Means for measuring the electron density gradients of the plasma sheath formed around a space vehicle Patent

Development of method for measuring electron density gradients of plasma sheath around space vehicle during atmospheric entr

Large aircraft handling qualities

The short period frequency requirements of MIL-F-8785C are applicable to the very large transport aircraft simulated. The large aircraft simulated meet the requirements of NASA CR-159236 for effective time delay and pitch transient peak ratio. However, the requirements of this reference for the effective rise time parameter are believed to be too convservative for very large transport aircraft. Data obtained to date as well as other data indicate that MIL-SPEC requirements for the parameter t(phi=30 degrees) are too conservative for very large transport aircraft. The results of the present study indicate that t(phi=30 degrees) of less than 6 sec should result in ""acceptable'' roll response characteristics, and t(phi=30 degrees) of less than 4.0 sec should result in ""satisfactory'' roll response

Antenna design for surface wave suppression Patent

Development of method for suppressing excitation of electromagnetic surface waves on dielectric converter antenn

WHAT'S SPACE GOT TO DO WITH IT? DISTANCE AND AGRICULTURAL PRODUCTIVITY BEFORE THE RAILWAY AGE

Owing to the high cost of transporting farm produce before the railway age, the land-intensiveness of European mixed farming caused both production and consumption of foodstuffs and intermediate farm inputs in the steady state to be highly dispersed, a spatial configuration offering weak inducement to reorganize farm structure or to invest available labour and capital with a view to increasing output. In such conditions the most common cause of rising agricultural productivity was spatial concentration of demand, which raised the demand price of farm produce and farm inputs within the privileged space bounded by discontinuities in the cost of land transport. The ultimate cause of observed changes in agricultural productivity before the nineteenth century must therefore be sought outside the farming sector in the development of markets for tradable manufactures, tradable services, and the economies of scale in their provision that supported spatial concentration of population.

Preliminary ISIS users manual

The Interactive Software Invocation (ISIS), an interactive data management system, was developed to act as a buffer between the user and host computer system. The user is provided by ISIS with a powerful system for developing software or systems in the interactive environment. The user is protected from the idiosyncracies of the host computer system by providing such a complete range of capabilities that the user should have no need for direct access to the host computer. These capabilities are divided into four areas: desk top calculator, data editor, file manager, and tool invoker

WHAT'S SPACE GOT TO DO WITH IT? DISTANCE AND AGRICULTURAL PRODUCTIVITY BEFORE THE RAILWAY AGE

This paper argues that the conventional Malthusian account of pre-modern economies as constrained by diminishing returns resulting from a fixed land supplied is flawed because it does not recognize the importance of systematic indivisibilities in the production and distribution of farm produce that supported increasing return to additional inputs when the demand price of produce warranted them. Those indivisibilities locked in low-intensity farming practices in places where the demand for produce was diffuse. Most of pre-industrial Europe was in that situation, so average agricultural productivity was low. It was only in regions where urban concentrations of consumers aggregated demand to a level capable of inducing extra investment to exploit latent returns to scale in farming and transportation that the productivity of traditional mixed farming achieved its full potential.

Web interfaces to enhance CAL materials: Case studies from law and statistics

One impact of the ‘information age’ is that a variety of new learning resources have become available to both students and tutors. Using these resources effectively and with a sound pedagogical basis presents a whole array of issues for teaching professionals. In this paper the authors describe the development and implementation of a Web interface to existing computer‐based learning materials in an attempt to enhance the student learning experience. Although the innovations occurred in two very different disciplines ‐statistics and law ‐ there are common lessons to be learned about the process of learning and the use of technology

NASA future mission needs and benefits of controls-structures interaction technology

Two questions are addressed: (1) which future missions need Controls-Structures Interaction (CSI) technology for implementing large spacecraft in orbit; and (2) what specific benefits are to be derived if the technology is available? The answers to these questions were used to help formulate and direct the CSI technology development program. Many future NASA missions have common CSI technology needs which can best be developed in a broad-based, but focused, technology program to provide the greatest benefit to the largest number of users. Three CSI benefit studies were completed to date as part of ongoing assessment process: (1) missions requiring large antennas; (2) missions requiring large optical systems; and (3) missions requiring the use of closed-loop controlled, flexible, remote manipulator systems (RMS) for in-space assembly. The large antenna and flexible RMS mission benefits are discussed