Transaction Costs and Housing Affordability in Asia

Asia is home to some of the fastest growing cities in the world. As urbanization increases, demand for housing also increases. Well functioning housing markets can minimize problems associated with rapid urbanization such as unaffordable housing and urban slums. This paper explores the different aspects of the residential property sales markets in Asian countries. Using data gathered by the Global Property Guide, transaction costs associated with residential property purchases are analyzed. Housing markets are also examined in terms of tenure, protection of property rights, and openness and transparency. Roundtrip transaction costs for buying properties are high, above 10% in several countries in Asia. High transaction costs and unaffordable housing combined with weak protection of property rights are seen to be conducive to the creation of urban slums.Property markets, Transaction costs, Housing affordability, Slums

Precarious projects: conversions of (biomedical) knowledge in an East African city

This article explores the orientations of lay people in Kenya to science—specifically to biomedical knowledge about HIV—and their struggles to convert this knowledge into meaningful futures. In Kenya, the global response to the HIV-AIDS epidemic has resulted in a highly stratified landscape of intervention. Globally-funded treatment programs and clinical trials, focusing on HIV, channel transnational resources, expertise, and knowledge into specific sites—HIV clinics, NGOs, and research stations—inscribing these spaces as ‘global’ while leaving others decidedly ‘local.’ Rolled out in the form of ‘projects,’ these interventions offer resources and opportunities for a limited time only. Based on ethnographic fieldwork in the city of Kisumu, this article follows the circulation of biomedical knowledge through such projects and its conversion in ways beyond those imagined by policy-makers, as it meets the aspirations of city-dwellers and enters into local livelihoods. Mediated by nongovernmental organizations through workshops and certificates, this knowledge is both fragmentary and ephemeral. I explore the temporal and spatial implications of such knowledge for those who seek to attach themselves to it and shape their identities and futures in relation to it

Catalogue of solar activity during 1957

Catalog of major solar activity during 195

Solar activity catalogue. Volume I - Catalogue of solar activity during 1954 - 1956

Catalog of solar activity during 1954-195

Evaluation of range and distortion tolerance for high Mach number transonic fan stages. Task 2: Performance of a 1500-foot-per-second tip speed transonic fan stage with variable geometry inlet guide vanes and stator

A 0.5 hub/tip radius ratio compressor stage consisting of a 1500 ft/sec tip speed rotor, a variable camber inlet guide vane and a variable stagger stator was designed and tested with undistorted inlet flow, flow with tip radial distortion, and flow with 90 degrees, one-per-rev, circumferential distortion. At the design speed and design IGV and stator setting the design stage pressure ratio was achieved at a weight within 1% of the design flow. Analytical results on rotor tip shock structure, deviation angle and part-span shroud losses at different operating conditions are presented. The variable geometry blading enabled efficient operation with adequate stall margin at the design condition and at 70% speed. Closing the inlet guide vanes to 40 degrees changed the speed-versus-weight flow relationship along the stall line and thus provided the flexibility of operation at off-design conditions. Inlet flow distortion caused considerable losses in peak efficiency, efficiency on a constant throttle line through design pressure ratio at design speed, stall pressure ratio, and stall margin at the 0 degrees IGV setting and high rotative speeds. The use of the 40 degrees inlet guide vane setting enabled partial recovery of the stall margin over the standard constant throttle line

Optimal Finite Thrust Guidance Methods for Constrained Satellite Proximity Operations Inspection Maneuvers

Algorithms are developed to find optimal guidance for an inspector satellite operating nearby a resident space object (RSO). For a non-maneuvering RSO, methods are first developed for a satellite subject to maximum slew rates to conduct an initial inspection of an RSO, where the control variables include the throttle level and direction of the thrust. Second, methods are developed to optimally maneuver a satellite with on/off thrusters into a natural motion circumnavigation or teardrop trajectory, subject to lighting and collision constraints. It is shown that for on/off thrusters, a control sequence can be parameterized to a relatively small amount of control variables and the relative states can be analytically propagated as a function of those control variables. For a maneuvering RSO, differential games are formulated and solved for an inspector satellite to achieve multiple inspection goals, such as aligning with the Sun vector or matching the RSO\u27s energy. The developed algorithms lead to fuel and time savings which can increase the mission life and capabilities of inspector satellites and thus improve space situational awareness for the U.S. Air Force

Continuous hydroponic wheat production using a recirculating system

Continuous crop production, where plants of various ages are growing simultaneously in a single recirculating nutrient solution, is a possible alternative to batch production in a Controlled Ecological Life Support System. A study was conducted at John F. Kennedy Space Center where 8 trays (0.24 sq m per tray) of Triticum aestivum L. Yecora Rojo were grown simultaneously in a growth chamber at 23 C, 65 percent relative humidity, 1000 ppm CO2, continuous light, with a continuous flow, thin film nutrient delivery system. The same modified Hoagland nutrient solution was recirculated through the plant trays from an 80 L reservoir throughout the study. It was maintained by periodic addition of water and nutrients based on chemical analyses of the solution. The study was conducted for 216 days, during which 24 trays of wheat were consecutively planted (one every 9 days), 16 of which were grown to maturity and harvested. The remaining 8 trays were harvested on day 216. Grain yields averaged 520 g m(exp -2), and had an average edible biomass of 32 percent. Consecutive yields were unaffected by nutrient solution age. It was concluded that continual wheat production will work in this system over an extended period of time. Certain micronutrient deficiencies and toxicities posed problems and must be addressed in future continuous production systems