LANDSAT/MMS propulsion module design. Volume 1: Task 4.3, trade studies

Evaluations are presented of alternative LANDSAT follow-on launch configurations to derive the propulsion requirements for the multimission modular spacecraft (MMS). Two basic types were analyzed including use of conventional launch vehicles and shuttle-supported missions. It was concluded that two sizes of modular hydrazine propulsion modules would provide the most cost-effective combination for future missions of this spacecraft. Conceptual designs of the selected propulsion modules were performed to the depth permitting determination of mass properties and estimated costs

Field condensations and Noncritical String for c>1

Quantum theory of 2d gravity for $c>1$ is examined as a non-critical string theory by taking account of the loop-correction of open strings whose end points are on the 2d world surface of the closed string. This loop-correction leads to a conformal anomaly, and we obtain a modified target-space action which implies a new phase of the non-critical closed-string. In this phase, the dual field of the gauge field, which lives on the boundary, condenses and the theory can be extended to $c>1$ without any instability.Comment: 17 pages, Latex, no figur

Soliton model for proton conductivity in Langmuir films

A soliton model for proton conductivity in Langmuir films is presented. The model contains three real scalar fields describing the hydrogen involved in the conduction, the hydrophilic head of the Langmuir film, and the water. Soliton solutions that describe proton motion along the hydrogen bonds are found. Under compression of the film, the distance between the minima of the proton potential and the strength of the hydrogen bonds between the film molecule and the water are changed. Such changes increase the probability of soliton creation. The model presented allows proton conductivity data in Langmuir films to be explained.Comment: Revtex, 07 pages, 2 eps figures, to be published in Chem. Phys. Let

Unpackaging demand for water service quality : evidence from conjoint surveys in Sri Lanka

In the early 2000s, the Government of Sri Lanka considered engaging private sector operators to manage water and sewerage services in two separate service areas: one in the town of Negombo (north of Colombo), and one stretching along the coastal strip (south from Colombo) from the towns of Kalutara to Galle. Since then, the government has abandoned the idea of setting up a public-private partnership in these two areas. This paper is part of a series of investigations to determine how these pilot private sector transactions (forming part of the overall water sector reform strategy) could be designed in such a manner that they would benefit the poor. The authors describe the results of a conjoint survey evaluating the factors that drive customer demand for alternative water supply and sanitation services in Sri Lanka. They show how conjoint surveys can be used to unpackage household demand for attributes of urban services and improve the design of infrastructure policies. They present conjoint surveys as a tool for field experiments and a source of valuable empirical data. In the study of three coastal towns in southwestern Sri Lanka the conjoint survey allows the authors to compare household preferences for four water supply attributes-price, quantity, safety, and reliability. They examine subpopulations of different income levels to determine if demand is heterogeneous. The case study suggests that households care about service quality (not just price). In general, the authors find that households have diverse preferences in terms of quantity, safety, and service options, but not with regard to hours of supply. In particular, they find that the poor have lower ability to trade off income for services, a finding that has significant equity implications in terms of allocating scarce public services and achieving universal water access.Town Water Supply and Sanitation,Water and Industry,Economic Theory&Research,Water Use,Water Supply and Sanitation Governance and Institutions

A New Variety of Lomatium ravenii (Apiaceae) from the Northern Great Basin and Adjacent Owyhee Region

Variability in the group of Lomatium species comprising L. nevadense, L. ravenii, and L. foeniculaceum has led to conflicting classification schemes. While some taxonomists have treated L. ravenii as a distinct species made up of all the populations from California, Nevada, Idaho, and Oregon, others considered L. ravenii to be nothing more than a morphological extreme of L. nevadense. We examined morphological and phylogenetic data from across the range of L. ravenii, concluding that variation in the species warrants varietal distinction. Non-metric multidimensional scaling analysis of 29 populations shows two distinct groups—one from the vicinity of Ravendale, California, and one from the rest of the range in California, Nevada, Oregon, and Idaho. Phylogenetic analysis of the ITS, rps16 intron, and cpDNA rpl32-trnLUAG genes from seven populations supports these two groups. We refer to the geographically widespread population as Lomatium ravenii var. paiutense and recommend reassessment of the conservation status of the more narrowly endemic Ravendale populations