Dual laser excitation of a photochromic system: application to DODCI

A technique based on a combination of pump-and-probe fluorescence and absorption detection was developed in order to obtain the emission parameters of the pholoisomeric (P) species of dyes with noncompletely overlapped absorption spectra of P and the starting species (N ). Near total population transfer to the ground state of P was achieved using a continuous wave high fluence pump laser. A pulsed laser probed this population in its absorption region in such a way that the pulsed emission corresponded to fluorescence from P. Absorption measurements allowed us to follow the P population and to establish its relationship with pump fluence and wavelength. The direct monitoring of the P concentration increased the accuracy of the previously reported values for several photophysical parameters. Temperature dependent fluorescence quantum yield and lifetime, emission spectrum, and Arrhenius parameters of the nonradiative decay processes of P from 3,3' diethyloxa dicarbocyanine iodide (DODCI) are given. The mechanism for the direct transformation between N and P through the singlet excited states of DODCI is reevaluated

Q-switched all-fiber laser based on magnetostriction modulation of a Bragg grating

We report an actively Q-switched all-fiber laser based on magnetostriction modulation of a Bragg grating. The laser employs a pair of Bragg gratings as reflective mirrors, one of which is bonded to a magnetostrictive element. Lengthening of the magnetostrictive element when a magnetic field is applied shifts the Bragg wavelength of the grating, allowing control of the Q-factor of the cavity and, thus, performing active Q-switching. The magnetostrictive modulator is small, compact and requires less than 300 mW electrical drive power. Using erbium-doped fiber and a maximum pump power of 120 mW, Q-switch pulses of more than 1 W peak power were obtained, with a pulse repetition rate that can be continuously varied from 1 Hz to 125 kHz

An Improved QSPR Modeling of Hydrocarbon Dipole Moments

Dipole moments of hydrocarbons are not an easy property to model with conventional 2D descriptors. A comparison of the performance of the most commonly used sets of topological descriptors is presented, each set containing descriptors derived from the regular and Detour distance matrix, Electrotopological State Indices, and the basic number of atoms of each type and bonds. Data were taken on a representative set of 35 hydrocarbon dipole moments previously reported and the classical multivariable regression analysis for establishing the models is employed

QSAR study and molecular design of open-chain enaminones as anticonvulsant agents

Present work employs the QSAR formalism to predict the ED50 anticonvulsant activity of ringed-enaminones, in order to apply these relationships for the prediction of unknown open-chain compounds containing the same types of functional groups in their molecular structure. Two different modeling approaches are applied with the purpose of comparing the consistency of our results: (a) the search of molecular descriptors via multivariable linear regressions; and (b) the calculation of flexible descriptors with the CORAL (CORrelation And Logic) program. Among the results found, we propose some potent candidate open-chain enaminones having ED50 values lower than 10 mg·kg-1 for corresponding pharmacological studies. These compounds are classified as Class 1 and Class 2 according to the Anticonvulsant Selection Project.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

Análisis geoquímico de la calidad de agua en el Valle de Chaschuil-Catamarca

El agua es uno de los recursos más significativos de consumo en todo el planeta y especialmente en zonas áridas, como las localidades del departamento Tinogasta, donde las áreas de cultivos presentan una actividad alternativa para el desarrollo de la región. Dado que la cantidad y calidad de agua disponible para diferentes usos es variable, la calidad de agua del acuífero fue evaluado para el uso en cultivos. Por ello, se realizó un estudio para analizar la distribución espacial del acuífero de acuerdo a los parámetros de calidad y para identificar lugares con la mejor calidad basado en el análisis fisicoquímico de las muestras. Los resultados fueron comparados con los valores recomendados por la Organización Mundial de la Salud para el consumo y salud público. Del análisis realizado se puede clasificar las muestras como Aceptable para el riego con moderada restricción de uso, teniendo en cuenta la concentración de carbonatos/bicarbonatos encontrada.Water is one of the most significant consumption resources in the whole planet, especially in arid areas, such as the localities from Tinogasta Department, where crop areas represent an alternative activity for regional development. Since the quantity and quality of water available for different uses is variable, water quality of the aquifer was evaluated for use in crops. Therefore, a study was carried out to analyze the spatial distribution of the aquifer according to quality parameters and to identify places with the best quality based on the physicochemical analysis of the samples. Results were compared with the values recommended by the World Health Organization for public health and consumption. From the analysis carried out, the samples could be classified as acceptable for irrigation with moderate restriction of use, taking into account the carbonate / bicarbonate concentration found.Fil: Ortiz, Erlinda del Valle. Universidad Nacional de Catamarca. Facultad de Tecnología y Ciencias Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Niz, Adriana Edith. Universidad Nacional de Catamarca. Facultad de Tecnología y Ciencias Aplicadas; ArgentinaFil: Savio, M. E.. Universidad Nacional de Catamarca. Facultad de Tecnología y Ciencias Aplicadas; ArgentinaFil: Lamas, C. A.. Universidad Nacional de Catamarca. Facultad de Tecnología y Ciencias Aplicadas; ArgentinaFil: Barbieri, N. R.. Universidad Nacional de Catamarca. Facultad de Tecnología y Ciencias Aplicadas; ArgentinaFil: Duchowicz, Pablo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

OCT in Applications That Involve the Measurement of Large Dimensions

The application of optical coherence tomography (OCT) technique is not very common when measuring large dimensions is required. This type of measurements can be critical to achieve satisfactory results in the manufacturing process of precision parts. Components and structures ranging from submillimeter to several centimeters size can be found in many fields including automotive, aerospace, semiconductor, and data storage industries to name a few. In this chapter, an interferometric system based on the swept source optical coherence tomography (SS-OCT) technique, which has a wide measurement range and good axial resolution, is presented and its constituent parts are analyzed. The scheme includes a self-calibration stage based on fiber Bragg gratings (FBGs) that allows monitoring the spectral position of the light source in each scan, having the advantage of being a passive system that requires no additional electronic devices. Several applications of the system are described, including measurement of distances up to 17 cm, characterization of multilayer transparent and semitransparent structures, simultaneous determination of thickness of the wall, internal and external diameter of glass ampoules or similar containers, thickness measurements in opaque samples or where the refractive index is unknown, etc

QSAR study and molecular design of open-chain enaminones as anticonvulsant agents

Present work employs the QSAR formalism to predict the ED50 anticonvulsant activity of ringed-enaminones, in order to apply these relationships for the prediction of unknown open-chain compounds containing the same types of functional groups in their molecular structure. Two different modeling approaches are applied with the purpose of comparing the consistency of our results: (a) the search of molecular descriptors via multivariable linear regressions; and (b) the calculation of flexible descriptors with the CORAL (CORrelation And Logic) program. Among the results found, we propose some potent candidate open-chain enaminones having ED50 values lower than 10 mg·kg-1 for corresponding pharmacological studies. These compounds are classified as Class 1 and Class 2 according to the Anticonvulsant Selection Project.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

Hydrogeological analysis of water quality in the Valle de Chaschuil – Catamarca

El agua es uno de los recursos más significativos de consumo en todo el planeta y especialmente en zonas áridas, como las localidades del departamento Tinogasta, donde las áreas de cultivos presentan una actividad alternativa para el desarrollo de la región. Dado que la cantidad y calidad de agua disponible para diferentes usos es variable, la calidad de agua del acuífero fue evaluado para el uso en cultivos. Por ello, se realizó un estudio para analizar la distribución espacial del acuífero de acuerdo a los parámetros de calidad y para identificar lugares con la mejor calidad basado en el análisis fisicoquímico de las muestras. Los resultados fueron comparados con los valores recomendados por la Organización Mundial de la Salud para el consumo y salud público. Del análisis realizado se puede clasificar las muestras como Aceptable para el riego con moderada restricción de uso, teniendo en cuenta la concentración de carbonatos/bicarbonatos encontrada.Water is one of the most significant consumption resources in the whole planet, especially in arid areas, such as the localities from Tinogasta Department, where crop areas represent an alternative activity for regional development. Since the quantity and quality of water available for different uses is variable, water quality of the aquifer was evaluated for use in crops. Therefore, a study was carried out to analyze the spatial distribution of the aquifer according to quality parameters and to identify places with the best quality based on the physicochemical analysis of the samples. Results were compared with the values recommended by the World Health Organization for public health and consumption. From the analysis carried out, the samples could be classified as acceptable for irrigation with moderate restriction of use, taking into account the carbonate / bicarbonate concentration found.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

Hydrogeological analysis of water quality in the Valle de Chaschuil – Catamarca

El agua es uno de los recursos más significativos de consumo en todo el planeta y especialmente en zonas áridas, como las localidades del departamento Tinogasta, donde las áreas de cultivos presentan una actividad alternativa para el desarrollo de la región. Dado que la cantidad y calidad de agua disponible para diferentes usos es variable, la calidad de agua del acuífero fue evaluado para el uso en cultivos. Por ello, se realizó un estudio para analizar la distribución espacial del acuífero de acuerdo a los parámetros de calidad y para identificar lugares con la mejor calidad basado en el análisis fisicoquímico de las muestras. Los resultados fueron comparados con los valores recomendados por la Organización Mundial de la Salud para el consumo y salud público. Del análisis realizado se puede clasificar las muestras como Aceptable para el riego con moderada restricción de uso, teniendo en cuenta la concentración de carbonatos/bicarbonatos encontrada.Water is one of the most significant consumption resources in the whole planet, especially in arid areas, such as the localities from Tinogasta Department, where crop areas represent an alternative activity for regional development. Since the quantity and quality of water available for different uses is variable, water quality of the aquifer was evaluated for use in crops. Therefore, a study was carried out to analyze the spatial distribution of the aquifer according to quality parameters and to identify places with the best quality based on the physicochemical analysis of the samples. Results were compared with the values recommended by the World Health Organization for public health and consumption. From the analysis carried out, the samples could be classified as acceptable for irrigation with moderate restriction of use, taking into account the carbonate / bicarbonate concentration found.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

Hydrogeological analysis of water quality in the Valle de Chaschuil – Catamarca

El agua es uno de los recursos más significativos de consumo en todo el planeta y especialmente en zonas áridas, como las localidades del departamento Tinogasta, donde las áreas de cultivos presentan una actividad alternativa para el desarrollo de la región. Dado que la cantidad y calidad de agua disponible para diferentes usos es variable, la calidad de agua del acuífero fue evaluado para el uso en cultivos. Por ello, se realizó un estudio para analizar la distribución espacial del acuífero de acuerdo a los parámetros de calidad y para identificar lugares con la mejor calidad basado en el análisis fisicoquímico de las muestras. Los resultados fueron comparados con los valores recomendados por la Organización Mundial de la Salud para el consumo y salud público. Del análisis realizado se puede clasificar las muestras como Aceptable para el riego con moderada restricción de uso, teniendo en cuenta la concentración de carbonatos/bicarbonatos encontrada.Water is one of the most significant consumption resources in the whole planet, especially in arid areas, such as the localities from Tinogasta Department, where crop areas represent an alternative activity for regional development. Since the quantity and quality of water available for different uses is variable, water quality of the aquifer was evaluated for use in crops. Therefore, a study was carried out to analyze the spatial distribution of the aquifer according to quality parameters and to identify places with the best quality based on the physicochemical analysis of the samples. Results were compared with the values recommended by the World Health Organization for public health and consumption. From the analysis carried out, the samples could be classified as acceptable for irrigation with moderate restriction of use, taking into account the carbonate / bicarbonate concentration found.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta