Chemistry

Physics Maths Engineering

Impact of Low-Reactivity Calcined Clay on the Performance of Fly Ash-Based Geopolymer Mortar


Availability of aluminosiliceous materials is essential for the production and promotion of geopolymer concrete. Unlike fly ash, which can only be found in industrial regions, clays are available almost everywhere but have not received sufficient attention to their potential use as a precursor for geopolymer synthesis. This study investigates the effectiveness of calcined clay as a sole an...
1 week ago

Physics Maths Engineering

Hydration, Reactivity and Durability Performance of Low-Grade Calcined Clay-Silica Fume Hybrid Mortar


Low-grade calcined clay, due to its low cost, availability and low temperature calcination, has been gaining attention in recent times as a supplementary cementitious material (SCM) in the manufacture of revolutionary building materials to improve the fresh and hardened properties of concrete. Silica fume, on the other hand, has been used, over the years, to improve the performance of conc...
1 week ago

Physics Maths Engineering

“Noncovalent Interaction”: A Chemical Misnomer That Inhibits Proper Understanding of Hydrogen Bonding, Rotation Barriers, and Other Topics


We discuss the problematic terminology of “noncovalent interactions” as commonly applied to hydrogen bonds, rotation barriers, steric repulsions, and other stereoelectronic phenomena. Although categorization as “noncovalent” seems to justify classical-type pedagogical rationalizations, we show that these phenomena are irreducible corollaries of the same orbital-level conceptions of...
1 week ago

Physics Maths Engineering

A Fixed-Bed Column with an Agro-Waste Biomass Composite for Controlled Separation of Sulfate from Aqueous Media


Key Questions

Microbial Pigment Production

How can bacteria produce natural pigments? Bacteria can produce natural pigments by growing on feather meal biomass. Specifically, Chryseobacterium sp. kr6 was used to produce yellow pigmen...
2 weeks ago

Physics Maths Engineering

Boron Recovery from Organic Solutions Used in Brine Treatment through a Water Stream


Abstract

This research evaluates the modification of the lithium carbonate (Li2CO3) production process and particularly the boron removal step, which currently employs a recirculated stream. This recirculated stream is a liquor with low boron content but rich in lithium, currently being wasted. In this process, the recirculating stream ...
2 weeks ago

Physics Maths Engineering

Thermodynamics of Iron Ammonia Synthesis Catalyst Sintering


Key Takeaways

  • Thermodynamic Stability

    - The study presents a model demonstrating the thermodynamic parameters that govern the iron catalyst sintering process, focusing on stability aspects of nanocrystalline structures.
  • Catalyst Activation Mechanisms

    ...
    1 month ago

Physics Maths Engineering

Synthesis of Bisoxazole and Bromo-substituted Aryloxazoles


Herein, we report a bisoxazole derivative as well as a bromo-substituted oxazole derivatives via a simple approach. The synthesis begins with an inexpensive and readily available starting material, such as 2,5-dimethoxybenzaldehyde, hydroquinone, and p-toluenesulfonylmethyl isocyanide (TosMIC). This approach relies on the Van Leusen oxazole method and electrophilic aromatic bromination. The struct...
1 month ago

Physics Maths Engineering

Applications of Machine Learning to the Study of Crystalline Materials


This Special Issue, “Applications of Machine Learning to the Study of Crystalline Materials”, is a collection of seven original articles published in 2021 and 2022 and dedicated to applications of machine learning in materials research [...]...
1 month ago

Biomedical

Diazenium Betaines Derived from the Stable Free Radical DPPH with Diradicaloid Behavior


Starting from the well known stable free radical DPPH (or its reduced counterpart, 2,2-diphenyl-1-picryl-hydrazine) and several amino derivatives, novel zwitterionic compounds (diazenium betaines) were obtained and characterized by different means, like NMR, IR, MS, and UV–Vis. These betaines are highly intense blue-colored compounds that can be easily reduced by ascorbic acid (vitamin C) or sod...
1 month ago

Physics Maths Engineering

The Hydrophobic Effects: Our Current Understanding


Hydrophobic interactions are involved in and believed to be the fundamental driving force of many chemical and biological phenomena in aqueous environments. This review focuses on our current understanding on hydrophobic effects. As a solute is embedded into water, the interface appears between solute and water, which mainly affects the structure of interfacial water (the topmost water layer at th...
1 month ago

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