N.m.r. of solid biopolymers

The dynamical behaviour of four solid polypeptides (α-chymotrypsin, insulin, lysozyme, ribonuclease A) has been investigated by proton magnetic relaxation. The interpretation was supplemented by measurements on the constituent amino acids, and on dipeptides, tripeptides and homopolypeptides. The following motions were identified and characterized: methyl group reorientation, segmental motion, sidechain motion, proline ring puckering, reorientation of water molecules in the structure. Slow motions were investigated through measurements of the dipolar relaxation time T_ID.     

M.A.L.D.I.-T.O.F. mass spectrometry characterization of 4-alkyl substituted phenol-formaldehyde novalac type resins

Two methods of synthesis for 4-alkyl substituted phenol-formaldehyde resins are described. A common method for synthesis of novolac type phenol-formaldehyde resin uses sulfuric acid catalyst in the presence of xylene for azeotropic removal of water of reaction. By the use of M.A.L.D.I.-T.O.F. mass spectrometry we have demonstrated that m-xylene is incorporated into these polymers. Polymers free of impurities are best prepared using a cation exchange resin as catalyst in the presence of a less reactive solvent, e.g. chlorobenzene, or in the absence of solvents. © 1997 Elsevier Science Ltd.     

Simulation of M.S.F. desalination plants

A simulation program on the modeling of MSF desalination plants has been developed by the author (ref. 1). The program can be used to accurately either design or simulate plants in actual operation. Proprietory computer programs have been originated by a number of desalination designers for their own use. A few general ones have been published (refs. 2 & 3).The paper describes the design and modeling philosophy utilized in developing the said program. A typical application on Al-Khobar (Phase-I) MSF desalination plant is briefly illustrated as an example for the use of simulation mode of the code.