The Lion on the Move Towards the World Frontier: Catching Up or Remaining Stuck?

The remarkable growth spurt reported by the Sub-Saharan African (SSA) economy since the mid-1990s offers the opportunity to revisit the narrative of its economic development experience. We investigate whether the SSA economy has initiated a gradual process of convergence which reverses the long-term fall so far behind the U.S. frontier. Our framework begins with a top-down approach that performs a nested development accounting exercise. This aggregate analysis complements a bottom-up approach that tracks the sectoral origins of the SSA aggregate relative labor productivity performance. The application of this framework to a representative sample of the SSA economy over the 1970-2010 period suggests the following set of results. After one-quarter of a century of falling behind the U.S. level of real income per capita, the SSA economy observed a swift turnaround towards the end of the 1990s, yet without showing any sign of catch-up. Second, parallel to favorable demographic developments, SSA reports a startling relative labor productivity gap which accounts for much of its relative income per capita gap. Third, the use of the concept of cognitive skills reveals that human capital considerations have worsened o_ over time, making total factor productivity no longer the biggest part of the story underlying relative labor productivity differences. Fourth, the sectoral evidence points to the coexistence of headwinds (negative within- and reallocation-effects) and tailwinds (between-effects) which tend to cancel out each other, thus preventing SSA aggregate economic performance to get anywhere closer to the world frontier even during the growth spurt period

Micro droplet formation towards continuous nanoparticles synthesis

In this paper, micro droplets are generated in a microfluidic focusing contactor and then they move sequentially in a free-flowing mode (no wall contact). For this purpose, two different micro-flow glass devices (hydrophobic and hydrophilic) were used. During the study, the influence of the flow rate of the water phase and the oil phase on the droplet size and size distribution was investigated. Moreover, the influence of the oil phase viscosity on the droplet size was analyzed. It was found that the size and size distribution of the droplets can be controlled simply by the aqueous phase flow rate. Additionally, 2D simulations to determine the droplet size were performed and compared with the experiment.Marek Wojnicki, Magdalena Luty-Błocho, Volker Hessel, Edit Csapó, Ditta Ungor and Krzysztof Fitzne

The Lion on the Move Towards the World Frontier: Catching Up or Remaining Stuck?

The remarkable growth spurt reported by the Sub-Saharan African (SSA) economy since the mid-1990s offers the opportunity to revisit the narrative of its economic development experience. We investigate whether the SSA economy has initiated a gradual process of convergence which reverses the long-term fall so far behind the U.S. frontier. Our framework begins with a top-down approach that performs a nested development accounting exercise. This aggregate analysis complements a bottom-up approach that tracks the sectoral origins of the SSA aggregate relative labor productivity performance. The application of this framework to a representative sample of the SSA economy over the 1970-2010 period suggests the following set of results. After one-quarter of a century of falling behind the U.S. level of real income per capita, the SSA economy observed a swift turnaround towards the end of the 1990s, yet without showing any sign of catch-up. Second, parallel to favorable demographic developments, SSA reports a startling relative labor productivity gap which accounts for much of its relative income per capita gap. Third, the use of the concept of cognitive skills reveals that human capital considerations have worsened o_ over time, making total factor productivity no longer the biggest part of the story underlying relative labor productivity differences. Fourth, the sectoral evidence points to the coexistence of headwinds (negative within- and reallocation-effects) and tailwinds (between-effects) which tend to cancel out each other, thus preventing SSA aggregate economic performance to get anywhere closer to the world frontier even during the growth spurt period

Sectoral sources of sub-Saharan Africa's convergence

From 1970 to 2010, sub-Saharan African's (SSA) labour productivity hovered at around 6% of the US level. This lacklustre performance, which remained stubbornly low despite the SSA's growth spurt that started in the mid-1990s, masks a great deal of variations across sectors and countries. Using a structural decomposition, we examine, for a representative sample of SSA countries, the sectoral sources that hold back their convergence to the US frontier. Our results suggest the presence of strong - and possibly long-lasting - headwinds that have wiped out the favourable effects of substantial, yet circumstantial, tailwinds. Headwinds, quantified by the unfavourable within- and reallocation-effects, are indicative of significant capital-deepening and technology gaps, both of which are extremely hard to bridge. The tailwinds, represented by favourable between-effects, result from the convergence of the SSA labour force to sectors where some US sectors have seen a slowdown of their productivity relative to that of the whole economy - a development unrelated to the fundamentals underlying the SSA economy. Although few exceptions emerged out of this general pattern, these results are indicative of a bleak outlook for the SSA economic performance at least in the medium run

Strongly Large Module Extensions

In this paper, we introduce strongly large submodules and investigate their properties. A submodule N of a right R-module M is said to be strongly large in case for any m is an element of M, s is an element of R with ms not equal 0 there exists an r is an element of R such that mr is an element of N and mrs not equal 0. In this note, we also define and study strongly large closed submodules and strongly large complement submodules.WoSScopu

Stabilization parameters and smagorinsky turbulence model

For the streamline-upwind/Petrov-Galerkin and pressure-stabilizing/Petrov-Galerkin formulations for flow problems, we present in this paper a comparative study of the stabilization parameters defined in different ways. The stabilization parameters are closely related to the local length scales ("element length"), and our comparisons include parameters defined based on the element-level matrices and vectors, some earlier definitions of element lengths, and extensions of these to higher-order elements. We also compare the numerical viscosities generated by these stabilized formulations with the eddy viscosity associated with a Smagorinsky turbulence model that is based on element length scales

Rings For Which Every Cosingular Module Is Projective

Let R be a ring and M be an R-module. In this paper we investigate modules M such that every (simple) cosingular R-module is M-projective. We prove that every simple cosingular module is M-projective if and only if for N <= T <= M, whenever TAN is simple cosingular, then N is a direct summand of T. We show that every simple cosingular right R-module is projective if and only if R is a right GV-ring. It is also shown that for a right perfect ring R, every cosingular right R-module is projective if and only if R is a right GV-ring. In addition, we prove that if every delta-cosingular right R-module is semisimple, then (Z) over bar (M) is a direct summand of M for every right R-module M if and only if (Z) over bar (delta)(M) is a direct summand of M for every right R-module M.WoSScopu