Transient photon production in a QGP

We discuss the shortcomings of a formula that has been used in the literature to compute the number of photons emitted by a hot or dense system during a finite time, and show that the transient effects it predicts for the photon rate are unphysical.Comment: 4 pages, to appear in the proceedings of Hadron Physics - RANP 2004, Angra dos Reis, Brazi

Feasibility study for a secondary Na/S battery

The feasibility of a moderate temperature Na battery was studied. This battery is to operate at a temperature in the range of 100-150 C. Two kinds of cathode were investigated: (1) a soluble S cathode consisting of a solution of Na2Sn in an organic solvent and (2) an insoluble S cathode consisting of a transition metal dichalcogenide in contact with a Na(+)ion conducting electrolyte. Four amide solvents, dimethyl acetamide, diethyl acetamide, N-methyl acetamide and acetamide, were investigated as possible solvents for the soluble S cathode. Results of stability and electrochemical studies using these solvents are presented. The dialkyl substituted amides were found to be superior. Although the alcohol 1,3-cyclohexanediol was found to be stable in the presence of Na2Sn at 130 C, its Na2Sn solutions did not appear to have suitable electrochemical properties

Integrated Water Resources Management: A Theoretical Exploration of the Implementation Gap Between the Developed and Developing Worlds

As part of its Millennium Development Goals, the United Nations acknowledges that solving the world\u27s water woes requires giving one billion additional people access to safe and affordable drinking water, while also noting that this is a difficult goal to achieve considering present environmental challenges. Amidst this atmosphere of vanishing freshwater, the legislative policy community has begun to encourage diverse discourse on the topic of efficient resource management, but the form and function of such a solution present unique political and theoretical challenges for policymakers and scholars alike. The current consensus among water managers is that a multifaceted policy framework known as Integrated Water Resources Management (IWRM) is the most viable strategy for conserving freshwater resources, and as such, it provides a proactive solution for mitigating future bouts of water scarcity. There is a puzzling disparity in IWRM implementation, however, as developed states have experienced more success with the policy than states within the developing world. IWRM\u27s policy framework establishes a set of concrete goals for water use, including effective demand management, the encouragement of a water-oriented civil society, transparency in the policy creation process, conflict resolution guidelines regarding regional and international water issues, equitable access to water resources, the decentralization of water policy, and the privatization of water provision. Drawing from scholarship on the efficacy of spontaneous, negotiated, and imposed environmental policy regimes, this thesis considers the German, Indian, Canadian, and South African IWRM implementation experiences from the perspectives of the theoretical literatures on regimes, common-pool resources/public goods, privatization, and constructivist arguments about the development and diffusion of transnational human rights norms. While all the literatures prove useful at explaining various facets of the implementation puzzle, it is the scholarship on regimes that offers the most robust explanation of the problem at hand by highlighting the importance of a linear sequence of environmental regime creation, the integration of both decentralized and centralized water governance mechanisms, and the extant character of a region\u27s previous water management regimes as central components that help to explain disparate levels of IWRM implementation success

Classical solution of the wave equation

The classical limit of wave quantum mechanics is analyzed. It is shown that the general requirements of continuity and finiteness to the solution $\psi(x)=Ae^{i\phi(x)}+ Be^{-i\phi(x)}$, where $\phi(x)=\frac 1\hbar W(x)$ and $W(x)$ is the reduced classical action of the physical system, result in the asymptote of the exact solution and general quantization condition for $W(x)$, which yields the exact eigenvalues of the system.Comment: 8 Pages, 10 Refs, LaTe

Hydrogen production by photoelectrolytic decomposition of H2O using solar energy

Photoelectrochemical systems for the efficient decomposition of water are discussed. Semiconducting d band oxides which would yield the combination of stability, low electron affinity, and moderate band gap essential for an efficient photoanode are sought. The materials PdO and Fe-xRhxO3 appear most likely. Oxygen evolution yields may also be improved by mediation of high energy oxidizing agents, such as CO3(-). Examination of several p type semiconductors as photocathodes revealed remarkable stability for p-GaAs, and also indicated p-CdTe as a stable H2 photoelectrode. Several potentially economical schemes for photoelectrochemical decomposition of water were examined, including photoelectrochemical diodes and two stage, four photon processes

Entanglement criteria via the uncertainty relations in su(2) and su(1,1) algebra: detection of non-Gaussian entangled states

We derive a class of inequalities, from the uncertainty relations of the SU(1,1) and the SU(2) algebra in conjunction with partial transposition, that must be satisfied by any separable two-mode states. These inequalities are presented in terms of the su(2) operators J_x, J_y, and the total photon number N_a+N_b. They include as special cases the inequality derived by Hillery and Zubairy [Phys. Rev. Lett. 96, 050503 (2006)], and the one by Agarwal and Biswas [New J. Phys. 7, 211 (2005)]. In particular, optimization over the whole inequalities leads to the criterion obtained by Agarwal and Biswas. We show that this optimal criterion can detect entanglement for a broad class of non-Gaussian entangled states, i.e., the su(2) minimum-uncertainty states. Experimental schemes to test the optimal criterion are also discussed, especially the one using linear optical devices and photodetectors.Comment: published version, presentation polished with references added, 7 pages, 4 figure