scholarly journals Editorial for Special Issue “Mineral Surface Reactions at the Nanoscale”

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 185
Author(s):  
Christine Putnis
Keyword(s):  
Surface Reactions ◽  
Experimental Studies ◽  
Analytical Techniques ◽  
Aqueous Fluid ◽  
Mineral Surfaces ◽  
Special Issue ◽  
Mineral Surface ◽  
Electron Microscopies ◽  
Interface Control ◽  
The Earth

Reactions at mineral surfaces are central to all geochemical processes. As minerals comprise the rocks of the Earth, the processes occurring at the mineral–aqueous fluid interface control the evolution of the rocks and, hence, the structure of the crust of the Earth during such processes at metamorphism, metasomatism, and weathering. In recent years, focus has been concentrated on mineral surface reactions made possible through the development of advanced analytical techniques, such as atomic force microscopy (AFM), advanced electron microscopies (SEM and TEM), phase shift interferometry, confocal Raman spectroscopy, advanced synchrotron-based applications, complemented by molecular simulations, to confirm or predict the results of experimental studies. In particular, the development of analytical methods that allow direct observations of mineral–fluid reactions at the nanoscale have revealed new and significant aspects of the kinetics and mechanisms of reactions taking place in fundamental mineral–fluid systems. These experimental and computational studies have enabled new and exciting possibilities to elucidate the mechanisms that govern mineral–fluid reactions, as well as the kinetics of these processes, and, hence, to enhance our ability to predict potential mineral behavior. In this Special Issue “Mineral Surface Reactions at the Nanoscale”, we present 12 contributions that highlight the role and importance of mineral surfaces in varying fields of research.

scholarly journals A Lizardite–HCN Interaction Leading the Increasing of Molecular Complexity in an Alkaline Hydrothermal Scenario: Implications for Origin of Life Studies

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 661
Author(s):  
Saúl A. Villafañe-Barajas ◽  
Marta Ruiz-Bermejo ◽  
Pedro Rayo-Pizarroso ◽  
Santos Gálvez-Martínez ◽  
Eva Mateo-Martí ◽  
...  
Keyword(s):  
Chemical Evolution ◽  
Hydrogen Cyanide ◽  
Organic Molecule ◽  
Organic Molecules ◽  
Analytical Techniques ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Molecular Complexity ◽  
Molecule Production

Hydrogen cyanide, HCN, is considered a fundamental molecule in chemical evolution. The named HCN polymers have been suggested as precursors of important bioorganics. Some novel researches have focused on the role of mineral surfaces in the hydrolysis and/or polymerization of cyanide species, but until now, their role has been unclear. Understanding the role of minerals in chemical evolution processes is crucial because minerals undoubtedly interacted with the organic molecules formed on the early Earth by different process. Therefore, we simulated the probable interactions between HCN and a serpentinite-hosted alkaline hydrothermal system. We studied the effect of serpentinite during the thermolysis of HCN at basic conditions (i.e., HCN 0.15 M, 50 h, 100 °C, pH > 10). The HCN-derived thermal polymer and supernatant formed after treatment were analyzed by several complementary analytical techniques. The results obtained suggest that: I) the mineral surfaces can act as mediators in the mechanisms of organic molecule production such as the polymerization of HCN; II) the thermal and physicochemical properties of the HCN polymer produced are affected by the presence of the mineral surface; and III) serpentinite seems to inhibit the formation of bioorganic molecules compared with the control (without mineral).

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

scholarly journals Food Bioactive Compounds and Emerging Techniques for Their Extraction: Polyphenols as a Case Study

Foods ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 37 ◽  
Author(s):  
José S. Câmara ◽  
Bianca R. Albuquerque ◽  
Joselin Aguiar ◽  
Rúbia C. G. Corrêa ◽  
João L. Gonçalves ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Chemical Structure ◽  
Experimental Studies ◽  
Analytical Techniques ◽  
Convincing Evidence ◽  
Protective Effects ◽  
Extraction Techniques ◽  
Biological Impact ◽  
Preventive Effects

Experimental studies have provided convincing evidence that food bioactive compounds (FBCs) have a positive biological impact on human health, exerting protective effects against non-communicable diseases (NCD) including cancer and cardiovascular (CVDs), metabolic, and neurodegenerative disorders (NDDs). These benefits have been associated with the presence of secondary metabolites, namely polyphenols, glucosinolates, carotenoids, terpenoids, alkaloids, saponins, vitamins, and fibres, among others, derived from their antioxidant, antiatherogenic, anti-inflammatory, antimicrobial, antithrombotic, cardioprotective, and vasodilator properties. Polyphenols as one of the most abundant classes of bioactive compounds present in plant-based foods emerge as a promising approach for the development of efficacious preventive agents against NCDs with reduced side effects. The aim of this review is to present comprehensive and deep insights into the potential of polyphenols, from their chemical structure classification and biosynthesis to preventive effects on NCDs, namely cancer, CVDs, and NDDS. The challenge of polyphenols bioavailability and bioaccessibility will be explored in addition to useful industrial and environmental applications. Advanced and emerging extraction techniques will be highlighted and the high-resolution analytical techniques used for FBCs characterization, identification, and quantification will be considered.

scholarly journals Editorial for the Special Issue “Advanced Artificial Intelligence and Deep Learning for Remote Sensing”

2021 ◽  
Vol 13 (15) ◽  
pp. 2883
Author(s):  
Gwanggil Jeon
Keyword(s):  
Artificial Intelligence ◽  
Remote Sensing ◽  
Deep Learning ◽  
Special Issue ◽  
The Earth

Remote sensing is a fundamental tool for comprehending the earth and supporting human–earth communications [...]

scholarly journals Introduction to the Special Issue “Radiative Transfer in the Earth Atmosphere”

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 479
Author(s):  
Irina Sokolik
Keyword(s):  
Radiative Transfer ◽  
Earth Atmosphere ◽  
Special Issue ◽  
The Earth ◽  
Radiative Impact ◽  
Different Types ◽  
Recent Developments

This Special Issue aims at addressing the recent developments towards improving our understanding of the diverse radiative impact of different types of aerosols and clouds [...]

scholarly journals Organizing in the Anthropocene

Organization ◽  
2018 ◽  
Vol 25 (4) ◽  
pp. 455-471 ◽  
Author(s):  
Christopher Wright ◽  
Daniel Nyberg ◽  
Lauren Rickards ◽  
James Freund
Keyword(s):  
Social Sciences ◽  
Climate Change ◽  
Exponential Growth ◽  
Life Support ◽  
Earth System ◽  
Special Issue ◽  
Human Relations ◽  
Crucial Issue ◽  
The Earth ◽  
Introductory Article

The functioning of the biosphere and the Earth as a whole is being radically disrupted due to human activities, evident in climate change, toxic pollution and mass species extinction. Financialization and exponential growth in production, consumption and population now threaten our planet’s life-support systems. These profound changes have led Earth System scientists to argue we have now entered a new geological epoch – the Anthropocene. In this introductory article to the Special Issue, we first set out the origins of the Anthropocene and some of the key debates around this concept within the physical and social sciences. We then explore five key organizing narratives that inform current economic, technological, political and cultural understandings of the Anthropocene and link these to the contributions in this Special Issue. We argue that the Anthropocene is the crucial issue for organizational scholars to engage with in order to not only understand on-going anthropogenic problems but also help create alternative forms of organizing based on realistic Earth–human relations.

scholarly journals Organomineral nanocomposite carbon burial during Oceanic Anoxic Event 2

2014 ◽  
Vol 11 (5) ◽  
pp. 6815-6844
Author(s):  
S. C. Löhr ◽  
M. J. Kennedy
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
X Ray ◽  
Oceanic Anoxic Event ◽  
Carbon Burial ◽  
Anoxic Events ◽  
Mineral Surface Area

Abstract. Organic carbon (OC) enrichment in sediments deposited during Oceanic Anoxic Events (OAEs) is commonly attributed to elevated productivity and marine anoxia. We find that OC enrichment in the late Cenomanian aged OAE2 at Demerara Rise was controlled by co-occurrence of anoxic bottom-water, sufficient productivity to saturate available mineral surfaces and variable deposition of high surface area detrital smectite clay. Redox indicators show consistently oxygen-depleted conditions, while a strong correlation between OC concentration and sediment mineral surface area (R2=0.92) occurs across a range of TOC values from 9–33%. X-ray diffraction data indicates intercalation of OC in smectite interlayers while electron, synchrotron infrared and X-ray microscopy show an intimate association between clay minerals and OC, consistent with preservation of OC as organomineral nanocomposites and aggregates rather than discrete, μm-scale pelagic detritus. Since the consistent ratio between TOC and mineral surface area suggests that excess OC relative to surface area is lost, we propose that it is the varying supply of smectite that best explains variable organic enrichment against a backdrop of continuous anoxia, which is conducive to generally high TOC during OAE2 at Demerara Rise. Smectitic clays are unique in their ability to form stable organomineral nanocomposites and aggregates that preserve organic matter, and are common weathering products of continental volcanic deposits. An increased flux of smectite coinciding with high carbon burial is consistent with evidence for widespread volcanism during OAE2, so that organomineral carbon burial may represent a potential feedback to volcanic degassing of CO2.

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