Factors Affecting Line Intensities in the Flame Spectrometry of Metals in Organic Solvents.

1966 ◽  
Vol 38 (8) ◽  
pp. 1062-1063 ◽  
Author(s):  
Jacob. Elhanan ◽  
W. D. Cooke
Keyword(s):  
Organic Solvents ◽  
Factors Affecting ◽  
Line Intensities ◽  
Flame Spectrometry

Evaluation of Aspects Controlling Crystallization of Nitrofurantoin

2019 ◽  
Vol 800 ◽  
pp. 9-13
Author(s):  
Aija Trimdale ◽  
Agris Bērziņš
Keyword(s):  
Gibbs Energy ◽  
Quantum Chemical Calculations ◽  
Organic Solvents ◽  
Quantum Chemical ◽  
Polymer Additives ◽  
Factors Affecting ◽  
X Ray

Nitrofurantoin was crystallized from multiple mixtures of water and organic solvents with and without additives to try to find and identify factors affecting phase obtained in crystallization and provide possible information on crystallization control. Obtained crystals were identified with powder X-ray diffractometry. Crystallization control possibilities were evaluated by using polymer additives and crystallization additives, by also using quantum chemical calculations to investigate the association of nitrofurantoin and additive molecules and calculate Gibbs energy of association.

Factors affecting the lipase catalyzed transesterification reactions of 3-hydroxy esters in organic solvents.

1993 ◽  
Vol 4 (5) ◽  
pp. 1007-1016 ◽  
Author(s):  
Uwe Bornscheuer ◽  
Andrea Herar ◽  
Lars Kreye ◽  
Volker Wendel ◽  
Andreas Capewell ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Factors Affecting ◽  
Hydroxy Esters

Nanostructure of Binary Organogels via Trigonal Acids and Pyridine Derivatives

2013 ◽  
Vol 641-642 ◽  
pp. 777-780
Author(s):  
Min Li
Keyword(s):  
Organic Solvents ◽  
Crucial Role ◽  
Molecular Structures ◽  
Hydrophobic Core ◽  
Pyridine Derivatives ◽  
Factors Affecting ◽  
Gelation Behavior ◽  
Main Factors

We reported here the gelation behaviors of binary trigonal acids and bipyridine derivatives mixtures in various organic solvents. Their gelation behaviors in 20 solvents were tested as new organic gelators. It was shown that the molecular shapes and substituent groups in these compounds played a crucial role in the gelation behavior of the compounds. While the trigonal acid with aromatic core can gel in acetone and ethanol, another trigonal acid with hydrophobic core can only gel in aniline. The molecular structures and substituent groups of bipyridine derivatives have also played an important role in changing the gelation behaviors and assembly states. SEM observations reveal that the molecular structures and the identity of the solvents are the main factors affecting the structures of the aggregates in the gels. Experimentally, different microstructures of the gels were observed. As example, the aggregates of trigonal compound in acetone, ethanol, or aniline adopt structures of belt-like aggregates or thin nanofibers, respectively.

scholarly journals Study on the Gel Cleaning System for Removal of Poly (vinyl acetate) Fixative of the Mural Paintings of the Payathonzu Temple in Bagan, Myanmar (I) - Focusing on Properties and Removability of Gel Cleaners -

2021 ◽  
Vol 37 (4) ◽  
pp. 370-379
Author(s):  
Yeong Gyeong Yu ◽  
Gyu-Seong Han ◽  
Hwa Soo Lee ◽  
Kyeong Soon Han
Keyword(s):  
Vinyl Acetate ◽  
Organic Solvents ◽  
Stable Condition ◽  
Gelling Agent ◽  
Research Trend ◽  
Weakly Alkaline ◽  
Factors Affecting ◽  
Gelling Agents ◽  
Mural Paintings ◽  
The Stability

In the past, PVAc [poly(vinyl acetate)] was used as a fixative for the conservation of the murals in the murals of the Payathonzu temple located in Bagan, Myanmar. In this study, attention was paid to gel cleaning as a method for stably removing such PVAc fixatives. Based on the recent research trend related to the cleaning of murals in Bagan ruins, 3 types of gelling agents (Nevek®, Laponite®RD, Carbopol®980) and 2 types of organic solvents (Acetone, Dimethyl carbonate) were selected. Six types of gel cleaners were prepared by mixing gelling agents and organic solvents, and the properties and fixative removability of these cleaners were compared. As a result of confirming the properties of the prepared gel cleaners, the pH of the cleaners was all in the weak acidic to weakly alkaline range, which was a stable condition for mural application. Also, there was no difference in the viscosity of the cleaners depending on the type of solvent, but there was a difference depending on the type of gelling agent used. Regarding the weight loss ratio of PVAc, which is an indicator of removability, the exposure conditions of the gel cleaners, the boiling point of the solvent used, and the viscosity of the gelling agent acted as factors affecting. As a result of comparing the removability of gel cleaners, it was confirmed that the solvent’s fixative solubility, the volatility of the solvent itself, and the solvent release control properties of the gelling agent had a great effect on the removability of the gel cleaners. In Part 2, the stability and the running applicability of the gel cleaners will be investigated by making mockup samples reflecting the properties of the materials and techniques used to produce the mural paintings in the Payathonzu Temple.

scholarly journals Biodiesel production by enzyme-catalyzed transesterification

2005 ◽  
Vol 59 (3-4) ◽  
pp. 49-59 ◽  
Author(s):  
Olivera Stamenkovic ◽  
Miodrag Lazic ◽  
Vlada Veljkovic ◽  
Dejan Skala
Keyword(s):  
Organic Solvents ◽  
Vegetable Oils ◽  
Industrial Application ◽  
Biodiesel Production ◽  
Alkyl Esters ◽  
Factors Affecting ◽  
Catalysed Reaction ◽  
Ecological Problems ◽  
The Cost ◽  
Kinetics Of

The principles and kinetics of biodiesel production from vegetable oils using lipase-catalyzed transesterification are reviewed. The most important operating factors affecting the reaction and the yield of alkyl esters, such as: the type and form of lipase, the type of alcohol, the presence of organic solvents, the content of water in the oil, temperature and the presence of glycerol are discussed. In order to estimate the prospects of lipase-catalyzed transesterification for industrial application, the factors which influence the kinetics of chemically-catalysed transesterification are also considered. The advantages of lipase-catalyzed transesterification compared to the chemically-catalysed reaction, are pointed out. The cost of down-processing and ecological problems are significantly reduced by applying lipases. It was also emphasized that lipase-catalysed transesterification should be greatly improved in order to make it commercially applicable. The further optimization of lipase-catalyzed transesterification should include studies on the development of new reactor systems with immobilized biocatalysts and the addition of alcohol in several portions, and the use of extra cellular lipases tolerant to organic solvents, intracellular lipases (i.e. whole microbial cells) and genetically-modified microorganisms ("intelligent" yeasts).

Factors affecting yields of α hormones of Phytophthora parasitica obtained by adsorption

1996 ◽  
Vol 42 (2) ◽  
pp. 172-176 ◽  
Author(s):  
L. L. Chern ◽  
W. H. Ko ◽  
C. S. Tang
Keyword(s):  
Natural Products ◽  
Sexual Reproduction ◽  
Key Words ◽  
Organic Solvents ◽  
Original Method ◽  
Phytophthora Parasitica ◽  
Hormone Production ◽  
Millipore Filter ◽  
Polycarbonate Membrane ◽  
Factors Affecting

The conditions for improved yields of the α hormones of Phytophthora parasitica compared with those of the original technique established by Ko are described. Both hormones al and α2 were adsorbed on the Millipore filter by exposing both sides of the filter directly to freshly inoculated 40% V-8 agar blocks for 4 days. Usage of polycarbonate membrane in the original method to maintain sterility of the filter was replaced by sterilization of the filter with ethanol. Among five organic solvents tested, 95% ethanol was the most effective in extracting both α hormones from the Millipore filter. A 1-min shaking of the hormone-loaded filter with 95% ethanol was sufficient to extract ca. 95% of hormones α1 and α2. Results on the solubility properties suggest that the α hormones of Phytophthora parasitica are lipid-like natural products and that hormone α2 is more polar than hormone α1.Key words: sex hormone, hormone production, sexual reproduction, Phytophthora parasitica.

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