride formed near the surface by hydrogen charging. The driving force is considered to be residual stress caused by hydride formation. In the present paper, the stress distribution has been calculated near the boundary using Finite element method to clarify the crack initiation mechanism. As a result, the high-stress area corresponded to the area where the cracks were observed in the experiment.
Evaluation of Fatigue Resistance of Laser Welded High Pressure Vessels Steel P355 Considering Fracture Mechanics Approach
Authors: Černý Ivo , Kec Jan
Published: December 2019

Laser welding is an innovative technology of joining metallic materials. In comparison with conventional arc welding, it has numerous advantages, like high energy of laser beam and high effectiveness, very good reproducibility, possibilities of automation, low energy consumption etc. High pressure vessels and high pressure pipeline industry represent perspective new fields of application. However, since pressure vessels and pipelines are usually operated at conditions of repeated or cyclic loading, an acceptable resistance to fatigue loading of the welds has to be demonstrated. In this contribution, results of an experimental programme aimed at an evaluation of high-cycle fatigue resistance in and near laser welds of a P355 pressure vessel steel are presented and discussed. Particular attention is paid to evaluation of crack initiation mechanisms in connection to laser weld character and welding imperfections. The programme is completed by measurement of fatigue crack growth rates and threshold values in the weld. Results of high-cycle fatigue tests of some groups of specimens were characteristic by a considerable scatter. The reason of the scatter was found in welding defects in some parts of the welds. Fatigue results are discussed also from the viewpoint of fracture mechanics and threshold values of fatigue crack growth.
Nanofillers’ Effects on Fracture Energy in Composite Aerospace Structures
Authors: Sellitto Andrea , Riccio Aniello , Russo A. , Garofano Antonio , Zarrelli Mauro
Published: December 2019

Composite materials damage behaviour is, nowadays, extensively investigated in the frame of aerospace research programmes. Among the several failure mechanisms which can affect composites, delamination can be considered as the most critical one, especially when combined to compressive loading conditions. In this context, nanofillers can represent an effective way to increase the composites fracture toughness with a consequent reduction of the delamination onset and evolution. Hence, in this paper, the toughening effect of the nanofillers on the delamination growth in composite material panels, subject to compressive load, has been numerically studied. A validated robust numerical procedure for the prediction of the delamination growth in composite materials panel, named SMXB and based on the VCCT-Fail release approach, has been used to perform numerical analyses by considering two different types of nanofillers. Reference material, without nanofillers insertion, has been used as benchmark in order to assess the capability of nanofillers to enhance the fracture toughness in composite laminates.
Strain Energy Decomposition Influence in the Phase Field Crack Modelling at the Microstructural Level of Heterogeneous Materials
Authors: Seleš Karlo , Tonković Zdenko , Jurčević Ante , Sorić Jurica
Published: December 2019

The prediction of a crack initiation and propagation occurring on the microstructural level of heterogeneous materials can be a very demanding problem. According to the results of recent investigations, the emerging phase field approach to fracture has a strong potential in modelling the complex crack behaviour in a simple manner. In this study, recently developed phase field staggered solution scheme with the residual norm stopping criterion has been employed for the fracture analysis of heterogeneous microstructure exhibiting complex crack phenomena. The microstructural geometries based on the metallographic images of the nodular cast iron and the material properties of an academic brittle material have been used in numerical simulations where the graphite nodules have been considered as porosities. Two commonly used energy decomposition models, the spectral decomposition and the spherical-deviatoric split, and their effects on the results of the phase field modelling are investigated. Numerical results show that the proposed algorithm recovers the complicated crack path driven by the complex microstructural topology.