1,720,982 research outputs found
Production and characterisation of cold-bonded lightweight aggregates from biomass waste ash by cementing and one-part alkali-activation method / Lin Jiayi
No full textNowadays, increasing amounts of biomass ash are being sent to landfills, occupying substantial land space and causing health problems due to inadequate control measures. Rapid industrialization has also led to the over consumption of natural aggregates, creating environmental problems. Consequently, the production of artificial aggregates using biomass ash has gained considerable interest as it reduces the consumption of natural aggregates and landfill areas while recycling biomass ash. This study explored the feasibility of producing cold-bonded lightweight aggregates (CBLWA) using biomass ash, namely municipal woody biomass ash (MWBA) and palm oil fuel ash (POFA). First, the granulation parameters for MWBA-based cementing aggregate (MCA) were optimized. It was determined that an optimal water content of 27–29%, a rotation angle of 55° and a rotation speed of 60 rpm resulted in high granulation efficiency of 97.84%. The MCA exhibited a loose bulk density of 841 to 1058 kg/m3, a water absorption of 22 to 25% and a crushing strength of 2.2 to 2.6 MPa with 20% cement content. A low greenhouse gas emissions method for manufacturing another type of MWBA-based CBLWA, known as MWBA-based one-part alkali-activated aggregate (MAA), was also investigated. The MAA showed a loose bulk density, water absorption and crushing strength of 875–919 kg/m3, 11.2–13.8% and 1.7–2.3 MPa, respectively. With 15% Na2SiO3.5H2O, increasing GGBS content from 0 to 30% significantly enhanced crushing strength from 0.84 to 2.25 MPa and reduced water absorption from 24.0 to 12.5%. Secondly, the granulation parameters for POFA-based one-part alkali-activated aggregate (PAA) were optimized. Response surface methodology modeling revealed that the optimal rotation angle and speed for PAA manufacturing were 55° and 50 rpm, respectively, greatly improving the granulation efficiency of PAA from 79.9 to 88.2%. The PAA had a loose bulk density of 718.3 to 742.3 kg/m3 and crushing strength of 2.1 and 2.7 MPa. Thirdly, the characteristics of lightweight aggregate concretes (LWAC) made with these CBLWA were evaluated, obtaining an oven-dried density of 1682–1878 kg/m3 and 28 d compressive strength from 25.0 to 33.0 MPa. The MWBA-based alkali-activated aggregate concrete (MAAC) showed better high temperature resistance properties, with a 60% strength loss comparable to other LWAC. POFA-based alkali-activated aggregate concrete (PAAC) demonstrated a thermal conductivity value of 0.49 W/m·K per 1000 kg/m3, similar to other LWAC. Lastly, the environmental impacts of the produced CBLWA and LWAC were assessed using life-cycle assessment. MAA had the highest cumulative energy demand and global warming impact among CBLWA. PAAC, with the highest effective energy demand (232.4 MJ/MPa), was deemed less feasible with its current manufacturing method, while POFA-based cementing aggregate concrete (PCAC) recorded the lowest at 165 MJ/MPa. Leaching tests showed that the heavy metal concentrations in LWAC met multiple environmental safety standards, proving them safe for use. Overall, the study highlights the potential and environmental benefits of recycling MWBA and POFA into CBLWA and LWAC
An alkaline fungal laccase overexpressed in Coprinopsis cinerea shows application potential in treating high-salt dye wastewater
No full text[Objective] To homologously overexpress an alkaline fungal laccase PIE5 (CcPIE5) in Coprinopsis cinerea FA2222 under the control of the Agaricus bisporus gpdII promoter. [Methods] The laccase activity reached (24.2±1.1) U/mL in the supernatant after 7 days of cultivation at 37 ℃ in the mKjalke medium. The purified CcPIE5 showcased the best performance at pH 8.0 and 60 ℃. [Results] Unlike other characterized fungal laccases, CcPIE5 was tolerant to high concentrations of NaCl. Particularly, both k cat and K m decreased when the concentration of NaCl was increased from 0 to 1.5 mol/L, which indicated that CcPIE5 demonstrated application potential in the dye decoloring of texile finishing. In dye decolorization, CcPIE5 efficiently degraded (92.9±2.3)% indigo carmine at pH 8.5 and 60 ℃, with syringic acid as the mediator. Isatin 5-sulfonic acid (ISA) was identified by LC-MS as the primary byproduct of indigo carmine degradation. [Conclusion] CcPIE5 is best-suited in decolorizing dyes under high temperatures and alkaline and salty conditions. It serves as a good candidate for specific applications in the environment and industry
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
