Synthesis of YBa2Cu3O7−x powder by autoignition of citrate-nitrate gel

1993 ◽  
Vol 8 (11) ◽  
pp. 2761-2766 ◽  
Author(s):  
Sukumar Roy ◽  
Das A. Sharma ◽  
S.N. Roy ◽  
H.S. Maiti
Keyword(s):  
Large Scale ◽  
Reduction Reaction ◽  
Ignition Process ◽  
Scale Production ◽  
Thermally Induced ◽  
Oxidation Reduction ◽  
Large Scale Production ◽  
Fine Particle Size ◽  
Oxidation Reduction Reaction ◽  
Good Potential

A simple and convenient method for the synthesis of YBa2Cu3O7−x powder is described. The technique involves autoignition of a citrate-nitrate gel resulting from a thermally induced oxidation-reduction reaction to yield an ash that upon calcination produces the desired compound. The resulting powder is pure, homogeneous, and possesses a reasonably fine particle size. The autoignition is restricted to a particular range of citrate-nitrate ratio in the gel. Attempts have been made to understand the ignition process with the help of Thermogravimetry (TG) and Differential Thermal Analysis (DTA) of the samples. The process appears to have a higher degree of reproducibility and a good potential for large-scale production.

Low-temperature synthesis of ultrafine La0.84Sr0.16MnO3 powder by an autoignition process

1994 ◽  
Vol 9 (4) ◽  
pp. 986-991 ◽  
Author(s):  
Amitava Chakraborty ◽  
P. Sujatha Devi ◽  
Sukumar Roy ◽  
H. S. Maiti
Keyword(s):  
Low Temperature ◽  
Large Scale ◽  
Ultrafine Particle ◽  
Reduction Reaction ◽  
Ignition Process ◽  
Scale Production ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Thermally Induced ◽  
Oxidation Reduction

A simple and convenient method for low-temperature synthesis of La0.84Sr0.16MnO3 powder is described. The technique involves autoignition of a carboxylate (citrate + acetate)-nitrate gel resulting from a thermally induced anionie oxidation-reduction reaction to yield an ash, which upon calcination produces the desired powder. The resulting powder is pure, homogeneous, and possesses ultrafine particle size of the order of 0.3 to 0.5 μm. The autoignition is restricted to a particular range of carboxylate to nitrate ratio in the gel. Attempts have been made to understand the ignition process with the help of Thermogravimetry (TG) and Differential Thermal Analysis (DTA) of the samples. The process appears to have a higher degree of reproducibility and a good material yield (more than 96%) suitable for large-scale production.

scholarly journals Electrochemically derived functionalized graphene for bulk production of hydrogen peroxide

2020 ◽  
Vol 11 ◽  
pp. 432-442 ◽  
Author(s):  
Munaiah Yeddala ◽  
Pallavi Thakur ◽  
Anugraha A ◽  
Tharangattu N Narayanan
Keyword(s):  
Large Scale ◽  
Reduction Reaction ◽  
Single Step ◽  
Scale Production ◽  
Functionalized Graphene ◽  
Large Scale Production ◽  
Production Of Hydrogen ◽  
Electron Reduction ◽  
Bulk Production ◽  
Carbon Based

On-site peroxide generation via electrochemical reduction is gaining tremendous attention due to its importance in many fields, including water treatment technologies. Oxidized graphitic carbon-based materials have been recently proposed as an alternative to metal-based catalysts in the electrochemical oxygen reduction reaction (ORR), and in this work we unravel the role of C=O groups in graphene towards sustainable peroxide formation. We demonstrate a versatile single-step electrochemical exfoliation of graphite to graphene with a controllable degree of oxygen functionalities and thickness, leading to the formation of large quantities of functionalized graphene with tunable rate parameters, such as the rate constant and exchange current density. Higher oxygen-containing exfoliated graphene is known to undergo a two-electron reduction path in ORR having an efficiency of about 80 ± 2% even at high overpotential. Bulk production of H2O2 via electrolysis was also demonstrated at low potential (0.358 mV vs RHE), yielding ≈34 mg/L peroxide with highly functionalized (≈23 atom %) graphene and ≈16 g/L with low functionalized (≈13 atom %) graphene, which is on par with the peroxide production using state-of-the-art precious-metal-based catalysts. Hence this method opens a new scheme for the single-step large-scale production of functionalized carbon-based catalysts (yield ≈45% by weight) that have varying functionalities and can deliver peroxide via the electrochemical ORR process.

scholarly journals 3D interconnected nitrogen-self-doped carbon aerogels as efficient oxygen reduction electrocatalysts derived from biomass gelatin

RSC Advances ◽  
2019 ◽  
Vol 9 (69) ◽  
pp. 40301-40308 ◽  
Author(s):  
Haoqi Yang ◽  
Shuqing Kou ◽  
Zhiyuan Li ◽  
Zhiyong Chang ◽  
Mi Wang ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Large Scale ◽  
Reduction Reaction ◽  
Carbon Aerogels ◽  
Manufacturing Cost ◽  
Scale Production ◽  
Environmental Friendliness ◽  
Metal Free ◽  
Large Scale Production

Development of efficient metal-free electrocatalysts derived from biomass with high activity towards oxygen reduction reaction (ORR) has gained significance attention due to their low manufacturing cost, environmental friendliness and easy large-scale production.

I. S. A. Baud. Forms of Production and Women's Labour: Gender Aspects of Industrialisation in India and Mexico. New Delhi: Sage Publications. 1992. 321 pp.Hardbound. Price: Indian Rs 295.00.

1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha
Keyword(s):  
Large Scale ◽  
Indian Society ◽  
New Delhi ◽  
Scale Production ◽  
Female Labour ◽  
Self Employment ◽  
Commodity Production ◽  
Large Scale Production ◽  
Mexican Society ◽  
Small Production

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.

An Efficient and Improved Process for the Synthesis of Itopride Hydrochloride and Trimethobenzamide Hydrochloride

2018 ◽  
Vol 15 (4) ◽  
pp. 572-575 ◽  
Author(s):  
Ponnusamy Kannan ◽  
Samuel I.D. Presley ◽  
Pallikondaperumal Shanmugasundaram ◽  
Nagapillai Prakash ◽  
Deivanayagam Easwaramoorthy
Keyword(s):  
Large Scale ◽  
Hydroxylamine Hydrochloride ◽  
Scale Production ◽  
One Pot ◽  
Hydrochloride Salt ◽  
Environmental Friendly ◽  
Large Scale Production ◽  
Non Ulcer Dyspepsia ◽  
Itopride Hydrochloride ◽  
Yield And Purity

Aim and Objective: Itopride is a prokinetic agent used for treating conditions like non-ulcer dyspepsia. Itopride is administered as its hydrochloride salt. Trimethobenzamide is used for treating nausea and vomiting and administered as its hydrochloride salt. The aim is to develop a novel and environmental friendly method for large-scale production of itopride and trimethobenzamide. Materials and Methods: Itopride and trimethobenzamide can be prepared from a common intermediate 4- (dimethylaminoethoxy) benzyl amine. The intermediate is prepared from one pot synthesis using Phyrdroxybenzaldehye and zinc dust and further reaction of the intermediate with substituted methoxy benzoic acid along with boric acid and PEG gives itopride and trimethobenzamide. Results: The intermediate 4-(dimethylaminoethoxy) benzylamine is prepared by treating p-hydroxybenzaldehyde and 2-dimethylaminoethyl chloride. The aldehyde formed is treated with hydroxylamine hydrochloride. The intermediate is confirmed by NMR and the purity is analysed by HPLC. Conclusion: Both itopride and trimethobenzamide were successfully synthesized by this method. The developed method is environmental friendly, economical for large-scale production with good yield and purity.

scholarly journals Cyanobacteria—From the Oceans to the Potential Biotechnological and Biomedical Applications

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 241
Author(s):  
Shaden A. M. Khalifa ◽  
Eslam S. Shedid ◽  
Essa M. Saied ◽  
Amir Reza Jassbi ◽  
Fatemeh H. Jamebozorgi ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Biomedical Applications ◽  
Large Scale ◽  
Biological Activities ◽  
Scale Production ◽  
Pharmacological Activities ◽  
Large Scale Production ◽  
Marine Products ◽  
Hiv 1 ◽  
Successful Phase

Cyanobacteria are photosynthetic prokaryotic organisms which represent a significant source of novel, bioactive, secondary metabolites, and they are also considered an abundant source of bioactive compounds/drugs, such as dolastatin, cryptophycin 1, curacin toyocamycin, phytoalexin, cyanovirin-N and phycocyanin. Some of these compounds have displayed promising results in successful Phase I, II, III and IV clinical trials. Additionally, the cyanobacterial compounds applied to medical research have demonstrated an exciting future with great potential to be developed into new medicines. Most of these compounds have exhibited strong pharmacological activities, including neurotoxicity, cytotoxicity and antiviral activity against HCMV, HSV-1, HHV-6 and HIV-1, so these metabolites could be promising candidates for COVID-19 treatment. Therefore, the effective large-scale production of natural marine products through synthesis is important for resolving the existing issues associated with chemical isolation, including small yields, and may be necessary to better investigate their biological activities. Herein, we highlight the total synthesized and stereochemical determinations of the cyanobacterial bioactive compounds. Furthermore, this review primarily focuses on the biotechnological applications of cyanobacteria, including applications as cosmetics, food supplements, and the nanobiotechnological applications of cyanobacterial bioactive compounds in potential medicinal applications for various human diseases are discussed.

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