1,720,958 research outputs found
Production of biopolymers from pumpkin shell waste and its effect on filtration and rheological properties of water-based drilling mud- toward sustainable drilling
Get PDFMeeting global energy demand in a sustainable way requires cost-effective, environmentally friendly, and biodegradable water-based drilling fluid (WBDF) that can be used for sustainable drilling. Nevertheless, the fluid loss into the formation during the drilling is a major issue of WBDF. Various chemical-based fluid loss additives in the industry have been used to control WBDF loss into formation. However, using chemical additives poses a risk to the environment, pollutes water reserves, and threatens the ecosystem. In this study, based on pumpkin peel waste (PPW), a biopolymer additive was introduced to enhance WBDF filtration and rheological properties. The sample of the PPW was dried, crushed and grounded using a ball mill into two very fine (10μm) and fine (75μm) particle sizes. Then, the samples were added to the conventional WBDF at optimum weight concentrations of 3wt%, and the rheological and filtration properties of the proposed WBDF were investigated using industry API filtration and rheological tests. Furthermore, major elemental analyses of the samples were carried out using an energy-dispersive x-ray spectrometer (EDX), fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The results of filtration test indicate adding 3wt% of very fine (10μm) and fine (75μm) PPW biopolymer reduced fluid loss by 38.8% (from 18cc to 11cc) and 33.3% (from 18cc to 11cc) for the duration of 25 minutes. This also resulted in formation of thin filter cakes of 3mm and 2.5mm when very fine and fine particles of PPW were added to the mud, respectively.
The rheological property tests indicated that using PPW biopolymer in WBDF increases mud density slightly by 1.12%. Moreover, the apparent viscosity of the reference WBDF was increased by 50% (from 4cp to 8cp) and 35% (from 10cp to 13.5cp) adding 3wt% PPW of 10μm and 75μm, respectively. In addition, adding same concentration of very fine and fine particles of PPW would increase the yield point of the WBDF by 33% (from 12 to 18 Ib/100ft2) and 7.7% (from 12 to 13 Ib/100ft2).
The proposed biopolymer not only has environmental benefits but also offers technical enhancements to drilling fluid performance, particularly in filter cake formation where they contribute to improved sealing capabilities and fluid loss control
Communicating and sharing knowledge via the web: a contextual study of Web-based communication platforms in project teams
No full textThis thesis explores the contextual factors that can affect the use of Web-based communication platforms for work purposes. Although several position papers have described potential benefits that Web-based communication platforms might have within organisations, the success of any digital product or service will depend, in part, on whether the product satisfies its context of use (Cockton, 2004; Maguire, 2001). Therefore, this thesis specifically examines the context of use through (a) understanding users and non-users and their daily activities and (b) understanding the way that Web-based communication platforms are implemented within the users’ daily work activities.
Three empirical studies were conducted. Study one identified and characterised the contextual factors associated with the use of Web-based communication platforms based on the PACT (People, Activity, Context, and Technology) framework proposed by Benyon et al. (2005). The results show that the use of Web-based communication platforms varies for participants in managerial and non-managerial roles. Additionally, the level of use depends on the nature of the Web-based communication platform (social network or proprietary software), team structure (centralised or distributed), time of use and type of activities performed using the software. Moreover, from the results of open-ended questions, the researcher found that the variables of the technology acceptance model (TAM) introduced by Davis (1986) also impact the use of Web-based communication platforms for work purposes.
The second study explored how project teams use Web-based communication platforms and identified actual benefits, challenges, and barriers to use of these platforms when implemented and used within a project context. This study considered non-users, in addition to users, to understand their current communication methods and reasons for not using Web-based communication platforms for work purposes. Interview results were separated into four specific high-level codes for non-users, seven specific high-level codes for users and four common high-level codes for users and non-users. As the results of this study contributed to the outline of a Persona skeleton, the researcher found that the original Pruitt and Grudin (2003) Persona skeleton could be expanded to include (a) problems in use, (b) management style/implementation problems, (c) technology benefits, and (d) motivation to learn. In total, six Personas were created, of which, three followed the original Persona foundation document and were called “Actual Personas” and three stemmed from the findings of this research and were called “Enhanced Personas”.
The third study validated the Personas using eleven criteria of reality, validity, believability, personified, empathy, credibility, engaging, completeness, willingness to use, usefulness, and memorability. These criteria were extracted from studies of Nieters et al. (2007), Wikberg Nilsson et al. (2010), Matthews et al. (2012) and Salminen et al. (2018)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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