Mechanical and Durability Properties of Hybrid Fiber Reinforced High Performance Concrete using Multiple Mineral Admixtures

A study has been made for the high performance concrete of grade M70, where two mineral admixtures like GGBS and Metakaolin has been used with the two fibers, one B glass fibers and asbestos fibers. If two fibers are used in the concrete then we are call is having a fiber reinforced concrete the asbestos fibers percentage was kept constant of about 0.33% and glass fibers % have been changed from 0.25, 0.75 and 1.0%. The cubes are casted for different water cement ratios which is 0.25,0.30 and 0.35. there cubes are tested for the strength teste and durability zero.

An Inter-loop Approach on Hydrothermal Carbonization of Sewage Sludge for the Production of Biochar and Its Application as an Adsorbent for Lead-acid Battery Recycling

This work presents an inter-loop approach in which the hydrothermal carbonization (HTC) of sewage sludge allows the production of biochars capable of removing iron ions, which usually harm the lead-acid batteries performance, from spent sulfuric acid without any activation step. The HTC process was performed at three different water/biomass ratios under 180 ºC by 24 h, and except for water, no additional chemical input was used. The moisture content of the sludges ranged from 76 to 91 wt.%. Biochars were characterized by XRD, FTIR, SEM, TGA and N2 adsorption-desorption. Results suggest a high dependence of their textural and surface properties on the water amount inside the reactor vessel. The expressive presence of multiple mineral phases in the sewage sludge allowed the formation of a hydrophilic surface, which was fundamental for the iron ions adsorption at strong acidic conditions. Porosity was strongly influenced by the water/biomass ratio, with biochar’s surface displaying pore dimensions in nano and micro domains. Furthermore, the non-activated biochar presented an adsorption capacity up to 148 mgFe g-1, whereas the commercial activated carbon “as received” achieved 178 mgFe g-1. Results show the potential of the HTC technique for sewage sludge conversion into biochar without pre-drying, and the possibility of interconnecting two or more industrial processes in order to make them cleaner and more sustainable, matching the principles of circular economy.

A petrological and conceptual model of Mayon volcano (Philippines) as an example of an open-vent volcano

Mayon is a basaltic andesitic, open-vent volcano characterized by persistent passive degassing from the summit at 2463 m above sea level. Mid-size (< 0.1 km3) and mildly explosive eruptions and occasional phreatic eruptions have occurred approximately every 10 years for over a hundred years. Mayon’s plumbing system structure, processes, and time scales driving its eruptions are still not well-known, despite being the most active volcano in the Philippines. We investigated the petrology and geochemistry of its crystal-rich lavas (~ 50 vol% phenocrysts) from nine historical eruptions between 1928 and 2009 and propose a conceptual model of the processes and magmatic architecture that led to the eruptions. The whole-rock geochemistry and mineral assemblage (plagioclase + orthopyroxene + clinopyroxene + Fe-Ti oxide ± olivine) of the lavas have remained remarkably homogenous (54 wt% SiO2, ~ 4 wt% MgO) from 1928 to 2009. However, electron microscope images and microprobe analyses of the phenocrysts and the existence of three types of glomerocrysts testify to a range of magmatic processes, including long-term magma residence, magma mixing, crystallization, volatile fluxing, and degassing. Multiple mineral-melt geothermobarometers suggest a relatively thermally buffered system at 1050 ± 25 °C, with several magma residence zones, ranging from close to the surface, through reservoirs at ~ 4–5 km, and as deep as ~ 20 km. Diffusion chronometry on > 200 orthopyroxene crystals reveal magma mixing timescales that range from a few days to about 65 years, but the majority are shorter than the decadal inter-eruptive repose period. This implies that magma intrusion at Mayon has been nearly continuous over the studied time period, with limited crystal recycling from one eruption to the next. The variety of plagioclase textures and zoning patterns reflect fluxing of volatiles from depth to shallower melts through which they eventually reach the atmosphere through an open conduit. The crystal-rich nature of the erupted magmas may have developed during each inter-eruptive period. We propose that Mayon has behaved over almost 100 years as a steady state system, with limited variations in eruption frequency, degassing flux, magma composition, and crystal content that are mainly determined by the amount and composition of deep magma and volatile input in the system. We explore how Mayon volcano’s processes and working model can be related to other open-vent mafic and water-rich systems such as Etna, Stromboli, Villarrica, or Llaima. Finally, our understanding of open-vent, persistently active volcanoes is rooted in historical observations, but volcano behavior can evolve over longer time frames. We speculate that these volcanoes produce specific plagioclase textures that can be used to identify similar volcanic behavior in the geologic record.

Intraspecific Variability Largely Affects the Leaf Metabolomics Response to Isosmotic Macrocation Variations in Two Divergent Lettuce (Lactuca sativa L.) Varieties

Mineral elements are essential for plant growth and development and strongly affect crop yield and quality. To cope with an everchanging environment, plants have developed specific responses to combined nutrient variations. In this work, we investigated the effects of multifactorial treatments with three macrocations (K, Ca, and Mg) on lettuce (Lactuca sativa L.) varieties that strongly diverge in leaf pigmentation (full red or green). Specifically, we monitored main leaf parameters and metabolomics profiles of hydroponically grown plants fed with isosmotic nutrient solutions that have different proportions of macroelements. The result revealed a high biochemical plasticity of lettuce, significantly affected by the genotype, the nutrient solution, and their interaction. Our work also provided evidence and insights into the different intraspecific responses to multifactorial variation of macrocations, with two varieties having distinct strategies to metabolically respond to nutrient variation. Overall, plant adaptive mechanisms increased the phytochemical diversity between the varieties both among and within the main classes of plant secondary metabolites. Finally, our work also implies that the interaction of a pre-existing phytochemical diversity with the management of multiple mineral elements can offer added health-related benefits to the edible product specific to the variety.

COMPARATIVE NUTRITIVE VALUE OF AN INVASIVE EXOTIC PLANT SPECIES, Prosopis glandulosa TORR. var. glandulosa, AND FIVE INDIGENOUS PLANT SPECIES COMMONLY BROWSED BY SMALL STOCK IN THE BORAVAST AREA, SOUTH-WESTERN BOTSWANA

Nutritive value of an invasive exotic plant species, Prosopis glandulosa Torr. var. glandulosa, and five indigenous plant species commonly browsed by livestock in Bokspits, Rapplespan, Vaalhoek and Struizendam (BORAVAST), southwest Botswana, was determined and compared. These five indigenous plant species were Vachellia hebeclada (DC.) Kyal. & Boatwr. subsp. hebeclada, Vachellia erioloba (E. Mey.) P.J.H. Hurter, Senegalia mellifera (Vahl) Seigler & Ebinger subsp. detinens (Burch.) Kyal. & Boatwr., Boscia albitrunca (Burch.) Gilg & Gilg-Ben. var. albitrunca and Rhigozum trichotomum Burch. The levels of Crude Protein (CP), Phosphorus (P), Calcium (C), Magnesium (Mg), Sodium (Na) and Potassium (K) were determined for the plants foliage and pods (where available). All plant species had a CP value higher than the recommended daily intake. There are however multiple mineral deficiencies in the plant species analysed. Nutritive value of Prosopis glandulosa is comparable to those other species despite the perception that livestock that browse on it are more productive than those that browse on the other plant species.

Assessing the effects of intra-granule precipitation in a full-scale industrial anaerobic digester

In this paper, a multi-scale model is used to assess the multiple mineral precipitation potential in a full-scale anaerobic granular sludge system. Reactor behaviour is analysed under different operational conditions (addition/no addition of reject water from dewatering of lime-stabilized biomass) and periods of time (short/long term). Model predictions suggest that a higher contribution of reject water promotes the risk of intra-granule CaCO3 formation as a result of the increased quantity of calcium arriving with that stream combined with strong pH gradients within the biofilm. The distribution of these precipitates depends on: (i) reactor height; and (ii) granule size. The study also exposes the potential undesirable effects of the long-term addition of reject water (a decrease in energy recovery of 20% over a 100-day period), caused by loss in biomass activity (due to microbial displacement), and the reduced buffer capacity. This demonstrates how both short-term and long-term operational conditions may affect the formation of precipitates within anaerobic granules, and how it may influence methane production and consequently energy recovery.