Powerful Photogenerated Reducing Agents

1988 ◽  
Author(s):  
David Tyler
Keyword(s):  
Reducing Agents

Methods for the Concentration of Bovine Ac-Globulin (Factor V)

1961 ◽  
Vol 06 (03) ◽  
pp. 435-444 ◽  
Author(s):  
Ricardo H. Landaburu ◽  
Walter H. Seegers
Keyword(s):  
Room Temperature ◽  
Barium Carbonate ◽  
Deae Cellulose ◽  
Reducing Agents ◽  
Factor V ◽  
Isoelectric Precipitation ◽  
Stabilizing Agent ◽  
Bovine Plasma ◽  
The Stability

SummaryAn attempt was made to obtain Ac-globulin from bovine plasma. The concentrates contain mostly protein, and phosphorus is also present. The stability characteristics vary from one preparation to another, but in general there was no loss before 1 month in a deep freeze or before 1 week in an icebox, or before 5 hours at room temperature. Reducing agents destroy the activity rapidly. S-acetylmercaptosuccinic anhydride is an effective stabilizing agent. Greatest stability was at pH 6.0.In the purification bovine plasma is adsorbed with barium carbonate and diluted 6-fold with water. Protein is removed at pH 6.0 and the Ac-globulin is precipitated at pH 5.0. Rivanol and alcohol fractionation is followed by chromatography on Amberlite IRC-50 or DEAE-cellulose. The final product is obtained by isoelectric precipitation.

The study of the drilling mud fluid loss reducing agents based on carboxymethyl starch and cellulose

2017 ◽  
pp. 102-105
Author(s):  
R.R. Sagitov ◽  
◽  
K.M. Minaev ◽  
A.S. Zakharov ◽  
A.S. Korolev ◽  
...  
Keyword(s):  
Reducing Agents ◽  
Fluid Loss ◽  
Drilling Mud ◽  
Carboxymethyl Starch

A Facile Synthesis of Cu2O and CuO Nanoparticles Via Sonochemical Assisted Method

2018 ◽  
Vol 15 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Sathish Mohan Botsa ◽  
Ramadevi Dharmasoth ◽  
Keloth Basavaiah
Keyword(s):  
Diffuse Reflectance Spectroscopy ◽  
Cupric Oxide ◽  
Copper Acetate ◽  
Chemical Properties ◽  
Copper Oxide Nanoparticles ◽  
Reducing Agents ◽  
Sonochemical Method ◽  
Phase Purity ◽  
X Ray ◽  
Cuo Nps

Background: During past two decades, functional nanomaterials have received great attention for many technological applications such as catalysis, energy, environment, medical and sensor due to their unique properties at nanoscale. However, copper oxide nanoparticles (NPs) such as CuO and Cu2O have most widely investigated for many potential applications due to their wide bandgap, high TC, high optical absorption and non-toxic in nature. The physical and chemical properties of CuO and Cu2O NPs are critically depending on their size, morphology and phase purity. Therefore, lots of efforts have been done to prepare phase CuO and Cu2O NPs with different morphology and size. Method: The synthesis of cupric oxide (CuO) and cuprous oxide (Cu2O) NPs using copper acetate as a precursor by varying the reducing agents such as hydrazine sulphate and hydrazine hydrate via sonochemical method. The phase, morphology and crystalline structure of a prepared CuO and Cu2O NPs were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray (EDS) and UV-Visible Diffuse reflectance spectroscopy (DRS). Results: The phase of NPs was tuned as a function of reducing agents.XRD patterns confirmed the formation of pure phase crystalline CuO and Cu2O NPs. FTIR peak at 621 cm-1 confirmed Cu(I)-O vibrations, while CuO vibrations confirmed by the presence of two peaks at 536 and 586 cm-1. Further investigation was done by Raman, which clearly indicates the presence of peaks at 290, 336, 302 cm-1 and 173, 241 cm-1 for CuO and Cu2O NPs, respectively. The FESEM images revealed rod-like morphology of the CuO NPs while octahedral like shape for Cu2O NPs. The presence of elemental Cu and O in stoichiometric ratios in EDS spectra confirms the formation of both CuO and Cu2O NPs. In summary, CuO and Cu2O NPs were successfully synthesized by a sonochemical method using copper acetate as a precursor at different reducing agents. The bandgap of CuO and Cu2O NPs was 2.38 and 1.82, respectively. Furthermore, the phase purity critically depends on reducing agents.

Diastereoselective Reduction of Selected α-substituted β-keto Esters and the Assignment of the Relative Configuration by 1H-NMR Spectroscopy

2020 ◽  
Vol 07 ◽  
Author(s):  
Christian Trapp ◽  
Corinna Schuster ◽  
Chris Drewniok ◽  
Dieter Greif ◽  
Martin Hofrichter
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Selective Reduction ◽  
Reducing Agents ◽  
Relative Configuration ◽  
Curtius Rearrangement ◽  
Keto Esters ◽  
Hydroxy Esters ◽  
Diastereoselective Reduction

Background:: Chiral β-hydroxy esters and α-substituted β-hydroxy esters represent versatile building blocks for pheromones, β-lactam antibiotics and 1,2- or 1,3-aminoalcohols. Objective:: Synthesis of versatile α-substituted β-keto esters and their diastereoselective reduction to the corresponding syn- or anti-α-substituted β-hydroxy esters. Assignment of the relative configuration by NMR-spectroscopy after a CURTIUS rearrangement of α-substituted β-keto esters to 4-substituted 5-methyloxazolidin-2-ones. Method:: Diastereoselective reduction was achieved by using different LEWIS acids (zinc, titanium and cerium) in combination with complex borohydrides as reducing agents. Assignment of the relative configuration was verified by 1H-NMR spectroscopy after CURTIUS-rearrangement of α-substituted β-hydroxy esters to 4-substituted 5-methyloxazolidin-2-ones. Results:: For the syn-selective reduction, titanium tetrachloride (TiCl4) in combination with a pyridine-borane complex (py BH3) led to diastereoselectivities up to 99% dr. High anti-selective reduction was achieved by using cerium trichloride (CeCl3) and steric hindered reducing agents such as lithium triethylborohydride (LiEt3BH). After CURTIUS-rearrangement of each α-substituted β-hydroxy ester to the corresponding 4-substituted 5-methyloxazolidin-2-one, the relative configuration was confirmed by 1H NMR-spectroscopy. Conclusion:: We have expanded the procedure of LEWIS acid-mediated diastereoselective reduction to bulky α-substituents such as the isopropyl group and the electron withdrawing phenyl ring.

Impact of Acid-Reducing Agents on Gastrointestinal Physiology and Design of Biorelevant Dissolution Tests to Reflect These Changes

2019 ◽  
Vol 108 (11) ◽  
pp. 3461-3477 ◽  
Author(s):  
Domagoj Segregur ◽  
Talia Flanagan ◽  
James Mann ◽  
Andrea Moir ◽  
Eva M. Karlsson ◽  
...  
Keyword(s):  
Reducing Agents ◽  
Gastrointestinal Physiology ◽  
Biorelevant Dissolution ◽  
Dissolution Tests

Controlled synthesis of functional Ag, Ag–Au/Au–Ag nanoparticles and their Prussian blue nanocomposites for bioanalytical applications

RSC Advances ◽  
2015 ◽  
Vol 5 (61) ◽  
pp. 49671-49679 ◽  
Author(s):  
Prem. C. Pandey ◽  
Richa Singh ◽  
Yashashwa Pandey
Keyword(s):  
Prussian Blue ◽  
Ag Nanoparticles ◽  
Active Role ◽  
Reducing Agents ◽  
Controlled Synthesis ◽  
Bioanalytical Applications

A facile method for the synthesis of functional AgNPs and bimetallic Ag–Au/Au–Ag are reported, enabling the formation of nanocomposite with prussian blue in a crystalline framework for bioanalytical applications, showing the active role of organic reducing agents and 3-aminopropyltrimethoxysilane.

scholarly journals The Influence of Water Reducing Agents on Early Hydration Property of Ferrite Aluminate Cement Paste

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 731
Author(s):  
Chunlong Huang ◽  
Zirui Cheng ◽  
Jihui Zhao ◽  
Yiren Wang ◽  
Jie Pang
Keyword(s):  
Setting Time ◽  
Critical Role ◽  
Hydration Product ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Hydration Process ◽  
Early Hydration ◽  
Cement Pastes ◽  
Hydration Rate ◽  
Aluminate Cement

The ferrite aluminate cement (FAC) could rapidly lose fluidity or workability due to its excessive hydration rate, and greatly reduce the construction performance. Chemical admixtures are commonly used to provide the workability of cement-based materials. In this study, to ensure required fluidity of FAC, chemically different water reducing agents are incorporated into the FAC pastes. The experiments are performed with aliphatic water reducing agent (AP), polycarboxylic acid water reducing agent (PC) and melamine water reducing agent (MA), respectively. Influence of the water reducing agents on fluidity, setting time, hydration process, hydration product and zeta potential of the fresh cement pastes is investigated. The results show that PC has a better dispersion capacity compared to AP and MA. Besides decreasing water dosage, PC also acts as a retarder, significantly increasing the setting times, delaying the hydration rate and leading to less ettringite in the hydration process of FAC particles. The water reducing agents molecules are adsorbed on the surface of positively charged minerals and hydration products, however, for PC, steric hindrance from the long side chain of PC plays a critical role in dispersing cement particles, whereas AP and MA acting through an electrostatic repulsion force.

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