bluuebunny/crossref_metadata_2025 huggingface dataset:
Disposable Voltammetric Immunosensors Integrated with Microfluidic Platforms for Biomedical, Agricultural and Food Analyses: A Review
Authors: Felix Fabiana , Baccaro Alexandre , Angnes Lúcio
Published: November 2018

Disposable immunosensors are analytical devices used for the quantification of a broad variety of analytes in different areas such as clinical, environmental, agricultural and food quality management. They detect the analytes by means of the strong interactions between antibodies and antigens, which provide concentration-dependent signals. For the herein highlighted voltammetric immunosensors, the analytical measurements are due to changes in the electrical signals on the surface of the transducers. The possibility of using disposable and miniaturized immunoassays is a very interesting alternative for voltammetric analyses, mainly, when associated with screen-printing technologies (screen-printed electrodes, SPEs), and microfluidic platforms. The aim of this paper is to discuss a carefully selected literature about different examples of SPEs-based immunosensors associated with microfluidic technologies for diseases, food, agricultural and environmental analysis. Technological aspects of the development of the voltammetric immunoassays such as the signal amplification, construction of paper-based microfluidic platforms and the utilization of microfluidic devices for point-of-care testing will be presented as well.
The Development of a Novel Decision Support System for the Location of Green Infrastructure for Stormwater Management
Authors: Kazak Jan K. , Chruściński Jakub , Szewrański Szymon
Published: November 2018

In order to maximise the benefits of green infrastructure in a city’s structure for urban adaptation to climate change, there is a need to support decision-makers in the urban design domain with adequate information that would help them to locate such green infrastructure in the most suitable places. Therefore, the aim of this study was to develop a novel decision support system (DSS) for the location of green infrastructure. The goal of the designed solution is to inform users about the location of urban hydrological sinks, which gather stormwater in urban watersheds, and the amount of water which could accumulate in each location depending on the defined precipitation and the soil’s moisture conditions. The designed DSS is based on a multicomponent methodology including both atmospheric and soil conditions. The DSS was tested using a sample that presents the results of stormwater accumulation calculations. The obtained results show which green areas are the most suitable locations for green infrastructure solutions and which facility is optimal because of its retention abilities and amount of accumulated stormwater. The application of the designed DSS allows us to maximise the benefits of the implementation of green infrastructure within the existing urban land use. The fully editable component of hydrological conditions allows for testing projections of the potential amount of accumulated water in different precipitation scenarios. The study provides a DSS for use by local authorities which enables them to concentrate actions in order to better adapt cities to climate change and environmental extremes.
Sustainability Disclosure in Integrated Reporting: Does It Matter to Investors? A Cheap Talk Approach
Authors: Camodeca Renato , Almici Alex , Sagliaschi Umberto
Published: November 2018

The purpose of this study is to investigate the value-relevance of corporate sustainability disclosure through integrated reporting. Sustainability disclosure is subject to managers’ discretion. Besides, it is often hardly verifiable. In this respect, integrated reporting could provide the means for a verifiable disclosure, otherwise, in the jargon of game theory, it could be considered as a cheap talk. This paper investigates which of these hypotheses is most likely to occur in reality. In order to do this, a simple theoretical framework is introduced, where sustainability of corporate performances is modelled as a tail-risk for shareholders. Costless signaling games (cheap talk) and persuasion games are reviewed within this context, in order to derive competing theories of sustainability disclosure’s value relevance through integrated reporting. These alternative theories are tested empirically consistent with the theoretical framework presented, in order to identify key-parameters. In this respect, a systematic textual analysis (artificial intelligence) of integrated reports was employed as to build a synthetic measure of sustainability disclosure. The application of this methodology on a sample of European listed companies showed that sustainability disclosure through integrated reporting has no effect on market-valuations, confirming the null hypothesis of integrated reporting resulting in a cheap talk’s babbling equilibrium.
Analysis of Selected Building Constructions Used in Industrial Construction in Terms of Sustainability Benefits
Authors: Švajlenka Jozef , Kozlovská Mária , Pošiváková Terézia
Published: November 2018

Enormous development of technology over the past two centuries has been associated with a considerable drawdown of non-renewable raw materials and an increase in the amount of harmful emissions. Thus, building direction in the field of construction implies a significant implementation of sustainability. The preference for environmentally friendly technology solutions is the right way to meet the sustainability trend. The main aim of this study was to analyze and verify selected construction systems of buildings designed for agricultural primary production in terms of their environmental impacts. The supporting construction systems of the comparative design variants was designed from a variety of material bases (concrete, steel, and wood). To evaluate environmental construction systems, the LCA methodology in mode “Cradle to Gate” was used. Parameters of sustainability related to the environmental impact were analyzed. These results could be a useful tool for the evaluation and comparison to an appropriate choice of the design option for an industrial building designed for agricultural primary production in terms of environmental impact.
Is Labor Related to the Duality of Earnings Smoothing?
Authors: Huang Shengzhong , Lyu Chan , Lin Xiaojun
Published: November 2018

Previous accounting studies indicate that union strength is positively related to income smoothing and that management is more likely to smooth income when labor power is strong. Researchers debate about whether income smoothing has either a garbling or an informative role. This paper investigates the cross-country impact of labor power on the extent to which information about future prospects is efficiently communicated through income smoothing. It proposes that strong labor power will garble income smoothing, which means that the efficient communication of private information is constrained in strong labor protection settings. Consistent with our predictions, the results show that the informative role of income smoothing is restricted with strong labor protection after controlling for legal institutions, financial-market development, and economic wealth. This study provides new insights into the role of income smoothing by inspecting the linkage between labor protection and income smoothing.
The Environmental Strategy of Businesses as an Option under Recession in Greece
Authors: Fousteris Andreas E. , Didaskalou Eleni A. , Tsogas Markos-Marios H. , Georgakellos Dimitrios A.
Published: November 2018

In recent years and mostly during the last two decades, the decisive role of the environment in the business administration field and business life in general has emerged. In the modern, fast changing, and highly competitive business environment, and even more so in the context of the recent economic crisis, businesses constantly struggle to survive, trying to resolve problems and improve their performance and competitive advantage. Therefore, they must save and invest substantial sums of money to build strong infrastructure, to change procedures, and to produce environmentally friendly products. In view of the above, the current study attempted to examine the impact of environmental strategy on the growth of medium and large enterprises in all sectors in Greece, in a period of economic crisis. The study, carried out in February and March 2018, confirmed the positive correlation and the critical role of environmental strategy in the financial performance of Greek enterprises during this period of economic recession. Both eco-efficient practices and innovative practices lead to the creation of competitive advantage and, thus, to the improvement of the financial performance of a firm.
The Impact of Government Competition on Regional R&D Efficiency: Does Legal Environment Matter in China’s Innovation System?
Authors: He Baocheng , Wang Jiawei , Wang Jiaoyang , Wang Kun
Published: November 2018

Local governments are encouraged to compete in R&D investments and activities in China’s innovation system. We aim to understand the influence of government competition on regional R&D efficiency. We are also interested in examining how the attributes of legal environment act as a moderating variable for the relationship between government competition and R&D efficiency. We developed Tobit spatial models with spatial panel data of 30 provinces of China in 2008–2016. The results show that: (1) There exists spatial dependence of R&D efficiency, and the regions with high efficiency have “spillover effect” on the surrounding areas. (2) Government competition has a significant promoting effect on R&D efficiency and/or R&D efficiency spillover. Specifically, government competition has both R&D efficiency promotion and R&D efficiency “spillover” promotion in Eastern China, only R&D efficiency positive spillover promotion in Middle-area and R&D efficiency promotion but negative spillover in Western China. (3) The impact of government competition on efficiency is affected by the legal environment, and the promotion effect of government competition only exists in good legal environment. The results of this study reveal an important way to improve R&D efficiency by establishing a new R&D competition mechanism for local government which is oriented by efficiency and ruled by the legal environment.
Heritage Image and Attitudes toward a Heritage Site: Do They Really Mediate the Relationship between User-Generated Content and Travel Intentions toward a Heritage Site?
Authors: Mehmood Shafaqat , Liang Changyong , Gu Dongxiao
Published: November 2018

Traveling to heritage sites represents a growing sector with great potential in the context of heritage tourism, which is a relevant topic but has received little scholarly attention. The present study tries to bridge this gap by investigating the mediating role of heritage image and attitudes toward a heritage site in the relationship between user-generated content (UGC) and travel intention toward a heritage site. In particular, we applied partial least squares structural equation modeling (PLS-SEM), which is a relatively popular new method, instead of the traditionally used covariance-based structural equation modeling (CB-SEM) method. The rise in popularity of PLS-SEM has been particularly noticeable since 2013, but in the area of heritage tourism, research is still in an early stage of development because the heritage discipline has hardly exploited the benefits of this approach. We proposed a multimediation model for heritage tourism to address this relatively new research avenue. It was discovered that exogenous variables directly and indirectly influenced travel intentions toward a heritage site through their mediators (i.e., heritage image and attitudes toward a heritage site). The findings provide an appropriate empirical and theoretical conclusion as well as valuable insights for heritage management organizations (HMOs) into the performance of heritage tourism, both for local professionals and the host communities that assist in increasing the development of heritage tourism.
Credit Constraint, Credit Adjustment, and Sustainable Growth of Farmers’ Income
Authors: Wang Xiaohua , Chen Meilan , He Xi , Zhang Fangfang
Published: November 2018

Research on financial theory and practice has shown that the development of transition economies generally faces two major challenges. First, the less developed regions face more severe financial repression, which leads to imbalanced and unsustainable development of regional economies. Second, farmers face different credit constraints because of their productivity differences, which can further polarize the internal inequality of their income. Based on cross-sectional data of 2037 counties in 30 provinces of China in 2010, this paper employs quantile regression to investigate the relationships among credit constraints, credit adjustment, and the sustainable growth of farmers’ income. Our results confirm that rural residents generally face credit constraints, and there are significant stratified differences in the impact of farmer credit on farmers’ income. Farmers with higher income are more likely to obtain bank credit and continue to grow their income, while farmers with lower income are more likely to fall into the “vicious circle of poverty” because of their lack of capital accumulation. Therefore, to promote more fair and sustainable growth of farmers’ income, it is important to increase the credit available to farmers. Furthermore, it is critical to promote healthy competition among county financial institutions and accelerate the establishment of inclusive financial systems. This can ultimately help ensure sustainable development of agriculture and rural economy.
Resistance-Related l-Pyroglutamic Acid Affects the Biosynthesis of Trichothecenes and Phenylpropanoids by F. graminearum Sensu Stricto
Authors: Bilska Katarzyna , Stuper-Szablewska Kinga , Kulik Tomasz , Buśko Maciej , Załuski Dariusz , Perkowski Juliusz
Published: November 2018

Fungicide application remains amongst the most widely used methods of fungal control in agroecosystems. However, the extensive use of fungicides poses hazards to human health and the natural environment and does not always ensure the effective decrease of mycotoxins in food and feed. Nowadays, the rising threat from mycotoxin contamination of staple foods has stimulated efforts in developing alternative strategies to control plant pathogenic fungi. A substantial effort is focused on the identification of plant-derived compounds inhibiting mycotoxin production by plant pathogenic fungi. l-Pyroglutamic acid has recently been suggested as playing a role in the response of barley to toxigenic Fusaria. Considering the above, we studied the response of various strains of F. graminearum sensu stricto to different levels of l-pyroglutamic acid on solid YES (yeast extract sucrose) media. l-Pyroglutamic acid decreased the accumulation of trichothecenes in all examined strains. Gene expression studies addressing Tri genes (Tri4, Tri5, and Tri10), which induce the biosynthesis of trichothecenes, revealed the production of mycotoxins by l-pyroglutamic acid to be inhibited at the transcriptional level. Besides inhibitory effects on mycotoxin production, l-pyroglutamic acid exhibited variable and concentration-related effects on phenylpropanoid production by fungi. Accumulation of most of the fungal-derived phenolic acids decreased in the presence of 100 and 400 µg/g of l-pyroglutamic acid. However, a higher dose (800 µg/g) of l-pyroglutamic acid increased the accumulation of trans-cinnamic acid in the media. The accumulation of fungal-derived naringenin increased in the presence of l-pyroglutamic acid. Contrasting results were obtained for quercetin, apigenin, luteolin, and kaempferol, the accumulation of which decreased in the samples treated with 100 and 400 µg/g of l-pyroglutamic acid, whereas the highest l-pyroglutamic acid concentration (800 µg/g) seemed to induce their biosynthesis. The results obtained in this study provide new insights for breeders involved in studies on resistance against Fusaria.
Conceptual Framework for Sediment Management in Torrents
Authors: Hübl Johannes
Published: November 2018

Torrential catchments are complex systems showing a huge diversity of sediment and flow regime reactions. Therefore, it seems reasonable to decrease the complexity by introducing a conceptual framework to obtain a general idea of the torrential system’s behavior. The aim of the manuscript is to provide a conceptual framework and a stepwise procedure to develop a reproducible sediment management concept. This involves starting with a definition of torrential process types. These processes are then routed through the drainage system, which is divided into homogeneous reaches. Each reach transfers a flow process from the upstream node to the adjacent downstream reach, based on driving geomorphic factors of sediment mobilization and deposition. Additionally, a sediment budget, derived from cumulative erosion and deposition volumes, is calculated. The estimated flow process together with the sediment budget enables the selection of a sediment management strategy. The implementation of the strategy is based upon the selection of functions, which define the desired modification with regard to the torrential system. Ultimately, the sum of each function’s performance must lead to the fulfilment of the overall protection objective.
An Improvement of Port-Hamiltonian Model of Fluid Sloshing Coupled by Structure Motion
Authors: Abdollahzadeh Jamalabadi Mohammad Yaghoub
Published: November 2018

The fluid–solid interaction is an interesting topic in numerous engineering applications. In this paper, the fluid–solid interaction is considered in a vessel attached to the free tip of a cantilever beam. Governing coupled equations of the system include the Euler–Bernoulli equation for bending of a beam, torsion of a beam, 2-D motion of the rigid vessel, and rotating shallow water equation of fluid sloshing in the vessel. As an essential portion in the numerical simulation of the vibration control of this fluid–plate system is the accurate modeling of sloshing; the partial differential equations of the system are modified by approximation of velocity profile. The suggested method is validated by experimental results of a piezoelectric actuated clamped rectangular plate holding a cylindrical vessel. These sloshing interactions with elastic test cases illustrate the mass conservative characteristics of the method as well as its stability in a prompt change of the vessel situations.
Sustainability Assessment of the Water Management System for the Boukan Dam, Iran, Using CORDEX- South Asia Climate Projections
Authors: Emami Farzad , Koch Manfred
Published: November 2018

The present study aimed to quantify the future sustainability of a water supply system using dynamically-downscaled regional climate models (RCMs), produced in the South Asia Coordinated Regional Downscaling Experiment (CORDEX) framework. The case study is the Boukan dam, located on the Zarrine River (ZR) of Urmia’s drying lake basin, Iran. Different CORDEX- models were evaluated for model performance in predicting the temperatures and precipitation in the ZR basin (ZRB). The climate output of the most suitable climate model under the RCP45 and RCP85 scenarios was then bias-corrected for three 19-year-long future periods (2030, 2050, and 2080), and employed as input to the Soil and Water Assessment Tool (SWAT) river basin hydrologic model to simulate future Boukan reservoir inflows. Subsequently, the reservoir operation/water demands in the ZRB were modeled using the MODSIM water management tool for two water demand scenarios, i.e., WDcurrent and WDrecom, which represent the current and the more sustainable water demand scenarios, respectively. The reliability of the dam’s water supply for different water uses in the study area was then investigated by computing the supply/demand ratio (SDR). The results showed that, although the SDRs for the WDrecom were generally higher than that of the WDcurrent, the SDRs were all <1, i.e., future water deficits still prevailed. Finally, the performance of the water supply system was evaluated by means of risk, reliability, resiliency, vulnerability, and maximum deficit indices, and the combination of the indices to estimate the Sustainability Group Index (SGI). The findings indicated that, compared to the historical period for both the water demand scenarios, WDcurrent and WDrecom, the average SGI of each RCP would be decreased significantly, particularly, for the more extreme RCP85 scenario. However, as expected, the SGI decrease for the WDrecom was less than that of the WDcurrent, indicating the advantage of implementing this more sustainable water demand scenario.
Étude cristallographique de sulfures de terres rares et de sodium
Authors: Ballestracci Régis , Lewy-Bertaut Erwin Félix
Published: November 2018

On décrit deux catégories de sulfures de terres rares et de sodium. Dans les deux cas, la terre rare T et l'ion Na ont la coordinence six. La première catégorie comprend les terres rares T = La, Ce, Pr, Nd. La structure peut être considérée comme étant du type NaCl, lacunaire et désordonnée. Les anions S forment un paquetage cubique compact tandis que les cations occupent au hasard les sites des Na de la même façon que dans BiNaS₂.

A la deuxième catégorie, appartiennent les terres rares T = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er et Y. La structure est rhomboédriquement déformée, mais encore apparentée au type NaCl. Le groupe d'espace est R ˗3m˗ (D⁵3d). Dans le paquetage compact, presque cubique des anions S en 6c) les cations T occupent les sites 3a) et les cations Na les sites 3 b), formant ainsi un type de structure de formule TNaS₂ analogue à celle de CrNaS₂.
Étude des réactions d'échange d'ions Na — K dans la série muscovite˗paragonite
Authors: Iiyama Jean Toshimichi
Published: November 2018

L'étude des réactions d'échange d'ions entre des solutions sodipotassiques et la série des micas blancs a montré que dans ces minéraux le potassium et le sodium sont échangeables dans les conditions hydrothermales. Il existe un équilibre entre les compositions de la solution et celles du solide.

Sous une pression de 1 000 bars, la muscovite et la paragonite ne forment pas une solution solide continue.

Aux températures les plus basses, la paragonite est stable mais elle ne peut coexister, en équilibre, qu'avec des solutions exceptionnellement riches en sodium. Au contraire, la muscovite est stable pour un vaste domaine de compositions de la solution.

Par suite de l'instabilité de la paragonite au dessus de 570° C, sous 1 000 bars, la muscovite réagit, au dessus de cette température, avec des solutions sodiques en donnant un mélange de feldspaths alcalins et de corindon.

Ces résultats ont été utilisés pour préciser les assemblages stables du système Al₂O₃ — KAlSi₃O₈ (orthose) — NaAlSi₃O₉ (albite) — H₂O dans le domaine de températures compris entre 500° et 650° C sous une pression de 1 000 bars.
Étude diffractométrique du carbonate de strontium et du carbonate de baryum entre 20 et 1 000° C
Authors: Moreau R.
Published: November 2018

Nous établissons, aussi rigoureusement que possible, l'évolution des paramètres de la forme « basse » orthorhombique jusqu'à la forme « haute » hexagonale de la strontianite, SrCO₃ et de la withérite, BaCO₃.

1. — Jusqu'à 400° C, les comportements de SrCO₃ et de BaCO₃ suivant a, b et c diffèrent peu de celui de l'aragonite.

2. — Une discontinuité de la dilatation apparaît au-delà de 400° C, surtout marquée dans le cas de BaCO₃.

3. — Le passage à la forme hexagonale est brutal mais des réserves doivent être apportées pour BaCO₃ dont les formes orthorhombique et hexagonale coexistent entre 800° C et 840° C.

4. — L'analogie du comportement des formes hexagonales et de celui de la calcite est particulièrement mise en évidence par l'obtention du coefficient négatif de dilatation suivant a de BaCO₃.
Étude de la paragenèse de quelques minéraux des pegmatites d'Alto Ligonha (Mozambique)
Authors: Goni J. c. , Guillemin Claude
Published: November 2018

Les auteurs décrivent des tourmalines qui présentent des phénomènes de remplacement par des feldspaths (surtout microcline) et par des minéraux micacés : muscovite violacée et de la leuchtenbergite.

Les tourmalines plus ou moins substituées peuvent renfermer des cristaux de manganotantalite. Cette paragenèse est interprétée en fonction des diagrammes géochimiques de Fersman et on discute la localisation, dans les processus pegmatitiques, des minéraux riches en tantale.
Nature de la magnétite obtenue après grillage magnétisant de la limonite lorraine
Authors: Koskas R. , Baro Raymond
Published: November 2018

Certaines propriétés de la magnétite, obtenue par grillage magnétisant de la limonite lorraine, diffèrent de celles de la magnétite pure : aimantation à saturation, dimension de la maille cristalline et rapport Fe⁺⁺/Fe total.

Ces écarts peuvent s'expliquer en admettant principalement une substitution des ions fer par l'ion Al³⁺ dans la magnétite obtenue, qui aurait la composition suivante : Fe₂,₆ Al₀,₄O₄.
Spectres de vibration et structure des cristaux du Cuivre 1 dicyanure de potassium
Authors: Moreau G. , Poulet Henri , Mathieu Jean-Paul
Published: November 2018

Détermination, du spectre de Raman et du spectre d'absorption infrarouge de monocristaux de KCu(CN)₂. L'étude détaillée des vibrations de tension CN s'accorde avec la structure des cristaux proposée par Cromer.
Étude de trois halogénomercurates de thallium
Authors: Huart J.
Published: November 2018

Deux composés déjà connus des chimistes : HgTlCl₃ et HgTlBr₃ et un composé nouveau Hg₃Tl₁₀Cl₁₆ ont été étudiés au point de vue cristallographique.

HgTICl₃ et HgTlBr₃ cristallisent dans le système orthorhombique et sont isomorphes de (NH₄)CdCl₃ et RbCdCl₃. Leurs données cristallographiques sont les suivantes :

HgTlCl₃ : a = 9,167 ± 0,007 Å ; b = 14,075 ± 0,01 Å ; c = 4,3578 ± 0,0005 Å. — Z = 4. — Dx = 6,04 ± 0,01.

HgTlBr₃ : a = 9,620 ± 0,007 Å ; b = 14,53 ± 0,01 Å ; c = 4,5657 ± 0,0005 Å. — Z = 4. — Dx = 6,71 ± 0,01.

Pour ces deux corps les groupes d'espace possibles sont Pnam ou Pna2₁.

Hg₃Tl₁₀Cl₁₆ cristallise dans le système quadratique et ses données cristallographiques sont :

a = 12,00 ± 0,03 Å ; c = 23,64 ± 0,06 Å ; c/a = 1,97 ± 0,01. — Z = 4. — Dx = 6,27 ± 0,05.
La guilleminite, une nouvelle espèce minérale
Authors: Pierrot Roland , Toussaint J. , Verbeek Théodore
Published: November 2018

La guilleminite se présente en cristaux orthorhombiques jaune serin d'environ 4/10 mm de long, a = 7,25, b = 16,84, c = 7,08 Å. Groupe spatial P ncm Raies intenses du diagramme de poudre 8,39 F (020) 7,29 F (100) 3,55 mF (210) 6,68 m (110).

Clivage parfait (100) — dmes = 4,88 ; dₓ = 4,92.

Biaxe négatif : 2 V = 35°. Dispersion forte avec r > v — ng = 1,805, nm = 1,798, np = 1,720.

L'analyse quantitative fournit les résultats suivants :

SeO₂ = 16,8 %, BaO = 10,8 %, UO₃ = 64,5 %, H₂O = 7,1 % total : 99,2 et conduit à la formule : Ba(UO₂)₃(OH)₄(SeO₃)₂.3H₂O. La courbe thermopondérale est donnée.

Ce nouveau minéral provient de Musonoï (Katanga), gîte cuprocobaltifère de type stratiforme. Les échantillons types sont conservés à l'École Nationale Supérieure des Mines de Paris. Le nom de guilleminite est proposé en l'honneur de C. Guillemin.
La grotte de Saint-Marcel (Ardèche) : un référentiel pour l'évolution des endokarsts méditerranéens depuis 6 Ma
Authors: Mocochain Ludovic , Bigot Jean-Yves , Clauzon Georges , Faverjon Marc , Brunet Philippe
Published: November 2018

Le plateau de Saint-Remèze est formé d'une plate-forme carbonatée d'âge mésozoïque qui borde la moyenne vallée du Rhône. Cette plate-forme est intensément karstifiée, comme l'atteste la grotte de Saint-Marcel dont le développement dépasse 53 km. La grotte de Saint-Marcel présente un étagement des réseaux sur plusieurs niveaux. Deux de ces niveaux (intermédiaire et supérieur) présentent des conduits dont une grande partie est abandonnée par les écoulements, ils présentent de grandes sections de conduits qui se développent horizontalement sur plusieurs kilomètres. Le troisième niveau (inférieur) est actif et partiellement noyé, il a été reconnu en plongée jusqu'à 65 m sous le niveau de l'Ardèche. L'étagement des niveaux horizontaux n'a aucun lien avec la structure géologique qui est recoupée sans distinction. Cette observation permet de saisir le rôle structurant du niveau de base et de prendre en compte son évolution dans la formation du karst ardéchois.

Dans le périmètre des gorges de l'Ardèche et de la moyenne vallée du Rhône, l'investigation des niveaux repères générés par la crise de salinité messinienne permet une restitution de l'évolution du niveau de base régional. Cette restitution de l'évolution des niveaux a permis d'étudier la grotte de Saint-Marcel dans un cadre géodynamique et chronologique d'une durée de six millions d'années. Couplées aux variations du niveau de base, les investigations morphologiques menées dans la grotte ont restitué trois grandes phases de spéléogenèse et deux grands modes de circulation des eaux souterraines. Il s'agit en premier lieu de la structuration en profondeur du drainage du plateau de Saint-Remèze lors du creusement des canyons messiniens durant la crise de salinité. Au lendemain de la crise, à 5,32 Ma, la transgression pliocène a provoqué une brusque remontée du niveau de base produisant un refoulement hydrologique aux exutoires du karst messinien. La résistance hydraulique a déclenché le creusement per ascensum de conduits vaudusiens : les puits-cheminées. La réponse du système de drainage s'est reproduite au cours du Pliocène à chaque stade de la remontée du niveau de base. Durant le Pliocène (5,32 à 2 Ma), lors du remblaiement des rias, l'Ardèche a aussi connu de longues phases de stabilité propices à la spéléogenèse.

Il s'agit d'un drainage des eaux du plateau de Saint-Remèze sur lequel se sont connectés de larges recoupements souterrains de méandre de l'Ardèche. L'observation détaillée des grands niveaux de l'endokarst a révélé en retour l'existence de stades intermédiaires dans l'évolution du niveau de base et permis d'affiner et d'enrichir la connaissance de l'évolution du niveau de base régional.
Étude des transferts de masse et de chaleur dans la grotte de Lascaux : le suivi climatique et le simulateur
Authors: Lacanette Delphine , Malaurent Philippe , Caltagirone Jean-Paul , Brunet Jacques
Published: November 2018

La grotte de Lascaux, découverte en 1940 et située en Dordogne dans la vallée de la Vézère est inscrite au Patrimoine Mondial de l'Unesco. Elle est considérée comme l'une des grottes ornées les plus importantes au monde. Les visites qui ont suivi sa découverte ont perturbé l'équilibre de la cavité et induit sa fermeture en 1963. Depuis, elle a retrouvé un état à peu près stable, jusqu'en 2001 où une attaque de micro-organismes a eu lieu. Suite à cette prolifération, un comité scientifique international pluridisciplinaire a été créé par le ministre de la Culture et de la Communication. Ce comité a d'emblée souhaité disposer d'une meilleure compréhension des écoulements présents dans la cavité. Pour répondre à cette demande un nouvel outil a été créé, le «Simulateur Lascaux», basé sur un code de mécanique des fluides numérique. Un des principaux atouts de cette méthode est son caractère non intrusif. Deux configurations climatiques ont été choisies dans cet article. En septembre 1981, la grotte était dans des conditions «stables» : les températures dans la roche entourant la grotte suivaient le schéma classique augmentant avec la profondeur. La seconde configuration (en décembre 1999) concerne une période précédant des travaux dans la cavité : les températures se sont inversées se trouvant être plus élevées à la voûte qu'au sol.

Cette inversion a conduit au confinement de la grotte. Finalement, les écoulements résultant du retrait d'une cloison ont été appréciés grâce au simulateur, et il a été montré un impact négligeable de ce retrait sur l'équilibre de la cavité.
Epithelial-To-Mesenchymal Transition and Migration of Human Peritoneal Mesothelial Cells Undergoing Senescence
Authors: Kawka Edyta , Witowski Janusz , Sandoval Pilar , Rudolf Andras , Vidal Angela Rynne , Cabrera Manuel Lopez , Jörres Achim
Published: November 2018

Background

Epithelial-to-mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs) contributes to fibrotic thickening of the peritoneum that develops in patients on peritoneal dialysis (PD). The process is thought to be largely mediated by transforming growth factor-beta (TGF-β). As TGF-β has also been implicated in senescence of HPMCs, we have performed an exploratory study to examine if senescent HPMCs can undergo EMT.

Methods

Omentum-derived HPMCs were rendered senescent by repeated passages in culture. Features of EMT were assessed by immunostaining and quantitative polymerase chain reaction (qPCR) at various stages of the HPMC lifespan and after treatment with or without TGF-β. The motility of HPMCs was assessed in a scratch wound migration assay.

Results

Replicative senescence of HPMCs was associated with a gradual increase in the constitutive expression of EMT markers, including increased production of extracellular matrix proteins. However, senescent HPMCs also retained epithelial cell features such as cytokeratin, calretinin, and E-cadherin and showed decreased, rather than increased, motility. In contrast, exposure to TGF-β resulted in an up-regulation of mesenchymal markers and down-regulation of epithelial markers. Such effects of TGF-β occurred both in young and senescent cells, although they were less pronounced in senescence.

Conclusions

Senescence of HPMCs is associated with spontaneous development of several EMT features. At the same time, senescent HPMCs preserve epithelial cell-like characteristics and are less prone to develop a full EMT phenotype in response to TGF-β. These observations may support the concept of cellular senescence being antagonistically pleiotropic with regard to EMT.
Ternary nanocomposites of reduced graphene oxide, polyaniline and hexaniobate: hierarchical architecture and high polaron formation
Authors: Silva Claudio H B , Iliut Maria , Muryn Christopher , Berger Christian , Coldrick Zachary , Constantino Vera R L , Temperini Marcia L A , Vijayaraghavan Aravind
Published: November 2018

Nanostructured systems, such as nanocomposites, are potential materials for usage in different fields since synergistic effects of their components at the nanoscale domain may improve physical/chemical properties when compared to individual phases. We report here the preparation and characterisation of a new nanocomposite composed of polyaniline (PANI), reduced graphene oxide (rGO) and hexaniobate (hexNb) nanoscrolls. Atomic force microscopy images show an interesting architecture of rGO flakes coated with PANI and decorated by hexNb. Such features are attributed to the high stability of the rGO flakes prepared at room temperature. Detailed characterisation by X-ray photoelectron and Raman spectroscopies indicates an intermediate reduction degree for the rGO component and high doping degree of the PANI chains compared to the neat polymer. The latter feature can be attributed to cooperative effects of PANI chains with rGO flakes and hexNb nanoscrolls, which promote conformational changes of the polymer backbone (secondary doping). Spectroscopic and electrochemistry data indicate a synergetic effect on the ternary nanocomposite, which is attributed to interactions between the components resulting from the morphological aspects. Therefore, the new nanocomposite presents promising properties for development of new materials in the film form on substrates for sensing or corrosion protection for example.
Computational model and physical and technical factors determining the plutonium proliferation resistance
Authors: Kulikov Yevgeny , Kulikov Gennady , Apse Vladimir , Shmelev Anatoly , Geraskin Nikolay
Published: November 2018

Since the closed nuclear fuel cycle suggests that plutonium is extracted from irradiated fuel and is recycled in nuclear reactors as part of the loaded fuel, proliferation resistance of fissile materials (plutonium) is becoming a problem of a practical significance. It is important to understand to what extent the physical and technical properties of fissile materials are capable to prevent these from being diverted to nonenergy uses. This paper considers the term ”proliferation resistance” from a physical and technical point of view with no measures taken for the physical protection, accounting and control of nuclear materials. Thus, proliferation resistance of plutonium means that it is technically impossible to fabricate a nuclear explosive device (NED) of the implosion type due to the overheating of the device’s components and the resultant NED failure.

The following conclusions have been made.

The assessment of the plutonium proliferation resistance is not justified where it relies on the analysis of an implosion-type NED excluding the use of modern heat-resistant and heat-conducting chemical explosives (CE) which are inaccessible.

Consideration of the asymptotic temperature profile in the NED components is not justified enough for the development of plutonium proliferation resistance recommendations.

No options enabling the slowdown of the NED warm-up process have been exhausted for analyzing the physical and technical factors that determine the proliferation resistance of plutonium.

The assessment of the plutonium proliferation resistance is not justified where it relies on the analysis of an implosion-type NED excluding the use of modern heat-resistant and heat-conducting chemical explosives (CE) which are inaccessible.

Consideration of the asymptotic temperature profile in the NED components is not justified enough for the development of plutonium proliferation resistance recommendations.

No options enabling the slowdown of the NED warm-up process have been exhausted for analyzing the physical and technical factors that determine the proliferation resistance of plutonium.

General conclusion. The underlying rationale in a fundamental monograph by Dr. G. Kessler proved to be insufficiently valid, which has led to an unfounded inference as to the status of the plutonium proliferation resistance. The development of the procedures used and other factors taken into account are expected to increase the requirements to the content of the 238Pu isotope in plutonium for ensuring its proliferation resistance.
Lead reactor of small power with metallic fuel
Authors: Khorasanov Georgiy , Samokhin Dmitriy , Zevyakin Aleksandr , Zemskov Yevgeniy , Blokhin Anatoliy
Published: November 2018

The possibility for obtaining a hard neutron spectrum in small reactor cores has been considered. A harder spectrum than spectra in known fast sodium cooled and molten salt reactors has been obtained thanks to the selection of relatively small core dimensions and the use of metallic fuel and natural lead (natPb) coolant. The calculations for these compositions achieve an increased average neutron energy and a large fraction of hard neutrons in the spectrum (with energies greater than 0.8 MeV) caused by a minor inelastic interaction of neutrons with the fuel with no light chemical elements and with the coolant containing 52.3% of 208Pb, a low neutron-moderating isotope.

An interest in creating reactors with a hard neutron spectrum is explained by the fact that such reactors can be practically used as special burners of minor actinides (MA), and as isotope production and research reactors with new consumer properties. With uranium oxide fuel (UO2) substituted by metallic uranium-plutonium fuel (U-Pu-Zr), the reactors under consideration have the average energy of neutrons and the fraction of hard neutrons increasing from 0.554 to 0.724 MeV and from 18 to 28% respectively. At the same time, the one-group fission cross-section of 241Am increases from 0.359 to 0.536 barn, while the probability of the 241Am fission increases from 22 to 39%. It is proposed that power-grade plutonium resulting from regeneration of irradiated fuel from fast sodium cooled power reactors be used as part of the fuel for future burner reactors. It contains unburnt plutonium isotopes and some 1% of MAs which transmutate into fission products in the process of being reburnt in a harder spectrum. This will make it possible to reduce the MA content in the burner reactor spent fuel and to facilitate so the long-term storage conditions for high-level nuclear waste in dedicated devices.
Potential of application of IRT-T research reactor as the solution of the problem of graphite radwaste disposal
Authors: Pavliuk Alexander , Kotlyarevskiy Sergey , Bespala Evgeny , Bespala Yuliya
Published: November 2018

Aspects of handling irradiated graphite during decommissioning uranium-graphite reactors (UGR) of different types were investigated. It was demonstrated that handling reactor graphite is complicated by the presence in the composition of graphite of long-lived radionuclides, especially 14C, which may get entrained in biological cycles since carbon constitutes one of the main components of biological chains. Practical implementation of the process of selective separation of 14С can significantly reduce potential danger represented by graphite radioactive wastes due to the reduction of graphite activity as related to the isotope in question, as well as due to the reduction of the leaching rate by separating 14С isotope which is the most weakly bound within the graphite structure. Conclusion was formulated that analytical measurement methodologies and calculation methods allow reliably estimating only the total quantity of 14C accumulated in graphite, the contribution of 14C accumulation channel from 13C(n, γ)14C reaction, as well as the total contribution of 14N(n, p)14C reaction on nitrogen impurities and on nitrogen contained in purge gas. Method was suggested for estimating the values of contributions of different channels of accumulation on nitrogen impurities and nitrogen contained in purge gas using IRT-T research reactor (Tomsk, Tomsk Region). Parallel irradiation of batches of samples of non-irradiated (fresh) reactor-grade graphite contained in different gaseous media constitutes the basis of the study. Algorithm was suggested for calculating contributions of all channels of 14C accumulation according to the results of measurements to be obtained in the proposed studies. Recommendations were formulated on the use of all brands of graphite applied for manufacturing elements of graphite stacks of uranium-graphite reactors designed in Russia for determining selectively separated fraction of 14C for all types of graphite radioactive wastes by the companies in the RF which operated (are operating) the uranium-graphite reactors. Time of exposure of samples of irradiated graphite in the GEK-4 horizontal experimental channel of the IRT-T reactor was calculated and was found to be equal to ~ 10 days. Methodology was suggested for conducting a series of experiments for determining the values of contributions of 14C accumulation channels in the irradiated reactor graphite. The methodology suggested can be applied for determining fraction of selectively separated 14C in irradiated graphite elements of practically all uranium-graphite nuclear reactors, including reactors operated abroad Russia, under the condition of maintaining carbon dioxide gas atmosphere in one of the irradiated containers.
Analysis of acoustic leak signals for enhancing sensitivity of control due to the creation of effective diagnostic indicators
Authors: Leskin Sergey , Shvetsov Dmitry , Trykov Evgeny , Puzakov Aleksey
Published: November 2018

Acoustic leak control systems (for instance, SAKT) are used at present for controlling leak tightness of equipment and pipelines, as well as for detecting in timely manner coolant leaks from the primary cooling circuit of nuclear reactor installations (NRI) during operation of power unit on different power levels in the modes of normal operation and during disturbances of normal operation. Time averaged dispersion of acoustic signal is used as the main diagnostic indicator for detecting leaks in these systems. Sensitivity of this indicator is determined by the exceedance by the signal of the preset threshold value which is defined in accordance with the background. Here, background values of acoustic signal depend on the operational modes of the equipment and do not allow in many cases determining coolant leak during early stages of leak development.

New approach to the formation of diagnostic indicators for detecting loss of sealing in the circuit during early stage of development of coolant leak is suggested.

Methodology for obtaining diagnostic indicators is based on the processing in different frequency bands of acoustic signal accompanying coolant leakage from the pipeline using the method of principal components.

Efficiency of the developed methodology of coolant leak detection is illustrated by processing acoustic signals for experimental facility modeling coolant leakage in case of loss of sealing of the circuit.

Even in the presence of significant acoustic background sensitivity of the method allows detecting leaks with significantly lower flow rates (up to five times smaller) than the conventional processing of acoustic signals.

Implementation of the developed methodology will not require significant expenditures for upgrading already existing leak control systems operated at present on different NPPs.
A taxonomic revision of the Neotropical genus Cremastosperma (Annonaceae), including five new species
Authors: Pirie Michael D. , Chatrou Lars W. , Maas Paul J. M.
Published: November 2018

We present a taxonomic revision ofCremastosperma, a genus of Neotropical Annonaceae occurring in lowland to premontane wet forest, mostly in areas surrounding the Andean mountain chain. We recognise 34 species, describing five as new here: from east of the Andes,C.brachypodumPirie & Chatrou,sp. nov.andC.dolichopodumPirie & Maas,sp. nov., endemic to Peru;C.confusumPirie,sp. nov., from southern Peru and adjacent Bolivia and Brazil; andC.alticolaPirie & Chatrou,sp. nov., at higher elevations in northern Peru and Ecuador; and from west of the Andes,C.osicolaPirie & Chatrou,sp. nov.endemic to Costa Rica, the most northerly distributed species of the genus. We provide an identification key, document diagnostic characters and distributions and provide illustrations and extensive lists of specimens, also presenting the latter in the form of mapping data with embedded links to images available online. Of the 34 species, 22 are regional endemics. On the basis of the extent of occurrence and area of occupancy of species estimated from the distribution data, we designate IUCN threat categries for all species. Fourteen species proved to be endangered (EN) and a further one critically endangered (CR), reflecting their rarity and narrow known distributions.
Eco-Friendly Flame-Retardant Additives for Polyurethane Foams: A Short Review
Authors: Ali Mohd Hafiz Mohd , Rahman Hamimah Abdul , Amirnordin Shahrin Hisham , Khan Najeed Ahmed
Published: November 2018

Polyurethane (PU) materials are extensively used in the construction industry as core material insulation for sandwich panel application, such as wall cladding, structure insulation and roof panel. Demands on PU application have escalated given its significant advantages to reduce energy consumption. Meanwhile, rigid PU (RPU) foams are combustible materials characterized by rapid flame spread, high heat-release rates, and ability to produce large quantities of toxic gases in original form. Thus, flame-retardant (FR) additives are used to improve the thermal properties of PU. However, some commercial additives used today have are hazardous to humans and the environment, and their extensive application is limited by their negative effects on polymer mechanical properties. Accordingly, identifying materials that are environmentally friendly and harmless to humans has become urgent. Some alternative additives that are gaining research interest are clay and fly ash, which are natural and recyclable resources that can enhance the FR properties of other polymers. However, room for improvement is always present as the related technology is continually being developed. This review focuses on studies aiming to enhance the flame retardancy of RPU foam using fly ash and local clay as additives.