Conducão eletrônica e propriedades termodinâmicas da molécula de DNA

In this thesis, we study the thermo-electronic properties of the DNA molecule. For this purpose, we used three types of models with the DNA, all assuming a at geometry (2D), each built by a sequence of quasiperiodic (Fibonacci and / or Rudin-Shapiro) and a sequence of natural DNA, part of the human chromosome Ch22. The first two models have two types of components that are the nitrogenous bases (guanine G, cytosine C, adenine A and thymine T) and a cluster sugar-phosphate (SP), while the third has only the nitrogenous bases. In the first model we calculate the density of states using the formalism of Dyson and transmittance for the time independent Schr odinger equation . In the second model we used the renormalizationprocedure for the profile of the transmittance and consequently the I (current) versus V (voltage). In the third model we calculate the density of states formalism by Dean and used the results together with the Fermi-Dirac statistics for the chemical potential and the quantum specific heat. Finally, we compare the physical properties found for the quasi-periodic sequences and those that use a portion of the genomic DNA sequence (Ch22).

Dinâmica do uso e ocupação do solo no litoral de Macau-RN no período de 1978 a 2008

This study was developed in the northern coast of the city of Macau, a total area of 88,52 km², located in the State of Rio Grande do Norte. It presents relatively plain surface, with interlaced of streams and gamboas, characterized by contributions of oceanic water, flooding areas of swamps. Altogether, the climatic and topographical conditions provide an ideal environment for the development of saline activity. Inserted in the geologic context of the Potiguar Basin, the region presents favorable conditions for the production of hydro-carbons. It still presents natural conditions for shrimp breeding and artisanal fishing. This work analyzes the transformations occurred in the land use, using air photographs of 1978, Landsat 5 ETM Images of 1988, 1998 and 2008. A secular analyzes was carried through the dynamics of the use of the territory and the transformations occurred in the landscape due to the increment of the productive activities. In the survey of the data for study of the area, it was verified that little alteration occurred in the 30 years. The saline activity that was present since the year of 1978 having an increase of about 5% in thirty years; the shrimp breeding activity that had its presence in the decade of 1990, presented a high growth in the land use, therefore in 1998 it presented 0.45% and currently it presents 6.59%. In the field it was observed that great areas used previously for the saline activity, today it is prepared for shrimp breeding and that the areas of petroleum exploration occupy salt mines, beaches and trays. In 1988 it presented a percentage of 0, 07% and currently it occupies 0.46%, having grown 50% in the last 10 years. Although the variation of the occupation of the area has been little expressive, shrimp breeding showed a growth of 1,200% in only 10 years. In regards to petroleum activity, there wasn t any demonstration of an increasing impact in the land use in the area of study in 26 years of exploration