scholarly journals THE EFFECT OF MICROFRACTURING IN GABBRO-DOLERITES ON THEIR PHYSICAL PROPERTIES

2019 ◽  
Vol 1 (2) ◽  
pp. 39-50
Author(s):  
Vitali Shekov ◽  
O. Myasnikova
Keyword(s):  
Building Materials ◽  
Structural Parameters ◽  
Iron Concentration ◽  
Considerable Effect ◽  
Building Stone ◽  
Fennoscandian Shield ◽  
Physical Parameters ◽  
Geophysical Research ◽  
Geophysical Field ◽  
The Impact

Simple and cheap methods for the study of building stone deposits for the production of blocks of commercial size can be used to make geological work more efficient. However, physical processes in a massif are hard to understand when doing geophysical research, and the effect of microstructural parameters, mainly the microfracturing of rocks, on geophysical field indices is poorly understood. The authors have studied the impact of microfracturing on the physico-mechanical properties on coarse- to giant-grained rapakivi granites from the Salmi massif, Fennoscandian Shield. The goal of the present study is to assess the physical and physico-mechanical parameters in fine- and medium-grained quartz-free rocks. The authors have studied the various physical and physico-mechanical indices of gabbro-dolerites from the Ropruchei sill (Fennoscandian Shield, within the deposit prospected and revealed the effect of microfracturing indices on them. The study of these properties have shown that microfracturing in gabbro-dolerites is an essential factor which forms the physical parameters of a rock. The testing of this rock type has shown the rate of travel of an elastic wave is clearly related to the microfracturing of samples. The magnetic properties of gabbro-dolerite are due to high concentrations of titanomagnetite, the mineral grains of which formed upon the crystallization of magma during its interstratal intrusion. The distribution of titanomagnetite, based on size and concentration in the rock, depends on liquation conditions in the active stress field. The dependence of the microfracturing of gabbro-dolerites on their iron concentration (FeO+Fe2O3) shows that these «damages» appeared at a ‘brittle” stage in the evolution of the massif in the form of microfractures, the structural parameters of which have inherited the parameters of the stress and deformation field which existed in the massif at that time and which accumulated iron. As a result, microfracturing has a considerable effect on the parameters of the electromagnetic indices of the massif by accumulating iron oxides in the pores, and the higher the index, the higher the geophysical medium indices. Understanding of the physical problem, which accompanies the formation of a gabbro-dolerite complex, helps conduct the geophysical study of a massif, interpret data more objectively and more accurately delineate massive zones in the medium that could be used as high-quality building materials.

Martian Dichotomy from a Giant Impact: Mantle Convection Models

2021 ◽  
Author(s):  
Kar Wai Cheng ◽  
Antoine B. Rozel ◽  
Gregor J. Golabek ◽  
Harry Ballantyne ◽  
Martin Jutzi
Keyword(s):  
Mantle Convection ◽  
Thickness Distribution ◽  
Thermal Anomaly ◽  
Crustal Thickness ◽  
Annual Review ◽  
Physical Parameters ◽  
Geophysical Research ◽  
Giant Impact ◽  
The Impact ◽  
Crustal Dichotomy

<p>The Martian crustal dichotomy is one of the most prominent features on the planet, featuring a ≈5.5 km difference in topography and a ≈25 km difference in crustal thickness between the southern highland and northern lowland [1]. It Is thought to have formed within the first 400-500 Myr of Martian history [2]. While its formation process remains unclear, there have been different hypotheses to explain it, including an endothermic degree-1 convection mode [3, 4], and the excavation of the lowland crust by a giant impact [5]. In this study we focus on the hybrid hypothesis, where an early giant impact created a magma pond, and subsequent mantle convection alters the internal mantle structure as well as crustal distribution in the next 4 billion years [6, 7].  By imposing a parametrized giant impact as a thermal anomaly as an initial condition, we simulate the long-term evolution of the crust and mantle using the thermochemical convection code StagYY [8]. In particular, we investigate the effect of physical parameters of both the solid mantle and the impact-induced magma pond, as well as those of the crust production process, on the crystallisation of such pond, its interaction with surrounding mantle and the preservation of impact signature. Diagnostics including topography and crust thickness from these different models will be presented and compared.</p><p> </p><p>[1] Watters, T., McGovern, P., & Irwin III, R. (2007). Hemispheres Apart: The Crustal Dichotomy on Mars. Annual Review of Earth and Planetary Sciences, 35(1), 621-652.</p><p>[2] Taylor, S., & McLennan, S. (2009). Planetary crusts. Cambridge, UK: Cambridge University Press.</p><p>[3] Roberts, J., & Zhong, S. (2006). Degree-1 convection in the Martian mantle and the origin of the hemispheric dichotomy. Journal of Geophysical Research, 111(E6).</p><p>[4] Keller, T., & Tackley, P. (2009). Towards self-consistent modeling of the martian dichotomy: The influence of one- ridge convection on crustal thickness distribution. Icarus, 202(2), 429-443.</p><p>[5] Andrews-Hanna, J., Zuber, M., & Banerdt, W. (2008). The Borealis basin and the origin of the martian crustal dichotomy. Nature, 453(7199), 1212-1215.</p><p>[6] Golabek, G., Keller, T., Gerya, T., Zhu, G., Tackley, P., & Connolly, J. (2011). Origin of the martian dichotomy and Tharsis from a giant impact causing massive magmatism. Icarus, 215(1), 346-357.</p><p>[7] Reese, C., Orth, C., & Solomatov, V. (2011). Impact megadomes and the origin of the martian crustal dichotomy. Icarus, 213(2), 433-442.</p><p>[8] Tackley, P. (2008). Modelling compressible mantle convection with large viscosity contrasts in a three- dimensional spherical shell using the yin-yang grid. Physics of The Earth and Planetary Interiors, 171(1-4), 7-18</p><p> </p><p> </p>

THE IMPACT OF WIND CONDITIONS ON THE LEVELS OF TOTAL IRON CONTENT IN THE SEA OF AZOV

2017 ◽  
Author(s):  
Yuri Fedorov ◽  
Yuri Fedorov ◽  
Irina Dotsenko ◽  
Irina Dotsenko ◽  
Leonid Dmitrik ◽  
...  
Keyword(s):  
Bottom Sediments ◽  
Iron Content ◽  
Iron Concentration ◽  
Total Iron ◽  
Sea Of Azov ◽  
Open Area ◽  
The Sea Of Azov ◽  
Dissolved Iron ◽  
The Impact ◽  
Taganrog Bay

The distribution and behavior of certain of trace elements in sea water is greatly affected by both physical, chemical and hydrometeorological conditions that are showed in the scientific works of prof. Yu.A. Fedorov with coauthors (1999-2015). Due to the shallow waters last factor is one of the dominant, during the different wind situation changes significantly the dynamics of water masses and interaction in the system “water – suspended matter – bottom sediments”.Therefore, the study of the behavior of the total iron in the water of the sea at different wind situation is relevant. The content of dissolved iron forms migration in The Sea of Azov water (open area) varies from 0.017 to 0.21 mg /dm3 (mean 0.053 mg /dm3) and in Taganrog Bay from 0.035 to 0.58 mg /dm3 (mean 0.11 mg /dm3) and it is not depending on weather conditions.The reduction in the overall iron concentration in the direction of the Taganrog Bay → The Sea of Azov (open area) is observed on average more than twice. The dissolved iron content exceeding TLV levels and their frequency of occurrence in the estuary, respectively, were higher compared with The Sea of Azov (open area).There is an increase in the overall iron concentration in the water of the Azov Sea on average 1.5 times during the storm conditions, due to the destruction of the structure of the upper layer and resuspension of bottom sediments, intensifying the transition of iron compounds in the solution.

Quantitative relations between structure and antiinflammatory activity of aryloxoalkanoic acids

1988 ◽  
Vol 53 (8) ◽  
pp. 1862-1872 ◽  
Author(s):  
Miroslav Kuchař ◽  
Eva Maturová ◽  
Bohumila Brunová ◽  
Jaroslava Grimová ◽  
Hana Tomková ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Structural Changes ◽  
Antiinflammatory Activity ◽  
Structural Parameters ◽  
Considerable Effect ◽  
Antiinflammatory Effect ◽  
Prolonged Action ◽  
Preclinical Development ◽  
Indicator Variables ◽  
Inhibitory Activities

The antiinflammatory effect of a series of aryloxoalkanoic acids II and of their biphenyl derivatives III was examined by measuring the inhibition of the development of carageenan- and adjuvant-induced edemas. The quantitative relations between the antiinflammatory effect and physicochemical and structural parameters of the compounds tested were evaluated. The equations obtained by the method of regression analysis showed a significant linear dependence of both inhibitory activities on the lipophilicity of the compounds and a considerable effect of some structural changes as expressed by indicator variables. The antiinflammatory effect is especially enhanced in both tests by the presence of a cyclic substituent at the aromatic ring. The high antiinflammatory effect of biphenylyl derivatives III is paralleled by their prolonged action. The prolongation of the effect is most likely a result of a suitable biotransformation of acid III to an efficient metabolite. The structural requirements which resulted from both the regression analysis and from the hypothesis of biotransformation of acids III were utilized in the synthesis of suitably substituted biphenylyloxoalkanoic acids. By this approach derivatives IIIe-i were obtained some of which showed a high antiinflammatory and also protracted effect. 4-(2',4'-Difluorbiphenylyl)-4-oxo-2-methylbutanoic acid (VÚFB-16 066, Flobufen) was chosen for further preclinical development.

scholarly journals Damage Evolution of Granodiorite after Heating and Cooling Treatments

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Mohamed Gomah ◽  
Guichen Li ◽  
Salah Bader ◽  
Mohamed Elkarmoty ◽  
Mohamed Ismael
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Failure Mode ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Physical Parameters ◽  
Slow Cooling ◽  
Heating And Cooling ◽  
Natural Rock ◽  
The Impact

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

scholarly journals Fire Resistance Behaviour of Geopolymer Concrete:An Overview

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar
Keyword(s):  
Compressive Strength ◽  
Thermal Resistance ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Construction Materials ◽  
Flexural Behavior ◽  
Thermal Shrinkage ◽  
Physico Chemical ◽  
The Impact ◽  
Loss Of Strength

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.

scholarly journals A Review of Photocatalytic Materials for Urban NOx Remediation

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 675
Author(s):  
Hugo Savill Russell ◽  
Louise Bøge Frederickson ◽  
Ole Hertel ◽  
Thomas Ellermann ◽  
Steen Solvang Jensen
Keyword(s):  
Photocatalytic Oxidation ◽  
Urban Air Pollution ◽  
Field Trials ◽  
Urban Environments ◽  
Physical Parameters ◽  
Nox Removal ◽  
Removal Efficiencies ◽  
The Impact ◽  
By Products ◽  
Photocatalytic Materials

NOx is a pervasive pollutant in urban environments. This review assesses the current state of the art of photocatalytic oxidation materials, designed for the abatement of nitrogen oxides (NOx) in the urban environment, and typically, but not exclusively based on titanium dioxide (TiO2). Field trials with existing commercial materials, such as paints, asphalt and concrete, in a range of environments including street canyons, car parks, tunnels, highways and open streets, are considered in-depth. Lab studies containing the most recent developments in the photocatalytic materials are also summarised, as well as studies investigating the impact of physical parameters on their efficiency. It is concluded that this technology may be useful as a part of the measures used to lower urban air pollution levels, yielding ∼2% NOx removal in the immediate area around the surface, for optimised TiO2, in some cases, but is not capable of the reported high NOx removal efficiencies >20% in outdoor urban environments, and can in some cases lower air quality by releasing hazardous by-products. However, research into new material is ongoing. The reason for the mixed results in the studies reviewed, and massive range of removal efficiencies reported (from negligible and up to >80%) is mainly the large range of testing practices used. Before deployment in individual environments site-specific testing should be performed, and new standards for lab and field testing should be developed. The longevity of the materials and their potential for producing hazardous by-products should also be considered.

scholarly journals Modelling H2 and its effects on star formation using a joint implementation of gadget-3 and KROME

2021 ◽  
Vol 504 (2) ◽  
pp. 2325-2345
Author(s):  
Emanuel Sillero ◽  
Patricia B Tissera ◽  
Diego G Lambas ◽  
Stefano Bovino ◽  
Dominik R Schleicher ◽  
...  
Keyword(s):  
Star Formation ◽  
Formation Rate ◽  
Physical Parameters ◽  
Density Profiles ◽  
Star Forming ◽  
Chemical Enrichment ◽  
Numerical Resolution ◽  
Stellar Radiation ◽  
Wide Range ◽  
The Impact

ABSTRACT We present p-gadget3-k, an updated version of gadget-3, that incorporates the chemistry package krome. p-gadget3-k follows the hydrodynamical and chemical evolution of cosmic structures, incorporating the chemistry and cooling of H2 and metal cooling in non-equilibrium. We performed different runs of the same ICs to assess the impact of various physical parameters and prescriptions, namely gas metallicity, molecular hydrogen formation on dust, star formation recipes including or not H2 dependence, and the effects of numerical resolution. We find that the characteristics of the simulated systems, both globally and at kpc-scales, are in good agreement with several observable properties of molecular gas in star-forming galaxies. The surface density profiles of star formation rate (SFR) and H2 are found to vary with the clumping factor and resolution. In agreement with previous results, the chemical enrichment of the gas component is found to be a key ingredient to model the formation and distribution of H2 as a function of gas density and temperature. A star formation algorithm that takes into account the H2 fraction together with a treatment for the local stellar radiation field improves the agreement with observed H2 abundances over a wide range of gas densities and with the molecular Kennicutt–Schmidt law, implying a more realistic modelling of the star formation process.

scholarly journals Monoclinic and Orthorhombic NaMnO2 for Secondary Batteries: A Comparative Study

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1230
Author(s):  
Jessica Manzi ◽  
Annalisa Paolone ◽  
Oriele Palumbo ◽  
Domenico Corona ◽  
Arianna Massaro ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Reversible Capacity ◽  
Beta Phase ◽  
X Ray Diffraction ◽  
Positive Electrodes ◽  
Detailed Structural Analysis ◽  
Physico Chemical ◽  
Sodium Batteries ◽  
The Impact ◽  
First Time

In this manuscript, we report a detailed physico-chemical comparison between the α- and β-polymorphs of the NaMnO2 compound, a promising material for application in positive electrodes for secondary aprotic sodium batteries. In particular, the structure and vibrational properties, as well as electrochemical performance in sodium batteries, are compared to highlight differences and similarities. We exploit both laboratory techniques (Raman spectroscopy, electrochemical methods) and synchrotron radiation experiments (Fast-Fourier Transform Infrared spectroscopy, and X-ray diffraction). Notably the vibrational spectra of these phases are here reported for the first time in the literature as well as the detailed structural analysis from diffraction data. DFT+U calculations predict both phases to have similar electronic features, with structural parameters consistent with the experimental counterparts. The experimental evidence of antisite defects in the beta-phase between sodium and manganese ions is noticeable. Both polymorphs have been also tested in aprotic batteries by comparing the impact of different liquid electrolytes on the ability to de-intercalated/intercalate sodium ions. Overall, the monoclinic α-NaMnO2 shows larger reversible capacity exceeding 175 mAhg−1 at 10 mAg−1.

Implications of Building Material Choice on Outdoor Microclimate for Sustainable Built Environment

2015 ◽  
Vol 650 ◽  
pp. 82-90 ◽  
Author(s):  
D. Kannamma ◽  
A. Meenatchi Sundaram
Keyword(s):  
Thermal Comfort ◽  
Building Material ◽  
Building Materials ◽  
Climatic Factors ◽  
Outdoor Environment ◽  
Outdoor Thermal Comfort ◽  
Physical Factors ◽  
Physiological Equivalent Temperature ◽  
Material Choice ◽  
The Impact

The climatic conditions in a man-made urban environment may differ appreciably from those in the surrounding natural or rural environs.... each urban man-made buildings, roads, parking area, factories......creates around and above it a modified climate with which it interacts [1].Outdoor thermal comfort has gained importance in thermal comfort studies especially in tropical countries. In country like India, culturally the activities are spread both indoors and outdoors. Therefore the need for ambient outdoor environment gains importance. As there are many factors that contribute to outdoor thermal comfort (climatic factors and physical factors), this study aims in analyzing the impact of building material contribution, in an institutional courtyard. In order to understand the thermal contribution of various building materials and to suggest material choice to designers, ENVIMET is used for simulation purpose. The outdoor thermal comfort index employed in this study is PET (Physiological Equivalent Temperature), calibrated using RAYMAN.

scholarly journals The influence of physical parameters on the in-situ metal carbonyl complex formation studied with the Fast On-line Reaction Apparatus (FORA)

2021 ◽  
Vol 109 (4) ◽  
pp. 261-281
Author(s):  
Yves Wittwer ◽  
Robert Eichler ◽  
Dominik Herrmann ◽  
Andreas Türler
Keyword(s):  
Gas Flow ◽  
Metal Carbonyl ◽  
Fission Products ◽  
Reaction Chamber ◽  
Single Atom ◽  
Physical Parameters ◽  
Carbonyl Complex ◽  
Reaction Conditions ◽  
On Line ◽  
The Impact

Abstract The Fast On-line Reaction Apparatus (FORA) was used to investigate the influence of various reaction parameters onto the formation and transport of metal carbonyl complexes (MCCs) under single-atom chemistry conditions. FORA is based on a 252Cf-source producing short-lived Mo, Tc, Ru and Rh isotopes. Those are recoiling from the spontaneous fission source into a reaction chamber flushed with a gas-mixture containing CO. Upon contact with CO, fission products form volatile MCCs which are further transported by the gas stream to the detection setup, consisting of a charcoal trap mounted in front of a HPGe γ-detector. Depending on the reaction conditions, MCCs are formed and transported with different efficiencies. Using this setup, the impact of varying physical parameters like gas flow, gas pressure, kinetic energy of fission products upon entering the reaction chamber and temperature of the reaction chamber on the formation and transport yields of MCCs was investigated. Using a setup similar to FORA called Miss Piggy, various gas mixtures of CO with a selection of noble gases, as well as N2 and H2, were investigated with respect to their effect onto MCC formation and transport. Based on this measurements, optimized reaction conditions to maximize the synthesis and transport of MCCs are suggested. Explanations for the observed results supported by simulations are suggested as well.

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