A broad line NMR and MRI study of water and water transport in Portland cement pastes.

The results of a magnetic resonance spin-spin relaxation analysis and broad-line magnetic resonance imaging (MRI) (gradient-echo and stray-field imaging) study of water and water transport in Portland cement pastes are presented. The effect of varying the cure conditions and the water to cement (w/c) ratio of the sample of mix are discussed. The water sorptivity and the concentration dependence of the hydraulic diffusion coefficient are calculated for samples prepared with a 0.5 w/c ratio and, therefore, an open pore structure. In the case of 0.3 w/c ratio samples, little water transport is observed, and a closed pore structure is inferred.

[Seroprevalence of anti-HIV antibodies in a rural Haitian population]. / Etude de la séroprévalence des anticorps anti-VIH dans une population rurale haitienne.

A sero-epidemiological study was conducted from July to August 1988, in a haitian population living in rural area. Out of 116 serum samples searched for H1V1 antibodies and anti-HTLV1, 5.2% and 4.3% were reactive, respectively. Both positivity H1V1/HTLV1 was observed in one case. HBs Ag carriers were 13%. Analysis of seroreactive people in this population enhances the epidemiological trends of AIDS in Caribbean (rural spreading, heterosexual transmission, sex ratio levelling) which relate to african type AIDS.