Evaluation of Cement Performance Using Industrial Byproducts Such as Nano MgO and Fly Ash from Greece

The need for environmentally friendly construction materials is growing more and more these days. This paper investigates byproducts from Greece, such as magnesite tailings from Evoia and fly ash from Kardia (Ptolemais), in order to evaluate their suitability as cement additives. For this purpose, the raw materials were tested and studied regarding their mineralogical and chemical components for their morphological characteristics. Different cement specimens of various mixtures of raw materials were produced and tested. These raw materials are considered suitable for cement additives. The effect of nano MgO content seems to have played a more critical role in the physicomechanical performance of produced cement compared to that of the fly ash content. Furthermore, more satisfactory results in the physicomechanical properties of the produced cement gave samples of group II containing 3–4% of nano MgO. Nano MgO content up to 4% seems to have negative influence on the compressive strength of the produced cement, simultaneously reducing its durability. The increase of nano MgO content leads to the increase of the expansion of the produced cement specimens. In the early stage, the expansion rate was intensively larger. With the consumption of nano MgO, the expansion in the later stage gradually slowed down and tended to stabilize.

PHA Production from Cheese Whey and “Scotta”: Comparison between a Consortium and a Pure Culture of Leuconostoc mesenteroides

It is urgent to expand the market of biodegradable alternatives to oil-derived plastics owing to (i) increasingly limited oil availability/accessibility, and (ii) the dramatic impact of traditional plastics on aquatic life, the food chain, all Earth ecosystems, and ultimately, human health. Polyhydroxyalkanoates (PHAs) are promising biodegradable polymers that can be obtained through microbial fermentation of agro-industrial byproducts, e.g., milk and cheese whey. Here, the PHA-accumulating efficiency of a mixed microbial culture (MMC, derived from activated sludges) grown on dairy byproducts (cheese and scotta whey) was measured. Bioreactor tests featuring temperature and pH control showed that both scotta and pre-treated Toma cheese whey could be used for PHA production by MMC, although scotta cheese whey supported higher PHA yield and productivity. The advantages of open MMCs include their plasticity and versatility to fast changing conditions; furthermore, no growth-medium sterilization is needed prior to fermentation. However, the use of pure cultures of efficient PHA producers may support better metabolic performances. Therefore, PHA-producing strains were isolated from an MMC, leading to the satisfactory identification of two bacterial strains, Citrobacter freundii and Leuconostoc spp., whose ability to accumulate PHAs in synthetic media was confirmed. A more detailed investigation by mass spectrometry revealed that the strain was L. mesenteroides. Although the validation of L. mesenteroides’ potential to produce PHA through fermentation of agro-industrial byproducts requires further investigations, this is the first study reporting PHA production with the Leuconostoc genus.

Utilization of Industrial Byproducts for Enhancing the Properties of Cement Mortars at Elevated Temperatures

The research on industrial byproducts, such as slags and fly ash, was intense during the last decades in the building sector. Apart from the environmental benefits coming from their exploitation, their application may lead to the production of cost effective and durable building materials, such as mortars and concrete. The impact of industrial byproducts on the resistance of materials to fire and elevated temperatures was assessed by many scientists, however, it is still an open field of research. In this study, locally available byproducts were investigated, including High Calcium Fly Ash (HCFA), coming from lignite-fired power plants, as well as Ladle Furnace Steel (LFS) slag and Electric Arc Furnace (EAF) slag aggregates, originating from the steel making industry. Six mortar compositions were manufactured with substitution of Ordinary Portland Cement (OPC) with HCFA and LFS slag (20% w/w) and of natural aggregates with EAF slag (50% w/w). At the age of 7, 28, and 90 days, the physico-mechanical properties of the specimens were recorded, while they were further exposed at elevated temperatures, concerning 200 °C, 400 °C, 600 °C, 800 °C, and 1000 °C. After each exposure, their physico-mechanical and microstructure characteristics were identified. From the evaluation of the results, it was asserted that HCFA and EAF slag aggregates enhanced the overall performance of mortars, especially up to 600 °C. LFS was beneficial only in combination with EAF slag aggregates.

Retraction Notice To: Potential Health Benefits of Broccoli-A Chemico-Biological Overview

The article “Potential health benefits of broccoli- a chemico-biological overview, published in Mini-Rev Med Chem 2009 Jun;9(6):749-59. By Hannah R. Vasanthi, Subhendu Mukherjee and Dipak K. Das” has been retracted by the Editorial office of the journal Mini-reviews in Medicinal Chemistry, as the text in this review article are from sources which have been retracted or under investigation on the basis of data fabrication and falsification, authorship misconduct, duplicate publication, unethical research practices, text recycling/self-plagiarism, and unresolved concerns about data integrity and research conduct. The authors were informed of this complaint and were requested to give justification on the matter in their defense [1]. Some sources that have been retracted are as follows: 1) Agarwal et al. Dynamic Action of Carotenoids in Cardioprotection and Maintenance of Cardiac Health, Molecules 2012, 17, 4755-4769. http: https://pubmed.ncbi.nlm.nih.gov/24896014/ 2) Nagendran Balasundram, KalyanaSundram, SamirSamman. Phenolic compounds in plants and agri-industrial byproducts: Antioxidant activity, occurrence, and potential uses. Food Chemistry 2006, 99(1), 191-203. https://www.sciencedirect.com/science/article/abs/pii/S0308814605006242 Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused. The Bentham Editorial Policy on Article Retraction can be found at https://benthamscience.com/editorial-policies-main.php. REFERENCES [1] Hannah R Vasanthi, Subhendu Mukherjee, Dipak K Das. Potential health benefits of broccoli- a chemico-biological overview. Mini Rev Med Chem., 2009, 9(6), 749-759. doi: 10.2174/138955709788452685. https://pubmed.ncbi.nlm.nih.gov/19519500/ Bentham Science Disclaimer: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.