Light output simulation of LYSO single crystal

We used the Geant4 simulation toolkit to estimate the light collection in a LYSO crystal by using cosmic muons and E=105 MeV electrons. The light output as a function of the crystal length is studied. Significant influence of the crystal wrapping in the reflective paper and optical grease coupling to the photodetectors on the light output is demonstrated.Comment: 9 pages, 5 figure

Bound state eigenfunctions need to vanish faster than ∣x∣−3/2|x|^{-3/2}

In quantum mechanics students are taught to practice that eigenfunction of a physical bound state must be continuous and vanishing asymptotically so that it is normalizable in $x\in (-\infty, \infty)$. Here we caution that such states may also give rise to infinite uncertainty in position $(\Delta x=\infty)$, whereas $\Delta p$ remains finite. Such states may be called loosely bound and spatially extended states that may be avoided by an additional condition that the eigenfunction vanishes asymptotically faster than $|x|^{-3/2}$.Comment: One Fig. (3 parts), 6 pages, Text around Eq. (13,14) modifie

Gaussian-random Ensembles of Pseudo-Hermitian Matrices

Attention has been brought to the possibility that statistical fluctuation properties of several complex spectra, or, well-known number sequences may display strong signatures that the Hamiltonian yielding them as eigenvalues is PT-symmetric (Pseudo-Hermitian). We find that the random matrix theory of pseudo-Hermitian Hamiltonians gives rise to new universalities of level-spacing distributions other than those of GOE, GUE and GSE of Wigner and Dyson. We call the new proposals as Gaussian Pseudo-Orthogonal Ensemble and Gaussian Pseudo-Unitary Ensemble. We are also led to speculate that the enigmatic Riemann-zeros (${1 \over 2}\pm i t_n)$ would rather correspond to some PT-symmetric (pseudo-Hermitian) Hamiltonian.Comment: Invited Talk Delivered in II International Workshop on `Pseudo-Hermitian Hanmiltonians in Physics' at Prague, June 14-16, 200

Carbon Dioxide Enhanced Oil Recovery

Imperial Users onl

Impact of Global Financial Crisis on IDB Member Countries: The Case of Gulf Cooperation Council and Sub-Saharan Africa

2008 was a challenging year for the Islamic Development Bank (IDB) Group as well as its member countries because of unprecedented crises (food, energy, financial and economic crises). In particular, the ongoing global financial and economic crisis is source of concern for the IDB Group because of the magnitude of its impact on member countries. The banking sector faced unexpected challenges in terms of business growth, profitability, assets quality and liquidity, especially in the Gulf Cooperation Council (GCC) region. The year also witnessed steep fall in the stock markets in GCC and Sub-Saharan Africa (SSA) regions. 2009 is also expected to be another challenging year as the global financial meltdown is causing rising unemployment and pushing more people into the poverty trap. IDB member countries may face a sizable decline in foreign capital inflows both from public and private sources. Due to weakening global economy, economic growth is to decelerate in both GCC and SSA regions. The current account surplus in GCC region is to squeeze, while in SSA region it is likely to turn into deficit. These trends portend a setback for member countries, especially in SSA region in achieving the millennium development goals (MDGs). However, the GCC region is relatively well placed to weather the ongoing financial crisis due to huge oil surpluses accumulated during the last few years, lower public debt levels, and more than one trillion sovereign wealth funds, which have cushioned the adverse impacts on investment plans in the region. In response to these crises, IDB Group has continued to enhance its development assistance and taken a number of special initiatives to help member countries mitigate the adverse impacts of these crises on their socio-economic development. However, economic recovery in member countries in the coming years will critically depend upon the deepness of the economic recession and their policy actions to revive their economies through effective socio-economic reforms. The instruments of Islamic finance can be considered a possible cure for the ailing global financial markets.Global Financial Crisis, IDB Member Countries, Gu lf Cooperation Council, Sub-Saharan Africa