5 research outputs found
Termodinámica del no equilibrio : La física ante la complejidad del mundo real y el carácter evolutivo del universo
Gracias al notable desarrollo de la física del no equilibrio durante los últimos años hoy podemos conocer cómo la Naturaleza realiza sus estructuras más delicadas y complejas, y cómo la flecha del tiempo puede ser fuente de orden.Instituto de Física de Líquidos y Sistemas Biológico
On the dielectric spectra of proteins in conducting media
The effect of conductivity on the dielectric measurements of proteins is studied. For that purpose the dielectric spectra (0.03–13 MHz) of serum albumin and myoglobin in solutions of varying conductivities were recorded. The results presented confirm that Maxwell's prediction of a threshold frequency in conducting materials also holds for protein solutions. The threshold frequency of a serum albumin solution is experimentally determined and the ionic screening of the electric field when performing dielectric spectra of these samples discussed. Three distinct frequency regions must be considered: a low frequency region where the sample behaves like a conductor; an intermediate region centered around the threshold frequency where the free charges partially screen the fixed charges; and a high frequency region where the sample behaves like a good dielectric. Dielectric measurements in the low frequency region defined above, are not possible.Instituto de Física de Líquidos y Sistemas Biológico
Procesado óptico de datos y su aplicación a geofísica
Se presentan los fundamentos del método de computación óptica y se muestran los resultados obtenidos con un sistema óptico preparado al efecto, que utiliza luz láser coherente, el cual se aplica al filtrado de datos sísmicos y fotografías espaciales.The basis of a method of optical computation are presented, and the results obtained with an optical system especially prepared that uses coherent light from a laser are given, applied to sismic data and spacial pictures.Asociación Argentina de Geofísicos y Geodesta
Grandes catástrofes naturales
Se describe y analiza tanto el proceso como las consecuencias que puede llegar a tener para la vida y nuestra civilización un acontecimiento natural pero de extraordinaria magnitud como lo son: el impacto de un gran asteroide, la erupción de un supervolcán y una megaexplosión solar dirigida hacia la Tierra. Eventos que ya han sucedido en el pasado, en varias ocasiones, con consecuencias seriamente trágicas y que tienen el riesgo de poder volver a repetirse en cualquier momento. Se considera la capacidad y posibilidades que tenemos de prevenir y mitigar tales hechos.It describes and analyzes both the process and the consequences that might have for life and our civilization a natural occurrence but of extraordinary magnitude as they are: the impact of a large asteroid, the eruption of a supervolcano and a solar megaexplosion directed toward the Earth. These events have already happened in the past, on several occasions, with seriously tragic consequences and which are at risk of being able to recur at any time. The capacity and possibilities that we have to prevent and mitigate such events is considered.Este trabajo recibió el “Premio Dr. Eduardo Braun Menéndez” 2012 correspondiente al mejor trabajo de divulgación científica, otorgado por la Asociación Argentina para el Progreso de las Ciencias (AAPC).Facultad de Ciencias Exacta
On the Thermal Stability of DNA in Solution of Mixed Solvents
The study of the changes in UV absorbance of DNA solutions in water/dioxane and water/ethylene glycol mixture at different concentrations shows that the thermal denaturation of DNA is sensitive to the electrical permittivity of the media and the water content. At relative low concentrations of co-solvent the dominant feature is the electrical permittivity. When water content is lower than a critical value, the electrical permittivity is no longer the determinant of the denaturation temperature but the partial volume fraction of water. The critical water content is about 0.69 partial volume fraction of water.Instituto de Física de Líquidos y Sistemas Biológico