scholarly journals Flammability of litter sampled according to two different methods: comparison of results in laboratory experiments

2014 ◽  
Vol 23 (8) ◽  
pp. 1061 ◽  
Author(s):  
Anne Ganteaume ◽  
Marielle Jappiot ◽  
Thomas Curt ◽  
Corinne Lampin ◽  
Laurent Borgniet

In the laboratory, different types of litter samples (constructed v. intact) can be used in flammability experiments but the sampling method of these litters could affect litter flammability results. To assess this effect, samples of litters were collected in South-eastern France, according to two different methods previously used in other studies, one keeping intact the structure of the litter layers (non-constructed litter) and the other requiring the construction of the litter, using mainly the surface litter layer (constructed litter). The comparison of flammability results showed that the sampling method had a significant effect on litter bulk-density, rate of spread and rate of consumption, intact litter being more flammable than reconstructed litter that was artificially compacted. The type of vegetation had a significant effect on litter depth, ignitability, sustainability, consumability and combustibility (except on rate of spread) and the litter composition could explain in part this fire behaviour. The effect of the construction of litters on flammability parameters and its magnitude also differed according to vegetation types. Intact litter structure appeared to be an important driver of its flammability, especially of combustibility and consumability. The assessment of these flammability components will differ when using constructed litter samples instead of intact litter samples, especially according to vegetation types. Future research on litter flammability should take into account the bias due to the litter sampling method when the litter is constructed.

1995 ◽  
Vol 5 (3) ◽  
pp. 153 ◽  
Author(s):  
JL Dupuy

Laboratory fire experiments were conducted in both Pinus pinaster and Pinus halepensis litters in order to investigate the effect of slope on fire behaviour for different levels of fuel load. Simulated slopes ranged between -30 degrees and +30 degrees. The results are reported in terms of rate of spread and rate of mass loss when observed fire was quasi-steady. Upslope fires were observed, on the present devices, to be unsteady, and their flame to be three-dimensionnal, when slope and fuel load exceeded certain limits. The heat transfers involved in the explanation of the observed behaviours are discussed, especially on the base of the quite different results obtained in the two tested fuel. beds.


Author(s):  
Hairul Azhar Mohamad ◽  
Muhammad Luthfi Mohaini ◽  
Pavithran Ravinthra Nath

This research investigated into the lexical density and frequencies of five types of lexical chunks located in 300 online business letters. Top 10 websites on business correspondence had been identified in terms of traffic visitors and bounce rate under one million web rankings worldwide. Criterion Sampling method was identified prior to extracting the sample letters from the websites. The data was then run with Antconc Concordance Program (ACP) for lexical density and frequency analysis. Top 15 lexical chunks in online business letters (OBL) were compared against those top 15 in Business Letter Corpus (BLC). Findings revealed that there was a total of 39 916-word tokens and 939 counts of lexical chunks found in this corpus. It was found that more lexical words do not imply more lexical chunks used in based on types of business letters.  All 5 types of lexical chunks were identified and ranked in descending order; Sentence Builders (SB) as the most frequent type, followed by Collocations (COL), Deictic locutions (DLs), Polywords (POLs) and Institutionalized Expressions (IUs) as the least frequent type of lexical chunk. Sub-divisional analysis indicated that Grammatical Collocations (GCs) were more common than Lexical Collocations (LCs). Majority of lexical chunks were formed more at sentence level than phrasal level. Comparative analysis between top 15 lexical chunks in OBL and BLC discovered that most top lexical chunks in online business letters are representative of those corporate business letters in BLC. Pedagogical implications in terms of the reliability of online business letters for academic reference and future research considerations are also addressed.


Author(s):  
Е.М. Григорьева

Постановка задачи. Статья посвящена детальному анализу фразеологизмов английского языка различных тематических групп и особенностям их регистрации в англо-английских и англо-русском словарях и справочных пособиях. Рассматривается ряд характеристик, которые отличают фразеологические единицы от свободных словосочетаний. Кроме того, исследуется вопрос включения пословиц в состав фразеологического фонда того или иного языка. Впоследствии отобранные методом сплошной выборки фразеологические единицы классифицируются по различным основаниям, а также проводится детальный анализ особенностей их отражения в представленных изданиях. Результаты. Осуществляется классификация фразеологизмов по следующим категориям: функция в коммуникации, определяемая их структурно-семантическими особенностями, а также тематическое деление. Отдельно рассматриваются фразеологизмы-эвфемизмы, относящиеся к нескольким тематическим группам, среди которых смерть, ругательства и беременность. Выделяются и описываются характерные особенности организации микроструктуры (словарной статьи) каждого отдельно взятого издания. Выводы. На основании проведенного анализа регистрации английских фразеологизмов сделаны выводы о том, что данная лексика получает подробное и точное отражение в справочниках. Проведенный анализ теоретической литературы показал правомерность включения пословиц во фразеологический фонд, поскольку они принадлежат к культурному наследию того или иного народа и воспроизводятся в речи в исходной форме. Тип и адресат справочника определяют особенности организации словарной статьи, а также компоненты, которые входят в нее (дефиниция, переводной эквивалент, иллюстративный пример, грамматическая, стилистическая, региональная и этимологическая пометы, графическая иллюстрация). Statement of the problem. The article is devoted to a detailed analysis of the phraseological units of the English language of various thematic groups and the features of their registration in the English-English and English-Russian dictionaries and reference books. Features that distinguish phraseological units from free phrases are studied. More than that, the question of belonging proverbs to phraseological stock is studied. Then phraseological units selected by the continuous sampling method are classified according to different grounds, and a detailed analysis of the features of their reflection in the analyzed sources is carried out. Results. Phraseological units are classified into some categories according to the following criteria: function in communication, determined by their structural and semantic features and thematic division. Phraseological units-euphemisms related to several thematic groups, including death, curse words and pregnancy are studied. The characteristic features of microstructure organization of each individual source are described. Conclusion. The analysis of English phraseological units registration showed that this lexis is reflected in dictionaries in a proper way. Theoretical literature analysis shows justification of proverbs inclusion into phraseological stock as they are a part of national cultural heritage and are reproduced in speech in the basic form. Further, the author comes to a conclusion that dictionary type and addressee of the reference book determine features of microstructure organization and their components (definition, translation equivalent, illustrative example, grammar, stylistic, regional and etymological labels, graphic illustration).


Author(s):  
Xu Pei-Zhen ◽  
Lu Yong-Geng ◽  
Cao Xi-Min

Background: Over the past few years, the subsynchronous oscillation (SSO) caused by the grid-connected wind farm had a bad influence on the stable operation of the system and has now become a bottleneck factor restricting the efficient utilization of wind power. How to mitigate and suppress the phenomenon of SSO of wind farms has become the focus of power system research. Methods: This paper first analyzes the SSO of different types of wind turbines, including squirrelcage induction generator based wind turbine (SCIG-WT), permanent magnet synchronous generator- based wind turbine (PMSG-WT), and doubly-fed induction generator based wind turbine (DFIG-WT). Then, the mechanisms of different types of SSO are proposed with the aim to better understand SSO in large-scale wind integrated power systems, and the main analytical methods suitable for studying the SSO of wind farms are summarized. Results: On the basis of results, using additional damping control suppression methods to solve SSO caused by the flexible power transmission devices and the wind turbine converter is recommended. Conclusion: The current development direction of the SSO of large-scale wind farm grid-connected systems is summarized and the current challenges and recommendations for future research and development are discussed.


Author(s):  
Bianca Beersma ◽  
Gerben A. van Kleef ◽  
Maria T. M. Dijkstra

This chapter provides an overview of the antecedents and consequences of gossip in work groups. First, the chapter reviews the different motives for gossip in work groups (i.e., bonding, entertainment, emotional venting, information exchange, maintenance of group norms/social order, and interpersonal aggression) and links each motive to psychological theory. Second, the chapter reviews the different types of influence that gossip can have on various indicators of group effectiveness. Reflecting on the motives underlying gossip in work groups, as well as on its outcomes, it argues that future research should start integrating the diverse insights provided by earlier research on both gossip motives and outcomes, and it provides a number of suggestions for doing so.


2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.


Robotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 53
Author(s):  
Luiz F. P. Oliveira ◽  
António P. Moreira ◽  
Manuel F. Silva

The development of robotic systems to operate in forest environments is of great relevance for the public and private sectors. In this sense, this article reviews several scientific papers, research projects and commercial products related to robotic applications for environmental preservation, monitoring, wildfire firefighting, inventory operations, planting, pruning and harvesting. After conducting critical analysis, the main characteristics observed were: (a) the locomotion system is directly affected by the type of environmental monitoring to be performed; (b) different reasons for pruning result in different locomotion and cutting systems; (c) each type of forest, in each season and each type of soil can directly interfere with the navigation technique used; and (d) the integration of the concept of swarm of robots with robots of different types of locomotion systems (land, air or sea) can compensate for the time of executing tasks in unstructured environments. Two major areas are proposed for future research works: Internet of Things (IoT)-based smart forest and navigation systems. It is expected that, with the various characteristics exposed in this paper, the current robotic forest systems will be improved, so that forest exploitation becomes more efficient and sustainable.


2021 ◽  
pp. 875697282199534
Author(s):  
Natalya Sergeeva ◽  
Graham M. Winch

This article develops a framework for applying organizational narrative theory to understand project narratives that potentially perform and change the future. Project narratives are temporal but often get repeated throughout the project life cycle to stabilize meaning, and could be about project mission, vision, identity, value creation, and so forth. Project narratives have important implications for organizational identity and image crafting. This article differentiates among different types of project narratives in relation to a project life cycle, providing case studies of project narratives on three major UK rail projects. We then set out the future research agenda into project narrative work.


Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 492
Author(s):  
Valentina Y. Guleva ◽  
Polina O. Andreeva ◽  
Danila A. Vaganov

Finding the building blocks of real-world networks contributes to the understanding of their formation process and related dynamical processes, which is related to prediction and control tasks. We explore different types of social networks, demonstrating high structural variability, and aim to extract and see their minimal building blocks, which are able to reproduce supergraph structural and dynamical properties, so as to be appropriate for diffusion prediction for the whole graph on the base of its small subgraph. For this purpose, we determine topological and functional formal criteria and explore sampling techniques. Using the method that provides the best correspondence to both criteria, we explore the building blocks of interest networks. The best sampling method allows one to extract subgraphs of optimal 30 nodes, which reproduce path lengths, clustering, and degree particularities of an initial graph. The extracted subgraphs are different for the considered interest networks, and provide interesting material for the global dynamics exploration on the mesoscale base.


2014 ◽  
Vol 25 (1) ◽  
pp. 2-29 ◽  
Author(s):  
Helena Rusanen ◽  
Aino Halinen ◽  
Elina Jaakkola

Purpose – This paper aims to explore how companies access resources through network relationships when developing service innovations. The paper identifies the types of resource that companies seek from other actors and examines the nature of relationships and resource access strategies that can be applied to access each type of resource. Design/methodology/approach – A longitudinal, multi-case study is conducted in the field of technical business-to-business (b-to-b) services. An abductive research strategy is applied to create a new theoretical understanding of resource access. Findings – Companies seek a range of resources through different types of network relationships for service innovation. Four types of resource access strategies were identified: absorption, acquisition, sharing, and co-creation. The findings show how easily transferable resources can be accessed through weak relationships and low-intensity collaboration. Access to resources that are difficult to transfer, instead, necessitates strong relationships and high-intensity collaboration. Research limitations/implications – The findings are valid for technical b-to-b services, but should also be tested for other kinds of innovations. Future research should also study how actors integrate the resources gained through networks in the innovation process. Practical implications – Managers should note that key resources for service innovation may be accessible through a variety of actors and relationships ranging from formal arrangements to miscellaneous social contacts. To make use of tacit resources such as knowledge, firms need to engage in intensive collaboration. Originality/value – Despite attention paid to network relationships, innovation collaboration, and external resources, previous research has neither linked these issues nor studied their mutual contingencies. This paper provides a theoretical model that characterizes the service innovation resources accessible through different types of relationships and access strategies.


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