External debt and the reform of the international monetary system

Includes bibliography

Stress distribution in implant-supported prosthesis with external and internal implant-abutment connections

Objective. This study aimed to investigate the stress distribution in screwed implant-supported prostheses with different implant-abutment connections by using a photoelastic analysis. Materials and methods. Four photoelastic models were fabricated in PL-2 resin and divided according to the implant-abutment connection (external hexagon (EH) and Morse taper (MT) implants (3.75 × 11.5 mm)) and the number crowns (single and 3-unit piece). Models were positioned in a circular polariscope and 100-N axial and oblique (45) loading were applied in the occlusal surface of the crowns by using a universal testing machine. The stresses were photographically recorded and qualitatively analyzed using software (Adobe Photoshop). Results. Under axial loading, the MT implants exhibited a lower number of fringes for single-unit crowns than EH implants, whereas for a 3-unit piece the MT implants showed a higher number of fringes vs EH implants. The oblique loading increased the number of fringes for all groups. Conclusion. In conclusion, the MT implant-abutment connection reduced the amount of stress in single-unit crowns, for 3-unit piece crowns the amount of stress was lower using an external hexagon connection. The stress pattern was similar for all groups. Oblique loading promoted a higher stress concentration than axial loading. © Informa Healthcare.

Desarrollo económico y social y las relaciones externas de América Latina = Economic and social development and external relations of Latin America

Incluye Bibliografía

Desarrollo económico y social y las relaciones económicas externas de América Latina = Economic and social development and the external economic relations of Latin America

Incluye Bibliografía

External desequilibrium in the economic development of Latin America: the case of Mexico

Includes bibliography

Latin American development and the international economic situation: second regional appraisal of the international development strategy, part 2: the external economic relations of Latin America and the international situation

Incluye Bibliografía

Políticas de ajuste y renegociación de la deuda externa = Adjustment policies and renegotiation of the external debt

Incluye Bibliografía

Problema de la deuda: gestación, desarrollo, crisis y perspectiva = Problem of the external debt: gestation, development, crisis and prospects = Le probleme de la dette: gestation, evolution, crise et perspectives

Incluye Bibliografía

External economic relations of Latin America in the 1980s

Includes bibliography

Progressive power lens measurement by low coherence speckle interferometry

This work proposes a method for dioptric power mapping of progressive lenses through dual wavelength, low-coherence digital speckle pattern interferometry. Lens characterization finds several applications and is extremely useful in the fields of ophthalmology and astronomy, among others. The optical setup employs two red diode lasers which are conveniently aligned and tuned in order to generate a synthetic wavelength. The resulting speckle image formed onto a diffusive glass plate positioned behind the test lens appears covered of contour interference fringes describing the deformation on the light wavefront due to the analyzed lens. By employing phase stepping and phase unwrapping methods the wavefront phase was retrieved and then expressed in terms of a Zernike series. From this series, expressions for the dioptric power and astigmatic power were derived as a function of the x- and y-coordinates of the lens aperture. One spherical and two progressive lenses were measured. The experimental results presented a good agreement with those obtained through a commercial lensometer, showing the potentialities of the method. © 2013 Elsevier Ltd.