The Preparation of Hexamethylcyclotriphosphazene

1975 ◽  
Vol 53 (20) ◽  
pp. 3038-3039 ◽  
Author(s):  
Richard T. Oakley ◽  
Norman L. Paddock
Keyword(s):  
High Yield ◽  
Simple Method ◽  
Principal Product ◽  
Methylamine Hydrochloride

Dimethyltrichlorophosphorane reacts with methylamine hydrochloride to give an oil which decomposes on heating, yielding the quaternary chloride N3P3Me6·MeCl as the principal product. The controlled pyrolysis of this salt gives N3P3Me6 in high yield. A simple method for the separation of N3P3Me6 and N4P4Me8 is described, based on the different solubilities of their salts in acetonitrile.

scholarly journals Microwave-Assisted Combustion Synthesis of ZnO Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
M. Kooti ◽  
A. Naghdi Sedeh
Keyword(s):  
Electron Microscopy ◽  
Zno Nanoparticles ◽  
Combustion Method ◽  
Zinc Nitrate ◽  
High Yield ◽  
Fast Method ◽  
Simple Method ◽  
X Ray ◽  
Microwave Assisted ◽  
Average Size

A new and simple method was applied for the synthesis of ZnO nanoparticles with an average size of 20 nm. In this microwave-assisted combustion method, glycine as a fuel and zinc nitrate as precursor were used. The final product was obtained very fast with high yield and purity. The synthesized nanoscale ZnO was characterized by X-ray Diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FT-IR). The size and morphology of the ZnO nanoparticles have been determined by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. This is a simple and fast method for the preparation of ZnO nanoparticles with no need for expensive materials or complicated treatments.

PREPARATION OF HUMAN GROWTH HORMONE

1961 ◽  
Vol 23 (3) ◽  
pp. 285-NP ◽  
Author(s):  
A. L. C. WALLACE ◽  
K. A. FERGUSON
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
High Yield ◽  
Pituitary Hormone ◽  
Simple Method ◽  
Anterior Pituitary Hormone ◽  
Epiphysial Cartilage ◽  
Diethylaminoethyl Cellulose ◽  
Hypophysectomized Rats

SUMMARY A simple method for the preparation of human growth hormone using chromatography on diethylaminoethyl-cellulose is described. Material prepared in this way, when assayed by growth of the tibial epiphysial cartilage in hypophysectomized rats, is at least as active as material prepared by published methods and is obtained in high yield. The only other anterior pituitary hormone activity present in any concentration is prolactin.

The synthesis of some novel N-chloro-Δ1-4-azasteroids by efficient N-chlorination of azasteroid lactams with trichloroisocyanuric acid

1991 ◽  
Vol 69 (9) ◽  
pp. 1482-1486 ◽  
Author(s):  
Thomas G. Back ◽  
Joseph H.-L. Chau ◽  
Brian P. Dyck ◽  
Patricia L. Gladstone
Keyword(s):  
Key Words ◽  
High Yield ◽  
Principal Product ◽  
Chloro Derivative ◽  
Trichloroisocyanuric Acid

The preparation of N-chloro-Δ1-4-azasteroids 2a–2c from lactams 1a–1c was achieved conveniently and in high yield with trichloroisocyanuric acid. The treatment of 20β-hydroxy-4-aza-5α-pregn-1-en-3-one (1d) with this reagent produced the less stable N-chloro compound 2d, which reacted further to afford 4-aza-5α-pregn-1-en-3,20-dione (4) as the principal product. The similar chlorination of 4-azacholest-5-en-3-one (5) occurred at C-6, giving 6-chloro-4-azacholest-5-en-3-one (6). Photolysis of N-chloro-4-aza-5α-cholest-1-en-3-one (2a) in methanol produced the transient N-acyl imine 7, which was trapped by the solvent to afford 5-methoxy-4-azacholest-1-en-3-one (8), along with 4-azacholesta-1,5-dien-3-one (9) and its 6-chloro derivative 10. Key words: N-chloroazasteroid, Δ1-4-azasteroid, N-chloro-Δ1-4-azasteroid, trichloroisocyanuric acid, N-chlorination.

Fabrication of Silver Nanoparticle Decorated AFM Tips for Tip-Enhanced Raman Scattering Applications

2013 ◽  
Vol 643 ◽  
pp. 195-198 ◽  
Author(s):  
Yu Hua Li ◽  
Chang Hui Xu ◽  
Min Han
Keyword(s):  
Gas Phase ◽  
Silver Nanoparticle ◽  
Enhancement Factor ◽  
High Yield ◽  
Raman Signal ◽  
Simple Method ◽  
Atomic Force ◽  
Afm Tips ◽  
Enhanced Raman Scattering ◽  
Tip Enhanced Raman Spectroscopy

We report on a simple method for the fabrication of metalized tips by depositing gas-phase synthesized silver nanoparticles onto atomic force microscope (AFM) tips. The method enables fabricating tips suitable for AFM based tip-enhanced Raman spectroscopy (TERS) with high yield. The performance of the fabricated silver nanoparticle decorated tips is examined by detecting low concentration BPE molecules using a transmission mode TERS setup. An 30-fold enhancement of the Raman signal is shown. The net TERS enhancement factor is calculated to be about 1000.

scholarly journals Efficient method for Knoevenagel condensation in aqueous solution of amino acid ionic liquids (AAILs)

2016 ◽  
Vol 18 (4) ◽  
pp. 90-95 ◽  
Author(s):  
Paula Ossowicz ◽  
Zbigniew Rozwadowski ◽  
Marcin Gano ◽  
Ewa Janus
Keyword(s):  
Ionic Liquids ◽  
Amino Acid ◽  
Knoevenagel Condensation ◽  
High Yield ◽  
Technological Parameters ◽  
Simple Method ◽  
Water As Solvent ◽  
Catalyst Content ◽  
Natural Amino Acids ◽  
Amino Acid Ionic Liquid

Abstract This work reports on the use of the amino acid ionic liquids (AAILs) which have been used as catalysts in Knoevenagel condensation of various aldehydes with malononitrile. For research we use tetrabutylammonium ionic liquids based on eight natural amino acids. The reaction was carried out in an aqueous medium. Using water as solvent provided efficient and simple method of isolation of pure product with high yield. Moreover, amino acid ionic liquid dissolved in water could be reused many times without any loss of its catalytic activity. The influence of the anion was studied. Moreover the effect of technological parameters such as: the temperature, the catalyst content, and the reaction time on yield of reaction were investigated.

scholarly journals Human plasma kallikrein. A rapid purification method with high yield

1981 ◽  
Vol 193 (1) ◽  
pp. 187-192 ◽  
Author(s):  
H Nagase ◽  
A J Barrett
Keyword(s):  
Human Plasma ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
High Yield ◽  
Gel Chromatography ◽  
Purification Method ◽  
Simple Method ◽  
Bean Trypsin Inhibitor ◽  
Rapid Purification ◽  
Sepharose 4B

A simple method for isolation of kallikrein from human plasma is described. Before activation of the enzyme with acetone, the plasma was treated with 0.2 M-methylamine at pH 8.2 to inactivate alpha 2-macroglobulin and thus prevent the irreversible binding of the active enzyme to the inhibitor. The enzyme was adsorbed on soya-bean trypsin inhibitor-Sepharose 4B and eluted with 5 mM-NaOH, pH 11.3. It was further purified by immunoadsorption of contaminating proteins, and gel chromatography on Ultrogel AcA 44. About 3 mg of kallikrein was obtained from 400 ml of plasma (35% yield). The purified enzyme was shown to be homogeneous by electrophoretic and immunological criteria. The specific activities against benzyloxycarbonylphenylalanylarginine methylcoumarylamide, prolylphenylalanylarginine methylcoumarylamide and tosylarginine methyl ester were higher than any previously reported. The purified enzyme was resolved into two forms of mol.wts. 88 000 and 86 000 in sodium dodecyl sulphate/polyacrylamide-gel electrophoresis without reduction. Each consisted of three chains linked by disulphide bonds, one containing the reactive serine residue (mol.wt. 36 000 or 34 000), and two additional chains (mol.wt. 28 000 and 22 000).

A simple method for high yield fabrication of sharp silicon tips

2008 ◽  
Vol 85 (3) ◽  
pp. 625-630 ◽  
Author(s):  
D.P. Burt ◽  
P.S. Dobson ◽  
L. Donaldson ◽  
J.M.R. Weaver
Keyword(s):  
High Yield ◽  
Simple Method

Influence of Growth Conditions on the Formation of Fish-Bone GNFs by CVD Using Ni Foam as Catalyst

2007 ◽  
Vol 121-123 ◽  
pp. 153-158
Author(s):  
W.Z. Huang ◽  
X.B. Zhang ◽  
F.Z. Kong ◽  
Y. Li ◽  
D. Lu ◽  
...  
Keyword(s):  
Gas Flow ◽  
Bone Structure ◽  
Growth Conditions ◽  
Fish Bone ◽  
High Yield ◽  
Growth Time ◽  
Hydrogen Treatment ◽  
Ni Foam ◽  
Simple Method ◽  
Optimized Conditions

GNFs with fish-bone structure were first produced by a simple method. To optimize the growth conditions, different hydrogen treatment of the catalyst, different growth time and growth temperature, as well as different gas flow rate were employed. The effects of these growth conditions on the morphology and yield of GNFs were studied in details. It is found that fish-bone GNFs with high yield and high purity can be produced under the optimized conditions.

A simple method for evaluating the safety of high-yield criteria

1986 ◽  
Vol 15 (4) ◽  
pp. 439-444 ◽  
Author(s):  
Robert L Wears ◽  
Donald R Kamens
Keyword(s):  
High Yield ◽  
Simple Method ◽  
Yield Criteria

scholarly journals Flexible transparent electrodes based on silver nanowires synthesized via a simple method

2017 ◽  
Vol 4 (9) ◽  
pp. 170756 ◽  
Author(s):  
De Li ◽  
Tao Han ◽  
Lei Zhang ◽  
Huai Zhang ◽  
Hui Chen
Keyword(s):  
Silver Nanowires ◽  
Cost Effective ◽  
Silver Nanowire ◽  
Vinyl Pyrrolidone ◽  
High Yield ◽  
Transparent Electrodes ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Uv Visible ◽  
Poly Vinyl Pyrrolidone

Silver nanowires (Ag NWs) with the length of approximately 60 µm and the diameter of approximately 300 nm are prepared via a simple, cost-effective, high-yield and eco-friendly procedure under a high molar concentration ratio of silver nitrate (AgNO 3 ) solution to poly(vinyl pyrrolidone) solution. The pre-synthesized Ag NWs were analysed by scanning electron microscopy, X-ray diffraction and UV–visible spectrophotometer. Furthermore, the as-prepared silver nanowires were roll-coated on the surfaces of the polyethylene terephthalate (PET) substrates. By optimizing the concentration of silver nanowire solution, the flexible Ag NW/PET transparent electrodes with a sheet resistance of 3.8 Ω sq −1 at a transmittance of 70% can be fabricated. The results reported in this paper provide a basis for optimizing the growth of silver nanowires and performances of transparent electrodes.

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