High power N2 laser with a modified gas flow system and discharge geometry

A high power Nz laser of the double-Blumlein type having a modified gas flow system, electrode configuration, and discharge geometry with minimum inductance is described. By incorporating a triggere’d-pressurized spark gap switch, arc-free operation was achieved for a wide E/P range. The device gives a peak power in excess of 700 kW with a FWHM of 3 ns and an efficiency of 0.51%, which is remarkably high for a pulsed nitrogen laser system. The dependence of output power on parameters such as operating pressure, voltage, and repetition rate are discussed.

Photoemission optogalvanic effect studies in N2, NO2 and Ar discharges under pulsed laser excitation

A two-photon induced photoemission optogalvanic effect which brings about a change in the discharge voltage when a pulsed dye laser beam is focused on a tungsten electrode has been described. The experiment is performed with N2, NO2 and Ar discharges. The magnitude of the signal voltage is studied as a function of laser energy and discharge current. The effective quantum efficiency in the discharge is found to be larger than that in the vacuum condition.

Photoemission optogalvanic effect studies in N2, NO2 and Ar discharges under pulsed laser excitation

A two-photon induced photoemission optogalvanic effect which brings about a change in the discharge voltage when a pulsed dye laser beam is focused on a tungsten electrode has been described. The experiment is performed with N2, NO2 and Ar discharges. The magnitude of the signal voltage is studied as a function of laser energy and discharge current. The effective quantum efficiency in the discharge is found to be larger than that in the vacuum condition.

High resolution optogalvanic spectrum of N2-rotational structure of (11, 7) band in the first positive system

High resolution optogalvanic spectrum of the (11, 7) band in the first positive system of nitrogen molecule has been recorded from 17179 to 17376 cm- 1. Assignment of 432 rotational lines belonging to the 27 branches of this band has been carried out.

Fabrication And Parametric Measurements Of N2 Laser Pumped Dye Laser And Its Application To Energy Transfer Studies In Mixed Dyes

Eventhough a large number of schemes have been proposed and develoned for N9 laser ouined dye lasers the relatively low efficiency compelled the scientists to device new methods to improve the system efficiencs. Energy transfer mechanism has been shown to he a convenien tool for the enhancement of efficiency of dye lasers. Th p resent work covers a detailed study of the performance characteristics of a N2 laser pumped dye laser in the con— ventional mode and also, when pumped by the energy transfer mechanism. For .th.e present investigations a dye laser pumped by a'N2 laser (A4200 kw peak power) was fabricated. The grating at grazing incidence was used as the beam expanding device; A t its best performance the system was giving an output peak power of l5 kW for a 5 X lC"3H/l Rh—€ solution in methanol. T he conversion efficiency was 7.5; The output beam was having 3 divergence of 2 mrad and bandwidth o.9 A. Suitable modifications were suggested for obtaining better conversion efficiency and bandwidth.

Conseguir la educación primaria universal : objetivo nõ2 de los Objetivos de Desarrollo del Milenio : infantil.

Manos Unidas durante su campaña Objetivos de Desarrollo del Milenio elabora materiales educativos para ofrecer a los profesores del curso 2006-2007. Este material tiene como objetivo lograr para el año 2015 la educación primaria universal. Estos materiales se realizan para los niveles de infantil, primaria y secundaria y se componen fundamentalmente de actividades dinámicas, fácilmente aplicables en la clase y que ofrecen a los docentes recursos que permiten trabajar en el aula la educación en valores y la educación para el desarrollo. Los materiales constan de una carpeta-caja para cada uno de los niveles de enseñanza. La carpeta de infantil contiene un cuaderno con documentación y actividades, un cuadernillo en color con cuentos relacionados con valores, y seis carteles tamaño A3 con estos mismos cuentos.

Conseguir la educación primaria universal : objetivo nõ2 de los objetivos de Desarrollo del Milenio : Primaria.

Manos Unidas durante su campaña Objetivos de Desarrollo del Milenio elabora materiales educativos para ofrecer a los profesores del curso 2006-2007. Este material tiene como objetivo lograr para el año 2015 la educación primaria universal. Estos materiales se realizan para los niveles de infantil, primaria y secundaria y se componen fundamentalmente de actividades dinámicas, fácilmente aplicables en la clase y que ofrecen a los docentes recursos que permiten trabajar en el aula la educación en valores y la educación para el desarrollo. Los materiales constan de una carpeta-caja para cada uno de los niveles de enseñanza. La carpeta de primaria está formada por un cuaderno con documentación y actividades, un cuadernillo en color con cuentos relacionados con valores y con el objetivo que se trabaja este año, doce pósters tamaño A3 con estos mismos cuentos, y dos pósters tamaño A2 que reflejan el tema de lograr la educación primaria universal .

Conseguir la educación primaria universal : objetivo nõ2 de los Objetivos de Desarrollo de Milenio : Secundaria.

Manos Unidas durante su campaña Objetivos de Desarrollo del Milenio elabora materiales educativos para ofrecer a los profesores del curso 2006-2007. Este material tiene como objetivo lograr para el año 2015 la educación primaria universal. Estos materiales se realizan para los niveles de infantil, primaria y secundaria y se componen fundamentalmente de actividades dinámicas, fácilmente aplicables en la clase y que ofrecen a los docentes recursos que permiten trabajar en el aula la educación en valores y la educación para el desarrollo. Los materiales constan de una carpeta-caja para cada uno de los niveles de enseñanza. El material para secundaria consiste en un cuaderno con documentación y actividades, un DVD con dos documentales para trabajar en la clase los objetivos de este año, y dos pósters tamaño A2 sobre los Objetivos de Desarrollo del Milenio y el objetivo de este año.

Free atmospheric CO2 enrichment increased above ground biomass but did not affect symbiotic N2-fixation and soil carbon dynamics in a mixed deciduous stand in Wales

Through increases in net primary production (NPP), elevated CO2 is hypothesizes to increase the amount of plant litter entering the soil. The fate of this extra carbon on the forest floor or in mineral soil is currently not clear. Moreover, increased rates of NPP can be maintained only if forests can escape nitrogen limitation. In a Free atmospheric CO2 Enrichment (FACE) experiment near Bangor, Wales, 4 ambient CO2 and 4 FACE plots were planted with patches of Betula pendula, Alnus glutinosa and Fagus sylvatica on a former arable field. Four years after establishment, only a shallow L forest floor litter layer had formed due to intensive bioturbation. Total soil C and N contents increased irrespective of treatment and species as a result of afforestation. We could not detect an additional C sink in the soil, nor were soil C stabilization processes affected by FACE. We observed a decrease of leaf N content in Betula and Alnus under FACE, while the soil C/N ratio decreased regardless of CO2 treatment. The ratio of N taken up from the soil and by N2-fixation in Alnus was not affected by FACE. We infer that increased nitrogen use efficiency is the mechanism by which increased NPP is sustained under elevated CO2 at this site.

Nonlinear symmetric stability of planetary atmospheres

The energy–Casimir method is applied to the problem of symmetric stability in the context of a compressible, hydrostatic planetary atmosphere with a general equation of state. Formal stability criteria for symmetric disturbances to a zonally symmetric baroclinic flow are obtained. In the special case of a perfect gas the results of Stevens (1983) are recovered. Finite-amplitude stability conditions are also obtained that provide an upper bound on a certain positive-definite measure of disturbance amplitude.

Folding of graphene slit like pore walls—a simple method of improving CO2 separation from mixtures with CH4 or N2

We report for the first time a detailed procedure for creating a simulation model of energetically stable, folded graphene-like pores and simulation results of CO2/CH4 and CO2/N2 separation using these structures. We show that folding of graphene structures is a very promising method to improve the separation of CO2 from mixtures with CH4 and N2. The separation properties of the analyzed materials are compared with carbon nanotubes having similar diameters or S/V ratio. The presented results have potential importance in the field of CO2 capture and sequestration.

Paulistana nº2 de Cláudio Santoro : uma análise musical

O objetivo deste artigo é o de analisar a organização rítmica de uma obra para piano do compositor brasileiro Cláudio Santoro. A análise da obra denominada Paulistana n.º 2 – Tempo de Catira – apoia-se na fundamentação teórica postulada por Grosvenor Cooper & Leonard Meyer (1960). Este trabalho alia os pressupostos teóricos fundamentados em estudos recentes sobre o ritmo e sua organização, em agrupamentos e em níveis hierárquicos com o propósito de delinear uma interpretação musical. Neste contexto, as considerações teóricas são utilizadas para entender a partitura. Os dois pólos, o teórico e o prático, são complementares e juntos contribuem para um entendimento musical equilibrado.