Two concomitant polymorphs and two isomorphous forms with different chemical compositions, which transform into the same substance upon thermal treatment

CrystEngComm ◽  
2002 ◽  
Vol 4 (50) ◽  
pp. 277-281 ◽  
Author(s):  
Dario Braga ◽  
Gianna Cojazzi ◽  
Dario Emiliani ◽  
Lucia Maini ◽  
Marco Polito ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Chemical Compositions

scholarly journals A Mini Review on Pyrolysis of Natural Algae for Bio-Fuel and Chemicals

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2042
Author(s):  
Wei Xu ◽  
Keqiang Ding ◽  
Lihua Hu
Keyword(s):  
Thermal Treatment ◽  
Environmental Protection ◽  
Resource Utilization ◽  
Inert Atmosphere ◽  
Chemical Compositions ◽  
Research Gaps ◽  
Operation Conditions ◽  
Bio Oil ◽  
The Subject ◽  
Water Blooms

The disposal and use of natural algae have recently been the subject of great interest, due to increasing concern for environmental protection and resource utilization. In this paper, a mini review of recent research on the pyrolysis of natural algae, especially the algae from water blooms, is presented. The chemical compositions of the natural algae are summarized, and the pyrolysis properties of different compositions are reviewed. Non-catalytic, catalytic, and integrated catalytic processes are reviewed. Different ideas and methods for the production of bio-fuel or chemicals are discussed. Apparently, deoxygenation and denitrogenation are highly necessary for algae-based bio-fuel and catalysts play an important role in these processes. In addition, the integrated catalytic process, which involves catalysis and other operation conditions aside from the thermal treatment under inert atmosphere, shows potential for the valorization of algae-based bio-oil. Based on the recent concept and progress, the research gaps are discussed, followed by the challenges and proposals to achieve high-value utilization of the natural algae.

scholarly journals Changes in physical-mechanical properties and chemical compositions of Toona sinensis wood before and after thermal treatment.

Wood Research ◽  
2020 ◽  
Vol 65 (6) ◽  
pp. 877-884
Author(s):  
JIULONG XIE ◽  
LIN CHEN ◽  
HUIJUAN SHAO ◽  
LU HE ◽  
YONGZE JIANG ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Chemical Compositions ◽  
Toona Sinensis ◽  
Before And After

FACTORS AFFECTING THE INTENSITY OF LEADING TARNED DISPLAYED GLASS BY FLUOROCHLORINE-CONTAINING GAS-SHAPING REAGENTS

2018 ◽  
Vol 1 (11(56)) ◽  
pp. 69-72
Author(s):  
V.A. Sharagov ◽  
G.I. Kurikeru
Keyword(s):  
Thermal Treatment ◽  
Sulfur Dioxide ◽  
Surface State ◽  
Thermochemical Treatment ◽  
Chemical Compositions ◽  
Colorless Glass ◽  
Factors Affecting ◽  
Gaseous Reagent ◽  
Gas Medium ◽  
Treatment Concentration

The aim of the undertaken experiments was to determine the factors affecting the process of dealkalization of container colorless glass with fluorine–and chlorine–containing gaseous reagents.The subjects of investigation were various types containers (bottles, jars and flasks) of colorless glass. Hydrogen chloride, difluorodichloro-methane and difluorochloromethane and mixtures of these reagents with sulfur dioxide were used for the chemical treatment of glass. We have investigated the influence of the following factors on the process of dealkalization of container colorless glass with fluorine–and chlorine–containing reagents: temperature, chemical compositions of the gas medium, duration of the thermochemical treatment, concentration and humidity of gaseous reagent, re-peated thermal treatment and surface state of the samples

scholarly journals Analysis of the Possibility of Using Slags from the Thermal Treatment of Municipal Waste as Potential Component of Cement—Case Study

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6491
Author(s):  
Monika Czop ◽  
Beata Łaźniewska-Piekarczyk ◽  
Małgorzata Kajda-Szcześniak
Keyword(s):  
Thermal Treatment ◽  
Cement Mortar ◽  
Raw Materials ◽  
Municipal Waste ◽  
Chemical Compositions ◽  
High Loss ◽  
Cement Mortars ◽  
Potential Component ◽  
Reduction Of Co2

In Europe there are nearly 500 incinerators. There are over 2000 of them in the world. It is estimated that the combustion of 1 ton (Mg) of waste produces about 250–300 kg of slag. Due to the large amounts of this waste, the construction industry’s demand for raw materials and the reduction of CO2 emissions, research was undertaken to use slags as a cement component. The problem was complex because slags generated in the thermal treatment of municipal waste have different chemical compositions and physical properties and contain variable amounts of impurities. The choice of chemical analyses of slag was dictated by the potential influence on the properties of cement mortars. The total moisture of raw slag (4–10%), the bulk density (600–1267 kg/m3) and the specific surface after grinding (over 3000 cm2/g) were determined. The pH (11.9) and the content of sulphates (3.5% by weight), chlorides (0.3% by weight) and selected heavy metals (Cd, Cu, Fe, Mn, Zn, Pb) were measured in the aqueous extract. The obtained results of the washing test were compared with the values resulting from the currently binding legal regulations. In the next step, cement mortars with 30% addition of tested slags were designed and made. The article presents the results of compressive strength tests, which were compared with the results of samples without the addition of slag. The addition of slag to the cement mortar decreased S_MSWI 1 by 64% and S_MSWI 2 by 31%. The high loss of strength and the swelling of the S_MSWI 1 test led to the activation of the NaOH slag. In the endurance test, an increase from 16 to 32 MPa was recorded. Preliminary studies show that the addition of slag in the cement mortar allows obtaining the strength at the level of 30–32 MPa.

scholarly journals Investigation of the mechanism of mercury removal from silver- amalgam alloy

2004 ◽  
Vol 69 (12) ◽  
pp. 1111-1120 ◽  
Author(s):  
Zoran Odanovic ◽  
M. Djurdjevic
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Treatment ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Dental Amalgam ◽  
Mercury Removal ◽  
Chemical Compositions ◽  
Removal Mechanism ◽  
Scanning Electron

An investigation of silver dental amalgam decomposition and the mercury removal mechanism was performed. The decomposition process was analyzed during thermal treatment in the temperature interval from 400 ?C to 850 ?C and for times from 0.5 to 7.5 h. The chemical compositions of the silver dental amalgam alloy and the treated alloy were tested and microstructure analysis using optical and scanning electron microscopy was carried out. The phases were identified using energy disperse electron probe microanalysis. A mechanism for the mercury removal process from silver dental amalgam alloy is suggested.

Pollutant Identification by Selected Area Electron Diffraction

1974 ◽  
Vol 32 ◽  
pp. 532-533
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson ◽  
C. W. Walker
Keyword(s):  
Thermal Treatment ◽  
Electron Diffraction ◽  
Sample Preparation ◽  
Crystal Structures ◽  
Water Samples ◽  
Environmental Samples ◽  
Short Review ◽  
Selected Area Electron Diffraction ◽  
Multiple Component

Selected area electron diffraction (SAD) has been used successfully to determine crystal structures, identify traces of minerals in rocks, and characterize the phases formed during thermal treatment of micron-sized particles. There is an increased interest in the method because it has the potential capability of identifying micron-sized pollutants in air and water samples. This paper is a short review of the theory behind SAD and a discussion of the sample preparation employed for the analysis of multiple component environmental samples.

Development of Crystallinity in Turbostratic Boron Nitride Derived from Polymeric Precursors

1991 ◽  
Vol 49 ◽  
pp. 954-955
Author(s):  
X. Qiu ◽  
A. K. Datye ◽  
T. T. Borek ◽  
R. T. Paine
Keyword(s):  
Thermal Treatment ◽  
Boron Nitride ◽  
Diffraction Pattern ◽  
Polymeric Precursors ◽  
Polymer Precursors ◽  
Diffuse Ring

Boron nitride derived from polymer precursors is of great interest for applications such as fibers, coatings and novel forms such as aerogels. The BN is prepared by the polymerization of functionalized borazine and thermal treatment in nitrogen at 1200°C. The BN powders obtained by this route are invariably trubostratic wherein the sheets of hexagonal BN are randomly oriented to yield the so-called turbostratic modification. Fib 1a and 1b show images of BN powder with the corresponding diffraction pattern in fig. 1c. The (0002) reflection from BN is seen as a diffuse ring with occational spots that come from crystals of BN such as those shown in fig. 1b. The (0002) lattice fringes of BN seen in these powders are the most characteristic indication of the crystallinity of the BN.

Analytical Electron Microscopy of Ion-Implanted Metals

1985 ◽  
Vol 43 ◽  
pp. 282-285
Author(s):  
D.I. Potter ◽  
M. Ahmed ◽  
K. Ruffing
Keyword(s):  
Electron Microscopy ◽  
Ion Implantation ◽  
Friction And Wear ◽  
Analytical Electron Microscopy ◽  
Chemical Compositions ◽  
Surface Chemical ◽  
Near Surface ◽  
The Past ◽  
Analytical Electron ◽  
Property Changes

Ion implantation, used extensively for the past decade in fabricating semiconductor devices, now provides a unique means for altering the near-surface chemical compositions and microstructures of metals. These alterations often significantly improve physical properties that depend on the surface of the material; for example, catalysis, corrosion, oxidation, hardness, friction and wear. Frequently the mechanisms causing these beneficial alterations and property changes remain obscure and much of the current research in the area of ion implantation metallurgy is aimed at identifying such mechanisms. Investigators thus confront two immediate questions: To what extent is the chemical composition changed by implantation? What is the resulting microstructure? These two questions can be investigated very fruitfully with analytical electron microscopy (AEM), as described below.

TEM/AEM characterization of fine-grained clay minerals in very-low-grade rocks: Evaluation of contamination by empa involving celadonite family minerals

1996 ◽  
Vol 54 ◽  
pp. 694-695
Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi
Keyword(s):  
Electron Microscopy ◽  
Volcanic Rocks ◽  
Analytical Electron Microscopy ◽  
Metamorphic Rocks ◽  
New Mineral ◽  
Chemical Compositions ◽  
Low Grade ◽  
Fine Grained ◽  
Depth Analysis ◽  
Mineral Aggregates

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.

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