bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil and Plant Characteristics in a Restored Area under Mid-Term Site Management
Authors: Martelletti Sara , Meloni Fabio , Freppaz Michele , Paone Andrea , Lonati Michele , Pittarello Marco , Ferrarato Massimiliano , Motta Renzo , Nosenzo Antonio
Published: June 2020

Mid- and long-term monitoring of restoration projects have to be performed, as short-term evaluations do not give comprehensive information about their outcomes. In this study, we assessed the results of a forest restoration project, implemented in former road builder’s yards. We evaluated the recovery of the soil’s physical and chemical properties, the effectiveness and naturalness of sward restoration, and the success of woody species planting. Our hypotheses were that soil–plant interaction strongly influenced the restoration dynamics. The areas were restored in 2016. In 2014, we collected data from 28 restored areas. Eight years after the restoration, the physical and chemical properties of the soil indicated good quality. Suitable soil conditions were reflected in the herbaceous vegetation cover, which was higher than 60% in all the areas. The sown mixture successfully contained spontaneous species, and perennials prevailed over annuals, indicating stability in the composition of the sward. Alien species cover (generally < 10%) was controlled by sown species. Sown species also outcompeted ruderal and typical grassland species, reducing the naturalness of the herbaceous layer. Tree and shrub growth was low, and soil properties did not affect their height. Our results underline the importance of sowing an herbaceous species mixture in degraded areas in order to efficiently restore the soil cover and to reduce the colonization of alien species. Moreover, in our study, we showed how soil properties differently affected plant species groups.
Social Innovation and Food Provisioning during Covid-19: The Case of Urban–Rural Initiatives in the Province of Naples
Authors: Cattivelli Valentina , Rusciano Vincenzo
Published: June 2020

This paper draws on the theoretical framework based on social innovation determinants to analyze how and to what extent the recent and self-organized initiatives for food provisioning are contributing to increase food accessibility at the time of personal and mobility restrictions due to Covid-19. Based on this, the paper firstly maps the initiatives activated during the first months of the Covid-19 emergency (March and April 2020) in the urban–rural territories in the province of Naples (Italy). Secondly, it characterizes these initiatives in relation to their capacity to enhance outcome and social well-being, as well as to involve local society in answer to social challenges through a desk research. Thirdly, the paper describes the case of Masseria Ferraioli, which emerges as social innovative best practice among the previous mapped initiatives. Even in these days, the Masseria distributes to people who cannot afford the purchase due to the emergency vegetables grown on land confiscated from the Camorra, the local mafia. Its configuration as social innovative experience is also confirmed directly by the Masseria´s project manager, who was required to answer to a semi-structured interview. Based on the evidence of the desk research and this interview, the paper demonstrates the importance of the combined commitment of local communities and volunteering association as a reaction to food provisioning problems in the time of Covid-19, as well as an increasing interest in reconnecting with local food practices, above all when food access has become a priority.
Sustaining What Is Unsustainable: A Review of Urban Sprawl and Urban Socio-Environmental Policies in North America and Western Europe
Authors: Bueno-Suárez Carlos , Coq-Huelva Daniel
Published: June 2020

Urban sprawl and its economic, social, and environmental consequences are central issues for approaching more sustainable forms of life and production. This review provides a broad theoretical exploration of the main features of urban sprawl but also of sustainable urban policies in Western Europe and North America. Urban sprawl can be observed in both continents, as the search for higher standards of economic, social, and environmental sustainability is also an essential feature of urban governance in the last years. Urban sprawl has been slightly weaker in Western Europe, as its are cities generally more compact. Moreover, in Western Europe, urban sprawl has sometimes been confronted with ex-ante preventive policies. However, in North America, urban sprawl from the 1950s has been an essential element of the social ordering and, thus, of the American way of life. In both cases, urban sprawl has generated successive rounds of accumulation of built capital, which is currently managed in sustainable ways essentially through ex-post and palliative measures, that is, trying to “sustain what is unsustainable”. In other words, the idea is to make urban sprawl more sustainable but without altering its main morphological elements.
Opinions on the Orchard of the Lower Segura River: A Changing Space under Great Human Pressure
Authors: Ponce-Sánchez María Dolores , García-Marín Ramón , Canales-Martínez Gregorio , Lozano-Parra Javier
Published: June 2020

What makes the Lower Segura River (southeast of Spain) unique is the existence of a densely populated and entropized territory around a smallholder agricultural activity that for centuries has shaped the so-called “Segura Orchard.” In recent years, there has been widespread occupation due to the construction of secondary residences, which has clearly changed the rural appearance, sometimes creating an image more typical of disorderly residential urbanization than of an inhabited agricultural territory. The objective of this paper is to determine the attitude and position of the resident population regarding the situation and future prospects that are envisioned for this area. In this paper, we have conducted a personal and open interview as a technique to collect the information. If we are not capable of generating sustainable socio-economic activity, we will not be able to preserve, protect and transcend what we still know as an orchard. This spatial structure is undoubtedly singular and complex, and after a process of loss of identity and alteration of traditional uses, it requires an intervention that tends to organize it and protect the important territorial heritage that it still preserves.
Energy, Exergy, and Sustainability Analyses of the Agricultural Sector in Bangladesh
Authors: Chowdhury Tamal , Chowdhury Hemal , Ahmed Ashfaq , Park Young-Kwon , Chowdhury Piyal , Hossain Nazia , Sait Sadiq M.
Published: June 2020

Globally, the agriculture sector consumes a considerable portion of energy. Optimizing energy consumption and energy loss from different fuel-based types of machinery will increase the energy sustainability of this sector. Exergy analysis is a useful optimizing method that applies the thermodynamic approach to minimize energy loss. The main goal of this study is to highlight the impact of exergy loss on the energy sustainability of the agriculture sector. Hence, this study focuses on the implementation of exergy-based sustainability parameters to determine the sustainability of the agricultural sector in Bangladesh. A comprehensive analysis combining energy, exergy, and sustainability indicators was conducted based on the data obtained from 1990 to 2017. Overall energy and exergy efficiencies varied between 29.86% and 36.68% and 28.2% and 35.4%, respectively, whereas the sustainability index varied between 1.39 and 1.54. The values of relative irreversibility and lack of productivity indices from diesel fuel are higher than that of other fuel types. Maximum relative irreversibility is 0.95, whereas maximum lack of productivity is 2.50. The environmental effect factor of diesel fuel is the highest (2.47) among all the analyzed fuel types. Replacing old farming devices and selecting appropriate farming methods, appliances, and control systems will reduce exergy loss in this sector.
Around the Anthropocene in Eighty Names—Considering the Urbanocene Proposition
Authors: Chwałczyk Franciszek
Published: June 2020

There are now at least 80–90 proposed alternatives to the term “the Anthropocene”, following critique mainly from the social sciences. The most popular seem to be Moore’s Capitalocene and Haraway’s Chthulucene, but there are others, such as: Hornborg’s Technocene, Mann’s Homogenocene, Wilson’s Eremocene, Stiegler’s neganthropocene, Parikka’s Anthrobscene… Furthermore, similar recognitions and critiques have been made in urban studies (Urban Age, Planetary Urbanization…). What should we make of this multiplicity? Those propositions are approached here from the philosophical and cultural studies perspectives, in the spirit of Galison’s trading zones and Bal’s travelling concepts. They are treated with engaged pluralism (introduced through geography and urban studies) and, because of their eschatological dimension, with (secular) negative theology. The Urbanocene is also outlined using Nowak’s ontological imagination. None of the propositions are sufficient on their own. Most contribute to a better understanding of the Anthropocene. Those concerning the role of cities and urbanization (Astycene, Urbanocene, Urbicene, Metropocene) are insufficient. This entails that there is a need for an Urbanocene proposition to be formulated. This proposition draft is briefly outlined here by linking an example of exceeded planetary boundaries (levels of phosphorus and nitrogen) with urbanization, drawing on the works of Mumford and Gandy.
Opportunities and Challenges of Green-Lean: An Integrated System for Sustainable Construction
Authors: Tafazzoli Mohammadsoroush , Mousavi Ehsan , Kermanshachi Sharareh
Published: June 2020

Although the two concepts of lean and sustainable construction have been developed due to different incentives, and they do not pursue the same exact goals, there exists considerable commonality between them. This paper discusses the potentials for integrating the two approaches and their practices and how the resulting synergy from combining the two methods can potentially lead to higher levels of fulfilling the individual goals of each of them. Some limitations and challenges to implementing the integrated approach are also discussed. Based on a comprehensive review of existing papers related to sustainable and lean construction topics, the commonality between the two approaches is discussed and grouped in five categories of (1) cost savings, (2) waste minimization, (3) Jobsite safety improvement, (4) reduced energy consumption, and (5) customers’ satisfaction improvement. The challenges of this integration are similarly identified and discussed in the four main categories of (1) additional initial costs to the project, (2) difficulty of providing specialized expertise, (3) contractors’ unwillingness to adopt the additional requirements, and (4) challenges to establish a high level of teamwork. Industry professionals were then interviewed to rank the elements in each of the two categories of opportunities and challenges. The results of the study highlight how future research can pursue the development of a new Green-Lean approach by investing in the communalities and meeting the challenges of this integration.
How Organizational Citizenship Behavior Affects ERP Usage Performance: The Mediating Effect of Absorptive Capacity
Authors: Kwahk Kee-Young , Yang Sung-Byung , Ahn Hyunchul
Published: June 2020

Enterprises have implemented enterprise resource planning (ERP) systems as a strategic vehicle to gain a competitive edge. However, such ERP systems do not always guarantee successful results. While ERP systems may provide an organization with numerous benefits, they can also destroy a business if not successfully adopted, owing to enormous investment losses coupled with low business efficiency. To explore a way to reverse this situation, we examine how organizational citizenship behavior influences the successful management of ERP systems. Moreover, the mediating role of absorptive capacity in this relationship is investigated. The empirical analysis results, based on 188 surveyed organizations in Korea, reveal a partial mediating role of absorptive capacity on the relationship between organizational citizenship behavior and ERP usage performance. The findings of the study shed light on the ways of how the companies that adopt ERP systems to facilitate ERP usage and to gain business sustainability.
Structural Gender Differences in LMS Use Patterns among College Students
Authors: Lim Keol , Nam Yeong Ok , Eom Sanghyeon , Jang Yoonho , Kim Donjeong , Kim Mi Hwa
Published: June 2020

The aim of this study is to investigate male and female college students’ use patterns of a learning management system (LMS) in an e-learning environment. This study evaluated the structural differences between male and female college students in their LMS use patterns through a multifactor model. The research was conducted with 443 participants at a university in Korea. Four factor structures comprising 14 items measured on a five-point Likert scale were used for the analyses. After confirmatory structures for each gender were modified, the equivalence was examined by testing for factorial invariance and the latent means. The results indicated that, for three factors, male students used the LMS more than females and that neither gender preferred communicating and collaborating with each other. It was also found that students understood learning activities in more diverse ways than through theories. The results, which reflected Korea’s general educational context, indicated that a gender digital divide issue remains to be bridged and left recommendations for comprehensive development including the search for strategies for more participative LMS operations.
From Progressive Property to Progressive Cities: Can Socially Sustainable Interpretations of Property Contribute toward Just and Inclusive City-Planning? Global Lessons
Authors: Mualam Nir , Sotto Debora
Published: June 2020

This paper explores if and how the idea of progressive property can help to shape more inclusive, sustainable, and just cities around the globe. While quite nuanced, at its heart the progressive perspective on property considers property as a means of addressing important human needs. It is consistent with reciprocal and communitarian approaches to property rights. Nowhere are these insights more relevant or needed than in cities—dense urban areas where legacies of exclusion have deprived disadvantaged groups of housing and public services. In cities and neighboring suburbs, the right to exclude collides head-on with the need to share limited space with those of little means. By re-examining the work of progressive property scholars, we suggest concrete ways of reconceptualizing access to the city. This paper ties legal theory to housing and city-planning by proposing an international perspective to progressive property scholarship, with a focus on local government policies pertaining to housing. We do so by comparatively examining case studies from the United States (US), Spain, Brazil, and Israel—four countries that are actively experimenting with progressive definitions of property in a manner which affects urban planning and housing in cities.
Organizational Life Cycle Assessment of a Service Providing SME for Renewable Energy Projects (PV and Wind) in the United Kingdom
Authors: Marx Hendrik , Forin Silvia , Finkbeiner Matthias
Published: June 2020

Companies are increasingly interested in reducing their environmental footprint. Thereby, they face the challenge of identifying and mitigating their specific impacts and hotspots and simultaneously avoid burden shifting. The organizational life cycle assessment (OLCA) method was conceived and successfully tested for the assessment if companies’ potential environmental impacts. Still, the method poses methodological challenges for the application to service providing organizations. In this paper, OLCA was applied to a service providing SME in the photovoltaic and wind energy business in the United Kingdom. The environmental impact profile of the reporting organization is dominated by transport activities, including the technicians’ trips to the solar farms, employee commuting, and business travels. According to the main goals of the study (gaining insights in internal operations and improving organizational procedures), recommendations to reduce travel-related impacts are provided. For existing methodological challenges like selecting the reporting flow and setting the system boundaries, innovative solutions like defining multiple reporting flows for different activities and to partly include service receiving objects in system boundaries are discussed with the aim to facilitate future applications.
Personal Growth and Psychobiological Stress Responsiveness to the Trier Social Stress Test in Students
Authors: Mihara Kengo , Okamura Hisayoshi , Shoji Yoshihisa , Tashiro Kyoko , Kinoshita Yukie , Tsuda Akira
Published: June 2020

The current study aimed to examine the effects of personal growth (PG) on psychobiological responses at baseline and responsiveness to laboratory acute stress in students. Twenty-four healthy students were recruited as participants. Participants were screened from 203 candidates according to levels of PG using Ryff’s scale and classified into high and low PG groups. During the laboratory session, 13 high and 11 low PG participants underwent the Trier Social Stress Test. Heart rate and high-frequency (HF) heart rate variability were monitored throughout the experiment. Salivary free-3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) and perceived stress were measured at baseline, immediately after tasks and after a recovery period. Baseline and recovery perceived stress (tense arousal) were significantly lower in the high PG group compared with the low PG group. Free-MHPG and HF component returned to baseline levels during recovery significantly more rapidly in the high PG group compared with the low PG group. There were no significant group differences in heart rate. The results showed that high PG students have lower noradrenaline and higher parasympathetic nervous system activity before and after acute stress. These findings suggest a protective psychobiological pathway linking PG with better psychosomatic health in students.
Entrepreneurship and Innovation in Soccer: Web of Science Bibliometric Analysis
Authors: Escamilla-Fajardo Paloma , Núñez-Pomar Juan Manuel , Ratten Vanessa , Crespo Josep
Published: June 2020

According to the existing literature, there is growing interest in the sports industry by individuals involved in entrepreneurship and innovation. However, no bibliometric analyses on the importance of and interest that these individuals have in the football industry have been conducted. A total of 220 articles and reviews retrieved from Thomson Reuters Web of Science (Core Collection™) between 1997 and 2019 were analysed. These articles were published in 169 different journals by 609 authors from 340 different institutions in 46 countries. The following basic bibliometric analyses and co-occurrence networks were carried out: co-authorship and co-words. As a result, four clusters that summarise the following four different thematic areas were found: (1) football, entrepreneurship and social development, (2) football, innovation and management, (3) football, efficiency and new technology, and (4) football, injuries and innovation in rehabilitation. A thematic analysis of the four clusters found was carried out. Finally, practical implications and future lines of research were presented.
Brand Behavioral Intentions of a Theme Park in China: An Application of Brand Experience
Authors: Wang JunHui , Choe Yunseon , Song HakJun
Published: June 2020

Despite theme parks being a research hotspot, there is a paucity of research to understand the forming process of brand behavioral intentions (i.e., the intention of revisiting a theme park and the visit intentions of other theme parks under the same brand). For identifying the developing process of brand behavioral intentions from the perspective of experience, the current study developed a theoretical framework in which brand experience and memory affect visitors’ satisfaction and behavioral intentions to revisit a particular theme park as well as to visit other theme parks of the same brand. The empirical results of current study showed that visitors’ theme park experiences were good enough antecedents of their memories and satisfaction. It was also found that, when visitors’ memory and satisfaction are high, they are likely to have stronger impact on intentions to revisit the theme park and to visit theme parks of the same brand than did memory.
Dynamical Approach to Decays of XYZ States
Authors: Dubnička Stanislav , Dubničková Anna Zuzana , Ivanov Mikhail A. , Liptaj Andrej
Published: June 2020

We review the existing results on the exotic XYZ states and their decays obtained within the confined covariant quark model. This dynamical approach is based on a non-local Lagrangian of hadrons with quarks, has built-in quark confinement, and is suited well for the description of different multiquark states, including the four quark ones. We focus our analysis on the various decay modes of five exotic states, X ( 3872 ) , Z c ( 3900 ) , Y ( 4260 ) , Z b ( 10610 ) , and Z b ′ ( 10650 ) , aiming to clarify their internal quark structures. By considering mostly branching fractions and decay widths using the molecular-type or the tetraquark-type interpolating currents, conclusions about the nature of these particles are drawn: the molecular structure is favored for Z c ( 3900 ) , Z b ( 10610 ) , and Z b ′ ( 10650 ) and the tetraquark for X ( 3872 ) and Y ( 4260 ) .
Regional Transmission and Reassortment of 2.3.4.4b Highly Pathogenic Avian Influenza (HPAI) Viruses in Bulgarian Poultry 2017/18
Authors: Venkatesh Divya , Brouwer Adam , Goujgoulova Gabriela , Ellis Richard , Seekings James , Brown Ian H. , Lewis Nicola S.
Published: June 2020

Between 2017 and 2018, several farms across Bulgaria reported outbreaks of H5 highly-pathogenic avian influenza (HPAI) viruses. In this study we used genomic and traditional epidemiological analyses to trace the origin and subsequent spread of these outbreaks within Bulgaria. Both methods indicate two separate incursions, one restricted to the northeastern region of Dobrich, and another largely restricted to Central and Eastern Bulgaria including places such as Plovdiv, Sliven and Stara Zagora, as well as one virus from the Western region of Vidin. Both outbreaks likely originate from different European 2.3.4.4b virus ancestors circulating in 2017. The viruses were likely introduced by wild birds or poultry trade links in 2017 and have continued to circulate, but due to lack of contemporaneous sampling and sequences from wild bird viruses in Bulgaria, the precise route and timing of introduction cannot be determined. Analysis of whole genomes indicates a complete lack of reassortment in all segments but the matrix protein gene (MP), which presents as multiple smaller clusters associated with different European 2.3.4.4b viruses. Ancestral reconstruction of host states of the hemagglutinin (HA) gene of viruses involved in the outbreaks suggests that transmission is driven by domestic ducks into galliform poultry. Thus, according to present evidence, we suggest the surveillance of domestic ducks as they are an epidemiologically relevant species for subclinical infection. Monitoring the spread due to movement between farms within regions and links to poultry production systems in European countries can help to predict and prevent future outbreaks. The 2.3.4.4b lineage which caused the largest recorded poultry epidemic in Europe continues to circulate, and the risk of further transmission by wild birds during migration remains.
Engagement with and delivery of the ‘parkrun practice initiative’ in general practice: a mixed methods study
Authors: Fleming Joanna , Bryce Carol , Parsons Joanne , Wellington Chrissie , Dale Jeremy
Published: June 2020

Background

The parkrun practice initiative, a joint collaboration between parkrun and the Royal College of General Practitioners, was launched to encourage general practices to improve the health and wellbeing of patients and staff through participating in local 5 km parkrun events. Why and how practices engage with the initiative is unknown.

Aim

To investigate engagement with and delivery of the parkrun practice initiative in general practice.

Design and setting

Mixed methods study conducted from April–July 2019 comprising an online survey of all registered parkrun practices, and interviews and a focus group with practice staff in the West Midlands.

Method

The designated contacts at 780 registered parkrun practices were invited to complete an online survey. A purposive sample of parkrun practice staff and non-registered practice staff took part either in semi-structured interviews or a focus group, with transcripts analysed thematically.

Results

Of the total number of parkrun practices, 306 (39.2%) completed the survey. Sixteen practice staff (from nine parkrun practices and four non-registered practices) took part in either semi-structured interviews (n = 12) or a focus group (n = 4). Key motivators for becoming a parkrun practice were: to improve patient and staff health and wellbeing, and to become more engaged with the community and enhance practice image. Practices most commonly encouraged patients, carers, and staff to take part in parkrun and displayed parkrun flyers and posters. Challenges in implementing activities included lack of time (both personal and during consultations) and getting staff involved. Where staff did engage there were positive effects on morale and participation. Non-registered practices were receptive to the initiative, but had apprehensions about the commitment involved.

Conclusion

Practices were keen to improve patient and staff health. Addressing time constraints and staff support needs to be considered when implementing the initiative.
ANALYSIS OF THE RESULTS OF MONITORING OF DYNAMIC IMPACTS DURING EXPERIMENTAL IMMERSION OF DRIVING PILES AT THE CONSTRUCTION SITE OF THE CAMPUS OF SFU
Authors: Evlahova E. , Ivanova A. , Zheleznyakov V.
Published: June 2020

in the framework of the work the values of the vibrodynamic loads when driving of the two piles and their impact on the existing slab on pile foundation of dormitory № 8b and at the gas station in the 25-meter zone from the place of piling were determined. Calculations of the actual impact of the immersion of piles in the residential area of the campus of SFU (dormitory No. 8b) on the existing slab were made, the results of which revealed that the impact on the existing building does not exceed the maximum permissible value. At the same time, calculations were carried out on the existing gas station, the results of which showed that at a distance of 15.0 m, the clogging will not cause the development of deformations of the bases of existing structures of any type, based on soils from soft-plastic to hard consistency.
STRESS-STRAIN STATE OF THE SYSTEM "COMBINED TOWER-REINFORCED CONCRETE FOUNDATION-FOUNDATION SOIL" OF HIGH-RISE STRUCTURES
Authors: Mailyan L. , Yazyev S. , Sabitov L. , Konoplev Yu. , Radaykin Oleg
Published: June 2020

The aim of the work was to evaluate the effectiveness of the system "combined tower-reinforced concrete foundation-foundation soil" for high-rise structures on the example of a wind power plant (wind turbine) with a capacity of 1.5-2.0 MW using computer modeling in the PC "Ansys". Thus, under the combined tower the article refers to high-rise building, consisting of two parts: the lower composite, the upper – in the form of a thin-walled core-shell closed profile. In both cases, the shell is a pipe with a weak taper. As an analogue, the WPP considered in foreign literature is adopted: the radius of the rotor is R=41 m, the height to the axis of the wind wheel is zhub=80 m. The shell is made of high-strength C355 steel and, unlike the analog in this work, the cavity of the lower part of the tower to a height of 20 m was filled with B60 class concrete. The modeling took into account the spatial work of the elements of the structural system and the physical nonlinearity of the materials from which they are made. At the same time, the Mises strength theory was used for steel, the Williams – Varnake theory for concrete, and the Drukker – Prager theory for the foundation soil. Comparison of the calculation results with the analog showed that the destructive load of the tower increased by 37% due to filling the lower part of it with concrete, which indicates the effectiveness of the proposed solution. In this case, the destruction of the tower with a concrete core and without it occurred from the loss of local stability of the steel shell at the level of the junction of the tower with the foundation (with a compressed zone).
A simple derivation of the finite wavelength, high frequency dielectric constant of a classical Coulomb plasma
Authors: Baus Marc
Published: June 2020

The lowest order collisional contribution to the frequency and wave vector dependent dielectric constant of a classical plasma is obtained through a simple diagram summation similar to the well known summation leading to the Vlassov polarizability. The connection with the infinite wavelength results is explicitly given.
The harmonic oscillator in prolate spheroidal coordinates. I. Coulomb interaction of an oscillator proton with an exterior charge
Authors: Demeur Marcel , Reidemeister G.
Published: June 2020

The three dimensional harmonie oscillator has been quantized in prolate spheroidal coordinates using the properties of the constants of the motion. The coulomb interaction of an oscillator proton with an exterior charge has been investigated by means of both a first order perturbation calculation and the variational method. The same problem modified by the presence of a spin-orbit interaction has been emphasized. Comparison with other works related to the subject has been made.
A variational formulation applied to heat conduction equation
Authors: Lorenzini Enrico
Published: June 2020

Con una formulazione variazionale viene affrontato il problema della conduzione stazionaria e transitoria con conducibilita termica variabile comunque con la temperatura in un mezzo di volume arbitrario con una funzione di generazione interna di calore qualsiasi.

Si considera poi, la applicazione della teoria precedente all'elemento cilindrico, riportando quindi in grafici i risultati ottenuti.
On an identity concerning the projection operators in non-equilibrium statistical mechanics
Authors: George Claude D.
Published: June 2020

The possibility of projecting out of the complete dynamical behaviour of a many-body system, the coherent behaviour associated with a thermodynamical description rests on a relation between asymptotic operators. We present a direct proof of this relation.
Sur une équation linéaire fonctionnelle—différentielle—aux différences (première note)
Authors: Mangeron Démètre J. , Oguztöreli Mehmet N.
Published: June 2020

Les auteurs étudient dans cette Note l'équation fonctionnelle-différentielle-aux différences F(x + y ; α) = F(n)(x ; α — 1) + F(n)(y ; α — 1) + Q(α), où Q (α) est une fonction sommable donnée de α et F(n)(x ; α) = δnF(x ; α)/δxn, n étant un nombre entier positif.
Sur le système canonique des surfaces algébriques triples
Authors: Godeaux Lucien
Published: June 2020

Construction du système canonique des surfaces algébriques images d'involutions cycliques n'ayant qu'un nombre fini de points unis appartenant à des surfaces algébriques.
Sur les surfaces intersections complètes de variétés algébriques
Authors: Godeaux Lucien
Published: June 2020

Détermination du genre arithmétique d'une surface complète intersection d'hypersurfaces algébriques.
Construction de quelques surfaces algébriques projectivement canoniques
Authors: Godeaux Lucien
Published: June 2020

Construction de surfaces algébriques dont le système canonique coïncide avec celui des sections hyperplanes.
Étude de la substitution nucléophile aromatique. I. Cinétique de la réaction du dinitro-2,4 chlorobenzène et du chlorure de picryle avec les amines primaires et secondaires
Authors: Bruylants Albert , Minetti R.
Published: June 2020

The reactivity of 2,4dinitro-chlorobenzene (DNCB) and of 2,4,6trinitro-chlorobenzene, or picryl chloride (PC), with various primary and secondary amines has been studied.

These reactions occur nearly quantitatively generating the corresponding dinitro-(DNA) or trinitro-anilines (TNA). They are governed by a second order law, V = k2[DNCB] [Amine] or V = k2[PC] [Amine], of which corresponding values of k2 has been determined at 20 °C, using the experimental absorbance as a measure of the concentration of the formed DNA or TNA, respectively.

It is shown that PC is about 104 time more reactive than DNCB ; primary amines are reacting faster than secondary amines, except piperidine which is far the fastest, and also that reactions of DNCB only conform to the usual free energy correlation with the nucleophilicity parameter (log k2/n).
Variational and moment methods for shock structure
Authors: Narasimha R.
Published: June 2020

The inter-relations among various approximate methods of solving the Boltzmann equation for the structure of a shock wave are discussed. It is shown that a certain class of moment methods and variational principles, including the local potential technique, have many desirable properties, and give the best results, in a least square sense, at infinite Mach number. A simple explanation for this apparent coincidence is found in the principle of balancing delta functions. It is also shown that the so-called minimum local error method can be interpreted as the "best" moment method in the sense that it minimizes the maximum error among all moment method solutions.
Étude de la substitution nucléophile aromatique. II. Cinétique de la réaction du chlorure de picryle avec l'imidazole et schéma réactionnel de l'action des amines sur les chloro-nitro-arènes
Authors: Bruylants Albert , Minetti R.
Published: June 2020

Picrylchloride (CP, on mole) reacts quantitatively with imidazole (IA, two moles), in CHC13 as solvent, giving N-picrylimidazole (PI, one mole), as it was already mentionned in the first paper of this series.

This system (CP-IA) does not follow a simple kinetic law : it has been observed that at relatively low concentration in IA ([IA] = b ; [CP] = a. ml-1) the apparent second order rate constant, k'2, depends linearly of b(k'2 = k2o + k3b, if b = 2a) ; at relatively high concentration (b > 20a), on the contrary, k'2 is independent of [IA], being a true second order constant

(k'2 = k2).

Now considering the whole body of our experimental results, relatively to the systems of DNCB-Amines, CP-Amines (first paper), and CP-Imidazoles (this paper), taking also in account the fact that a foreign base (diaza-bicyclo-octane) does not affect the reactivity of the formers, while it accelarates the last, which is also sensitive to the catalysis by the solvent (CHCl3), we developed a reaction scheme consisting of two steps : both reactants (A and B) generate an intermediate (Z), which decomposes in the products. As to the concentration of Z, the kinetic law is based on the steady state treatment which conforms to the experimental equation. The difference in behaviour of the various systems can best be explained in terms of structural differences of Z.
Nouvelles recherches sur les involutions cycliques appartenant à une surface algébrique (première note)
Authors: Godeaux Lucien
Published: June 2020

Détermination des systèmes linéaires partiels de courbes tracées sur une surface algébrique composés au moyen d'une involution cyclique n'ayant qu'un nombre fini de points unis de première espèce appartenant à cette surface et faisant partie d'un même système linéaire.
Sur la stabilité des ondes simples de compression et de raréfaction
Authors: Glansdorff Paul , Banaï Nozar
Published: June 2020

We consider in this paper the linear stability problem of an isentropic, one-dimensional flow of a perfect fluid. In particular, we investigate the stability of the simple rarefaction and compression wave. We prove the instability of the compression wave when dissipative effects are disregarded. We follow the method formerly established by one of us and Prigogine on the stability of non equilibrium states (Physica 46, 344, 1970). The example treated, belongs to the class of time dependent stability problems.
Effet de la température sur l'intensité apparente des bandes de vibration de valence OH de solides inorganiques
Authors: Rouxhet Paul G. , Fripiat José Jean
Published: June 2020

Lorsqu'on enregistre les bandes de valence OH de nombreux minéraux maintenus à température élevée, tout en supprimant l'effet de l'émission, on observe une diminution de l'intensité d'absorption en fonction de la température.
Cause de la mort dans la saprolégniose expérimentale du poisson
Authors: Nolard-Tintigner Nicole
Published: June 2020

Deux souches de Saprolegnia : Saprolegnia ferax et Saprolegnia sp. ont été inoculées dans la région caudale à deux espèces de poissons exotiques : Lebistes reticulatus et Xyphophorus helleri. Les résultats des études histopathologiques ont permis de mettre en évidence un envahisse¬ ment mycélien des organes profonds. Le champignon envahi les vaisseaux, particulièrement l'aorte et la veine caudale, détruit leur paroi et provoque d'importantes hémorragies. Il envahi également la moelle épinière dont les cellules entrent en nécrose.
Nouvelles recherches sur les involutions cycliques appartenant à une surface algébrique (quatrième note)
Authors: Godeaux Lucien
Published: June 2020

Étude du comportement en un point uni des courbes d'un système linéaire appartenant à une involution.
Sur les oscillations toroïdales de modèles planétaires sphériques
Authors: Denis Carlo
Published: June 2020

Some general properties of the second order system for torsional modes of a solid sphere are established by showing that this system is strictly equivalent to a classical Sturm-Liouville eigenvalue problem of type II. The general form of the regular eigenfunction near the centre is given, and a particular form of the system is derived which enables one to start numerical integration right at the centre.
Sur les transformations de Ribaucour des systèmes triples orthogonaux
Authors: Backès Fernand
Published: June 2020

Si deux points P, Q engendrent de tels systèmes triples orthogonaux, nous caractérisons le complexe des cercles de foyers P. Q. Nous indiquons aussi un mode d'obtention des cercles communs à deux sphères engendrant des complexes conjugués. Nous caractérisons aussi les cercles de Demoulin, porteurs de deux séries de points décrivant des systèmes triples orthogonaux.
Mathematical systems with mixed structures. Functional integral and integro-differential equations of Cauchy's type
Authors: Oguztöreli Mehmet N.
Published: June 2020

In this paper we investigate certain functional integral and integro-differential equations related with the classical functional equation of Cauchy.
Phonon dispersion in rare-gas crystals
Authors: Gupta R. K.
Published: June 2020

A central-force, rigid-atom model has been used to study the lattice dynamics of frozen rare gases. The model assumes central, short-range, two-body forces derivable from a modified Buckingham (exp, 6) potential. The intermolecular potential parameters of rare-gas solids have been calculated using crystal data of the sublimation energy and lattice spacing extrapolated to 0°K. The model takes account of zero-point energy and its volume derivatives by the Debye-theory of specific heats. The contribution of cubic and quartic terms of potential energy expansion to lattice free energy at 0°K has been taken into account by successive approximations. The theoretical frequency distribution and phonon dispersion curves computed on the basis of Born-Karman theory, using the above potential parameters are found to compare reasonably well with the available experimental data.
Détermination de la structure d'un point uni d'une involution cyclique appartenant à une surface algébrique
Authors: Godeaux Lucien
Published: June 2020

Détermination de la structure d'un point uni d'une involution cyclique d'ordre premier p = 9v² + 3v + 1, appartenant à une surface algébrique, auquel sont attachés les nombres a = 3v² + 2v -f 1 et β = 9v² + 2.
Generalized geodesies in a Finsler space
Authors: Srivastava Subhash Chandra
Published: June 2020

In Riemannian space Hayden [1] studied the asymptotic lines of order p and Srivastava [4] obtained geodesies of order p for the same space. For the Finsler space Srivastava and Sinha studied the asymptotic lines of order p in one of their papers [5]. In this paper we define geodesies of order p, investigate their properties and establish relationship with the asymptotic lines of order p.
Diagramme gradients -pentes concernant des galaxies et des quasars
Authors: Vandekerkhove Edgard
Published: June 2020

Pour le rayonnement de galaxies et de quasars, au repos ou de faible vitesse radiale, et les régions spectrales de 0,50μ et 0,34μ, un diagramme plan est présenté ; ses coordonnées rectangulaires sont les gradients spectrophotométriques ou bien les pentes correspondantes du fond continu qui est déduit de la courbe des densités de flux absolues. Les points relatifs à trois galaxies compactes de Zwicky sont bien situés entre ceux de vingt-quatre quasars, neuf galaxies Seyfert, M 31, M 32 et huit galaxies géantes elliptiques. La situation de tous ces objets est aussi bien marquée relativement au corps noir et aux radiateurs tels que Fv = kv-α

et Fv = [FORMULA]. Les gradients du noyau ponctuel de la galaxie Seyfert NGC 4151 sont semblables à ceux du quasar 3C 273, tandis que les gradients d'une région centrale, étendue de 10n, sont très supérieurs à ceux d'une galaxie elliptique.

Le diagramme est complété par l'indication de la différence des densités de flux absolues pour les régions considérées. Les discontinuités de Balmer qui ont pu être mesurées sont toutes négatives ; leur valeur moyenne est - 0,08 pour cinq quasars et elle est - 0,07 pour la galaxie Seyfert NGC 7469. L'ensemble des signes des pentes, des différences de densités de flux absolues et de la discontinuité de Balmer, caractérise la forme du fond continu des densités de flux absolues dans ces régions spectrales.
Un Marronnier centenaire privé d'écorce. II. Racines et Mycorhizes
Authors: Martens Pierre
Published: June 2020

Cette étude fait suite à la relation de la survie extraordinairement prolongée d'un Aesculus hippocastanum, après une décortication basale complète du tronc. Des greffes ou soudures naturelles avec des racines d'arbres voisins de même espèce n'ont pas été trouvées. Par contre, les radicelles de l'arbre décortiqué, croissant à proximité de la surface du sol, sont, en grande abondance, de type mycorhizique endotrophe ; elles sont courtes, vésiculeuses, non ramifiées, privées de coiffe, de méristème terminal et de poils absorbants (fig. 1). Leur anatomie révèle une abondante infection mycélienne extra-et surtout intracellulaire dans le cortex (réseau de Hartig et arbuscules), sans pénétration dans la stèle (fig. 2-8).

A part l'infection mycélienne, la morphologie et la structure de ces radicelles correspondent exactement aux descriptions données, pour les radicelles de la même espèce, par Klein & Szabo ou Waage (1880, 1891) ; ces auteurs y voyaient un type radiculaire original et non des racines mycorhizées.

Les radicelles d'un Marronnier voisin et normal présentent, en surface, la même allure, la même structure interne et la même infection mycélienne corticale (fig. 9-13). L'espèce peut donc être admise comme normalement mycorhizée.

On s'est demandé si — et dans quelle mesure — la présence de mycorhizes pourrait justifier la survie pratiquement indéfinie de l'arbre décortiqué. La difficulté réside ici dans le bilan physiologique, admis le plus généralement entre les deux partenaires de la symbiose, et selon lequel les sucres photo-synthétisés par l'hôte constitueraient le bénéfice principal du champignon. Or c'est précisément de sucres qu'une décortication devrait surtout priver les racines, si le liber reste la seule voie normale de descente de ces produits. Néanmoins certaines données expérimentales vont dans un autre sens et nous n'excluons pas une intervention possible et limitée des mycorhizes dans la nutrition glucidique des racines. Qu'elle ait pu suffire à justifier la survie constatée est, selon nous, exclu ; et il ne pourrait s'agir, en tout cas, que d'un éventuel appoint. Car la persistance de l'accumulation massive d'amidon dans toute la colonne de bois dénudé reste un témoignage plus concret de la descente abondante de glucides solubles par cette voie.
Élimination du temps et équation différentielle des trajectoires dans le problème des trois corps restreint, circulaire, plan
Authors: Sergysels-Lamy Anne , Sergysels Roland
Published: June 2020

It is well known that the system of differential equations of motion in the circular, planar, restricted problem of three bodies can be reduced to the second order, using the Jacobian integral to eliminate time. However, the differential equation of trajectories, so obtained, is extremely complex and is of no practical use.

But, in the case of weakly perturbed Keplerian motion and not using the Jacobian integral to eliminate time, the differential equation of trajectories has a form that makes possible its study by known methods of nonlinear mechanics.
Homogeneous r-tangent structures
Authors: Eliopoulos Hermes A.
Published: June 2020

Définition des espaces homogènes de Lie aux structures r-tangentes. Conditions nécessaires et suffisantes pour qu'un espace homogène puisse être doué d'une structure homogène r-tangente.
Note sur la découverte de dents de mammifères dans le Montien continental du Hainaut (Belgique)
Authors: Godfriaux Ivan , Thaler L.
Published: June 2020

Découverte dans le Montien continental d'Hainin (Hainaut-Belgique) de dents de mammifères qui se rapprochent des espèces nord-américaines du Paléocène moyen et supérieur.

Dans le Tertiaire européen, cette faune est la plus ancienne datée.
Ondes liquides de gravité au-dessus d'un cylindre circulaire immergé
Authors: Sips Robert
Published: June 2020

Étude de la propagation des ondes liquides de gravité au-dessus d'un cylindre circulaire immergé. Comparaison entre la solution exacte et une solution approchée obtenue par une nouvelle méthode.
Description microscopique des deux premiers niveaux de 9Be
Authors: Fuld-Rouserez M.
Published: June 2020

A microscopic calculation of the intrinsic energies of the ground state and of the first positive parity state (at. 1.75 MeV) of the Be9 nucleus is presented. We generalize the cluster model of Brink to a two a particle system with an additional neutron described by means of a definite parity molecular wave function. The variational calculation is made by using spherical and spheroidal orbitals.
Structure et évolution des amas stellaires dans la phase de relaxation
Authors: Talpaert Yves
Published: June 2020

Dynamical models related to the clusters structure in the relaxation phase are presented as well as their evolution using a series of equilibrium models of King's type, each one corresponding to a determined central concentration.

This study takes into account the cluster limits imposed by the tidal force of the Milky Way and an increasing velocity space anisotropy at greater distances from the center of the system. The introduction of this anisotropy leads to a better fit between the theorical projected density curves and King's empirical curves.

However, to reduce the difference between these curves, we had to intro¬ duce a mass spectrum so that the projected densities are corresponding exactly to the empirical densities.

For given masses, escape rates are obtained which remain pratically unchanged during evolution. Contrarily to King's equal masses models, where the evaporation is practically the same everywhere, the star loss is the greatest in the central regions. Evaporation times estimations are given for co Cen. and NGC 7789 clusters.
Construction de quelques surfaces projectivement canoniques (2e note)
Authors: Godeaux Lucien
Published: June 2020

Compléments aux résultats obtenus dans la première note.