RESUMO
We present a summary of the physical principles and design of the Dynamic Albedo of Neutrons (DAN) instrument onboard NASA's 2009 Mars Science Laboratory (MSL) mission. The DAN instrument will use the method of neutron-neutron activation analysis in a space application to study the abundance and depth distribution of water in the martian subsurface along the path of the MSL rover.
Assuntos
Laboratórios , Marte , Nêutrons , Voo Espacial/instrumentação , United States National Aeronautics and Space Administration , Hidrogênio/análise , Análise Numérica Assistida por Computador , Solo/análise , Estados UnidosRESUMO
The portable pulsed neutron generators developed and designed by VNIIA are presented. The neutron methods are good tools for non-destructive assay of dangerous materials. The samples of various systems for the detection of high explosives in luggage, identification of toxic agents in chemical munitions, and also for the prevention of illicit trafficking of fissile elements in passengers' luggage are discussed.
Assuntos
Terrorismo Químico/prevenção & controle , Substâncias Perigosas/análise , Análise de Ativação de Nêutrons/métodos , Explosões/prevenção & controle , Análise de Ativação de Nêutrons/instrumentação , Fissão Nuclear , Radioisótopos/análiseRESUMO
A physical model describing in detail the process of fast neutron imaging in luminescent screens is presented. The detection quantum efficiency, luminosity and inherent spatial resolution of the screen were calculated using this model. Properties of transparent and disperse screens were compared. Two imaging systems were suggested to improve the detection efficiency and spatial resolution. A stack consisting of alternating neutron converters and image plates can help in obtaining both high spatial resolution and efficiency. A system containing a screen of special form and a diaphragm can be of use especially in the case of the fan beam.
RESUMO
Cell factors of nonspecific immunity were estimated in 99 patients with different stages of melanoblastoma by delayed hypersensitivity skin test to tuberculin and DNCB (2,4-dinitrochlorobenzene). The skin test to DNCB is found to correlate with the clinical manifestations of the disease, while the skin test to tuberculin is not related with the degree of tumor spread. It is considered not rational to use the test concerned to define one of the immune cell factors in patients with melanoblastoma during the tumor progression.
