3 research outputs found
Costa Rica During the Global Recession: Fiscal Stimulus with Tight Monetary Policy
No full textThis paper shows that, in spite of a reasonably sized fiscal stimulus package, Costa Rica’s economy continues on a downward path, partly because fiscal policy is being offset by a tightening of monetary policy. The paper notes that the International Monetary Fund has insisted that Costa Rica’s monetary policy remain tight due to worries over inflation targets and a perceived risk of a balance of payments crisis. However, the author notes that the IMF could help prevent a balance of payments crisis through the provision of a credit line of foreign currency, as it has done, for example, in Mexico – a vastly larger economy. The paper also examines the government’s macroeconomic policies in recent years, prior to the world recession, to see what alternative policies might have done better.Costa Rica, IMF, stimulus
Random alloy growth of AlAs0.08Sb0.92 on GaSb under high Group-V flux condition
No full textThe growth of AlAs(x)Sb(1-x )epilayers with x<0.1 is crucial for various optoelectronic device applications. However, achieving the desired alloy composition and lattice-matched condition remains challenging. In this study, the epitaxial growth of the random alloy AlAsSb on GaSb was investigated using molecular beam epitaxy. The objective was to determine the optimal growth condition to obtain AlAs0.08Sb0.92 on GaSb (lattice-matched to GaSb) with a high growth rate and under a high group-V/III beam equivalent pressure (BEP) ratio. The growth parameters, including the group-V/III BEP ratio, growth rate, and temperature, were studied to monitor the change in the structural properties of the AlAsSb epilayer. It was shown that the As incorporation in AlAsSb was higher than expected at high growth rate and under high Sb BEP condition. The results demonstrated that increasing the growth temperature while decreasing the As BEP did not significantly improve the crystal quality where the optimization of group-V/III BEP ratio and As BEP is effective to obtain AlAs0.08Sb0.92 on GaSb and enhance the crystal quality. The findings provide valuable insights into the growth dynamics of AlAsSb to achieve high quality and lattice-matched epilayers grown on GaSb which is well-suited for a range of optoelectronic applications.Scientific and Technological Research Council of Turkey [121F168]; Council of Higher Education [(Y OK) 100/2000 PhD]; Scientific and Techno-logical Research Council of Turkey [(TUBITAK-B IDEB) 2211-C]; Eskisehir Technical University [23DRP024]This study was supported by the Scientific and Technological Research Council of Turkey TUBITAK (Grant No. 121F168) and by Eskisehir Technical University (Grant No. 23DRP024) . Author Ays e Ayguel Erguerhan have been supported by the Council of Higher Education (Y OK) 100/2000 PhD Scholarship and the Scientific and Techno-logical Research Council of Turkey (TUBITAK-B IDEB) 2211-C
X-ray imaging dosimeter performance in standard and non-standard radiography radiation fields in terms of air kerma
No full textIntroduction X-ray medical imaging developments have introduced needs for updated dosimetry practices. Methods Performance of commercially available dosimeters used for air kerma measurements in diagnostic and interventional radiology was examined. Ionization chambers and X-ray multimeters were tested in a wide range of air kerma rates, photon energies (using standard and non-standard radiation qualities), and angles of incidence with different dosimeter orientation and rotation. Stability and repeatability of the measured value, the influence of pulse duration, non-linearity of dosimeter response, energy and angular dependence were studied against the IEC 61674:2024 limits of variation. Energy response was tested using the standard RQR and RQT radiation qualities defined in IEC 61267:2005, as well as non-standard copper-filtered beams with added 0.9 mm Cu filtration. Results Most dosimeters complied with the IEC 61674:2024 standard limits of variation, for both standard and non-standard radiation fields. In some cases, observed performance was significantly better than the current limits allowing for the introduction of more stringent values. Conclusion Modification of the performance requirements was proposed, considering differences between reference-class and field-class dosimeters, while introducing more stringent requirements for reference-class dosimeters
