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Compressive strengths of water treatment Sludge-fly ash geopolymer at various compression energies

Lowland technology International 2015年第3期17卷 147-156页

作者： Suksiripattanapong, C. Srijumpa, T. Horpibulsuk, S. Sukmak, P. Arulrajah, A. Du, Y.J. Department of Civil Engineering Faculty of Engineering and Architecture Rajamangala University of Technology Isan Thailand Construction and Infrastructure Management Program Suranaree University of Technology Nakhon Ratchasima30000 Thailand School of Civil Engineering Suranaree University of Technology Nakhon Ratchasima30000 Thailand School of Engineering and Resources Walailak University Nakhon Si Thammarat80160 Thailand Swinburne University of Technology HawthornVIC3122 Australia Institute of Geotechnical Engineering Southeast University Nanjing Jiangsu210096 China

Sludge-fly ash geopolymer is a green material, which does not require cement as a cementitious binder. Sludge and fly ash (FA) are both by-products from Bang Khen water treatment plants and Mae Moh power plants, respectively. A liquid alkaline activator, L is a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide solution (NaOH). This article investigates the influence of compression energy (E) on the Unconfined Compressive Strength (UCS) of a novel sludge-fly ash geopolymer. The optimal liquid alkaline activator (L) content, sodium silicate solution to sodium hydroxide solution ratio (Na2SiO3/NaOH), heat temperature (T) and heat duration (D), providing the maximum UCS for each E is also investigated. Test results indicate that the optimal UFA ratio decreases as E increases. The optimal L/FA ratios for E = 592.5, 1346.6 and 2693.3 kJ/m3 are 1.5, 1.4 and 1.3, respectively. The Na2SiO3/NaOH ratio of 80:20 is considered as optimal for all E tested. The UCS of sludge-FA geopolymer at all E values tested increases with an increase of heat duration until a heat duration of 72 hours, after which the UCS becomes almost constant. The heat temperature accelerates the geopolymerization reaction and therefore enhances the strength. However, overheating results in micro-cracks in the samples due to the loss of moisture. As such, the optimal temperature is controlled by liquid content;the higher L/FA results in the lower optimal heat temperature. Since the optimal L/FA ratio decreases as E increases, the optimal T subsequently decreases with an increase in E;i.e., its values are 75, 85 and 95 °C for E = 2693.3, 1346.6 and 592.5 kJ/m3, respectively. The maximum UCS values of sludge-FA geopolymer at optimal ingredient and heat condition are 20, 18 and 16 MPa for E = 2693.3, 1346.6 and 592.5 kJ/m3, respectively, which meet the strength requirement of bearing masonry units as specified by the Thailand Industrial Standard (TIS).

关键词： Fly ash

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Modeling of Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD) in the Sirinhaém river, Pernambuco, Brazil

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Electronic Journal of Geotechnical engineering 2014年第P期19卷 3875-3886页

作者： Araújo, Ana Flávia Da Paz, Diogo Henrique Fernandes Da Silva, Simone Rosa Environmental Technology Institute of Technology Association of Pernambuco Recife Brazil Civil Engineering Postgraduate Program University of Pernambuco Recife Brazil

Water resources are very important for the maintenance of life on earth, and water quality results from a relationship between natural phenomena, potentially degrading human activities as well as aspects related to the use and occupation of land. In this context, the role of water resources management is to seek viable alternatives to the solution of the qualitative and quantitative problems of these resources and one of the tools used is the monitoring of water quality in watersheds. The aim of this paper was to apply the QUAL-UFMG model of water quality to assess the water quality of the Sirinhaém river to subsidize a future framework of rivers in classes according to preponderant use. The QUAL-UFMG model was used to simulate the Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD), and the calibration was perfomed manually. For the application of mathematical modeling, the organic load of domestic origin from the cities of Corts, Gameleira, and Sirinhaém and from industrial effluents of the Pedrosa, Cucaú and Trapiche plants were considered. The flow and hydraulic characteristics data were obtained through the fluviometric stations of the National Water Agency - (ANA) while the average values of DO, BOD, and temperature came from the systematic monitoring of the water quality stations. Based on the observed data, the model proved to be efficient in simulating the parameters of the river in this stretch. In the model's validation, a better result was obtained for the BOD than DO. © 2014 ejge.

关键词： Dissolved oxygen

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The study of physical and thermal conductivity properties of cement paste containing nanosilica 8th

The study of physical and thermal conductivity properties of...

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8th International Conference on Materials Science and technology, MSAT 2014

作者： Jittabut, Pongsak Chindaprasirt, Prinya Pinitsoontorn, Supree Physics and General Science Program Faculty of Science and Technology Nakhon Ratchasima Rajabhat University Nakhon Ratchasima30000 Thailand Sustainable Infrastructure Research and Development Center Department of Civil Engineering Khon Kaen University Khon Kaen40002 Thailand Department of Physics Faculty of Science Khon Kaen University Khon Kaen40002 Thailand

ISBN: (纸本)9783038355526

This research was presented the physical and thermal conductivity properties of cement pastes containing nanosilica by mixing three nanosilica particle sizes of 12, 50 and 150 nm, using nanosilica of 1-5 wt%. The water-cementitious ratio (W/C) was 0.5 for all samples. Thermal property coefficients were tested using a direct measuring instrument with surface probe (ISOMET2114). The influence of nanosilica on the physical properties were compressive strength, bulk density, XRD and SEM respectively. The results indicated that the use of nanosilica as an admixture can reduce the thermal conductivity and lowered the bulk density of specimen. The cement paste with nanosilica particle size of 50 nm with 4 wt% nanosilica at the age of 28 days showed the optimized properties. The thermal conductivity was lowest at 0.913 W/m-K, the compressive strength was highest at 51.62 MPa and the bulk density was 1,806 kg/m3 respectively. The compressive strength increases more than 50% higher than that of pure paste. The cement pastes with nanosilica particle sizes of 50 and 150 nm, have lower unit weight and thermal conductivity than typical control cement paste about 9% and 15% respectively. The nanosilica mixed cement paste is very interesting for energy saving when used as wall insulating material. © (2015) Trans Tech Publications, Switzerland.

关键词： Thermal conductivity

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Improved User Experience and Scientific Understanding of Anti-Icing and Pre-Wetting for Winter Roadway Maintenance in North America

Improved User Experience and Scientific Understanding of Ant...

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International Symposium on Systematic Approaches to Environmental Sustainability in Transportation: Environmental Sustainability in Transportation Infrastructure

作者： Cui, Na Shi, Xianming Winter Maintenance and Effects Program Western Transportation Institute Montana State University P.O. Box 174250 BozemanMT59717-4250 United States School of Transportation Science and Engineering Harbin Institute of Technology Heilongjiang Harbin150090 China Department of Civil and Environmental Engineering Washington State University P.O. Box 642910 PullmanWA99164-2910 United States

ISBN: (数字)9780784479285

ISBN: (纸本)9780784479285

In recent years, North American highway agencies have increasingly adopted innovative snow and ice control strategies, including anti-icing and pre-wetting practices. In 2005, to synthesize the benefits and challenges of implementing such strategies, a national survey was conducted. However, insufficient information and limited understanding were found to account for their low usage at that time. A decade later, research is needed to document improved user experience and scientific understanding on these strategies, which can be used in a comparative manner. Through a follow-up survey launched in April 2014 with the same focus as the 2005 survey, a contrastive synthesis is presented which summarizes changes in the evolution of anti-icing and pre-wetting over the past decade, including the implementation of these snow and ice control strategies, related costs, environmental concerns, corrosion, and community response. The research demonstrates the elevated and indispensable status of anti-icing and pre-wetting strategies in current winter roadway maintenance activities, compared with their limited use ten years ago. The research further supports their positive effects on economic, environmental and social goals, which is attributable to the proactive nature and environmentally responsible performance of anti-icing and pre-wetting. Finally, gaps in current operations and the need for further research are discussed. © ASCE.

关键词： Surveys

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Conversion factors for the compressive strength of Self Compacting Concrete (SCC)

Betonwerk und Fertigteil-Technik/Concrete Plant and Precast ...

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Betonwerk und Fertigteil-Technik/Concrete Plant and Precast technology 2015年第12期81卷 42-51页

作者： Boel, Veerle Craeye, Bart Desnerck, Pieter Van Der Vurst, Farid Van Itterbeeck, Petra De Schutter, Geert University College Ghent Ghent University Study Program of Civil Engineering Technology Belgium University of Antwerp Faculty of Applied Engineering EMIB Research Group Belgium Magnel Laboratory for Concrete Research Ghent University Belgium Vrije Universiteit Brussel Belgium

Different shapes and dimensions of test specimens are used for the determination of the uniaxial compressive strength of concrete. In order to compare strength results conversion formulas are needed. Those formulas are well-known for vibrated concrete (VC), whereas this is not the case for self-compacting concrete (SCC). In the paper, strength ratios of SCC are compared to those for VC as suggested by different standards. In total 24 powder-type SCC mixtures and 2 VC mixtures have been prepared and studied in order to analyze the effect on the strength ratio of several parameters, including the type of cement. The influence of the water-to-cement ratio (W/C), the cement-to-powder ratio (C/P) and the powder content (P) is investigated as well. The same mix procedure is applied in the three laboratories. In the mixtures SCC P520, SCC P560, SCC ref and SCC P640, the powder content varies, while C/P and W/C are kept constant. The effect is studied by replacing gravel by crushed limestone or crushed porphyry. The influence of the water-to-cement ratio, the cement-to-powder ratio, the powder content, the type of cement, the filler, the superplasticizer and the aggregate, on the compressive strength conversion factors seems to be insignificant or too scattered to be considered.

关键词： Self compacting concrete

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Review of the LEED Category in Materials and Resources for Developing Countries

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Procedia engineering 2015年 118卷 1145-1152页

作者： Asli Pelin Gurgun Ruveyda Komurlu David Arditi Yildiz Technical University Department of Civil Eng. Davutapasa Campus Esenler Istanbul 34220 Turkey Kocaeli University Department of Architecture Kocaeli 41300 Turkey Illinois Institute of Technology Construction Engineering and Management Program Chicago USA

Material selection in sustainable projects affects the environment a great deal. Selected materials gain importance as they can contaminate the environment and can produce waste during construction. Use of limited resources has also environmental impacts. Thus, considering sustainable materials in the projects and appropriate consumption of available resources are important for sustainability considerations. The danger of running out of resources and the consequences of contamination of the habitat point out to the importance of green building certification systems. Issues such as storage and collection of recyclables, waste management planning, PBT source reduction, sourcing of raw materials, material ingredients, and design for flexibility that are treated in this category are difficult to implement in developing countries, mainly because they are based on local practices. The use of materials and resources accounts approximately for 11% of the points a building can receive for LEED v4 certification. However, the use of LEED in countries other than the U.S. can be controversial as local conditions are effective in earning credentials required for certification. This study aims to review the “materials and resources” category of LEED. Comparison of local practices in selected developing countries is made based on credits in this category to provide guidelines for green projects in those countries. It is expected that practitioners in developing countries will benefit from the outcome of this study.

关键词： Sustainability LEED Developing countries Sustainable materials

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Correlation Equation to Predict HHV of Tropical Peat Based on its Ultimate Analyses

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Procedia engineering 2015年 125卷 298-303页

作者： Wiwiek Setyawati Enri Damanhuri Puji Lestari Kania Dewi Faculty of Civil and Environmental Engineering Bandung Institute of Technology Jl. Ganesha 10 Bandung 40132 Indonesia Centre for Atmospheric Science and Technology LAPAN Jl. Dr Djundjunan 133 Bandung 40173 Indonesia Graduate Program Bandung Institute of Technology Jl. Ganesha 10 Bandung 40132 Indonesia

The aim of the research is to develop correlation equation to predict HHV of tropical peat based on its ultimate analysis. The Eijkelkamp peat sampler was employed to take samples of peat in five different districts in Pontianak, Indonesia. Samples were taken up to 2 m depth with 50 cm increments therefore total 20 samples were obtained. Ultimate analyses and higher heating value (HHV) of peat were evaluated in order to predict HHV based on its ultimate analyses results. It was found that C, H, O, S, N and ash contents in dry bases (in weight %) had ranges of 15.63 – 59.43%, 2.63 – 6.47%, 13.35 – 36.84%, 0.12 – 3.86%, 0.48 – 2.01% and 1.00 – 64.05%, respectively. HHV had ranges of 8.07 – 21.69 MJ/kg. Based on chemical composition of dry peat therefore new equation formulae to predict HHV peat was HHV = 17.830 + 1.508 H + 0.102 N + 0.575 S – 0.192 O-0.205 Ash, with an average absolute error and bias error of 2.18% and 0.17%, respectively.

关键词： Tropical peat Pontianak ultimate analysis high heating value prediction

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Author Correction: The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

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Scientific data 2021年第1期8卷 72页

作者： Gilberto Pastorello Carlo Trotta Eleonora Canfora Housen Chu Danielle Christianson You-Wei Cheah Cristina Poindexter Jiquan Chen Abdelrahman Elbashandy Marty Humphrey Peter Isaac Diego Polidori Markus Reichstein Alessio Ribeca Catharine van Ingen Nicolas Vuichard Leiming Zhang Brian Amiro Christof Ammann M Altaf Arain Jonas Ardö Timothy Arkebauer Stefan K Arndt Nicola Arriga Marc Aubinet Mika Aurela Dennis Baldocchi Alan Barr Eric Beamesderfer Luca Belelli Marchesini Onil Bergeron Jason Beringer Christian Bernhofer Daniel Berveiller Dave Billesbach Thomas Andrew Black Peter D Blanken Gil Bohrer Julia Boike Paul V Bolstad Damien Bonal Jean-Marc Bonnefond David R Bowling Rosvel Bracho Jason Brodeur Christian Brümmer Nina Buchmann Benoit Burban Sean P Burns Pauline Buysse Peter Cale Mauro Cavagna Pierre Cellier Shiping Chen Isaac Chini Torben R Christensen James Cleverly Alessio Collalti Claudia Consalvo Bruce D Cook David Cook Carole Coursolle Edoardo Cremonese Peter S Curtis Ettore D'Andrea Humberto da Rocha Xiaoqin Dai Kenneth J Davis Bruno De Cinti Agnes de Grandcourt Anne De Ligne Raimundo C De Oliveira Nicolas Delpierre Ankur R Desai Carlos Marcelo Di Bella Paul di Tommasi Han Dolman Francisco Domingo Gang Dong Sabina Dore Pierpaolo Duce Eric Dufrêne Allison Dunn Jiří Dušek Derek Eamus Uwe Eichelmann Hatim Abdalla M ElKhidir Werner Eugster Cacilia M Ewenz Brent Ewers Daniela Famulari Silvano Fares Iris Feigenwinter Andrew Feitz Rasmus Fensholt Gianluca Filippa Marc Fischer John Frank Marta Galvagno Mana Gharun Damiano Gianelle Bert Gielen Beniamino Gioli Anatoly Gitelson Ignacio Goded Mathias Goeckede Allen H Goldstein Christopher M Gough Michael L Goulden Alexander Graf Anne Griebel Carsten Gruening Thomas Grünwald Albin Hammerle Shijie Han Xingguo Han Birger Ulf Hansen Chad Hanson Juha Hatakka Yongtao He Markus Hehn Bernard Heinesch Nina Hinko-Najera Lukas Hörtnagl Lindsay Hutley Andreas Ibrom Hiroki Ikawa Marcin Jackowicz-Korczynski Dalibor Janouš Wilma Jans Rachhpal Jassal Shicheng Jiang Tomomichi Kato Myr Computational Research Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA. gzpastorello@lbl.gov. DIBAF University of Tuscia Viterbo 01100 Italy. Euro-Mediterranean Centre on Climate Change Foundation (CMCC) Lecce 73100 Italy. Climate & Ecosystem Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA. Computational Research Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA. Department of Civil Engineering California State University Sacramento CA 95819 USA. Department of Geography Environment and Spatial Sciences Michigan State University East Lansing MI 48823 USA. Department of Computer Science University of Virginia Charlottesville VA 22904 USA. TERN Ecosystem Processes Menzies Creek VIC3159 Australia. Max Planck Institute for Biogeochemistry Jena 07701 Germany. Laboratoire des Sciences du Climat et de l'Environnement (LSCE) CEA CNRS UVSQ UPSACLAY Gif sur Yvette 91190 France. Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China. Department of Soil Science University of Manitoba Winnipeg MB R3T2N2 Canada. Department of Agroecology and Environment Agroscope Research Institute Zürich 8046 Switzerland. School of Geography and Earth Sciences McMaster University L8S4K1 Hamilton ON Canada. Department of Physical Geography and Ecosystem Science Lund University Lund 22362 Sweden. Department of Agronomy and Horticulture University of Nebraska-Lincoln Lincoln NE 68583 USA. School of Ecosystem and Forest Sciences The University of Melbourne Richmond VIC3121 Australia. Department of Biology Research Group PLECO University of Antwerp Antwerp 2610 Belgium. Joint Research Centre European Commission Ispra 21027 Italy. TERRA Teaching and Research Center University of Liege Gembloux B-5030 Belgium. Finnish Meteorological Institute Helsinki 00560 Finland. ES

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Development of a UAV-type jellyfish monitoring system using deep learning

Development of a UAV-type jellyfish monitoring system using ...

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International Conference on Ubiquitous Robots and Ambient Intelligence (URAI)

作者： Hangeun Kim Donghoon Kim Sungwook Jung Jungmo Koo Jae-Uk Shin Hyun Myung Civil & Environmental Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon Korea Urban Robotics Laboratory (URL) Robotics Program Korea Advanced Institute of Science and Technology (KAIST) Daejeon Korea Rastech Inc. Daejeon Korea

At present, unmanned aerial vehicles (UAVs) are the primary platforms widely used for environmental monitoring. The advantage of the UAV-type surveillance system is its low-cost with high observation performance. Using this system, we can extend the workable area of the jellyfish removal system. The proposed system observes jellyfish on the surface of the sea while flying, and can recognize a herd of jellyfish using deep learning. The preliminary results of the proposed system show that the proposed system improves the jellyfish removal system for efficient operation.

关键词： Robots Sea surface Surveillance Machine learning Global Positioning System Clustering algorithms

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Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study (vol 2, pg 144, 2021)

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LANCET GLOBAL HEALTH 2021年第4期9卷 E408-E408页

作者： Steinmetz, Jaimie D. Vision and Eye Research Institute Anglia Ruskin University Cambridge United Kingdom Biomedical Informatics Seoul National University Hospital Seoul South Korea Institute for Health Metrics and Evaluation University of Washington Seattle WA United States Department of Health Metrics Sciences School of Medicine University of Washington Seattle WA United States Institute of Health Services Research Yonsei University Seoul South Korea Department of Ophthalmology University of Washington Seattle WA United States Department of Mathematics Imperial College London London United Kingdom WHO Collaborating Centre for Public Health Education and Training Imperial College London London United Kingdom Department of Primary Care and Public Health Imperial College London London United Kingdom School of Population and Global Health University of Melbourne Carlton VIC Australia School of Optometry and Vision Science UNSW Sydney NSW Australia Brien Holden Vision Institute Sydney Australia Department of Ophthalmology University of Adelaide Adelaide SA Australia Department of Parasitology and Mycology Jahrom University of Medical Sciences Jahrom Iran Department of Clinical Sciences University of Sharjah Sharjah United Arab Emirates Ophthalmic Research Center Shahid Beheshti University of Medical Sciences Tehran Iran Department of Ophthalmology Shahid Beheshti University of Medical Sciences Tehran Iran Research Institute for Endocrine Sciences Shahid Beheshti University of Medical Sciences Tehran Iran Ophthalmic Epidemiology Research Center Shahid Beheshti University of Medical Sciences Tehran Iran Health Services Management Department Qazvin University of Medical Sciences Qazvin Iran Department of Systems Populations and Leadership University of Michigan Ann Arbor MI United States Department of Medicine Sofia Ismail Memorial Medical Centre Bogura Bangladesh The Fred Hollows Foundation Sydney NSW Australia Berhan Public Health & Eye Care Consultancy Addis A

Hospital El Salvador: a novel paradigm of intensive care in response to COVID-19 in central America. Lancet Glob Health 2021;9: e241?42?In this Comment, the conflict of interest statement should have included the following: ?By virtue of their roles within a public hospital or the Ministry of Health, MB, LC, WH, and XS are government employees. The findings and conclusions in the Comment are only those of the authors.? This correction has been made as of Feb 26, 2021.

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