1,720,964 research outputs found
Study of Effective Barite Concrete Mix Design for Gamma-ray Attenuation
Full text linkPreliminary study of heavyweight concrete has been conducted, providing basic information of mix design to attenuate γ-ray. This study summarizes some mixtures and compares with mixtures that are widely used in Thailand since the potential of local materials is needed to be more explored. Proportional determinations of heavyweight mixture are majority affected by workability, density, and material cost; the lack of these data is also another reason in performing this study. We limit our study into barite (BaSO4) because they are highly available in Thailand and we expect to use it for a mass production. Modification experiment is expected to achieve effective barite concrete mixture using local material from Thailand and measure relevancy when it applies in Thailand. This experiment evaluated density of concrete, compressive strength, and linear attenuation coefficient of concrete as parameter to determine the effectiveness of the mixture. 7 different barite concrete mixtures with 3 variations of w/c ratios and 3 classifications of coarse aggregate percentages will be examined. Using Cesium-137 and Cobalt-60 energy sources, linear attenuation coefficient (μ) of barite concrete will be measured with different energies which are 0.662 MeV, 1.173 MeV, and 1.332 MeV. W/c ratio has significant impact to workability, associated to strength of concrete and indirectly influences the concrete density. Not only w/c ratios, percentage of coarse aggregate in mixture also impact to linear attenuation coefficient of concrete. We concluded that the effective barite coarse percentage for appropriate workability but still has high density and strength is 0.65 for all water-cement ratios. Consideration addition percentage of coarse aggregate into mixture must be taken wisely due to segregation effect and voids in concrete. Furthermore, barite concrete has high capability to attenuate γ-ray due to high density. These novel insights may be useful for various applications e.g., nuclear power plant and medical units.
Optimization of Bar Cutting Lists in Reinforced Concrete Columns Utilizing the Particle Swarm Optimization Algorithm: A Case Study of a High-Rise Building
Full text linkIn the construction of reinforced concrete structures, rebar bending and cutting lists are commonly developed. However, in practice, engineers often develop them based on ease of design. This involves specifying splicing patterns manually, rather than using optimization techniques. To address this issue, a framework for optimizing rebar cutting and splicing patterns using Particle Swarm Optimization (PSO) is proposed in this study. Two areas of a high-rise building were used as a case study to demonstrate the practical application. The framework first organizes the columns by reinforcement patterns before further subdividing the column categories’ rebars by diameter and end patterns. Next, it randomizes splicing positions to serve as initial positions for PSO. Then, the corresponding cutting lengths are calculated and used for waste calculation. These processes are iterated to minimize waste. The results showed a significant reduction in waste across both areas, from 13.86% to 2.88%, compared to the as-built bar cutting list. This highlights the effectiveness of the framework in improving material efficiency and supporting sustainability. To validate practicality, the cutting and bending processes using machinery integrated with a QR code reader at a factory were demonstrated. This ensures the precise execution of the optimized list and enhances its robustness in real-world applications
Properties of Pervious Concrete Aiming for LEED Green Building Rating System Credits
Full text linkPervious concrete is a special type of concrete with high porosity. The use of pervious concrete may achieve many potential LEED green building rating system credits. The objective of this paper is to investigate the appropriate mix proportion which provides the high LEED points and also the good mechanical properties. Nine mix proportions based on possible LEED points were examined. The replacement of cement by fly ash (20% - 60%) and coarse aggregate by recycled aggregate (20% - 100%) were used. Properties of pervious concrete relating to LEED credits and design values such as permeability, void content, compressive strength and splitting tensile strength were evaluated. It was found that the proposed pervious concrete can achieve the stormwater design-quantity control, recycled content and recycled materials credits. According to the results, the mix proportions which cement was replaced by 40% and 60% of fly ash archived the highest LEED credit points and also provided the sufficient mechanical properties. Therefore, these mix proportions are recommended for green construction
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
- …
