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1.
J Phys Condens Matter ; 27(39): 395901, 2015 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-26360383

RESUMEN

Tris-sarcosine calcium chloride (TSCC) is a highly uniaxial ferroelectric with a Curie temperature of approximately 130 K. By suppressing ferroelectricity with bromine substitution on the chlorine sites, pure single crystals were tuned through a ferroelectric quantum phase transition. The resulting quantum critical regime was investigated in detail and was found to persist up to temperatures of at least 30-40 K. The nature of long-range dipole interactions in uniaxial materials, which lead to non-analytical terms in the free-energy expansion in the polarization, predict a dielectric susceptibility varying as 1/T(3)close to the quantum critical point. Rather than this, we find that the dielectric susceptibility varies as 1/T(2) as expected and observed in better known multi-axial systems. We explain this result by identifying the ultra-weak nature of the dipole moments in the TSCC family of crystals. Interestingly, we observe a shallow minimum in the inverse dielectric function at low temperatures close to the quantum critical point in paraelectric samples that may be attributed to the coupling of quantum polarization and strain fields. Finally, we present results of the heat capacity and electro-caloric effect and explain how the time dependence of the polarization in ferroelectrics and paraelectrics should be considered when making quantitative estimates of temperature changes induced by applied electric fields.

3.
J Community Psychol ; 7(3): 187-97, 1979 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10243179

RESUMEN

Over the past three years the Worcester Youth Guidance Center has developed a series of mental health programs directed to the Hispanic community of Worcester, Massachusetts. The model for these programs has been that of strategic intervention. This approach was based upon knowledge gained from the literature and extensive exploratory contacts with key Hispanic leaders. The Center's Hispanic Program consists of five components: (1) community education and training. (2) clinical consultation, (3) program consultation, (4) research, and (5) clinical intervention and case management. This article describes these components in detail and presents a rationale for strategic intervention.


Asunto(s)
Clínicas de Orientación Infantil/organización & administración , Centros Comunitarios de Salud Mental/organización & administración , Servicios Comunitarios de Salud Mental/organización & administración , Servicios de Salud del Indígena , Servicios de Salud , Técnicos Medios en Salud/educación , Niño , Características Culturales , Hispánicos o Latinos , Humanos , Massachusetts , Puerto Rico/etnología , Recursos Humanos
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