scholarly journals Alkali-reduced Bauxite Residue as Novel SCM

2020 ◽  
Vol 63 (2) ◽  
pp. 1-20
Author(s):  
Tobias Danner ◽  
Malin Sletnes ◽  
Harald Justnes
Keyword(s):  
Acetic Acid ◽  
Construction Industry ◽  
Large Scale ◽  
Bauxite Residue ◽  
Bound Water ◽  
Supplementary Cementitious Material ◽  
Pozzolanic Reactivity ◽  
First Results ◽  
Acetic Acid Treatment ◽  
High Alkalinity

AbstractBauxite residue is a major waste stream available in large volumes globally that can cause risks to the surrounding environment (e.g. ecotoxicity) when disposed and stored by conventional methods. There is yet no large-scale application and the utilization as supplementary cementitious material might be the best way to re-use bauxite residue. The main obstacle for the utilization of bauxite residue in the construction industry is the high alkalinity. This paper presents first results of a study on alkali reduction of bauxite residue by acetic acid treatment and the potential application of this alkali reduced bauxite residue as pozzolan in cementitious binders. A process of alkali reduction is presented that can help solving waste management problems of alumina refineries by transforming bauxite residue to a less hazardous waste, while producing a reactive pozzolan and Na-acetate that can find application in the construction and infrastructure market. 90% alkalinity reduction of bauxite residue could be achieved by simply washing with diluted acetic acid. Alkali-reduced bauxite residue showed good pozzolanic reactivity regarding portlandite consumption, bound water and 28-day compressive strength of mortars with 20% replacement of OPC.

Materials for the history of the gospel-Baptist movement in Ukraine

1996 ◽  
pp. 4-15
Author(s):  
S. Golovaschenko ◽  
Petro Kosuha
Keyword(s):  
Large Scale ◽  
Religious Studies ◽  
Theological Seminary ◽  
National Academy Of Sciences ◽  
Evangelical Christians ◽  
Evangelical Christian ◽  
First Results ◽  
History Of ◽  
Fruitful Cooperation ◽  
Academy Of Sciences

The report is based on the first results of the study "The History of the Evangelical Christians-Baptists in Ukraine", carried out in 1994-1996 by the joint efforts of the Department of Religious Studies at the Institute of Philosophy of the National Academy of Sciences of Ukraine and the Odessa Theological Seminary of Evangelical Christian Baptists. A large-scale description and research of archival sources on the history of evangelical movements in our country gave the first experience of fruitful cooperation between secular and church researchers.

Sustainable Production of Honeydew and Muskmelon in Western Mexico

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 495d-495
Author(s):  
J. Farias-Larios ◽  
A. Michel-Rosales
Keyword(s):  
Large Scale ◽  
Management Practices ◽  
Glomus Intraradices ◽  
Cultural Practices ◽  
Bare Soil ◽  
Western Mexico ◽  
First Results ◽  
Legume Cover Crop ◽  
Banana Leaves ◽  
Research Show

In Western Mexico, melon production depends on high-input systems to maximize yield and product quality. Tillage, plasticulture, fumigation with methyl bromide, and fertigation, are the principal management practices in these systems. However, at present several problems has been found: pests as sweetpotato whitefly (Bemisia tabaci Gennadius), aphids (Myzus and Aphis), leafminer (Liryomiza sativae); diseases as Fusarium, Verticilium, and Pseudoperenospora, and weeds demand high pesticide utilization and labor. There is a growing demand for alternative cultural practices, with an emphasis on reducing off-farm input labor and chemicals. Our research is based on use of organic mulches, such as: rice straw, mature maize leaves, banana leaves, sugarcane bagasse, coconut leaves, and living mulches with annual legume cover crop in melons with crop rotation, such as: Canavalia, Stilozobium, Crotalaria, and Clitoria species. Also, inoculations with mycorrhizal arbuscular fungi for honeydew and cantaloupe melon seedlings production are been assayed in greenhouse conditions for a transplant system. The use of life barriers with sorghum, marigold, and other aromatic native plants in conjunction with a colored yellow systems traps for monitoring pests is being studied as well. While that the pest control is based in commercial formulations of Beauveria bassiana for biological control. The first results of this research show that the Glomus intraradices, G. fasciculatum, G. etunicatum, and G. mosseae reached 38.5%, 33.5%, 27.0%, and 31.0% of root infection levels, respectively. Honeydew melons production with rice and corn straw mulches shows an beneficial effect with 113.30 and 111.20 kg/plot of 10 m2 compared with bare soil with 100.20 kg. The proposed system likely also lowers production cost and is applicable to small- and large-scale melon production.

Use of lime for the upgrading of existing wastewater treatment systems

1994 ◽  
Vol 29 (12) ◽  
pp. 279-282 ◽  
Author(s):  
C. Güldner ◽  
W. Hegemann ◽  
N. Peschen ◽  
K. Sölter
Keyword(s):  
Large Scale ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Precipitation ◽  
Fatty Acid Production ◽  
German States ◽  
Lime Solution ◽  
First Results ◽  
Pre Treatment

The integration of the chemical precipitation unit which would inject a lime solution into a series of mechanical-biological processes, including nitrification/denitrification, and the sludge treatment are the subject of this project. The essential target is the large-scale reconstruction of a mechanical-biological sewage treatment plant with insufficient cleaning performance in the new German states and the adjustment of the precipitation stage to the unsteady inflow of sewage. First results indicate that the pre-treatment performance could be improved by ≅ 20% and the discharge of concentrations of COD, BOD, N and P could be reduced and homogenized. In addition, experiments on hydrolysis and acidifiability of the pre-treatment sludge have been carried out on a laboratory level with the object of making sources of carbon readily available for denitrification. In the course of the experiment, inhibition of fatty acid production by calcareous primary sludge could not be detected. The characteristics of the sludge, such as draining and thickening were considerably improved by the adding of lime.

Quasar host galaxies and environments in the GAMA survey

2019 ◽  
Vol 15 (S356) ◽  
pp. 170-170
Author(s):  
Jari Kotilainen
Keyword(s):  
Galaxy Evolution ◽  
Large Scale ◽  
Group Membership ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Cluster Group ◽  
First Results ◽  
Triggering Mechanisms ◽  
Mass Assembly

AbstractWe present first results from our study of the host galaxies and environments of quasars in Galaxy And Mass Assembly (GAMA), a multiwavelength photometric and spectroscopic survey for ∼300,000 galaxies over ∼300 deg2, to a limiting magnitude of r ∼ 20 mag. We use a GAIA-selected sample of ∼350 quasars at z < 0.3 in GAMA. For all the quasars, we determine all surrounding GAMA galaxies and measure their star formation (SF) rate and SF history, and the host galaxy morphology and group membership of the quasars. As a comparison sample of inactive galaxies, we use 1000 subsets of galaxies in GAMA, matched in redshift and galaxy stellar mass to the quasars. We find that quasar activity does not depend on the large-scale environment (cluster/group/void), although quasars tend to prefer satellite location in their environment. Compared to inactive galaxies, quasars are preferentially hosted in bulge-dominated galaxies and have higher SF rates, both overall and averaged over the last 10 and 100 Myr. Quasars also have shorter median SF timescales, shorter median time since the last SF burst, and higher metallicity than inactive galaxies. We discuss these results in terms of triggering mechanisms of the quasar activity and the role of quasars in galaxy evolution.

scholarly journals An Alternative to Clay in Building Materials: Red Mud Sintering Using Fly Ash via Taguchi’s Methodology

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Suchita Rai ◽  
Dilip H. Lataye ◽  
M. J. Chaddha ◽  
R. S. Mishra ◽  
P. Mahendiran ◽  
...  
Keyword(s):  
Fly Ash ◽  
Construction Industry ◽  
Red Mud ◽  
Morphological Analysis ◽  
Building Materials ◽  
Sintering Temperature ◽  
Bauxite Residue ◽  
Significant Parameter ◽  
Alkaline Waste ◽  
Free Caustic Soda

“Red mud” or “bauxite residue” is a highly alkaline waste generated from alumina refinery with a pH of 10.5–12.5 which poses serious environmental problems. Neutralization or its treatment by sintering in presence of additives is one of the methods for overcoming the caustic problem as it fixes nearly all the leachable free caustic soda present in red mud. In the present study, feasibility of reducing the alkaline nature of red mud by sintering using fly ash as an additive via Taguchi methodology and its use for brick production, as an alternative to clay, is investigated. The analysis of variance (ANOVA) shows that sintering temperature is the most significant parameter in the process. A pH of 8.9 was obtained at 25–50% of red mud and 50–75% fly ash with water and temperature of . Alternatively 50% of red mud can be mixed with 50% of fly ash with water at temperature of to get a pH of about 8.4. The mechanism of this process has been explained with also emphasis on chemical, mineralogical, and morphological analysis of the sintered red mud. The results would be extremely useful in utilization of red mud in building and construction industry.

scholarly journals Star formation thresholds derived From THINGS

2006 ◽  
Vol 2 (S237) ◽  
pp. 397-397
Author(s):  
F. Bigiel ◽  
F. Walter ◽  
E. de Blok ◽  
E. Brinks ◽  
B. Madore
Keyword(s):  
Star Formation ◽  
Large Scale ◽  
Gravitational Instability ◽  
Critical Density ◽  
Nearby Galaxy ◽  
Uv Emission ◽  
Radial Profiles ◽  
Wide Range ◽  
First Results ◽  
Type Mass

AbstractWe present first results from THINGS (The HI Nearby Galaxy Survey), which consists of high quality HI maps obtained with the VLA of 34 galaxies across a wide range of galaxy parameters (Hubble type, mass/luminosity). We compare the distribution of HI to the UV emission in our sample galaxies. In particular we present radial profiles of the HI (tracing the neutral interstellar medium) and UV (mainly tracing regions of recent star formation) in our sample galaxies. The azimuthally averaged HI profiles are compared to the predicted critical density above which organized large-scale star formation is believed to start (this threshold is based on the Toomre-Q parameter, which in turn is a measure for local gravitational instability).

scholarly journals Accessing Voluntary HIV Testing in the Construction Industry: A Qualitative Analysis of Employee Interviews from the Test@Work Study

2021 ◽  
Vol 18 (8) ◽  
pp. 4184
Author(s):  
Sarah Somerset ◽  
Catrin Evans ◽  
Holly Blake
Keyword(s):  
Sexual Health ◽  
Hiv Testing ◽  
Construction Industry ◽  
Large Scale ◽  
Early Stage ◽  
Structured Interview ◽  
Health Check ◽  
Public Health Issue ◽  
Health Awareness ◽  
Health Checks

HIV, globally, remains a significant public health issue and community HIV testing can help to identify those with HIV at an early stage of disease. The workplace offers a prime location for provision of opt-in HIV testing as part of wider health promotion initiatives. The construction industry offers a key opportunity for HIV testing provision in a generally male-dominated group exhibiting some risky behaviors related to HIV. The intervention was an optional one-off individual health check with tailored health advice and signposting, offered to the construction workforce in health check events delivered as part of a large-scale multi-site research program called Test@Work. The events were undertaken at 10 participating organizations (21 events across 16 different sites), none had previously offered sexual health awareness or HIV testing to their workforce. Participants were invited to participate in a semi-structured interview following general health checks which included HIV testing. Out of 426 employees attending the health check events, 338 (79.3%) consented to interview on exit. Accessing HIV testing at work was valued because it was convenient, quick, and compatible with work demands. Interviewees identified HIV risks for construction including drug use, high numbers of sexual partners and job-related exposures, e.g., to used needles. Health seeking in construction was limited by stigma and low support, with particular barriers for non-permanent workers. The organization of the construction industry is complex with multiple organizations of different sizes having responsibility for varying numbers of employees. A disparity between organizational policies and employment circumstances is evident, and this generates significant health inequalities. To combat this, we recommend that organizations in the construction sector offer their employees awareness-raising around health behaviors and health protection in packages, such as toolbox talks. We recommend these be accompanied by annual health checks, including sexual health awareness and opt-in workplace HIV testing. This approach is highly acceptable to the workforce in the industry and removes barriers to access to healthcare.

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