72 research outputs found

    YOUTH EMPLOYMENT IN AFRICA: NEW EVIDENCE AND POLICIES FROM SWAZILAND

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    Drawing on the 2007 and 2010 Swaziland Labor Force Surveys, this paper provides first systematic evidence on recent youth employment challenges in Swaziland, a small, land-locked, middle-income country with one of the highest youth unemployment rates in Africa. The paper first documents the various labor market disadvantages faced by the Swazi youth, such as high unemployment and discouragement, and how they changed from 2007 to 2010. A multinomial logit regression analysis is then carried out to analyze the socio-economic drivers of the unfavorable youth labor market outcomes on the supply side. Since many of the factors that can unlock the employment potential of the Swazi youth are on the demand side of the labor market, the paper examines the barriers to job creation and youth entrepreneurship. It concludes with experiences of other countries that could inform design of more effective interventions for youth employment in Swaziland.http://deepblue.lib.umich.edu/bitstream/2027.42/133071/1/wp1052.pd

    Isoscalar giant monopole strength in 58^{58}Ni, 90^{90}Zr, 120^{120}Sn and 208^{208}Pb

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    Inelastic α\alpha-particle scattering at energies of a few hundred MeV and very-forward scattering angles including 0∘0^\circ has been established as a tool for the study of the isoscalar giant monopole (IS0) strength distributions in nuclei. An independent investigation of the IS0 strength in nuclei across a wide mass range was performed using the 0∘0^\circ facility at iThemba Laboratory for Accelerator Based Sciences (iThemba LABS), South Africa, to understand differences observed between IS0 strength distributions in previous experiments performed at the Texas A\&M University (TAMU) Cyclotron Institute, USA and the Research Center for Nuclear Physics (RCNP), Japan. The isoscalar giant monopole resonance (ISGMR) was excited in 58^{58}Ni, 90^{90}Zr, 120^{120}Sn and 208^{208}Pb using α\alpha-particle inelastic scattering with 196196 MeV α\alpha beam and scattering angles θLab=0∘\theta_{\text{Lab}} = 0^\circ and 4∘4^\circ. The K600600 magnetic spectrometer at iThemba LABS was used to detect and momentum analyze the inelastically scattered α\alpha particles. The IS0 strength distributions in the nuclei studied were deduced with the difference-of-spectra (DoS) technique including a correction factor for the 4∘4^\circ data based on the decomposition of L>0L > 0 cross sections in previous experiments. IS0 strength distributions for 58^{58}Ni, 90^{90}Zr, 120^{120}Sn and 208^{208}Pb are extracted in the excitation-energy region Ex=9−25E_{\rm x} = 9 - 25 MeV.Using correction factors extracted from the RCNP experiments, there is a fair agreement with their published IS0 results. Good agreement for IS0 strength in 58^{58}Ni is also obtained with correction factors deduced from the TAMU results, while marked differences are found for 90^{90}Zr and 208^{208}Pb.Comment: 12 pages, 10 figures, regular article submitted to PR

    Fine structure of the isoscalar giant monopole resonance in 58^{58}Ni, 90^{90}Zr, 120^{120}Sn and 208^{208}Pb

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    Over the past two decades high energy-resolution inelastic proton scattering studies were used to gain an understanding of the origin of fine structure observed in the isoscalar giant quadrupole resonance (ISGQR) and the isovector giant dipole resonance (IVGDR). Recently, the isoscalar giant monopole resonance (ISGMR) in 58^{58}Ni, 90^{90}Zr, 120^{120}Sn and 208^{208}Pb was studied at the iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) by means of inelastic α\alpha-particle scattering at very forward scattering angles (including 0∘0\circ). The good energy resolution of the measurement revealed significant fine structure of the ISGMR.~To extract scales by means of wavelet analysis characterizing the observed fine structure of the ISGMR in order to investigate the role of different mechanisms contributing to its decay width. Characteristic energy scales are extracted from the fine structure using continuous wavelet transforms. The experimental energy scales are compared to different theoretical approaches performed in the framework of quasiparticle random phase approximation (QRPA) and beyond-QRPA including complex configurations using both non-relativistic and relativistic density functional theory. All models highlight the role of Landau fragmentation for the damping of the ISGMR especially in the medium-mass region. Models which include the coupling between one particle-one hole (1p-1h) and two particle-two hole (2p-2h) configurations modify the strength distributions and wavelet scales indicating the importance of the spreading width. The effect becomes more pronounced with increasing mass number. Wavelet scales remain a sensitive measure of the interplay between Landau fragmentation and the spreading width in the description of the fine structure of giant resonances.Comment: 13 pages,7 figures, regular articl

    Towards Room Temperature Thermochromic Coatings with controllable NIR-IR modulation for solar heat management & smart windows applications

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    Solar heat management & green air-conditioning are among the major technologies that could mitigate heat islands phenomenon while minimizing significantly the CO2 global foot-print within the building & automotive sectors. Chromogenic materials in general, and thermochromic smart coatings especially are promising candidates that consent a noteworthy dynamic solar radiation Infrared (NIR-IR) regulation and hence an efficient solar heat management especially with the expected increase of the global seasonal temperature. Within this contribution, two major challenging bottlenecks in vanadium oxide based smart coatings were addressed. It is validated for the first time that the NIR-IR modulation of the optical transmission (∆TTRANS = T(T〈TMIT) − T(T〉TMIT) of Vanadium oxide based smart coatings can be controlled & tuned. This upmost challenging bottle-neck controllability/tunability is confirmed via a genuine approach alongside to a simultaneous drastic reduction of the phase transition temperature TMIT from 68.8 °C to nearly room temperature. More precisely, a substantial thermochromism in multilayered V2O5/V/V2O5 stacks equivalent to that of standard pure VO2 thin films but with a far lower transition temperature, is reported. Such a multilayered V2O5/V/V2O5 thermochromic system exhibited a net control & tunability of the optical transmission modulation in the NIR-IR (∆TTRANS) via the nano-scaled thickness’ control of the intermediate Vanadium layer. In addition, the control of ∆TTRANS is accompanied by a tremendous diminution of the thermochromic transition temperature from the elevated bulk value of 68.8 °C to the range of 27.5–37.5 ºC. The observed remarkable and reversible thermochromism in such multilayered nano-scaled system of V2O5/V/V2O5 is likely to be ascribed to a noteworthy interfacial diffusion, and an indirect doping by alkaline ions diffusing from the borosilicate substrate. It is hoped that the current findings would contribute in advancing thermochromic smart window technology and their applications for solar heat management in glass windows in general, skyscraper especially & in the automotive industry. If so, this would open a path to a sustainable green air-conditioning with zero-energy input
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