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Interconnection between PHA and Stress Robustness of Bacteria
Published in Martin Koller, The Handbook of Polyhydroxyalkanoates, 2020
Stanislav Obruca, Petr Sedlacek, Iva Pernicova, Adriana Kovalcik, Ivana Novackova, Eva Slaninova, Ivana Marova
Extreme thermophiles producing PHA include bacteria of the genus Thermus thermophilus. The cultivation temperature is 75°C and when sodium gluconate (1.5% w/v) or sodium octanoate (10 mM) are used as solo carbon sources, Thermus thermophilus can produce PHA at approximately 35 to 40% dry weight of biomass. By gas chromatography analysis, the production on gluconate was found to give a polyester composed mainly of 3-hydroxydecanoate (3HD) with the molar fraction of up to 64 mol-%. Other components in polyester, in addition to 3HD, were 3-hydroxyoctanoate (3HO), 3-hydroxyvalerate (3HV) and 3-hydroxybutyrate (3HB). However, the polyester produced when grown on octanoate as the only carbon source was composed of more than one monomer unit, namely 35.4 mol-% 3-hydroxyundecanoate (3HUD), 24.5 mol-% 3HB, 14.6 mol-% 3HD, 12.3 mol-% 3-hydroxynonanoate (3HN) and 7.8 mol-% 3-hydroxydodecanoate [33].
The Use of Superplasticizers in High Performance Concrete
Published in Yves Malier, High Performance Concrete, 2018
Experience shows that, with some rheologically reactive cements, the incorporation of a certain amount of retarding agent early on in mixing, (about 5 to 10% of the total volume of superplasticizer that is supposed to be used), can solve the slump-loss problem without unduly retarding the setting of the concrete. It seems better to use a retarding agent based on sodium gluconate rather than a lignosulphonate retarding agent, because the former entraps fewer air bubbles in the concrete and seems to be more effective. Moreover, sodium gluconate is a chemical product more controlled than lignosulphonate when used as a retarding agent. When the simultaneous use of a retarder and superplasticizer is required, the optimum dosage of both admixtures has to be found in terms of cost and short-term compressive strength. Too low a compressive strength at 1 day can delay removing the forms.
A proposal on a new curriculum for the smart eco-efficient built environment
Published in Alphose Zingoni, Insights and Innovations in Structural Engineering, Mechanics and Computation, 2016
These may include the use of admixtures based on renewable bio-based feedstock’s and or capable of biodegradation to replace chemical admixtures used in Portland cement concrete. Examples of biopolymers used in concrete include for instance lignosulfonate, pine root extract, protein hydrolysates or even vegetable oils. Biotechnological admixtures made in fermentation processes by using bacteria or fungi are receiving increased attention. This includes sodium gluconate, curdlan or Welan gum (Planck, 2004, 2005).
Use of hop cone extract obtained under supercritical CO2 conditions for producing antibacterial all-purpose cleaners
Published in Green Chemistry Letters and Reviews, 2018
Tomasz Wasilewski, Dominik Czerwonka, Urszula Piotrowska, Artur Seweryn, Zofia Nizioł-Łukaszewska, Marcin Sobczak
The formulations of APC also contain ingredients enhancing the cleaning performance – for example sequestrants which reduce water hardness, such as ethylenediaminetetraacetic acid disodium salt, sodium gluconate, sodium citrate, citric acid, calcium gluconate, gluconic acid, acetic acid, sodium phytate, calcium phytate (14–16). Other additions include substances intended to increase formulation appeal to consumers, for example hydrotropes which improve solution clarity – including salts of lower alkylaryl sulfonates, urea, ethanolamines (17) – but also colorants, fragrances, and preservatives.
Reasons for crack propagation and strength loss in refractory castables based on changes in their chemical compositions and micromorphologies with heating: special focus on the large blocks
Published in Journal of Asian Ceramic Societies, 2019
Water-reducing agents can be used to reduce the amount of water needed for refractory castable production. The common water-reducing agents used in high alumina castables are sodium citrate, gluconic acid, sodium or calcium lignosulphonate, and sodium gluconate as well as such superplasticizers as melamine formaldehyde sulfonate and naphthalene formaldehyde sulfonate. It should be noted, however, that although some of these water-reducing agents reduce the water requirement, they may also lead to a reduction in final strength [14].
Effects of sodium gluconate on hydration reaction, setting, workability, and strength development of calcium sulfoaluminate belite cement mixtures
Published in Journal of Sustainable Cement-Based Materials, 2022
Guangping Huang, Rajender Gupta, Wei Victor Liu
In addition to citric acid, sodium gluconate (HOCH2[CH(OH)]4COONa), the sodium salt of gluconic acid, has also shown an effective retarding effect on the hydration and setting of CSA-type cement mixtures, and it improves the workability of CSA-type cement mixtures [29–31]. For example, Zhang et al. [29] found that 0.15% of sodium gluconate extended the initial setting time of a CSA-type cement paste with a 1.25% dosage of polycarboxylate acid-based superplasticizer from 25 min to 70 min and increased the flow diameter of the pastes from 170 mm to about 270 mm at 15 min. A similar improvement in workability was also reported in the study from Li et al. [31], in which 0.09% of sodium gluconate expanded the flow diameter of CSA-type cement pastes from 170 mm to 235 mm at 15 min under 40 °C. These studies [29,31] indicate that sodium gluconate has the potential to be used as a retarder for CSA-type cement mixtures without compromising their workability. However, there has been no research investigating the influence of different dosages of sodium gluconate on the hydration reaction, setting time, workability, early-age strength, and long-term strength of CSA-type cement mixtures. In addition, previous studies [29–31] were mainly conducted on normal CSA cement, which has very different mineralogical contents when compared with CSAB cement. For example, the belite content in normal CSA cement is 0%-20%, while that for CSAB cement is 30% to 60% [5,32,33]. The different mineralogical contents may cause a large amount of differences in the performance of admixtures. Therefore, there is a research gap to conduct a comprehensive study for understanding the influence of sodium gluconate dosages on the hydration reaction, setting time, workability, and strength development of CSAB mixtures since it can help guide future mixture design to achieve desired properties, ultimately spreading the application of eco-friendly CSAB cement and reducing CO2 emissions associated with cement production.