We consider the effects of the elastic Thomson scattering between cosmic background radiation (CBR) and primordial molecules, like H2, H2(+), HeH(+), HD, HD(+), LiH, LiH(+): primary CBR anisotropies may be erased or attenuated for angular scales is less than or equal to 10 deg up to 50 deg and frequencies nu is less than or equal to 50 GHz, if LiH primordial abundance exceed 10-10(H). Conversely, CBR anisotropy data may be used to put stringent upper limits on the abundance of primordial elements. Already available data on CBR anisotropies at various frequencies impose primordial LiH abundance to be not larger than 2 x 10-9(H). Secondary anisotropies are expected at arcsecond-arcminute angular scales, due to the anisotropic scattering by moving molecular clouds: they are stronger in the millimetric region and close to be detected in IRAM 200 GHz observations

The possibility to detect cosmological signals from the post{recombination Universe is one of the main aims of modern cosmology. In a previous paper we emphasized the role that elastic resonant scattering through LiH molecules can have in dumping primary CBR anisotropies and raising secondary signals. Here we extend our analysis to all the evolutionary stages of a primordial cloud, starting with the linear phase, through the turn{around and to the non linear collapse. We have done calculations for proto{clouds in a CDM scenario and, more generally, for a set of clouds with various masses and various turn{around redshifts, in this case without referring to any particular structure formation scenario. We found that the rst phase of collapse, for t=t free fall = 0:05 0:2 is the best one for simultaneous detection of the rst two LiH rotational lines. The observational frequency falls between 30 and 250 GHz and the line width is between 10 5 and 10 4 . As far as we know this is the most favourable process to detect primordial clouds before they start star formation processes.

Diversos derivados de Cinchona foram testados como carregadores quirais móveis, para o transporte enantiosseletivo de D,L-fenilglicina e D,L-fenilalanina, através de uma membrana líquida orgânica volumosa (MLV). Os efeitos de vários parâmetros, como natureza do carregador, concentrações do solvente na membrana, do tampão, do soluto e do carregador, no enriquecimento quiral da MLV, foram avaliados. Somente a D,L-fenilglicina foi sujeita, em certo grau, ao transporte enantiosseletivo; a razão máxima de enantiosseletividade (as taxas de transporte iniciais do enantiômero L relativo ao antípoda) foi obtida empregando brometo de O-alil-N-(9-antracenilmetil) cinchonidínio como carregador. Em todos os casos, a seletividade mais alta foi observada durante os estágios iniciais do processo, indicando a taxa de aminoácido liberada da fase fonte (FF) para a fase orgânica da membrana (FM), como fator dirigente. O enriquecimento quiral pareceu depender mais de fatores termodinâmicos do que dos cinéticos, uma vez que a formação do complexo foi observada na interface (FF)/FM), enquanto a decomposição do complexo foi evidenciada na interface (FR)/(FM), onde FR é a fase receptora. O último fenômeno foi promovido pela presença de íons H + na FR. Different cinchona derivatives were tested as chiral mobile carriers for enantioselective transport of D,L-phenylglycine and D,L-phenylalanine through a bulk organic liquid membrane (BLM).The effects of several parameters such as carrier nature, membrane solvent, buffer, solute and carrier concentrations on BLM enrichment were evaluated. Only D,L-phenylglycine is subjected to enantioselective transport at a certain degree; the maximum enantioselectivity ratio (the initial transport rates of the L-enantiomer relative to the antipode) was reached by employing O-allyl-N-(9-anthracenylmethyl)cinchonidinium bromide as carrier. In all cases the highest selectivity was observed during the initial stages of the process, indicating the rate of amino acid release from the source phase (SP) to the membrane organic phase (MP) as the driving factor. Chiral enrichment appeared to depend on thermodynamic factors more than on kinetic ones, since the complex formation was observed at (SP)/MP) interface, while complex decomposition was evidenced at (RP)/(MP) interface, where RP is receiving phase. The last phenomenon was promoted by H + ions present in the RP.

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