Littérature scientifique sur le sujet « CB. User studies »
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Articles de revues sur le sujet "CB. User studies"
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Yaa Anima Adzobu, Nesba. « Building digital collections in a public university library in Ghana : priority-setting and user needs assessment ». Collection Building 33, no 2 (1 avril 2014) : 38–45. http://dx.doi.org/10.1108/cb-10-2013-0040.
Texte intégralRésumé :
Purpose – Although user needs assessment is an intrinsic element of service quality delivery in digital libraries (DLs), not much has been written on this topic in the context of African universities. This is understandable as academic digital libraries in Africa are rather nascent. Even so, the most frequently-used needs assessment methods do not directly involve the users. This study aims to assess priority setting by academic library administrators and the needs of patrons of digital collections of a public university library in Ghana. Design/methodology/approach – Analysis of official university documents and interviews with digital library patrons at the University of Cape Coast (UCC) in Ghana were carried out between September, 2011 and January, 2012. Five research questions were asked: what are the current conditions of the UCC digital library project, the user communities and their needs, what are the priorities set by the university administrators and library leaders at the UCC and the state of technological readiness in place and what are needed by the UCCDL. Also, what is the extent of collaboration by interested parties in the UCCDL? Findings – Three general digital library user communities were identified, that is, UCCDL staff- this community was composed of experts in both digital library systems and content, characterized as heavy users of the existing systems, as knowledgeable about articulated (formalized) user needs, and able to devote short (usually less than two hours) amounts of time to individual's needs. Next, are scholars and other visitors to the UCCDL – this community was characterized as having high levels of domain expertise and knowledge of library systems. They are also able to devote large but specific amounts of time (days or weeks) to their individual information needs. Visitors/Prospective users- this community was characterized as having varied levels of domain expertise and low levels of library systems knowledge. They are able to devote only short periods of time to their information needs or explorations. These user communities are influenced by diverse preferences, experiences, and knowledge structures. Practical implications – Academic libraries are increasingly advocating local user studies as a way to provide the digital library services that are relevant to the culture and user population of the academic institution. Replicating digital library user studies at the local level can provide information for improving existing services or developing new ones. Originality/value – In African public universities, there is little earlier research on digital library user needs assessments or DL priority-setting by academic library administrators.
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Hadi Putra, Panca O., Sendhy Nugroho et Achmad Nizar Hidayanto. « Factors Affecting User Retention of Mobile Mutual Fund Investment Applications : Evidence from Indonesia ». Human Behavior and Emerging Technologies 2022 (8 octobre 2022) : 1–13. http://dx.doi.org/10.1155/2022/7521680.
Texte intégralRésumé :
Mutual fund is one of the most popular investment programs, especially among small investors. Currently, many mobile-based applications are available, facilitating the buying and selling of mutual funds. This number of choices creates competition between application developers, pressuring them to find ways to maintain user loyalty by increasing user retention rates. However, only a few studies have currently discussed user retention in mutual fund investment applications. Furthermore, previous studies never examined the quality factor of the application but instead focused more on other factors outside the application. This study analyzed the factors influencing user retention on mutual fund investment applications in Indonesia from the application’s quality and usability aspects. This study was based on the expectation-confirmation model (ECM) as the underlying theory. Data were collected using a survey questionnaire resulting in 414 responses, which were then processed and analyzed using the covariance-based structural equation modeling (CB-SEM) technique. The results of this study indicate that three variables can directly affect user retention in mutual fund investment applications: satisfaction, perceived usefulness, and perceived enjoyment. The satisfaction variable had the most significant influence of these three variables. Several factors influenced satisfaction: perceived usefulness, enjoyment, ease of use, trust, confirmation, prompt response, and security.
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Jeon, Youngseung, Bogoan Kim, Aiping Xiong, DONGWON LEE et Kyungsik Han. « ChamberBreaker : Mitigating the Echo Chamber Effect and Supporting Information Hygiene through a Gamified Inoculation System ». Proceedings of the ACM on Human-Computer Interaction 5, CSCW2 (13 octobre 2021) : 1–26. http://dx.doi.org/10.1145/3479859.
Texte intégralRésumé :
Because of the increasingly negative impacts of the echo chamber effect, such as the dissemination of fake news and political polarization occurring in social networking services (SNSs), considerable efforts are being made to mitigate this effect. Prior HCI studies have presented the development of user interfaces to display information that reflects various standpoints, with the aim of nudging people to consume information in a more objective fashion. However, these efforts still lack the ability to highlight the characteristics, generation processes, and negative effects of echo chambers, so they may not be effective in helping people become sufficiently aware of the echo chamber effect and those who are already in an echo chamber. In this paper, we present ChamberBreaker (CB), which has been designed to help increase a player's awareness of and preemptively respond to an echo chamber effect based on psychological concepts: inoculation, heuristics for judging, and gamification. Through a user study with 882 participants (control group: 446, experimental group: 436), we demonstrated the feasibility of our game-based methodology to support the awareness of the echo chamber effect and the importance of maintaining diverse perspectives when consuming information. Our findings highlight the externalization of psychological standpoints in mitigating an echo chamber effect and suggest design implications for system development---the consideration of demographics, playing time, and the connection to fake news recognition---for digital literacy education. You can play CB at http://tiny.cc/chamberbreaker (The game only works with Chrome.)
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Lobato-Calleros, Odette, Karla Fabila-Rodríguez et Brian Roberts. « Methodology to Improve the Acceptance and Adoption of Circular and Social Economy : A Longitudinal Case Study of a Biodiesel Cooperative ». Sustainability 14, no 19 (29 septembre 2022) : 12394. http://dx.doi.org/10.3390/su141912394.
Texte intégralRésumé :
Purpose: The aim was this study was to test the effectiveness of the Mexican User Satisfaction Index of Circular and Social Economy (MUSI-CSE) methodology to improve user acceptance and the adoption of biodiesel from the Cowichan Bio-Diesel Co-op (CB-DC), a social enterprise that upcycles cooking oil waste. Approach: The external strategy is to study factors of user experience with products and/or services and internal processes. This type of economy tends to build its value chain independently to avoid barriers in the economic structure. Methodology/Techniques: MUSI-CSE presents a model of satisfaction (present acceptance) and loyalty (future acceptance) factors and a measurement system comprising the same factors. It also identifies and monitors interventions in key factors and evaluates their effectiveness. Here, MUSI-CSE has been tested through a longitudinal and prospective study. In-depth interviews, surveys, SEM, and PLS were used. Findings/originality/applicability: User acceptance and adoption are based on self-benefits and the achievement of specific sustainable local development goals. Satisfaction did not change. Loyalty did experience a statistically significant increase at a 95% confidence level, and sales increased by 26%. It can be concluded that MUSI-CSE innovation contributed to improving users’ future acceptance and adoption. In the future, MUSI-CSE will be adjusted based on other case studies and will support the co-creation of an international methodology and index of circular and social economy.
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Mason, Katherine F. « Using student activity trends to inform purchasing : a layered model for collection management ». Collection Building 35, no 2 (4 avril 2016) : 54–56. http://dx.doi.org/10.1108/cb-09-2015-0018.
Texte intégralRésumé :
Purpose The purpose of this paper is to explore the development of a layered model for describing student activity that librarians can use to inform collection management decisions. It proposes using student activity in the classroom and the library, physically and virtually, to increase understanding of student curricular and research needs. The model can be used as a tool to facilitate conversations and can be adapted for use in large and small projects. Design/methodology/approach The paper used a theoretical approach using Mathematics Department as an example, with supporting evidence from existing studies and research. As a theoretical paper, data are discussed in the framework of what information you might use. Findings Experimentation suggests that the framework of student activity provides a meaningful assessment of collection contents that can be used to inform collection development activities. Implementation of the model in response to a specific research question may build evidence towards the assertion that patterns of academic activity and library use should be used to improve collection offerings. Research limitations/implications Further research is required to determine which criteria are most appropriate for inclusion in specific collection development activities and which questions are best suited for modeling. Practical implications The paper includes implications for developing student “personas” that can be used in collection building and beyond. Social implications The framework introduced can be used by libraries of any size or type to develop a layered model of student, or more generally user, activity. Originality/value This paper adds a flexible, responsive process to the body of collection assessment methods.
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Oliva, Victor T. « Deselection of print monographs in the humanities and social sciences in the digital age ». Collection Building 35, no 2 (4 avril 2016) : 37–47. http://dx.doi.org/10.1108/cb-02-2016-0002.
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Purpose For most college and university libraries, deselection of monographs should be an essential component of collection development. Few of these libraries have unlimited space for book stack expansion. This research study aims to cover the reasons why this should be undertaken and how it can be accomplished in the humanities and social sciences. At the main campus of Adelphi University Libraries, a conservative approach was used to identify and carefully review monograph titles that were published more than 50 years ago, and, in most cases, this resulted in their deselection without significantly affecting the collection. For some of these titles, the author determined that they might be worth replacing with available e-books and the author did so. Design/methodology/approach A brief overview is provided to delineate why deselection is important, and how it can be accomplished. A literature review was prepared. It included a review of deselection at small-, medium- and large-sized college and university libraries. The pros and cons of print versus e-books for collection development were reviewed, including four case studies. The feasibility of replacing print reference titles with e-books was also covered. A review of the monograph weeding project at the Adelphi University Library in the humanities and social sciences is provided. Conclusions and a projection of next steps are also included. Findings An overwhelming majority of the monograph titles reviewed were deselected without adversely affecting the overall quality of the collection. A small number of available e-book editions were selected to replace some of these deselected titles. Research limitations/implications All of the titles deselected were published more than 50 years ago. All of these titles were in the social sciences and humanities. The deselection review was limited to philosophy, religion, history, political science, sociology, education and psychology. There were limitations on the amount of time available to review titles in most of these fields, and as a result, only a small percentage of the titles in our collection could be reviewed. Practical implications The library has very serious space constraints, which has made it difficult to provide the needed study space for members of the Adelphi University community. Some sections of the book collection are jam packed, with no room for expansion. Deselecting older less used titles and eliminating some sections of book shelves help address both of these problems. Replacing some of these print titles with e-books contributes as well. This deselection project has reduced the holdings of monograph print titles significantly. In the future, the author hopes to rely less on print titles and more on e-books for collection development. Social implications In most fields, college and university students would be better served for their research by more recently published titles. Older, less used titles, as well as those not used at all, should be deselected to make room for more useful and up-to-date titles. As more and more titles become readily available as e-books, the collections of print titles can be reduced. Being able to use e-books even when the library is closed is a great advantage. It should also be noted that these titles can be used by more than one user simultaneously. Originality/value In conducting the literature search, the author discovered that there were a large number of titles on deselecting print titles. There was also considerable research on e-book collection development. However, there were few that linked these two important topics. In this research article and case study, the author hopes to have made a significant contribution to linking them together.
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Kato, Atsushi, Maiko Nishioka, Yoshihiro Sato, Etsuko Nagano, Riko Yamashita, Norihito Kimura et Takehiko Taguchi. « STUDIES ON BOUND RUBBER OF CB BEFORE/AFTER VULCANIZATION OF ISOPRENE RUBBER ». Rubber Chemistry and Technology 87, no 3 (1 septembre 2014) : 471–85. http://dx.doi.org/10.5254/rct.14.86974.
Texte intégralRésumé :
ABSTRACT The high abrasion furnace (HAF), fast extrusion furnace (FEF), and fine thermal (FT) loadings used in this study were adjusted to keep the carbon black (CB)–specific area of cetyl trimethyl ammonium bromide adsorption to 2490 m2g−1. Their polyisoprene (IR) compounds and vulcanizates were investigated. Regarding the dependence of the CB gel fraction (FCB gel) on the IR gel/CB weight ratio (WRIR/CB), the amount of CB in the CB gel increased with a larger CB aggregate size, whereas the amount of the IR gel decreased. With regard to the dependence of the activation energy (ΔE(T2)) of the spin–spin relaxation time (T2) on the CB aggregate size, an immobilized rubber layer around CB formed more easily in the order of FT < FEF < HAF. Moreover, it became clear from the relationship between WRIR/CB and ΔE(T2) that the amount of the IR gel in the CB gel increased with decreasing ΔE(T2). The unique ratio of the surface area to the volume of CB aggregates (SCB/VCB) was obtained from results of three-dimensional transmission electron microscopy observation. The dependence of the amount of dibutyl phthalate (DBP) adsorption and compressed DBP adsorption on SCB/VCB was approximately linear, which suggested that SCB/VCB was closely related to CB aggregates and CB agglomerates. The linear relationship seen between SCB/VCB and ΔE(T2) revealed that an immobilized rubber layer was present around CB. The dependence of (qCB/qIR)(WRIR/CB) on SCB/VCB was also investigated using the densities (ρIR and ρCB) of IR and CB. The slope (tirl) of their approximately linear relationship was about 3.9 nm, which almost agreed with the bound rubber thickness reported in the literature to date. It is also inferred that because the intercept (α), which reflects the change in the IR gel weight fraction, was about 0.04 (4%), the IR gel weight fraction changed very little between before and after vulcanization.
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Miner, R. C. « What Does Obligation Add to Virtue-Descriptions ? Some Uses of Anscombe's Law/Game Analogy ». Christian Bioethics 14, no 2 (1 août 2008) : 165–74. http://dx.doi.org/10.1093/cb/cbn008.
Texte intégral
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Liu, Wei, Lin Li, Bing Kai Han et Cheng Zhong Zong. « Studies on Mechanical Properties and Dynamic Performance of SSBR/CB/Silica Composites ». Key Engineering Materials 717 (novembre 2016) : 52–56. http://dx.doi.org/10.4028/www.scientific.net/kem.717.52.
Texte intégralRésumé :
Carbon black ( CB ) and silica were used as two-component fillers to enhance the practicability of rubber. In this study, the microstructure, mechanical and dynamic properties of solution-polymerized styrene-butadiene rubber ( SSBR ) vulcanizates filled with carbon black and silica were characterized. 50 phr of total hybrid fillers was used as the base. A series of experiments with different ratios of CB/silica were carried out to determine the best contribution to the performance of SSBR vulcanizates. The studies have shown that when the vulcanizates exhibited the better overall mechanical and dynamic performance with 20 phr silica loading and 30 phr CB loading.
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Korb, Laura, Bhathika Perera et Ken Courtenay. « Challenging behaviour or untreated ADHD ? » Advances in Mental Health and Intellectual Disabilities 13, no 3/4 (12 juin 2019) : 152–57. http://dx.doi.org/10.1108/amhid-12-2018-0053.
Texte intégralRésumé :
Purpose The purpose of this paper is to illustrate the possible basis of challenging behaviour (CB) can lie in a treatable neurodevelopmental disorder. Design/methodology/approach Two case studies were used to illustrate the clinical characteristics of attention deficit hyperactivity disorder (ADHD) presenting as CB in people with intellectual disability (ID). Findings The findings of this paper show that the appropriate use of drug therapy for ADHD effectively reduced the behavioural challenges. Research limitations/implications Limited by two cases. Application of the findings of this paper is limited given it is a case study. This paper highlights an important clinical implications which need to be studied in a larger scale to make clinical recommendations. Practical implications Findings from the two case studies may be used when making decisions in clinical practice. Originality/value The paper explores the possibility of ADHD presenting as CB in people with ID.
Thèses sur le sujet "CB. User studies"
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Sequeiros, Paula. « Ler uma biblioteca nas inscrições de leitores, espaço e Internet : usos e representações de biblioteca pública ». Doctoral thesis, Porto : [Edição do Autor], 2010. http://hdl.handle.net/10216/50425.
Texte intégralRésumé :
Apresenta-se investigação, teoricamente orientada e empiricamente suportada, explorando e desenvolvendo possíveis relações entre usos da biblioteca pública, nas vertentes do uso de recursos documentais, do espaço e da Internet, por um lado, e, por outro, as suas representações. Recorrendo a uma abordagem qualitativa, aplicou-se o método de caso alargado, de Michael Burawoy, à Biblioteca Almeida Garrett na cidade do Porto. As ferramentas de recolha de informação foram entrevistas semiestruturadas, em profundidade, análise de desenhos de crianças, observação, análise documental de textos oficiais e fotografia. Entrevistaram-se vários leitores e leitoras, incluindo não-utilizadores de Internet, responsáveis, técnicos e pessoal de atendimento da biblioteca, assim como o arquitecto. Como resultados intermédios são apresentados vários perfis de utilizadores e é avançada uma explicação para a génese e funcionamento dum sistema tácito de regulação de condutas, sobretudo no que ao ruído diz respeito. Como resultado final conclui-se que não há nenhum «impacte» claramente disruptivo induzido pela Internet nas representações recolhidas e analisadas, colocadas em relação com as alterações recentemente registadas nas práticas leiturais: algumas imagens representacionais há em que a Internet reforça a imagem tradicional de biblioteca como organização enciclopédica, como conjunto de recursos diversificados; outras há em que, se o seu uso contribuirá, por um lado, para esse reforço, por outro, atualiza e democratiza essa representação pela abertura a práticas não eruditas e pela propiciação de usos recreativos, ou ainda de usos comunicacionais e instrumentais baseados na Internet; em situações mais extremas, quando biblioteca e Internet se usam como termos sinónimos da gramática representacional, (...).
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Chiong, Lanegra Luis Daniel. « Medición de la calidad del servicio de la Biblioteca de la Facultad de Letras y Ciencias Humanas de la UNMSM : una experiencia con LIBQUAL+TM ». Thesis, 2012. http://eprints.rclis.org/22908/1/tesis_daniel_chiong_libqual_unmsm.pdf.
Texte intégralRésumé :
The importance of libraries in academia is that they constitute one of the cores of the University , bring together teachers, researchers and students involved in the process of transforming information into knowledge. University libraries are very complex administration , there must manage and control large volumes of information . Also establish information services that meet the needs of the university community , considering that each segment of that community has key features.
The activity of managing a library should always aim at achieving the best possible results from foreseeable that might accrue as a result of that effort. Therefore is especially important in a library the process of obtaining information and data from the exercise of their management and valuation as a means weighted for management , ie the processes of management control and evaluation activities library.
The present work aims to evaluate the service provided by the Library of the Faculty of Letters and Human Sciences of the National University of San Marcos, using the LibQUAL instrument + ™ , which allows to know the perceptions of users about services library.
Chapter I describes the topic, objectives and methodology of work. Chapter II presents the theoretical framework supporting the work discussed , where information extracted from various authors is provided , as well as the background and methodology of the instrument used.
Chapter III presents a brief information about the Library of the Faculty of Letters and Human Sciences at the National University of San Marcos, and shows the results obtained after the instrument has been applied.
Finally, in chapter IV , proposals and conclusions that were reached at the end of this study are indicated.
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Aprile, Stefania. « La valutazione del livello di soddisfazione degli utenti della Biblioteca dell'Università di Milano-Bicocca ». Thesis, 2004. http://eprints.rclis.org/5431/1/tesiaprile.pdf.
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Cambiaghi, Simone. « Valutazione del livello di soddisfazione degli utenti della Biblioteca di scienze dell'Università di Milano Bicocca ». Thesis, 2005. http://eprints.rclis.org/7182/1/cambiaghi.pdf.
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Di, Sisto Luca. « Confronto della soddisfazione degli utenti della Biblioteca Centrale e della Biblioteca di Scienze dell'Università di Milano Bicocca ». Thesis, 2005. http://eprints.rclis.org/7183/1/disisto.pdf.
Texte intégralRésumé :
This thesis compares the results of the survey about the user satisfaction done in the Central Library and in the Science Library of Milano Bicocca University during january 2004.
Supervisor Prof. Walter Maffenini.
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Bajracharya, Radhika Maiya. « An Evaluation of Periodical Management System with Regard to Collection Strength and Usage of Journals by users of Science and Management Faculty at TUCL ». Thesis, 2010. http://eprints.rclis.org/20173/1/MLibSc%20Theses_RMB_CD1.pdf.
Texte intégralRésumé :
This study entitled “An evaluation of Periodical Management System with regard to Collection Strength and Usage of Journals by Users of Science and Management Faculty at TUCL” is carried out to evaluate the periodical management system and analyze the usage of journals by users of Tribhuvan University Central Library. The entire study is divided into six chapters namely i. Introduction. ii .Review of Literature, iii. Focus of Study. iv. Methodology. v. Presentation, Analysis and Interpretation. and vi. Summary, Conclusion and Recommendation. The first chapter as introduction has explained the history and origin of periodicals, development of periodical during the 20th century, meaning and definition of periodicals, types of periodicals, characteristics of periodicals, selection of Periodicals, Selection Tools of Periodicals, Acquisition of Periodicals, Payment procedures, methods of recording the receipt of periodicals, display of periodicals, completion of volume, accessioning, classification and cataloguing. Brief Description on Periodical Section. In addition, description on Statement of Problems includes the following problems: a. Increasing subscription cost of periodicals. b. Budgetary constraints. c. Gap in periodical receipt. d. Misplace of periodicals. e. Binding problem. f. Tearing of pages from journals. g. Lack of
adequate furniture. h. Lack of space. The objectives of this study are to:
i. Explore the total number of periodicals available in TUCL for Science and Management Faculty.
ii. Find out how the periodical are organized in TUCL.
iii. Find out users’ preference on print vs. electronic journals.
iv. Find out satisfaction of users about the adequacy of journals for Science and Management Faculty.
v. Recommend the appropriate periodical management system based on the suggestion of users. The scope of this study is limited to finding about the availability of total number of periodicals on Science and Management in TUCL only, portrays the collection strength of journals, and describes the organization and management of scientific journals only and does not include the daily newspaper, magazine. The significance of this study lies in the management of journals, finding out the collection strength of journals and finally it helps to know about users’ satisfaction about availability and adequacy of journals in TUCL.
VI. The study includes the terminology in order to explain the words and phrases that deals with library and information science, which are also included in this research. The Review of Literature section includes 10 literatures that are consulted for preparation of this study. These literatures are reviewed because these are relevant to this study as they document about various methods of periodical management system in different academic libraries of different countries.
The section “Focus of Study” is focused on explaining about the description of periodical section of TUCL with information about its activities regarding responsibilities, reader services, additional activities, creation of database, and detail record of periodicals on Science and Management Faculty. The study applies descriptive method and it is questionnaire-based data gathering survey containing 19 questions. A total of 100 questionnaires were distributed to the students of Science and Management faculty of Tribhuvan University, Kirtipur Campus, of which 69 responses were obtained with differing number of questionnaires attempted. The analysis and evaluation of the study is based on the responses received from them. Out of 69 responses analyzed, 39 (56.52%) respondents were from Science and 30 (43.48%) from Management faculty. Out of 57 respondents, 31 (54.38%) (Sci 18, Mgmt 13) opined the holdings (availability) of periodicals is satisfactory, 19 (33.33%) (Sci 13, Mgmt 6) indicated “Inadequate”. Out of 59 respondents, majority of respondents (34) (57.62%) (Sci 18, Mgmt 16), responded that they were able to find the periodicals for consulting. On the question “what they do to locate the information in eriodicals?”. Out of 59, 26 respondents (44.06%) (Sci 18, Mgmt, 8) consulted catalogues, 22 (22.02%) respondents (Sci 8, Mgmt 5) searched directly on display rack, 5 (8.47%) respondents (Sci 2, Mgmt 3) consulted or approached librarian for finding the information from periodicals. On the question of selecting their choice of periodical format, 28 respondents (Sci 17, Mgmt 11) preferred the print version (hardcopy) of periodicals, just 2 respondents from science faculty preferred their choice of periodical format as electronic. However, as many as 27 respondents (Sci 17, Mgmt 5) indicated their choice of periodical format of both the formats (print and electronic version). On the question to “rate the usefulness of periodicals, out of 69, 30 respondents (Sci 19, Mgmt 11) rated the periodicals of current year as "most" useful, 28 respondents (Sci 17, Mgmt 11) rated the
VII periodicals of last two years as "more" useful, 14 respondents’ (Sci 5, Mgmt 9) ratings on periodicals of last 5-10 years as "less" useful, and 17 (Sci 10, Mgmt 7) (24.63%) rated the periodicals of last 10 years and beyond are "least" useful.
On the organization/display of periodicals, 30 (50%) respondents (Sci 23, Mgmt 7) remarked on “lack of recent issues of periodicals on display racks, each 14 (23.33%) respondents (Sci 6, Mgmt 8) showed remarks on "good" and "not in proper order" and 2 respondents from management faculty opined the journal display as "bad". Four out of 61 respondents responded that they were able to find the journal/articles "immediately" and none of respondents from science faculty responded on this variable. 31 (Sci 24, Mgmt 7) (50.81%) respondents were able to find the journal/articles "occasionally", 16 (Sci 10, Mgmt 6) respondents responded "not in time of need" Only 10 (Sci 3, Mgmt 7) (16.39%)
respondents remarked that they were able to find the journal/articles "soon". On the question “are you happy with the organization of periodicals”, out of 63 respondents, 30 (Sci 19, Mgmt 11) (47.61%) responded that they were satisfied (happy) with the organization of periodicals. 33 respondents (Sci 19, Mgmt 14) (30.15%) opined "No". Evaluation of journals usage is a difficult but necessary task considering the wide range of choices available. Limited funding and space, as well as other factors, influence the need for a carefully planned strategy of journal selection. In order to enhance the use of collection, the following effective strategies have to be carried out. 1. Effective orientation program should be carried out by involving as many students as possible and more time should be offered for the program so that students get more familiarized. 2. In the selection of periodicals, students' opinion should be sought or suggestions box should
be kept. 3. Periodical section should place the periodicals in Display room soon after the completion of processing work and continue keeping vigilance to ensure the recent periodicals are on display. 4. A computer with Internet access should be in the Periodical section for user access. 5. Based on usability, frequency of use, the backdated volume of journals should be considered for withdrawal from the stack and should be planned for retention in space-saving manner. 6. TUCL should consider re-organizing the periodicals by following the scientific management system so that users could be better served. 7. Front desk service should be made available in Periodical Display room.
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Fitchett, Deborah. « Students' natural use of language for academic library concepts ». Thesis, 2006. http://eprints.rclis.org/19599/1/StudentsNaturalUseOfLanguage.pdf.
Texte intégralRésumé :
Library jargon is a barrier to users in their interactions with library staff and systems. Comprehension testing has shown that many students do not understand common library jargon. Usability testing and preference testing have successfully sought user feedback in order to develop more user-friendly interfaces.
In this study into language preferences, a questionnaire was based on 20 concepts taken from New Zealand university library websites. Participants were asked to label these concepts with terms of their own choosing. New Zealand university summer school coordinators were asked to forward a URL for the web-based questionnaire to students in their classes. Fifty valid responses were received.
Concepts that were central to students' library experiences were labelled with as few as 4 different terms, while less central concepts were labelled with more than 30. Library jargon was an important influence on students' choice of terminology. For many concepts, however, students used terms that had not been found on library websites.
Further research is recommended into a broader range of concepts, and into whether user-derived terminology outperforms library jargon in whole-library context usability testing.
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Garcia, Rodrigo-Moreira. « A busca da informação especializada e a efetividade de sua recuperação : interação entre bibliotecário, usuário e base de dados ». Thesis, 2005. http://eprints.rclis.org/16207/1/RodrigoMoreiraGarcia_2005_TCC.pdf.
Texte intégralRésumé :
The search activities and information retrieval consist of selecting of the information mass those elements that It assist satisfactorily the information needs of a group or individual, in the instant of your solicitation. Those activities, are own of the professional librarian, because, the essence of the Librarianship consists of locating, to treat, to store, to retrieval and to disseminate the information. But, with the development of the information and communication technologies the storage capacity in databases is growing, as well as the direct access of the users to the information, turning the information retrieval in half electronic a quite complex task. These factors take to investigate if the users have been getting to supply your information needs efficiently, without the professional librarian as intermediate. It was proposed the study of the behavior of a sample of the students of the powders graduation of the UNESP-Marília in the search activities and information retrieval in databases specialized, through the application of questionnaires and observations of your search procedures. With support of pertinent theoretical referential to the theme, the data were tabulated and analyzed quantitative and qualitative. As results, it was verified that several problems impede that the users take advantage of all the potentiality that the bases of data now offer for the information retrieval. It is ended that, the studies on the behavior of the users' search and the inherent knowledge to the librarian, they can contribute to the design of systems of information retrieval and more efficient search interfaces.
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Oliva, Laura. « La rilevazione della customer satisfaction in biblioteca : il caso di Milano-Bicocca ». Thesis, 2013. http://eprints.rclis.org/18631/1/Tesi_OLIVA_LAURA.pdf.
Texte intégralRésumé :
The document is about customer satisfaction in academic libraries.
The first part is about a theoretical presentation of the topic and it’s importance into the organizational change.
The second part is about the 2012 survey of customer satisfaction in Milano-Bicocca University library. There is the conceptual model, the quantitative and qualitative results. For the analysis of quantitative data it’s been used SPSS software, instead for the qualitative data it’s been used T-Lab.
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Shrestha, Nina. « A Study on Students Use of Library Resources and Self-efficacy ». Thesis, 2008. http://eprints.rclis.org/22623/1/NinaShrestha.pdf.
Texte intégralRésumé :
This study has been undertaken to determine the "Students use of the library resources and self-efficacy". This study has tried to find out the information seeking behavior of the graduate level students and their knowledge about the library resources and services made available to them. And how their familiarity with the resources and technology develops self-efficacy.
The study has tried to find out how the integration of the Internet has affected the information searching habit on students.
The study has collected empirical data on the information searching behavior of the students of the three respective colleges taken under study they are Thapathali College, NCCS(National College of Computer Science) and Kathmandu University. These data has been gathered from 25% of the actually targeted group of study. Questionnaire method has been obtained to collect primary data from the 200 full time students of which 127 has been returned which is the exact number of questionnaire tabulated for the study.
After tabulating and analyzing the data the findings of the study indicated that students are most in the need of intervention as they often come to college unprepared. The guidance in the use of library resources and services is necessary to help students meet some of the information requirements. It is also found that library books, e-journals and Internet are the most popular source of information for the course work and research and the place of Google in the student’s information behavior is prominent and positively co-related to use of traditional library resources.
The study shows that in today’s fast paced world the desire for expediency has promoted students to place a premium on information that can be found easily and quickly. To this end, many students limit their search to electronic resources, choosing format over substance and convenience over accuracy. In particular reliance on the world wide web as a primary and often sole research tool has impacted the quality and rigor of students projects and reduced students familiarity with more traditional print resources and bibliographical databases in their college library collection.
Internet has rapidly become one of the most powerful global sources of wide range of information presenting many possibilities for the efficient and unlimited dissemination of information. It has contributed positively in enhancing the search effectiveness. Which has lead to giving students psychological boost and problem solving ability. The newfound confidence due to the easily accessible information resources has upgraded the learning ways among them. Students have become more competent and confident about what they could achieve in the given situations and knowledgeable about the ways that leads to the achievement.
With the popularity of the electronic resources as the major information sources the study has also found that all the libraries is automated with some having their own online catalogue system with subscription to electronic journal sites and bibliographic indexes. Even if the library did not have various electronic resources they gave Internet services through computer labs and online catalogue. But without proper knowledge of accessing the information sources both electronic or print students are vulnerable to the overloaded information and was not seen so much keen on using the library’s electronic resources they preferred internet resources as its interface is easy to use and they could get unlimited information on the subjects.
Proper guidance and lack of professional person along with the inadequate collection in the material as well as insufficient networking computers has been the main drawbacks on students exploring the resources. For them to be more interested towards libraries librarians along with the faculty members need to work together in educating them about the services and resources that is available and library should also work towards networking with other libraries so that it could provide better range of materials in given subject.
In this study even though students are drawn to information sources that allow them to complete their research in “the easiest least painful way” the large percent of students are still motivated to learn about accessing their present library resources. With such a strong bias among students towards using the web as their primary research tool, library instruction should be considered a crucial means of introducing students to print resources of the library beside the web. Numerous studies have shown that positive change in student’s research skills and knowledge of the library and its resources after library instruction. This study has also tried to point towards that aspect of the library where it could educate its users by giving orientation so they can become an accurate searcher and make use of the right information at the right time.
Chapitres de livres sur le sujet "CB. User studies"
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Sala, Dariusz, et Bogusław Bieda. « Role of Stochastic Approach Applied to Life Cycle Inventory (LCI) of Rare Earth Elements (REEs) from Secondary Sources Case Studies ». Dans Towards a Sustainable Future - Life Cycle Management, 107–20. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-77127-0_10.
Texte intégralRésumé :
AbstractMonte Carlo (MC) simulation using Crystal Ball® (CB) software is applied to life cycle inventory (LCI) modelling under uncertainty. Input data for all cases comes from the ENVIREE (ENVIronmentally friendly and efficient methods for extraction of Rare Earth Elements), i.e. from secondary sources eco-innovative project within the second ERA-NET ERA-MIN Joint Call Sustainable Supply of Raw Materials in Europe 2014. Case studies described the flotation tailings from the New Kankberg (Sweden) old gold mine and Covas (Portugal) old tungsten mine sent to re-processing/beneficiation for rare earth element (REE) recovery. In this study, we conduct the MC analysis using the CB software, which is associated with Microsoft® Excel spreadsheet model, used in order to assess uncertainty concerning cerium (Ce), lanthanum (La), neodymium (Nd) and tungsten (W) taken from Covas flotation tailings, as well as Ce, La and Nd taken from New Kankberg flotation tailings, respectively. For the current study, lognormal distribution has been assigned to La, Ce, Nd and W. In the case of Covas, the weights of each selected Ce, La, Nd and W are 32 ppm, 16 ppm, 15 ppm and 1900 ppm, respectively, whereas in the case of New Kankberg, the weights of each selected Ce, La and Nd are 170 ppm, 90 ppm and 70 ppm, respectively. For the presented case, lognormal distribution has been assigned to Ce, La, Nd and W. The results obtained from the CB, after 10,000 runs, are presented in the form of frequency charts and summary statistics. Thanks to uncertainty analysis, a final result is obtained in the form of value range. The results of this study based on the real data, and obtained using MC simulation, are more reliable than those obtained from the deterministic approach, and they have the advantage that no normality is presumed.
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Venge, P., R. Brattsand, L. A. Laitinen et C. G. A. Persson. « Which Markers of Inflammation Should be used in Therapeutic Intervention Studies of CB/COAD ? » Dans Inflammatory Indices in Chronic Bronchitis, 289–94. Basel : Birkhäuser Basel, 1990. http://dx.doi.org/10.1007/978-3-0348-7488-5_23.
Texte intégral
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Bowring, Darren, et Sandy Toogood. « Positive Behavioral Support ». Dans Psychological Therapies for Adults with Autism, 93–106. Oxford University Press, 2022. http://dx.doi.org/10.1093/med-psych/9780197548462.003.0008.
Texte intégralRésumé :
Autism spectrum disorder (ASD) is associated with an increased risk of challenging behavior (CB). Positive behavioral support (PBS) is a multicomponent framework that aims to promote quality of life and reduce levels of CB. The purpose of this chapter is to explore the theoretical basis of PBS and its origins and to describe the interventions that together form the PBS framework model. Research on PBS will be presented which has historically focused on adults with intellectual disabilities including those with ASD. Emerging evidence from meta-analytic reviews and recent research studies will be described that demonstrate that PBS is effective at reducing levels of CB. Finally, a case study example is provided of how PBS was used to address a high-risk self-injurious behavior in an individual with ASD.
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Allison, Penelope M. « Casa del Menandro (I 10,4) ». Dans The Insula of the Menander at Pompeii. Oxford University Press, 2007. http://dx.doi.org/10.1093/oso/9780199263127.003.0014.
Texte intégralRésumé :
Giornali degli Scavi A,VI,6 (May 1912–Mar. 1929): 451–590 (intermittently from Nov. 1926–Mar. 1929). A,VI,7 (Apr. 1929–Dec. 1935): 56–235 (intermittently from July 1930–Oct. 1932). Maiuri 1933. The Casa del Menandro was excavated mainly between November 1926 and July 1932. The excavation reports of the 1920s and 1930s often recorded the state of the volcanic deposit: whether the deposit was disturbed or consisted of stratified ash and lapilli; whether finds were associated with an upper floor; and at what level above the pavement finds were made. Given that this large and reportedly ‘noble’ house was considered important by the excavators, they were perhaps more careful here than they had been with Houses I 10,1 and I 10,2–3. Description: fragments of at least 102 small bronze studs, with a flat circular head (diam.: 20 mm) and shaft of square section (max. l.: 15 mm; section: c.2 mm × 2 mm). Present location: Pompeii Collection, CB. Three others in situ in aedicula (inv. no. 4212). Discussion: The light weight of the heads and the shortness and fragility of the shafts indicate that these studs functioned as decoration, rather than structural support, on the wooden latticing of upper part of the aedicula. See discussion on studs. Dimensions: diam.: 1 m; h.: 180 mm. Description: Large sub-hemispherical bronze basin with omphalos at centre and horizontal rim with down-turned edge. Internal omphalos decorated with a floral pattern consisting of three rows of radiating petals. Upper surface of rim ribbed and edged with ovolo pattern. Present location: Pompeii Collection, GF (inv. no. 4261, reinventoried no. 25892). References: Maiuri 1933: 428–30, fig. 161 (on a modern pedestal); Riz 1990: pl. 71; PPM ii. 242, fig. 2 (standing on modern base); Tassinari 1993: i. 141; Stefani 2003: 25, 126– 7 no. A17. Discussion: The use of the term labrum for such a vessel is unsubstantiated. Its purpose in the ‘atrium’ was likely to have been largely for display but possibly also for water collection and washing. Dimensions: l.: 305 mm; rim diam.: 172 mm; h.: 50 mm; base diam.: 72 mm; handle l.: 130 mm. Description: Shallow bronze pan, with rolled rim and ring base. Underside of base modelled with a series of relief rings.
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« These studies indicate that homologous blood transfusion affects the outcome of clinical diseases in both beneficial and adverse ways. Experimental situations are not suitable for randomized clinical trials - transfusions cannot be given to prevent the onset of diabetes or wound strength measured in man following receipt of homologous or autologous blood. These experimental observations indicate that the outcomes of numerous clinical diseases which have not been studied may be manipulated by the use of homologous blood or that transfusion should be avoided. Several studies indicate that changes in immune function following transfusion are permanent. The number of clinical phenomena associated with immune suppression and attributable to blood transfusion is unknown. SUMMARY Given the evidence presented here it would be foolish to suggest that transfusion of homologous blood has no immunologic consequences for the recipient. Blood transfusion is the oldest form of transplant - no one would argue that transplantation between unrelated individuals has no influience on the immune system. In organ transplantation the immunologic sequelae are permanent and there is evidence that the same is true following homologous blood transfusion. Lymphocytopenia is present one year following surgery for Crohn's disease if patients receive perioperative blood transfusion (43). Colorectal cancer patients transfused more than seven years prior to diagnosis have significantly reduced numbers of lymphocytes and lower natural killer cytotoxicity than colorectal cancer patients who have never been transfused (44). Transfusion of neonates causes suppression of lymphocyte reactivity which is still demonstrable 25 to 30 years later (45). There is evidence that transfusion at any time prior to elective surgery increases susceptibility to infectious complications (14) and otherwise healthy transfused individuals may be at increased risk of developing malignancies (46). All the longterm consequences of blood transfusion are not negative : Survival of transplants is prolonged by pretransplant transfusion and some women suffering from recurrent spontaneous abortion can deliver at term if previously transfused with their spouse's leukocytes. In the future we will be able to transfuse blood without causing immune perterbations and the consequent clinical phenomena. Studies presented here suggest that removal of donor leukocytes reduces the risk of infection and cancer recurrence. The technology has not reached the point of reducing the leukocyte number in transfused blood below 10^/unit. An alternative which is increasingly being utilized is autologous blood programs. Physicians are discovering that patients tolerate hemoglobin levels which were previously unacceptably low and many patients prefer being anemic over the risks of receiving homologous blood. Since transfusion is an identifier of high cost hospitalized patients, alternatives to routine blood use are being studied in hopes of safely reducing the costs of transfusion. REFERENCES 1. Jubert AV, Lee ET, Hersh EM, McBride CM. J Surg Res 15:399-403, 1973. 2. M 19 u4n ( s3t ) e3r4A6-M 35 , 2 W , i1n9c8h1u . rch RA, Keane RM, Shatney CH, Ernst CB, Nuidema GD. Ann Surg ». Dans Transfusion Immunology and Medicine, 300. CRC Press, 1995. http://dx.doi.org/10.1201/9781482273441-29.
Texte intégralActes de conférences sur le sujet "CB. User studies"
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Cao, Guitao, He Zhu et Guangdong Liu. « Study on Frequency and Time Domain Analysis of Flow-Induced Vibration Response of Core Barrel ». Dans 2022 29th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/icone29-91777.
Texte intégralRésumé :
Abstract Different calculation methods of flow-induced vibration of the reactor vessel internals (RVI) are studied in this paper, that is frequency domain analysis and time domain analysis. Firstly, considering the fluid-structure interaction between the core barrel (CB) and the reactor pressure vessel (RPV), the CB and the heavy reflector, the finite element model of the CB in water is established and the results of its vibration characteristics are obtained, which is consistent with the test results. Based on the flow-induced vibration test of the RVI scale model, the fluctuating pressure data of the CB is obtained. The parameters such as power spectral density (PSD), correlation length and coherence function are obtained by processing the test data. Thus, the cross-power spectral density between any two points is got through these parameters. The root mean square (RMS) response of the CB is obtained by random vibration analysis (frequency domain). Then, the CFD model is established and large eddy simulation (LES) is used to obtain the time history of the fluctuating pressure of the CB. The response of the CB is obtained by time integration method (time domain). The calculation results by using these two methods are in good agreement with the experimental results.
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Mighri, Frej, Luc Nguyen et Said Elkoun. « Development and Characterization of Conductive Materials for PEMFC Bipolar Plates ». Dans ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33091.
Texte intégralRésumé :
The aim of this work was to develop and characterize electrically conductive bipolar plates (BPPs) used in proton exchange membrane fuel cells (PEMFCs). These BPPs were made from highly conductive blends of polyethylene terephthalate (PET) and polyvinylidene fluoride (PVDF), as matrix phase. The conductive materials were developed from carefully formulated blends composed of conductive carbon black powder (CB) mixed with pure PET, PVDF, or with PVDF/PET systems. They were first developed by twin screw extrusion (TSE) process then compression molded to give BPP final shape. Focus was made on the effect of crystallization of PVDF and PET polymers on the electrical through-plane resistivity of BPPs. It was observed that lower resistivity was obtained with PVDF/CB blends due to the higher interfacial energy between the PVDF matrix and CB and also the higher density and crystallinity of PVDF, compared to those of PET. For the different systems studied, slow cooling rates helped to attain the lowest values of through-plane resistivity since higher PET crystallinity led to smaller amorphous region in which CB was more concentrated. In addition, BPPs made from (PVDF/PET)/CB blends led to lower through-plane resistivity when the PVDF/PET phase had a co-continuous morphology. This is mainly due to the selective localization of the CB in the PET phase leading to a denser conductive carbon network. The lowest through-plane resistivity was around 0.3 Ohm.cm obtained with a (50/50 PVDF/PET)/CB filled with 30 wt% CB.
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Annamalai, K., N. T. Carlin, H. Oh, G. Gordillo Ariza, B. Lawrence, U. Arcot V., J. M. Sweeten, K. Heflin et W. L. Harman. « Thermo-Chemical Energy Conversion Using Supplementary Animal Wastes With Coal ». Dans ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-43386.
Texte intégralRésumé :
Researchers at Texas A&M University have studied properties of cattle biomass (CB or manure) fuels and their possible utility in combustion systems. Larger, more concentrated animal feeding operations (CAFO) and farms make manure disposal more difficult. At the same time, due to the concentration of the manure, the CAFOs can be a source of a more feasible and reliable CB feedstock for fossil fuel supplementation and emissions reduction technologies. This paper reviews the history of work conducted on animal biomass fuels and current research and experiments undertaken by Texas A&M University (TAMU) System research personnel. Feedlot biomass (FB), dairy biomass (DB), and chicken litter biomass (LB) are considered here. When cofiring with coal under rich conditions, the CB has the potential to reduce NOx and Hg emissions. Reburning coal with CB can be just as effective as and possibly more economical than reburning with conventional fuels like natural gas. In addition to cofiring and reburning, another possible energy conversion method is gasification of cattle biomass with air and air-steam oxidizing agents that can produce synthetic gases which can then be used in a variety of different combustion systems. The economic feasibility of utilizing animal-based biomass on existing coal-fired power plants is greatly dependent on the relative cost of coal, the biomass transportation distance to the combustion facility, and numerous other factors. Even though most of the methodologies and procedures, in this paper, deal with CB, similar schemes can be undertaken for most other animal or solid wastes.
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Stern, F., J. Longo et Z. J. Zhang. « Detailed Bow-Flow Data and CFD of a Series 60 CB= .6 Ship Model for Froude Number 0.316 ». Dans SNAME 24th American Towing Tank Conference. SNAME, 1995. http://dx.doi.org/10.5957/attc-1995-031.
Texte intégralRésumé :
The bow flow of the Series 60 CB 0. 6 ship model is reinvestigated using both experiments and CFD. More detailed bow-flow data is obtained by taking measurements of the wave elevation with a point gauge very near the bow. In the CFD, the bow flow is resolved in more detail by using the real bow geometry instead of the simplified vertical zero-thickness bow used in previous studies, which requires a much finer grid in the bow region. The experiments and CFD are briefly described; results are presented; and discussions are made concerning comparisons of the new and old CFD solutions with the extended data regarding the wave profile and elevation at the bow, the thin film and beads (i.e. attached spray sheet and bow vortices), and the stagnation effects. Finally some concluding remarks are made.
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Guarino, Maria, Marlene Lages, Ipek Suluova, Rui Fonseca Pinto et Nuno Lopes. « The CBmeter : designing innovative strategies for early diagnosis of metabolic diseases ». Dans 13th International Conference on Applied Human Factors and Ergonomics (AHFE 2022). AHFE International, 2022. http://dx.doi.org/10.54941/ahfe1001410.
Texte intégralRésumé :
Diabetes is a disease with high prevalence worldwide, however, about 44% of patients are asymptomatic, which leads to a later diagnosis of the disease and, consequently, increases the risk of developing complications. The development of new approaches for early diagnosis is imperative to allow proper adoption of preventive measures. From a motivational point of view, it is easier for patients to adopt healthy eating habits and lifestyles when there is an altered marker that indicates subclinical disease, particularly in a pathology that remains asymptomatic until advanced stages. Thus, timely diagnosis based on a measurable and monitorable indicator is extremely important so that such behaviors are implemented as early as possible, increasing effective health gains and reducing the costs related to this pathology. Pre-clinical studies in animal models have shown that the etiology of type 2 diabetes mellitus (T2DM) is related to alterations in the carotid bodies (CB), chemosensory organs located in the bifurcation of the carotid arteries. In animals with T2DM it has been observed that the CBs are overactivated causing an increased heart rate, respiratory rate, and blood glucose levels. In humans, this mechanism has been confirmed but is not yet well-characterized. This paper highlights the importance of developing a device that allows early detection of changes in CB activity correlating it with emerging diabetes. The design strategies to prototype the CBmeter were to model and characterize the features of interest for the diagnosis- respiratory rate, heart rate, peripheral oxygen saturation and glucose - in healthy people and people with diabetes using a combination of set commercial sensors pre-existent in the market that were integrated to collect real-time data. After determining health and disease patterns, the CBmeter development pipeline includes a co-design approach in which physiologists, endocrinologists, nurses, computer and electrical engineers, designers and patients are collaborating to develop an easy-to-use, portable, and minimally invasive medical device that associates CB function with endocrine dysregulation, with very small discomfort and risk for users. The definition and specification of the most appropriate architecture for the CBmeter, in order to allow its modularity, signal acquisition and consequently the communication between the sensor/device and the receiver/backend in the most efficient way is being allied to the selection of materials, tools and steps to create an innovative product, that will fill a technical gap in the market, designed for the early diagnosis of metabolic diseases, in a subclinical phase, with the potential to contribute with significant gains for public health in the medium/long term.
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Bain, Derek, Dana Fisk, Camila Gomez Serrano, Samantha Orlando et Patricia Iglesias. « Synthetic and Organic Supercharger Lubrication : The Tribological Performance of Ionic Liquids as Additives to Lubricants ». Dans ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-66073.
Texte intégralRésumé :
A supercharger is a mechanical device that can be added to an engine of a car to increase engine power. It works by sucking air in at atmospheric pressure into the rotors and compressing it at high revolutions per minute. With the rotors spinning at high speeds, the supercharger gears are exposed to high values of friction and wear, which results in a reduction of their service life. Ionic liquids (ILs) are substances that possess unique lubricating abilities when added to base oil or when used as neat lubricants. Properties include low volatility, non-flammability, as well high thermal resistance. These liquids are able to form ordered layers and tribofilms on the contacting surfaces which further protects the surface materials. In this work, the effect of adding ILs to low viscosity synthetic oil used to lubricate gears and to organic oil was investigated in the reduction of friction and overall wear of superchargers. Mobil 1 5W-30 Full Synthetic Engine Oil (MS) was used as a control and compared to coffee bean oil (CB). Additionally, the performance of these oils was observed with ionic liquids as additives at 1 wt. %. The chosen IL consisted of the cation Trihexyltetradecylphosphonium, [P6,6,6,14]+, with the anion Bis(trifluoromethylsulfonyl) amide, [NTf2]−. Lubricated flat disks of AISI 52100 stainless steel and 420C steel balls were studied using a Pin-on-Disk configuration. A total sliding distance of 500 meters was tested with a wear track diameter of 20 mm. Wear volume and average friction coefficient were measured according to ASTM-G99. Results showed that the addition of the ILs to the CB and MS reduced friction coefficient of the steel disks at medium speeds, and wear values achieved were comparable to the friction observed. The wear width values were also found to be reduced at medium speeds.
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Gordillo, Gerardo, et Kalyan Annamalai. « Char and Tar Production From Dairy Biomass Gasification Using Air-Steam for Partial Oxidation ». Dans ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44338.
Texte intégralRésumé :
The increase in air pollution caused by combustion of fossil fuels demands the exploration of renewable energy sources in order to mitigate the dependence on fossil fuels. Research includes the efforts to partially replace fossil fuels with renewable energy-sources in thermal conversion processes in order to reduce the emission of CO2. The animal wastes can be considered as biomass fuels since their properties are almost similar to ration fed to animals. Concentrated animal feeding operations (CAFOs) such as cattle feedlots and dairies produce a large amount of feedlot manure or feedlot biomass (FB) and dairy manure or dairy biomass (DB), which may lead to land, water, and air pollution if waste handling systems and storage and treatment structures are not properly managed. Both FB and DB are grouped under cattle manure or cattle biomass (CB). The concentrated production of low quality CB at these feeding operations can serve as a good feedstock for locally based gasification for syngas (CO and H2) production and subsequent use in combined heat and power generation. If thermal gasification technology is developed for DB fuels, the environmental impact from both animal feeding operations and fossil-fuels could be mitigated. The current paper presents experimental results obtained from adiabatic fixed-bed gasification of DB using a 10 KW fixed bed counter-flow gasifier and air-steam for partial oxidation. A mass spectrometer (ProLab Thermo ONIX) was used to analyze the gas composition continuously and at real time. The effect of the operating parameters studied, which includes equivalence ratio (1.6 < Φ < 6.4) and steam to fuel (S:F) ratio (0.4 < S:F < 0.8, on the yields of gases, char, and tar are discussed. Also, results from gasification of dairy biomass–ash blend (DB-Ash) and dairy biomass Wyoming coal blend (DB-WYC) is presented for comparison effects. In general, for the set of experiments performed using DB, the gas yield was 1.54 to 5.30 dry tar-free kg of gases per each kg of DAF DB gasified while the char production ranged from 0 to 0.18 kg of char per DAF kg of DB gasified. The average of tar concentration in gases leaving the gasifier was about 80 g/ SATP m3.
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Bossung, Kyle, Matthew DeRosa, Jose Salas et Patricia Iglesias. « Effect of Halogen-Free Ionic Liquids as Additives of Biolubricants for Room Temperature Titanium-Steel Contact ». Dans ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-66048.
Texte intégralRésumé :
The surface interactions and tribological behavior of titanium-steel contact have been previously studied under the application of several commercial Ionic Liquids (ILs). In certain cases, superior anti-wear characteristics have been experienced when lubricating using ILs. This is often attributed to the development of a protective tribolayer that forms during application. One anion in particular amide, [Tf2N], has exhibited these characteristics with particularly positive results. However, amide is an anion that contains halogens, which are toxic and can cause harm if not handled properly. Due to the toxicity of most lubricants there has been a growing need to transition to bio-lubricants due to their low impact to the environment. This particular work will investigate the use of Trihexyltetradecylphosphonium, [P6,6,6,14]-+, cation with anion decanoate [Deca] as a non-toxic alternative to amide [Tf2N]. [P6,6,6,14]-+[Deca] and [P6,6,6,14]-+[Tf2N] will be compared as additives (1.0 and 2.5 wt. %) in Coffee Bean oil (CB) for lubrication of titanium-steel contact at room temperature. In this work, tests are conducted using a ball-on-flat reciprocating tribometer as per ASTM G133 with lubricated titanium-steel contact. An AISI 420C stainless steel ball is used on a Grade 5 6Al-4V titanium alloy disk specimen. Friction and wear volume are measured, examined, and discussed.
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Ogbonnaya, E. A., S. Nitonye et J. C. Orji. « Optimized Method for Conversion of FPSO Build From VLCC ». Dans SNAME Maritime Convention. SNAME, 2014. http://dx.doi.org/10.5957/smc-2014-p7.
Texte intégralRésumé :
FPSOs are becoming extremely important economically. Many nations/organizations are using them to supplement the conventional oil rig/floating platform especially due to the refinery capability they exhibit in situ in the drilling environment. However many of the multinational oil and gas companies are drifting towards the conversion of VLCCs to FPSOs. It is against this backdrop that a work of this nature considered an optimized method of converting an FPSO from a VLCC. The various methods of producing such a vessel were looked at taking two FPSOs: BONGA (New Build) and MYSTRAS (Converted) operating in West African Waters as case studies. A number of vivid and valid ship construction parameters were taken into consideration using a computerized model. Analysis reveal that the block coefficient (CB) yields an important result that if put in place during the design phases of FPSOs – be it new build or converted will go a long way to enhance the conversion process. The CP of the new build FPSO was found to be 0.7202 while the converted one was 0.690 with sponsons and 0.818 excluding sponsons. The CP equally further supports the increased deck space which the modification provided with the strength analysis. Bending Moments and Shear Force distribution along the longitudinal axis (i.e. length) of the vessels with sponson fitted were determined and the section moduli of important/critical sections calculated. Stability analysis was carried out to cover the most critical modes and condition of the vessel’s operation. Righting levers was computed at prescribed loading conditions in the various operating regimes. Results obtained from the analysis showed that incorporating sponsons provided sufficient rigidity and good stability characteristics of the hull under all operating conditions. Finally, on the economic trend, the use of converted FPSO is favoured to those of new build due to the reduced lead-time.
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Lu, Xijia, Brock Forrest, Scott Martin, Jeremy Fetvedt, Michael McGroddy et David Freed. « Integration and Optimization of Coal Gasification Systems With a Near-Zero Emissions Supercritical Carbon Dioxide Power Cycle ». Dans ASME Turbo Expo 2016 : Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-58066.
Texte intégralRésumé :
The Allam Cycle is a semi-closed, recuperated, oxy-fuel, supercritical carbon dioxide (sCO2) Brayton power cycle, offering advantages over simple cycle and combined cycle arrangements. The Allam Cycle uniquely combines oxy-combustion with a substantially elevated operating pressure, high sCO2 recirculation flow, high gross turbine efficiency, and inventive low- and high-grade heat recuperation. As a result, the core Allam Cycle meets or exceeds the achievable net efficiencies of existing high efficiency combined cycle plants not equipped for carbon capture, while capturing substantially all CO2 emissions at purities and pressures necessary for downstream CO2 reuse and/or sequestration. Additionally, with minor alterations, the core cycle can operate with a variety of organic fuels. A 50MWt natural gas-fired demonstration of the core cycle is currently under development by 8 Rivers, NET Power, CB&I, Exelon, and Toshiba. This paper addresses the coal syngas-fired variant of the Allam Cycle system, extending beyond high-level feasibility analyses conducted in previous studies. The paper explores in detail the unique considerations, possible hurdles, and advantages of integrating a commercially-available coal gasifier with the Allam Cycle. In particular, the paper analyzes five (5) primary technical optimizations that drive the Allam Cycle’s advantages in efficiency and cost over conventional baselines. These include: (1) a simpler overall process, requiring fewer critical integration points while still providing for efficient high- and low-grade heat recuperation; (2) high efficiencies regardless of coal rank and type used — further, the efficiency drop when using low-rank coal in an Allam Cycle arrangement is smaller than IGCC arrangements; (3) high efficiencies regardless of syngas composition (such as H2:CO ratio), particularly when compared to gasification in the chemical industry and IGCC with carbon capture and sequestration; (4) the ability to utilize a singular, cost-effective post-combustion SOX/NOX removal mechanism; and (5) considerable water savings versus IGCC and SCPC baselines, with the ability to run substantially water free with only minor impacts to overall efficiency.