Electron fluence perturbation by gap-shaped and by cylindrical gas-filled ionization chambers with axes normal to the beam

For electron beam absorbed dose measurements using gas-ionization chamber, a perturbation correction factor has been defined to correct for the disturbance of the fluence. For a gap-shaped cavity, a revised perturbation factor is derived. The range of validity of the calculations is extended over that of a previous study. The direct calculations for cylindrical cavities are very difficult. Instead, the form of the cylinder is approximated by a square parallelepiped. Comparison with Monte Carlo calculations showed good agreement.     

The influence of chitosan and some of its depolymerized grades on natural color printing

Chitosan samples with different molecular weights were prepared using sodium nitrite in acidic medium. These samples were practically confirmed by measuring nitrogen content and average molecular weight. The chitosan samples were applied to cotton fabric by the pad dry method. The pretreated cotton fabric was printed with natural coloring matter, curcumin. The color yield of the prints increased by increasing the molecular weight of chitosan. Both wet and dry rubbing fastness of the prints was good. The stiffness results of the printed cotton fabric pretreated with low molecular weight chitosan showed better performance. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 559–563, 2005     

Detection of Streptococcus macedonicus in Greek cheeses

The aim of the present work was the detection and enumeration of Streptococcus macedonicus in Greek traditional cheeses. A total of 68 traditional cheese samples have been examined. Enumeration was performed by plating on the S. macedonicus differential medium Bromothymol Blue Streptococcus macedonicus (BBSM). Detection of S. macedonicus was confirmed by species-specific polymerase chain reaction (PCR), using as template either cheese DNA or DNA from colonies isolated from the BBSM medium. Counts of S. macedonicus on BBSM medium ranged from less than 1 to 6.84 log cfu g^?1. S. macedonicus has been detected in 15 samples out of the 68 tested, corresponding to 13 out of the 20 different cheese varieties examined, originating from various geographical areas in Greece. This indicates that S. macedonicus is widespread in Greek cheeses. However, its presence could not be correlated either with the cheese variety or the cheese manufacturing procedures.     

Organophosphoryl ethanolamine analogues II. Synthesis of methyl-N,N-dipropyl and piperidyl phosphonamidic acid esters

A series of phosphonamidic acid esters, containing ethanolamine analogue moieties, P-O-CH₂CH₂NRR¹, have been synthesised, as potential anticholinesterases. The infra-red spectral data confirm the chemical structure of the prepared compounds.     

Monk seal mortality: virus or toxin?

During the past few months, more than half of the total population of about 300 highly endangered Mediterranean monk seals (Monachus monachus) on the western Saharan coast of Africa, died in a mysterious disease outbreak. Epizootiological and postmortem findings were reminiscent of similar outbreaks amongst pinniped and cetacean species in recent years, which were caused by an infection with newly discovered morbilliviruses (for review see osterhaus et al.). Virological, as well as toxicological, analysis performed on tissue samples collected from relatively fresh carcasses during the outbreak indicate that infection with a virus closely related to dolphin morbillivirus (DMV), possibly originating from affected dolphins in the same area, was the primary cause of the outbreak. Therefore it is concluded that vaccination with a safe and effective non-replicating vaccine should be considered as a management tool in the conservation of Mediterranean monk seals.     

Effekt of Using a Starter Culture Grown on Soy Milk Medium on some Properties of “Ras” Cheese

Ras cheese was manufactured using a starter culture grown on soy milk medium. Resultant cheese was compared with that resulted by using the ordinary starter culture grown on skim milk medium. The use of the former starter resulted in increasing cheese acidity, total volatile fatty acids, formol and SCHILOVICH ripening indices throughout the ripening period. Also higher total bacterial number and lactic acid bacterial number were observed.     

Dielectric relaxation of monoesters based poly(styrene-co-maleic anhydride) copolymer

A series of alkyl-grafted copolymers based on styrene-maleic anhydride (SMA) copolymers were synthesized by esterification of SMA with several long chain normal aliphatic alcohols. The prepared copolymers were characterized by FT-IR and ¹H NMR and DSC. The dielectric behavior of these copolymers was investigated in the frequency 20–10⁵ Hz and temperature −40 to 180 °C ranges. Two relaxation processes were observed, α, and β-relaxation. The former is associated with the glass-rubber transition and is characterized by the Vogel–Fulcher–Tammann temperature dependence and the latter relaxation is related to the local motion of the ester side groups attached to the polymer backbone. The apparent activation energy for the β-relaxation was found to depend significantly on the alkyl chain length. The dielectric analysis of the β-relaxation process detected is discussed.     

Anodic oxidation and self-polarization of zinc metal

X-ray diffraction techniques have been applied to study the structural changes and processes which take place when zinc metal is subjected to oxidation and self-polarization at the metal-electrolyte interface. The effect of electrolyte concentration and anodizing voltage on the structure and composition of the ZnO layer formed was investigated.