Chromium oxide pigments

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gerhard Pfaff
Keyword(s):  
Thermal Stability ◽  
Chromium Oxide ◽  
Building Materials ◽  
Solid Phase ◽  
Oxide Hydrate ◽  
Application Systems ◽  
Ammonium Dichromate ◽  
Green Pigments

Abstract The chromium(III) oxide pigments Cr2O3 (chromium oxide green) and CrOOH (chromium oxide hydrate green) are representatives of the inorganic green and blue–green pigments. Cr2O3 pigments are very important for the coloration of paints, coatings, plastics, building materials and other application systems. CrOOH pigments have lost their technical importance because of the low thermal stability. Chromium oxide green pigments are characterized by excellent application properties. They are synthesized starting from alkali dichromates or ammonium dichromate by reduction in liquid or solid phase.

Evaluation of a Porous Imine-Based Covalent Organic Framework for Solid-Phase Extraction of Nitroimidazoles

2022 ◽  
Author(s):  
zhikai hong ◽  
yingjiao dong ◽  
ruijie wang ◽  
Guanhua Wang
Keyword(s):  
Thermal Stability ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
High Surface ◽  
Sample Pretreatment ◽  
Phase Extraction ◽  
Covalent Organic Framework ◽  
Framework Materials ◽  
Surface Areas ◽  
Organic Framework

Covalent organic framework materials (COFs), a kind of porous organic material, have excellent potential application in the field of sample pretreatment due to their high surface areas and thermal stability....

scholarly journals Remedial Treatment of Corroded Iron Objects by EnvironmentalAeromonasIsolates

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Wafa M. Kooli ◽  
Thomas Junier ◽  
Migun Shakya ◽  
Mathilde Monachon ◽  
Karen W. Davenport ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Building Materials ◽  
Solid Phase ◽  
Corrosion Products ◽  
Metal Corrosion ◽  
Economic Losses ◽  
Cytotoxic Activities ◽  
Iron Corrosion ◽  
Pathogenic Potential ◽  
Wide Range

ABSTRACTUsing bacteria to transform reactive corrosion products into stable compounds represents an alternative to traditional methods employed in iron conservation. Two environmentalAeromonasstrains (CA23 and CU5) were used to transform ferric iron corrosion products (goethite and lepidocrocite) into stable ferrous iron-bearing minerals (vivianite and siderite). A genomic and transcriptomic approach was used to analyze the metabolic traits of these strains and to evaluate their pathogenic potential. Although genes involved in solid-phase iron reduction were identified, key genes present in other environmental iron-reducing species are missing from the genome of CU5. Several pathogenicity factors were identified in the genomes of both strains, but none of these was expressed under iron reduction conditions. Additionalin vivotests showed hemolytic and cytotoxic activities for strain CA23 but not for strain CU5. Both strains were easily inactivated using ethanol and heat. Nonetheless, given a lesser potential for a pathogenic lifestyle, CU5 is the most promising candidate for the development of a bio-based iron conservation method stabilizing iron corrosion. Based on all the results, a prototype treatment was established using archaeological items. On those, the conversion of reactive corrosion products and the formation of a homogenous layer of biogenic iron minerals were achieved. This study shows how naturally occurring microorganisms and their metabolic capabilities can be used to develop bio-inspired solutions to the problem of metal corrosion.IMPORTANCEMicrobiology can greatly help in the quest for a sustainable solution to the problem of iron corrosion, which causes important economic losses in a wide range of fields, including the protection of cultural heritage and building materials. Using bacteria to transform reactive and unstable corrosion products into more-stable compounds represents a promising approach. The overall aim of this study was to develop a method for the conservation and restoration of corroded iron items, starting from the isolation of iron-reducing bacteria from natural environments. This resulted in the identification of a suitable candidate (Aeromonassp. strain CU5) that mediates the formation of desirable minerals at the surfaces of the objects. This led to the proof of concept of an application method on real objects.

scholarly journals The influence of the nature and textural properties of different supports on the thermal behavior of Keggin type heteropolyacids

2006 ◽  
Vol 71 (3) ◽  
pp. 235-249 ◽  
Author(s):  
Alexandru Popa ◽  
Viorel Sasca ◽  
Mircea Stefanescu ◽  
Erne Kis ◽  
Radmila Marinkovic-Neducin
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Thermal Behavior ◽  
Solid Phase ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Active Phase ◽  
Support Surface ◽  
Sem Images ◽  
The Stability

In order to obtain highly dispersed heteropolyacids (HPAs) species, H3PMo12O40 and H4PVMo11O40 were supported on various supports: silica (Aerosil - Degussa and Romsil types) and TiO2. The structure and thermal decomposition of supported and unsupported HPAs were followed by different techniques (TGA-DTA, FTIR, XRD, low temperature nitrogen adsorption, scanning electron microscopy). All the supported HPAs were prepared by impregnation using the incipient wetness technique with a 1:1 mixture of water-ethanol. Samples were prepared with different concentrations to examine the effect of loading on the thermal behavior of the supported acid catalysts. The thermal stability was evaluated with reference to the bulk solid acids and mechanical mixtures. After deposition on silica types supports, an important decrease in thermal stability was observed on the Romsil types and a small decrease on the Aerosil type. The stability of the heteropolyacids supported on titania increased due to an anion-support interaction, as the thermal decomposition proceeded in two steps. The structure of the HPAs was not totally destroyed at 450 ?C as some IR bands were still preserved. A relatively uniform distribution of HPAs on the support surface was observed for all compositions of the active phase. No separate crystallites of solid phase HPAs were found in the SEM images.

scholarly journals Fire Suppression and Thermal Behavior of Biobased Rigid Polyurethane Foam Filled with Biomass Incineration Waste Ash

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 683 ◽  
Author(s):  
Agnė Kairytė ◽  
Arūnas Kremensas ◽  
Saulius Vaitkus ◽  
Sylwia Członka ◽  
Anna Strąkowska
Keyword(s):  
Thermal Stability ◽  
Building Materials ◽  
Raw Materials ◽  
Fire Suppression ◽  
Waste Incineration ◽  
Supply Chain System ◽  
Smoke Suppressant ◽  
Foam Filled ◽  
Pu Foams ◽  
Thermal Stability Of

Currently, there is great demand to implement circular economy principles and motivate producers of building materials to integrate into a closed loop supply chain system and improve sustainability of their end-product. Therefore, it is of great interest to replace conventional raw materials with inorganic or organic waste-based and filler-type additives to promote sustainability and the close loop chain. This article investigates the possibility of bottom waste incineration ash (WA) particles to be used as a flame retardant replacement to increase fire safety and thermal stability under higher temperatures. From 10 wt.% to 50 wt.% WA particles do not significantly deteriorate performance characteristics, such as compressive strength, thermal conductivity, and water absorption after 28 days of immersion, and at 32 °C WA particles improve the thermal stability of resultant PU foams. Furthermore, 50 wt.% WA particles reduce average heat release by 69% and CO2 and CO yields during fire by 76% and 77%, respectively. Unfortunately, WA particles do not act as a smoke suppressant and do not reduce smoke release rate.

Custom design of solid–solid phase change material with ultra-high thermal stability for battery thermal management

2020 ◽  
Vol 8 (29) ◽  
pp. 14624-14633 ◽  
Author(s):  
Changren Xiao ◽  
Guoqing Zhang ◽  
Zhenghui Li ◽  
Xiaoqing Yang
Keyword(s):  
Thermal Stability ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Management ◽  
Solid Phase ◽  
High Thermal Stability ◽  
Management Performance ◽  
Battery Thermal Management ◽  
Custom Design ◽  
Change Material

The custom-designed solid–solid phase change material possesses ultra-high thermal stability and exhibits outstanding battery thermal management performance.

scholarly journals Load on the air conditioning system in a room with non-round-the-clock working day in the warm season

2019 ◽  
Vol 135 ◽  
pp. 03018
Author(s):  
Elena Malyavina ◽  
Alexander Lomakin
Keyword(s):  
Thermal Stability ◽  
Air Conditioning ◽  
Building Materials ◽  
Internal Heat ◽  
Warm Season ◽  
Maximum Load ◽  
Radiant Heat ◽  
Thermal Mode ◽  
Air Conditioner ◽  
Working Day

Calculations of the maximum load on the cooling units of air conditioning systems are important, as they determine the installation capacity of an air conditioner. The load value is influenced by the share of the radiant component in the sum of heat gains coming into a room and making up the load, and the internal thermal stability of the room. Herewith, as the theory of thermal stability states, the higher the internal resistance, the smoother the load peaks, since the heat that comes to an enclosing structure surface is more easily deviated into heavier building materials forming the room interior finishing. In addition, the maximum load on the part-time operating room cooling devices depends on the degree of the room overheating before the beginning of the working day. Moreover, when a room has a minor interior finishing, the heat coming to the inner surfaces of the enclosing structures does not move into the enclosing structure, but raises its temperature. Calculations of the room daily periodic unsteady thermal mode were performed by the method of finite differences in Cartesian coordinates according to an implicit scheme. Provision has been made of calculations of the rooms with different internal heat resistance, the windows of which are facing one of the cardinal directions: South, East, West. The performed calculations have shown the feasibility of heavy finishing for rooms with a high proportion of incoming radiant heat.

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