The amino acid composition and preparation of crystals for X ray diffraction analysis of guanylonbonuclease isolated from Streptomyces aureofa­ ciens is described. Single crystals have been grown from ammonium sulphate solutions. The crystals are orthorombic, space group P 2i2]2, cell dimmensions a = 6.47 nm, b = 7.89 nm, c = 3.93 nm. There are two molecules of a molecular weight of 10 600 in t...

We discuss the reorientation of a cylindrically symmetric probe in a biaxial orthorombic medium, such as a biaxial nematic. We write down and solve for the first time the rotational diffusion equation for a rod-like or disc-like uniaxial probe reorienting in a medium of biaxial symmetry. We calculate first and second rank correlation functions both in the uniaxial and biaxial phase, giving the ...

Pulsed laser deposition was used to produce vanadium oxide thin films on oxidized silicon substrates. Structural characterization concluded that the films consisted of two phases, orthorombic V2O5 and triclinc V7O16. Thin films performance as conductometric gas sensors was tested and they were found to be sensitive to ammonia gas already at ppb-level concentrations. Also selectivity of NH3 to N...

On a series of annealed and unannealed InSe thin films which were formerly produced by electrochemical deposition method, organic PMItz semiconductor compound was growth physical vapour (PVD) method. Structural analyses the carried out X-ray diffractometry (XRD) method revealed that glass/ITO/InSe film formed in hexagonal phase while glass/ITO/InSe(annealed) monoclinic In6Se7 orthorombic In4Se3...

The Zn(2+), Cd(2+), Hg(2+), Co(2+) and Ni(2+) ions produce zwitterionic type complexes with the ligands (L), 2-(alpha-hydroxy-benzyl)thiamine=HBT and 2-(alpha-hydroxy-cyclohexyl-methyl)thiamine = HCMT, of the type MLCl(3). The ligands are in the S conformation, the metals are bound to N(1), of the pyrimidine moiety of thiamine and the complexes have a trigonally distorted tetrahedral structure,...

monolithic aerogels of high molecular weight polyethylene (mw= 3x106- 6x106 g/mol) have been prepared by solvent extraction with supercritical carbon dioxide from thermoreversible gels prepared in decalin. these low density and highly porous aerogels present an apparent porosity up to 90%. the aerogel morphology observed by scanning electron microscopy (sem) is characterized by spherulitic stru...

In the present research synthesis of zeolites, merlinoite minerals of natural clinoptiloite mineral in the presence of alkaline mediums, was investigated. The analyzed variants are a result of a concentration of Na+ and K+ ions, temperature and time. Phase transition of clinoptiloite was conducted in the presence of an 8 molar potash solution (KOH) and a 4 molar soda solution (NaOH). Results in...

the reactions of pb(c10 ) , and pb(scn) with meso-5,7,7,12,14,14-hexamethyl- 1,4,8,ll ,tetra-azacyclotetradecane (c ,h ,n = l) yielded colorless crystals of lpb(ci o ) (1) and lpb(ncs) (2), respectively. their structures were determined by x-ray crystallography. crystal data: 1 monoclinic, p 2 /c, a =11.293 (4) ?, b = 16.382 (6) ? , c = 21.518(4) ?, ? = 92.14(2)?, z = 4, moka, 1824 observed (1>...