scholarly journals Thermodynamic aspect of sodium carbonate mechanical transformations under different environment

2020 ◽  
Vol 52 (4) ◽  
pp. 433-444
Author(s):  
Natasa Djordjevic ◽  
Slavica Mihajlovic ◽  
Aleksandra Pataric
Keyword(s):  
Carbon Dioxide ◽  
Structural Analysis ◽  
Mechanical Activation ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Chemical Characteristics ◽  
Activation Time ◽  
X Ray ◽  
Physico Chemical ◽  
The Subject

During mechanical activation, the energy of treated material is raised to a higher level that can lead to the chemical transformation of the activated material. This is the point that should be considered as a phenomenon of the mechanochemical transformations appearing as a result of mechanical activation. Sodium carbonate as a substance that is often subjected to mechanochemical synthesis was mechanically activated in this study. The subject was the monitoring of changes in the physico-chemical characteristics of sodium carbonate after exposure to different degrees of activation time within the range of 1-28 minutes. After activation, the samples were deposited in three environments, CO2, air, and vacuum, at room temperature, in a period of 64 days. The mass changes occurring during the treatment were measured depending on the processing environment. Increasing the mass was evident and was attributed to the chemisorption of moisture and carbon dioxide present in the air as a consequence of the sodium carbonate activation. The methods also used were calcimetric chemical analysis and X-ray structural analysis. According to obtained results, it was found that activated sodium carbonate is mass-transformed into sodium bicarbonate, whereby these changes are functionally dependent on activation time and the processing environment.

scholarly journals A Highly Sensitive Room Temperature CO2 Gas Sensor Based on SnO2-rGO Hybrid Composite

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 522
Author(s):  
Zhi Yan Lee ◽  
Huzein Fahmi bin Hawari ◽  
Gunawan Witjaksono bin Djaswadi ◽  
Kamarulzaman Kamarudin
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
Hybrid Composite ◽  
Room Temperature ◽  
Co2 Gas ◽  
X Ray ◽  
Wide Range ◽  
Co2 Gas Sensor

A tin oxide (SnO2) and reduced graphene oxide (rGO) hybrid composite gas sensor for high-performance carbon dioxide (CO2) gas detection at room temperature was studied. Since it can be used independently from a heater, it emerges as a promising candidate for reducing the complexity of device circuitry, packaging size, and fabrication cost; furthermore, it favors integration into portable devices with a low energy density battery. In this study, SnO2-rGO was prepared via an in-situ chemical reduction route. Dedicated material characterization techniques including field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) were conducted. The gas sensor based on the synthesized hybrid composite was successfully tested over a wide range of carbon dioxide concentrations where it exhibited excellent response magnitudes, good linearity, and low detection limit. The synergistic effect can explain the obtained hybrid gas sensor’s prominent sensing properties between SnO2 and rGO that provide excellent charge transport capability and an abundance of sensing sites.

scholarly journals СИНТЕЗ И ИССЛЕДОВАНИЕ СТЕКЛООБРАЗОВАНИЯ В СИСТЕМЕ AS2S3-ERS

2021 ◽  
Vol 7 (5(59)) ◽  
pp. 28-31
Author(s):  
ТЕЙМУР МАМЕД ИЛЬЯСЛИ ◽  
ДУНИЯ ТАЛЕХ ГАСАНОВА ◽  
ИМИР ИЛЬЯС АЛИЕВ
Keyword(s):  
Chemical Analysis ◽  
Solid Solutions ◽  
Glass Formation ◽  
Room Temperature ◽  
Slow Cooling ◽  
X Ray ◽  
Physico Chemical

To determine the area of glass formation in the system As2S3-ErS were synthesized alloys in the range of concentrations 0-30 mol. % ErS. The methods of physico-chemical analysis of differential-thermal (DTA), X-ray phase (RFA), microstructural (MCA) analyzes, as well as the measurement of microhardness and density determined the area of the glass and studied them physicо-chemical propertes. It is established that in the system As2S3-ErS on the basis of As2S3 during slow cooling the area of the glass reaches 17 mol. % ErS. Alloys in the concentration range 20-30 mol. % ErS are glass-crystalline. In the system at room temperature solid solutions on the basis of As2S3 are distributed up to 2.5 mol.% ErS, and on the basis of solid solutions ErS are practically not installed.

Comparing the Physico-Chemical Characteristics of Formulated and Marketed Yashada Bhasma

2021 ◽  
pp. 6392-6398
Author(s):  
Nitu Bhatnagar ◽  
Avani Pareek
Keyword(s):  
Inductively Coupled Plasma ◽  
Thermo Gravimetric Analysis ◽  
Human Consumption ◽  
Chemical Characteristics ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled ◽  
Physico Chemical ◽  
The Difference

The present study is aimed to observe the difference in the Physico-Chemical characteristics of the marketed and formulated bhasma samples through X-Ray Diffraction analysis (XRD), Dynamic Light Scattering (DLS), Zeta potential, Thermo-Gravimetric analysis (TGA), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray analysis (EDAX), apart from organoleptic methods. Inductively Coupled Plasma Mass Spectroscopy (ICPMS) analysis was also done to observe the presence of trace and heavy metals so that the safety of all these samples could be ensured. XRD shows variation in oxide nature of zinc as well crystallite size in all bhasma samples. DLS and SEM results show difference in particle size of marketed bhasma samples as compared to formulated Yashada bhasma. EDAX and ICPMS also confirm the alteration in elemental composition of all these bhasma samples. Thus, it can be concluded that these ayurvedic medicines should be prepared strictly using the formulation methods as mentioned in the Ayurvedic texts. This will help the prepared products to adopt the inherent quality of the ancient system of medicine, which shall be useful and devoid of any side effects for human consumption.

The Rare Earth(III) Nitrate Dimethyl Sulfoxide Adducts [( dmso )nLn(O2NO)3]

1996 ◽  
Vol 49 (9) ◽  
pp. 997 ◽  
Author(s):  
LI Semenova ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Dimethyl Sulfoxide ◽  
Metal Atom ◽  
Metal Ion ◽  
Room Temperature ◽  
X Ray ◽  
The Subject ◽  
Ion Radius ◽  
The Rare Earth

Adducts [( dmso )nLn(O2NO)3], obtained by the crystallizatior , of lanthanoid (III) nitrate ( Ln (NO3)3.-xH2O) with excess dimethyl sulfoxide (' dmso ') in methanol or ethanol, have been the subject of a series of room-temperature single-crystal X-ray studies, defining more clearly the manner in which stoichiometry and structure systematically vary with change in metal ion radius. All complexes studied are mononuclear, the metal ion being complexed by three bidentate nitrate ligands and a number of dmso ligands , four for La-Sm and three beyond. The array La- Sm is monoclinic C2/c, a ≈ 14.9, b ≈ 15.5, c ≈ 15.5 Ǻ, β ≈ 108.4°, Z = 4 f.u .; the metal atom is disposed on a crystallographic 2 axis, which also passes through one of the nitrate groups. The series Eu -Tm (inclusive also of Y) is monoclinic, P21/n, a ≈ 11.5, b ≈ 12.7, c ≈ 13.6 Ǻ, β ≈ 100°, Z = 4 f.u ., while Yb and Lu are also monoclinic, P21/c, a ≈ 10.0, b ≈ 12.6, c ≈ 16 Ǻ, β ≈ 100.6°, Z = 4 f.u.

scholarly journals Room Temperature Neutron Crystallography of Drug Resistant HIV-1 Protease Uncovers Limitations of X-ray Structural Analysis at 100 K

2017 ◽  
Vol 60 (5) ◽  
pp. 2018-2025 ◽  
Author(s):  
Oksana Gerlits ◽  
David A. Keen ◽  
Matthew P. Blakeley ◽  
John M. Louis ◽  
Irene T. Weber ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Room Temperature ◽  
Drug Resistant ◽  
X Ray ◽  
Hiv 1 ◽  
Neutron Crystallography

scholarly journals DTA/TG analysis of mechanochemicaly activated sodium carbonate

2021 ◽  
pp. 47-55
Author(s):  
Nataša Đorđević ◽  
Slavica Mihajlović ◽  
Gvozden Jovanović ◽  
Branislav Marković
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Relaxation Time ◽  
Environmental Protection ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Tg Analysis ◽  
Relaxation Period ◽  
Sorption Characteristics

Sodium carbonate is a material that is very good sorbent of carbon dioxide from the atmosphere, and it is a reason of it is increasing importance in environmental protection. In order to improve it is sorption characteristics, activation of Na2CO3 was performed by mechanochemical procedure and monitoring of changes during the relaxation time. This research is based on differential thermal analysis with thermogravimetry, in order to determine the changes that occurred on the activated samples during the relaxation period under controlled conditions. Sodium carbonate was activated for 2 and 7 minutes in a vibro mill, and then the activated samples were deposited in at room temperature and atmosphere of carbon dioxide at a humidity of 95% for 96h.

scholarly journals Physico-Chemical Characteristics of Shungite Rock of Kazakhstan

2013 ◽  
Vol 15 (3) ◽  
pp. 241 ◽  
Author(s):  
S.A. Efremov ◽  
S.V. Nechipurenko ◽  
M.K. Kazankapova ◽  
B. Washington ◽  
Kh.S. Tassibekov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Physicochemical Characteristics ◽  
Chemical Characteristics ◽  
X Ray ◽  
Elementary Analysis ◽  
Physico Chemical ◽  
Developed Surface ◽  
Scanning Electron ◽  
Shungite Carbon

Physico-chemical characteristics of shugite rocks of Kazakhstan (Bakyrchik deposit) were studied using the methods of elementary analysis, IR-spectroscopy, scanning electron microscopy, Raman spectroscopy and X-ray phase analysis. The content of carbon in shungite rock was determined to be from 3% to 19%. The flotation technology for shungite rocks of Kazakhstan was developed, the content of carbon in the concentrate reaching 40.0%. When studying the elemental composition, the mineral part of shungite rocks was stated to be presented, mainly, by silicon, aluminium, calcium, magnesium, potassium, sodium, iron and titanium oxides. IR-spectroscopic investigations showed that in the concentrate, apart from polycyclic hydrocarbons containing methylene groups, there appeared carboxyl groups. The results of scanning electron microscopy (SEM) showed that flotation and thermal activation of shungite rocks on carbon allow obtaining a more developed surface structure and porosity. The structure of shungite carbon was shown by the method of Raman scattering to be close to that of glassy carbon. The results of X-ray diffraction analysis (XRD) of natural shungite rocks showed that the samples under study contained a carbonaceous substance and a number of mineral components: quartz, illite, bassanite, burgerite, muscovite. It is shown that shungite carbon of “Bakyrchik” deposit is identical to shungite of Zazhogino deposit in Russia. The stated physicochemical characteristics allow to determine the directions of the use of carbon concentrate for solution of ecological and technological problems.

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