To study the permeability of oxygen through a membrane of silver (thickness 0.13 mm) and the definition of parameters, it has designed and constructed a reactor formed by a cone silver membrane inserted into a cylindrical glass tube borosilicate. This assembly is assembled within a cylindrical thermostated oven electronically. The membrane reactor was conentado to an oxygen tank, and two peristaltic pump mercury manometer, enabling control of inflow of methanol, the temperature and internal pressure and desorption of the permeated oxygen. With this device have been performed subsequent studies of oxidative reactions in primary alcohols.

In the context of atmospheric chemistry, two reactions radical-molecule of hydrogen abstraction have been studied. These are the OH' and NO3: radical (oxidizers agents in the troposphere) with formaldehyde in gas-phase. The calculations were carried out using the PM3 and <>. Ab initio methods of the UHF type. The results have allowed us to estimate the corresponding times of tropospheric permanency and the implications of these reactions in the removal of forrnaldehyde and similars from the low atmosphere.

Diverse structures have been studied involved in the initial stages of polymerization and of copolymerization with different positions of the bridges divinilbenceno (DVB) between two styrene polymers chains. The energy of the optimized geometries and vibrational frequencies calculated with methods HF and PM3 have shown that the conformation sindiotactic present the minimum of energy in relation to their similar isotactic and atactic. In the resin of exchange cationics the structures with minima of energy correspond those with bridges in intermediate positions in front of those of near or far away bridges.

The objective of this work has been to study the behavior of the one correlation energy functional Ec=[ño(R),ñ2o(R),{z}], through the calculation the dissociation energy in molecules of the series methane - tetrachloromethane (Ch4-nCln) obtained from the group of G2 molecules. The functional, once incorporate to the program Gaussian 92/DFT has been used to develop comparative monoconfigurational calculations with the method G2 implemented in the versions Gaussian 98 and 03. The results show a growing error with relationship to the increment of chlorine atoms, or the same thing with the number of electrons (N). In this sense, the functional show that the dependence with N can be improved.

With the objective of establishing a diffusion model of oxygen permeability and methanol oxidation with silver membrane, we develop experiments under controlled conditions of flow, temperature and pressures. The results of the products analyses with physical methods, VIS, IR and GC, have shown that the oxidation happens from a proportional way to the increment of the oxygen permeability and to the respective conditions.

The electronic energy and geometric parameters have been calculated, for the Phthalocyanine (Pc), Naphthalocyanine (Nc), Anthracenocyanine (Anc), ZnPc, ZnNc, ZnAnc, CuPc, CuNc and CuAnc. Obtained the results with Hartree-Fock (RHF/6-31G *) calculations show that certain correlation exists between the size of the system p-extended and the distances of the internal cavity. A minimum variation of the dihedral angles exists showing in general a planar tendency in all the structures.

lt has been designed and built a conductimeter that operates with alternating current of 700 mÅ, 7.85 V and frequency among 50 - 60 Hz. For the voltage measures and amperage, a digital multimeter CIE- 123 with 2000 mΩ. Two electrodes were used, one built with two bars of amorphous coal and another of platinum normalized. For comparative ends, a normalized conductimeter Hanna HI98129 has been used. The values of conductivity obtained according to the official protocols, they are compatible with the references them and the comparison apparatus.

To study the permeability of oxygen through a membrane of silver (thickness 0.13 mm) and the definition of parameters, it has designed and constructed a reactor formed by a cone silver membrane inserted into a cylindrical glass tube borosilicate. This assembly is assembled within a cylindrical thermostated oven electronically. The membrane reactor was conentado to an oxygen tank, and two peristaltic pump mercury manometer, enabling control of inflow of methanol, the temperature and internal pressure and desorption of the permeated oxygen. With this device have been performed subsequent studies of oxidative reactions in primary alcohols.

In the context of atmospheric chemistry, two reactions radical-molecule of hydrogen abstraction have been studied. These are the OH' and NO3: radical (oxidizers agents in the troposphere) with formaldehyde in gas-phase. The calculations were carried out using the PM3 and <>. Ab initio methods of the UHF type. The results have allowed us to estimate the corresponding times of tropospheric permanency and the implications of these reactions in the removal of forrnaldehyde and similars from the low atmosphere.

Diverse structures have been studied involved in the initial stages of polymerization and of copolymerization with different positions of the bridges divinilbenceno (DVB) between two styrene polymers chains. The energy of the optimized geometries and vibrational frequencies calculated with methods HF and PM3 have shown that the conformation sindiotactic present the minimum of energy in relation to their similar isotactic and atactic. In the resin of exchange cationics the structures with minima of energy correspond those with bridges in intermediate positions in front of those of near or far away bridges.

El objetivo de este trabajo ha sido estudiar el comportamiento del funcional de energía de correlación Ec=[ño(R),ñ2o(R),{z}], a través del cálculo de las energías de disociación en moléculas de la serie metano - tetraclorometano (CH4-nCln), obtenidas a partir del conjunto de moléculas G2. El funcional, una vez incorporado al programa Gaussian 92/DFT, ha sido utilizado para desarrollar cálculos monoconfiguracionales comparativos con los del método G2, implementados en las versiones Gaussian 98 y 03. Los resultados muestran un error creciente con relación al incremento de átomos de cloro, lo mismo que con el número de electrones (N). En este sentido, el funcional muestra que la dependencia con N puede ser mejorada.

Con el objetivo de establecer un modelo de difusión o permeación de oxigeno y oxidación de metanol con membrana de plata, desarrollamos experimentos bajo condiciones controladas de flujo, temperatura y presiones. Los resultados de los análisis de los productos por métodos físicos, VIS, IR y GC, han mostrado que la oxidación sucede de manera proporcional al incremento del oxigeno permeabilizado y a las condiciones respectivas.

Se han calculado las energías electrónicas y parámetros geométricos para la Ftalocianina (Pc), Naftalocianina (Nc), Antracenocianina (Anc), ZnPc, ZnNc, ZnAnc, CuPc, CuNc y CuAnc. Los resultados obtenidos con cálculos Hartree-Fock (RHF/6-31G*) muestran que existe cierta correlación entre el tamaño del sistema p-extendido y las distancias de la cavidad interna. Existe una variación mínima de los ángulos diedros, manteniéndose en general una tendencia planar en todas las estructuras.

lt has been designed and built a conductimeter that operates with alternating current of 700 mÅ, 7.85 V and frequency among 50 - 60 Hz. For the voltage measures and amperage, a digital multimeter CIE- 123 with 2000 mΩ. Two electrodes were used, one built with two bars of amorphous coal and another of platinum normalized. For comparative ends, a normalized conductimeter Hanna HI98129 has been used. The values of conductivity obtained according to the official protocols, they are compatible with the references them and the comparison apparatus.

The presence of copper in nature is due to natural or anthropogenic sources. Because Peruvian law limits set quite low and instrumental techniques have limitations ultratrace levels , a method of preconcentration of aqueous samples of copper ( 11) with commercial cation exchange resin of the PS- DVB- S03H type is proposed and a batch system or " batch ." it worked with concentrations from 100 ppm to 0.01 ppm. the procedure followed is the same as determined by atomic absorption precedente2 article ( EAAF) and elution with 6N HCl , gave recoveries acceptable , obtaining an average percent recovery of about 85 % with a standard deviation of 3%.

La presencia del cobre en la naturaleza se debe a fuentes naturales o antropogénicas. Debido a que las leyes peruanas establecen límites bastante bajos y las técnicas instrumentales tienen limitaciones a niveles de ultratrazas, se propone un método de preconcentración de muestras acuosas de cobre (11) con resina de intercambio catiónico comercial del tipo PS-DVB-S03H y en un sistema por lotes o "batch'. Se trabajaron con concentraciones desde 100 ppm hasta 0,01 ppm. El procedimiento seguido es el mismo que el establecido en un artículo precedente2 por absorción atómica (EAAF) y la elución con HCl-6N dio recuperaciones aceptables, obteniéndose un porcentaje de recuperación promedio de alrededor de 85% con una desviación estándar del 3%.

The objective of this work has been to develop a procedure for the determination of the concentration of chitosan in powder samples, by capillary viscosimetry of Ostwald (capillary of 0.55 ± 0.02 mm internal diameter). Standard chitosan solutions between 461 mg/liter up to 9138 mg/liter and pH 1.24 were prepared for all cases. Tests were also carried out at temperatures between 20° to 50°C, observing linearity with the concentration until before 9138 mg/liter. The most important dependence was the relative viscosity (ηr) versus the concentration (concordant with the Poiseuille equation) which in the range 461 mg/liter to 2808 mg/liter gave a linear dependence with r2= 0.995, enabling the analysis of samples for the content of chitosan with consistent results and comparable with the referentials.