Multiplication Operators on Weighted Banach Spaces of a Tree

We study multiplication operators on the weighted Banach spaces of an infinite tree. We characterize the bounded and the compact operators, as well as determine the operator norm. In addition, we determine the spectrum of the bounded multiplication operators and characterize the isometries. Finally, we study the multiplication operators between the weighted Banach spaces and the Lipschitz space by characterizing the bounded and the compact operators, determine estimates on the operator norm, and show there are no isometries

The Mystery of Capital and the Construction of Social Reality

John Searle’s The Construction of Social Reality and Hernando de Soto’s The Mystery of Capital shifted the focus of current thought on capital and economic development to the cultural and conceptual ideas that underpin market economies and that are taken for granted in developed nations. This collection of essays assembles 21 philosophers, economists, and political scientists to help readers understand these exciting new theories

Striving for Higher Impacts in Agricultural Research and Development

Over the years, substantial investments in agricultural research have been made in sub-Saharan Africa. The few studies on research investments show impressive returns that are comparable to those achieved in developed countries. However, problems such as recurrent hunger, poverty, food insecurity and natural resource degradation continue to plague the region. Agricultural development arena is changing rapidly toward non-linear innovation systems of complex actor networks and multiple sources of innovations characterized by dynamic and iterative learning processes that constantly inform, renew and advance the state of the systems. Most actors and institutions are not linked effectively often from imaginary boundaries created by prescribed mandates and parochial interests. While more investments in research and development are required for the region, it is becoming increasingly difficult to justify them in the wake of competing needs in the face of shrinking national budgets. The few impact assessments that have been carried out in the region have been incidental and not linked to the research planning cycle implying that lessons from previous research efforts are not used when planning for subsequent research and development efforts. We are proposing impact orientation to track impact to the attainment of institutional and overall development goals. This calls in part for impact assessment to be made an integral part of planning, monitoring and evaluation along with appreciation of the impact chain and actors involved in the innovation process to demonstrate relevance to development goals and thus justify funding.Research and Development/Tech Change/Emerging Technologies,

Rationalization and Harmonization of Seed Policies and Regulations in Eastern and Central Africa: Effecting Policy Change through Private Public Partnerships

Cereal grains are important staple foods in Africa but yields are still too low at 1.5 tons per ha for maize while compared with a global average of 4.5 tons per ha. This can be partly attributed to limited development of commercial seed markets, low use of improved seeds, small and highly fragmented seed markets. Many released varieties are not widely disseminated due to closed national markets dominated by a few international companies and parastatals, and restrictive laws, regulations and policies. Transactions costs within and across national boundaries are high because of differing arrangements across countries. Establishment of common regulatory structures is expected to reduce transactions costs and promote increased trade and hence use of improved seeds. This paper describes the process, results, experiences and lessons learned in developing and operationalizing a seed trade harmonization system in eastern and central Africa. It is clear that the public-private partnerships can play a pivotal role in catalyzing, facilitating and supporting the establishment, development and strengthening of national and regional seed trade. By building partnerships and wide participation, the project was able to apply lessons learned from older to newer countries. The technical, political and legislative processes in the policy-change-cycle are equally important and optimal outcomes must be based on trade-offs between technical issues and interests of the stakeholders.Seeds, harmonization, public-private partnerships, eastern Africa, Crop Production/Industries, Q18, Q19,

Analysis of opposed jet hydrogen-air counter flow diffusion flame

A computational simulation of the opposed-jet diffusion flame is performed to study its structure and extinction limits. The present analysis concentrates on the nitrogen-diluted hydrogen-air diffusion flame, which provides the basic information for many vehicle designs such as the aerospace plane for which hydrogen is a candidate as the fuel. The computer program uses the time-marching technique to solve the energy and species equations coupled with the momentum equation solved by the collocation method. The procedure is implemented in two stages. In the first stage, a one-step forward overal chemical reaction is chosen with the gas phase chemical reaction rate determined by comparison with experimental data. In the second stage, a complete chemical reaction mechanism is introduced with detailed thermodynamic and transport property calculations. Comparison between experimental extinction data and theoretical predictions is discussed. The effects of thermal diffusion as well as Lewis number and Prandtl number variations on the diffusion flame are also presented

Modeling of hydrogen-air diffusion flame

Work performed during the first six months of the project duration for NASA Grant (NAG-1-861) is reported. An analytical and computational study of opposed jet diffusion flame for the purpose of understanding the effects of contaminants in the reactants and thermal diffusion of light species on extinction and reignition of diffusion flames is in progress. The methodologies attempted so far are described

Core-crust transition in neutron stars: predictivity of density developments

The possibility to draw links between the isospin properties of nuclei and the structure of compact stars is a stimulating perspective. In order to pursue this objective on a sound basis, the correlations from which such links can be deduced have to be carefully checked against model dependence. Using a variety of nuclear effective models and a microscopic approach, we study the relation between the predictions of a given model and those of a Taylor density development of the corresponding equation of state: this establishes to what extent a limited set of phenomenological constraints can determine the core-crust transition properties. From a correlation analysis we show that a) the transition density $\rho_t$ is mainly correlated with the symmetry energy slope $L$, b) the proton fraction $Y_{p,t}$ with the symmetry energy and symmetry energy slope $(J,L)$ defined at saturation density, or, even better, with the same quantities defined at $\rho=0.1$ fm$^{-3}$, and c) the transition pressure $P_t$ with the symmetry energy slope and curvature $(J,K_{\rm sym})$ defined at $\rho=0.1$ fm$^{-3}$