Bio-medical flow sensor

A bio-medical flow sensor including a packageable unit of a bottle, tubing and hypodermic needle which can be pre-sterilized and is disposable. The tubing has spaced apart tubular metal segments. The temperature of the metal segments and fluid flow therein is sensed by thermistors and at a downstream location heat is input by a resistor to the metal segment by a control electronics. The fluids flow and the electrical power required for the resisto to maintain a constant temperature differential between the tubular metal segments is a measurable function of fluid flow through the tubing. The differential temperature measurement is made in a control electronics and also can be used to control a flow control valve or pump on the tubing to maintain a constant flow in the tubing and to shut off the tubing when air is present in the tubing

Electrophotolysis oxidation system for measurement of organic concentration in water

Methods and apparatus for determining organic carbon in aqueous solution are described. The method comprises subjecting the aqueous solution to electrolysis, for generating oxygen from water, and simultaneously to ultraviolet radiation, for oxidation of substantially all organic carbon to carbon dioxide. The carbon dioxide is measured and the value is related to the concentration of organic carbon in the aqueous solution

High-spin low-spin transition

Temperature dependent nuclear inelastic-scattering (NIS) of synchrotron radiation was applied to investigate both spin states of the spin-crossover complex [Fe(tpa)(NCS)(2)] (tpa = tris(2-pyridylmethyl)amine). A remarkable increase of the iron-ligand bond stretching upon spin crossover has unambiguously been identified by comparing the measured NIS spectra with theoretical simulations based on density-functional calculations

Building financial institutions in developing countries

Financial development and financial institution building are important prerequisites for economic growth. However, both the potential and the problems of institution building are still vastly underestimated by those who design and fund institution building projects. The paper first underlines the importance of financial development for economic growth, then describes the main elements of “serious” institution building: the lending technology, the methodological approaches, and the question of internal structure and corporate governance. Finally, it discusses three problems which institution building efforts have to cope with: inappropriate expectations on the part of donor and partner institutions regarding the problems and effects of institution building efforts, the lack of awareness of the importance of governance and ownership issues, and financial regulation that is too restrictive for microfinance operations. All three problems together explain why there are so few successful micro and small business institutions operating worldwide

National policies and the CDM: Avoiding perverse incentives

The CDM is a project-based mechanism to promote flexibility in mitigation climate change, by promoting investment in mitigation projects in developing countries. There has been concern about potential perverse incentives for developing countries like South Africa not to adopt progressive national policies, fearing that CDM projects implementing such policy would no longer be additional. The CDM rules on additionality require that emissions are reduced ‘below those that would have occurred in the absence of the registered CDM project activity’. The paper shows that recent decisions by the CDM Executive Board make it clear that such perverse incentives will not be created. The paper suggests concrete interpretations of this guidance for two possible project types. Projects implementing national policies that promote zero- or low-carbon emission technologies (e.g. South Africa’s renewable energy target) can still go through the CDM process. Where there are local regulations, as for landfill gas, projects would not be ruled out entirely, but would receive credit for the difference between actual methane capture and that needed to meet local safety, health and environmental standards. The author concludes that projects implementing progressive energy policies are still eligible for CDM investment

Side-jumps in the spin-Hall effect: construction of the Boltzmann collision integral

We present a systematic derivation of the side-jump contribution to the spin-Hall current in systems without band structure spin-orbit interactions, focusing on the construction of the collision integral for the Boltzmann equation. Starting from the quantum Liouville equation for the density operator we derive an equation describing the dynamics of the density matrix in the first Born approximation and to first order in the driving electric field. Elastic scattering requires conservation of the total energy, including the spin-orbit interaction energy with the electric field: this results in a first correction to the customary collision integral found in the Born approximation. A second correction is due to the change in the carrier position during collisions. It stems from the part of the density matrix off-diagonal in wave vector. The two corrections to the collision integral add up and are responsible for the total side-jump contribution to the spin-Hall current. The spin-orbit-induced correction to the velocity operator also contains terms diagonal and off-diagonal in momentum space, which together involve the total force acting on the system. This force is explicitly shown to vanish (on the average) in the steady state: thus the total contribution to the spin-Hall current due to the additional terms in the velocity operator is zero.Comment: Added references, expanded discussion, revised introductio