calix(6)arene hydroxamic acids (iii) are synthesised for the first time by reactingcalix(6)arene acid chloride(ii) with substituted hydroxylamines at low temperature in the presence ofsodium bicarbonate. the p-carboxycalix(6)arene(i) is obtained by an acid catalysed condensationreaction of p-hydroxybenzoic acid and formaldehyde. these calixarenes are characterised by meltingpoint, uv, ir, 1h nm...

background: there are great interests in photocatalytic oxidation of contaminants using titanium dioxide in recent years. the main objective of this research was to study photocatalytic disinfection of coliform bacteria as water microbial pollution index using tio2 and a low pressure uv lamp in a batch reactor. methods: the polluted water was prepared by adding a colony of coliform in raw water...

The current study belongs to a series of studies promoted by the EU funded project “PASION”, which focuses on augmenting social presence. The underlying assumptions to this series is that participants’ interventions in the shared environment represent a way to exhibit their being socially present in that environment. Therefore, the practices organizing these interventions define “when”, “why” a...

the current study aimed to detect the presence of helicobacter pylori in some water systems in egypt as well as in blood samples of patients suffering from stomach ulcers.fifty-one water samples collected from some egyptian governorates; giza, alexandria, monofia, beheira, minya, sohag, was subjected to physical and chemical analysis. urease gene urec, a highly specific sequence in h. pylori dn...

Despite the intense interest in the phenomena of presence, there have been limited attempts to explain the fundamental reason why human beings can feel presence when they use media and/or simulation technologies. This is mainly because previous studies on presence have focused on “what” questions—what are the causes and effects of presence?—rather than the “why” question. The current paper trie...