Mechanochemical synthesis of nanocrystalline nickel-molybdenum compounds and their morphology and application in catalysis: II. Effect of mechanochemical activation parameters—process power density and exposure time—on the composition and structure of nickel-molybdenum compounds

2014 ◽  
Vol 55 (1) ◽  
pp. 121-129 ◽  
Author(s):  
O. A. Knyazheva ◽  
O. N. Baklanova ◽  
A. V. Lavrenov ◽  
V. A. Drozdov ◽  
N. N. Leont’eva ◽  
...  
2021 ◽  
Vol 1045 ◽  
pp. 32-39
Author(s):  
Nikolai Shapkin ◽  
Natalia Maslova ◽  
Evgeniy Papynov ◽  
Vladimir Kaminskii ◽  
Alevtina Kapustina ◽  
...  

The interaction of magnesium carbonate with polyphenylsiloxane under the conditions of mechanochemical activation with subsequent heating has been investigated. Based on the TGA and DTA data, it has been shown that, upon heating up to 420°C, the reaction proceeded completely with the release of carbon dioxide. The polymer was dissolved in DMFA and purified by repeated precipitation with water. The polymer yield was 64%. The residue insoluble in organic solvents has been obtained by evaporation of an aqueous solution. The composition and structure of the synthesis products have been analyzed by means of element analysis, IR spectroscopy, and diffractometry. It has been demonstrated that the fraction soluble in DMFA had a silicon-to-magnesium ratio equal to 4.2, while the fraction isolated from water had this ratio equal to 1.0. The IR and XRD data enabled one to conclude that, regardless of the different compositions, the structures of all fractions were similar and corresponded to mesomorphic layered polymers produced by the ion exchange method.


2020 ◽  
Vol 33 (1) ◽  
pp. 161-175
Author(s):  
Ali S. Mahmood ◽  
Nadeem H. Meikha

Burn is one of the most important conditions in veterinary and human medicine. The purpose of this study is to evaluate the enhancing therapeutic effect of 790 nm diode laser on the burn healing. Twenty-five rabbits (mean weight was 2.3 ± 0.03 kg) were divided into 5 groups (A, B, F, H and control group), each group consists of 5 animals. All groups were inflected with burn (scalds) by 99 degree of Celsius hot water applied for 30 seconds, on skin of the femoral region. Four groups were treated by laser and one group was without laser irradiation as a control group. The animals were treated by diode laser five times a week at different power density. The power density (PD) of 58.9 mW/cm² with exposure time 120 seconds was used for group (A), but in group (B), the same PD used with exposure time of 60 seconds, for group (F) the PD was 255mW/cm² and for group (H) the PD was 888 mW/cm² and same exposure time of 20 seconds for both last 2 groups. Results of four groups were compared with control group clinically and histopathologically. The study showed a good response in burn healing in (F) and (B) and (A) group, with no differences between group (H) and control group. The treatment of 5 times a week gave benefit in acceleration of the burn healing. The histological examinations revealed an increase in the proliferation of epithelial cells from the burn edge and decrease in the inflammatory cells infiltration in group F, B and A .The statistical results showed that the best results are


2006 ◽  
Vol 422 (1-2) ◽  
pp. 53-57 ◽  
Author(s):  
D. Klissurski ◽  
M. Mancheva ◽  
R. Iordanova ◽  
G. Tyuliev ◽  
B. Kunev

2005 ◽  
Vol 37 (2) ◽  
pp. 93-105 ◽  
Author(s):  
M.V. Chaikina ◽  
Sergej Aman

The parameters of mechanical action on solids were determined for apatite and quartz as examples, providing separation between fracture, grinding and mechanical activation processes in solids. The texture, structural and chemical changes accompanying these processes in the samples under investigation are shown. The data on mechanochemical synthesis of isomorphous apatite modifications in multicomponent systems are reported. A reversible character of mechanochemical activation and mechanochemical synthesis is discovered.


2008 ◽  
Vol 22 (18n19) ◽  
pp. 3099-3106 ◽  
Author(s):  
M. H. FATHI ◽  
E. MOHAMMADI ZAHRANI

Recently fluoridated hydroxyapatite (FHA) has been developed since it possesses lower solubility than pure hydroxyapatite (HA), while maintaining the comparable bioactivity and biocompatibility in dental and orthopedic application. The aim of this work was to synthesize and characterize the FHA nanopowder via mechanochemical activation method. Mechanochemical reaction was performed in the planetary ball mill at 300 rpm rotation speed by using 8 balls with 2 cm diameter. XRD technique was used to evaluate phase and composition and determine the grain size of prepared FHA nanopowder. FTIR spectroscopy was utilized to identify the functional groups and to compare obtained powder with bone apatite. The results showed that the synthesis of FHA after 6 hr ball milling at 300 rpm was completed. Fluorhydroxyapatite grain size was almost 37nm after 6 hr of milling.


2006 ◽  
Vol 68 (4) ◽  
pp. 470-480 ◽  
Author(s):  
A. N. Streletskii ◽  
I. V. Povstugar ◽  
A. B. Borunova ◽  
S. F. Lomaeva ◽  
P. Yu. Butyagin

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