Effects on the physicochemical properties of partial substitution of Ni for Co in NixCo3-xO4 (x= 0, 0.4, 0.8) nickel-cobalt spinels using a new synthesis method (Pechini technique)

2006 ◽  
Vol 31 (1) ◽  
pp. 49-59
Author(s):  
Makhtar Guene ◽  
Abdou Aziz Diagne ◽  
Modou Fall ◽  
Mor Marème Dieng ◽  
Gérard Poillerat
2020 ◽  
Vol 17 (5) ◽  
pp. 382-388
Author(s):  
Aparna Wadhwa ◽  
Faraat Ali ◽  
Sana Parveen ◽  
Robin Kumar ◽  
Gyanendra N. Singh

Objective: The main aim of the present work is to synthesize chloramphenicol impurity A (CLRMIMP- A) in the purest form and its subsequent characterization by using a panel of sophisticated analytical techniques (LC-MS, DSC, TGA, NMR, FTIR, HPLC, and CHNS) to provide as a reference standard mentioned in most of the international compendiums, including IP, BP, USP, and EP. The present synthetic procedure has not been disclosed anywhere in the prior art. Methods: A simple, cheaper, and new synthesis method was described for the preparation of CLRM-IMP-A. It was synthesized and characterized by FTIR, DSC, TGA, NMR (1H and 13C), LC-MS, CHNS, and HPLC. Results: CLRM-IMP-A present in drugs and dosage form can alter the therapeutic effects and adverse reaction of a drug considerably, it is mandatory to have a precise method for the estimation of impurities to safeguard the public health. Under these circumstances, the presence of CLRM-IMP-A in chloramphenicol (CLRM) requires strict quality control to satisfy the specified regulatory limit. The synthetic impurity obtained was in the pure form to provide a certified reference standard or working standard to stakeholders with defined potency. Conclusion: The present research describes a novel technique for the synthesis of pharmacopoeial impurity, which can help in checking/controlling the quality of the CLRM in the international markets.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1906
Author(s):  
Marissa Pérez-Alvarez ◽  
Gregorio Cadenas-Pliego ◽  
Odilia Pérez-Camacho ◽  
Víctor E. Comparán-Padilla ◽  
Christian J. Cabello-Alvarado ◽  
...  

Copper nanoparticles (CuNP) were obtained by a green synthesis method using cotton textile fibers and water as solvent, avoiding the use of toxic reducing agents. The new synthesis method is environmentally friendly, inexpensive, and can be implemented on a larger scale. This method showed the cellulose capacity as a reducing and stabilizing agent for synthetizing Cellulose–Copper nanoparticles (CCuNP). Nanocomposites based on CCuNP were characterized by XRD, TGA, FTIR and DSC. Functional groups present in the CCuNP were identified by FTIR analysis, and XRD patterns disclosed that nanoparticles correspond to pure metallic Cu°, and their sizes are at a range of 13–35 nm. Results demonstrated that CuNPs produced by the new method were homogeneously distributed on the entire surface of the textile fiber, obtaining CCuNP nanocomposites with different copper wt%. Thus, CuNPs obtained by this method are very stable to oxidation and can be stored for months. Characterization studies disclose that the cellulose crystallinity index (CI) is modified in relation to the reaction conditions, and its chemical structure is destroyed when nanocomposites with high copper contents are synthesized. The formation of CuO nanoparticles was confirmed as a by-product, through UV spectroscopy, in the absorbance range of 300–350 nm.


2008 ◽  
Vol 91 (11) ◽  
pp. 3800-3802 ◽  
Author(s):  
Hu Hanjun ◽  
Zhou Wan-cheng ◽  
Luo Fa ◽  
Zhu Dong-Mei ◽  
Xu Jie

Author(s):  
Cássia S. Santana ◽  
Luiza S. Shine ◽  
Luiz H. Vieira ◽  
Ricardo J. Passini ◽  
Ernesto A. Urquieta-González ◽  
...  

2021 ◽  
Vol 317 ◽  
pp. 3-9
Author(s):  
Muhammad Suffian Sazali ◽  
Norazila Ibrahim ◽  
Zakiah Mohamed ◽  
Rozilah Rajmi ◽  
Ahmad Kamal Yahya

La0.7Ba0.3Mn1-xFexO3 (x = 0 and 0.02) were prepared by using solid state synthesis method to investigate the effect of Fe3+ substitution at Mn-site on electrical behaviour and structural properties. An analysis of X-ray diffraction, XRD data using refinement method shown both x = 0 and x = 0.02 samples were in single phased and crystallized in rhombohedral structural with Pnma space group. From ρ vs T curves shown resistivity decreased under increased of applied current of 10 mA to 20 mA for both samples in the temperature range of 20 K-300 K. The larger electroresistance, ER effect observed for x = 0.02 in temperature range of 20 K – 180 K compared to x = 0 sample is suggested due to the development of filamentary conduction path under increased of applied current. It is suggested that Fe substitution enhanced magnetic inhomogeneity which contribute to the growth of formation of conductive path under increased of applied current, lead to increase of ER effect. In the temperature range of 180 K – 300 K, the observed decreased in ER for Fe substituted sample (x = 0.02) is suggested due to the increased of scattering effect and reduction of available hopping site in metallic region and insulating region, respectively. Restriction in the movement of charge carrier had weakened the ER effect for Fe substituted sample. The observed ER effect indicates the compound has a potential for application such as for non-volatile memory elements.


Author(s):  
Juliana M. Juárez ◽  
Lisandro F. Venosta ◽  
Oscar A. Anunziata ◽  
Marcos B. Gómez Costa

1965 ◽  
Vol 7 (12) ◽  
pp. 2384-2385 ◽  
Author(s):  
D.G. Dimitrov ◽  
L.S. Gal'braikh ◽  
Z.A. Rogovin

2019 ◽  
pp. 191-236
Author(s):  
J. J. Prías‐Barragán ◽  
J. J. Prías‐Barragán ◽  
K. Gross ◽  
H. Ariza‐Calderón ◽  
P. Prieto

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