Selling Solar: Financing Household Solar Energy in the Developing World

Based on value chain analyses of case studies, outlines the issues and challenges for developing a solar energy industry, with a focus on the need for a financing infrastructure that serves purchasers, manufacturers, distributors, and investors

Antenna pointing systematic error model derivations

The pointing model used to represent and correct systematic errors for the Deep Space Network (DSN) antennas is presented. Analytical expressions are given in both azimuth-elevation (az-el) and hour angle-declination (ha-dec) mounts for RF axis collimation error, encoder offset, nonorthogonality of axes, axis plane tilt, and structural flexure due to gravity loading. While the residual pointing errors (rms) after correction appear to be within the ten percent of the half-power beamwidth criterion commonly set for good pointing accuracy, the DSN has embarked on an extensive pointing improvement and modeling program aiming toward an order of magnitude higher pointing precision

Collective Coordinates and the Absence of Yukawa Coupling in the Classical Skyrme Model

In systems with constraints, physical states must be annihilated by the constraints. We make use of this rule to construct physical asymptotic states in the Skyrme model. The standard derivation of the Born terms with asymptotic physical states shows that there is no Yukawa coupling for the Skyrmion. We propose a remedy tested in other solitonic models: A Wilsonian action obtained after integrating the energetic mesons and where the Skyrmion is a quantum state should have a Yukawa coupling.Comment: LATE

Hall coefficient and Hc2 in underdoped LaFeAsO0.95F0.05

The electrical resistivity and Hall coefficient of LaFeAsO0.95F0.05 polycrystalline samples were measured in pulsed magnetic fields up to m0H = 60 T from room temperature to 1.5 K. The resistance of the normal state shows a negative temperature coefficient (dr/dT < 0) below 70 K for this composition, indicating insulating ground state in underdoped LaFeAsO system in contrast to heavily doped compound. The charge carrier density obtained from Hall effect can be described as constant plus a thermally activated term with an energy gap DE = 630 K. Upper critical field, Hc2, estimated from resistivity measurements, exceeds 75 T with zero-field Tc = 26.3 K, suggesting an unconventional nature for superconductivity.Comment: 12 pages and 4 figure

Disruptive design in sanitation marketing: lessons from product and process innovations in Bangladesh

Based in Dhaka, the Sanitation Marketing (SanMark) team at iDE – Bangladesh, is harnessing principles of disruptive innovation to change the landscape of how latrines are produced and sold to rural households. iDE’s Bangladesh SanMark Pilot (BSMP) project (2012-2014) aimed to develop a proof of concept around private-sector led delivery of customer-oriented improved sanitation technologies through three phases: i) identification of existing disruptee conditions, ii) support of an “entry point” innovation that generated key “disruptive design principles”, and iii) robust ideation and prototyping of a disruptor system grounded in the design principles. Through these phases, the project experienced an initial “entry point innovation” through the plastic SaTo® Pan. The resulting design principles then informed development of the disruptor system of the plastic “Sanitation in a Box” (SanBox) offset plastic latrine, a promising sanitation product grounded in a scalable business model connecting grassroots latrine producers to a national supply chain