RESUMO
The design and validation of a dual polarization source for waveguide-coupled millimeter and sub-millimeter wave cryogenic sensors is presented. The thermal source is a waveguide mounted absorbing conical dielectric taper. The absorber is thermally isolated with a kinematic suspension that allows the guide to be heat sunk to the lowest bath temperature of the cryogenic system. This approach enables the thermal emission from the metallic waveguide walls to be subdominant to that from the source. The use of low thermal conductivity Kevlar threads for the kinematic mount effectively decouples the absorber from the sensor cold stage. Hence, the absorber can be heated to significantly higher temperatures than the sensor with negligible conductive loading. The kinematic suspension provides high mechanical repeatability and reliability with thermal cycling. A 33-50 GHz blackbody source demonstrates an emissivity of 0.999 over the full waveguide band where the dominant deviation from unity arises from the waveguide ohmic loss. The observed thermal time constant of the source is 40 s when the absorber temperature is 15 K. The specific heat of the lossy dielectric, MF-117, is well approximated by C(v)(T) = 0.12 T (2.06) mJ g(-1) K(-1) between 3.5 K and 15 K.
Assuntos
Serviços de Saúde da Criança , Planejamento em Saúde , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estados UnidosRESUMO
PIP: The primary objective of the paper is the implementation of family planning programs in and by the public sector. Providing health service is the category that family planning falls into within public welfare. Only 700,000 patients are now receiving family planning services from all public and private agencies combined. This is only 13% of the target population. All too many policy statments have been made with little done to implement them. The estimation is that in 1966 and 1967 HEW spent about three million dollars on family planning. Public programs have progressed farther through Office of Economic Opportunity than through HEW. Religious sources are the strongest opposition to welfare involvement in family planning. Social work as a profession has a role in family planning to the extent that it considers its role helping people and enhancing family functioning.^ieng
