Is Cycle 24 the Beginning of a Dalton-Like Minimum?

The unexpected development of cycle 24 emphasizes the need for a better way to model future solar activity. In this article, we analyze the accumulation of spotless days during individual cycles from 1798-2010. The analysis shows that spotless days do not disappear abruptly in the transition towards an active sun. A comparison with past cycles indicates that the ongoing accumulation of spotless days is comparable to that of cycle 5 near the Dalton minimum and to that of cycles 12, 14 and 15. It also suggests that the ongoing cycle has as much as 20 \pm 8 spotless days left, from July 2010, before it reaches the next solar maximum. The last spotless day is predicted to be in December 2012, with an uncertainty of 11 months. This trend may serve as input to the solar dynamo theories.Comment: 10 pages, 5 figures. The final publication is available at http://www.springerlink.co

Opinions and attitudes of practicing Consulting Foresters about the TVA/ACF Consulting Forester Assistance Program

In 1970, The Tennessee Valley Authority (TVA) initiated the Consulting Forester Assistance (CPA) Program. The program was a cooperative among TVA, the Association of Consulting Foresters (ACF), various state forestry agencies, and the U.S. Forest Service, State and Private Forestry. The program\u27s objective was to assist in the establishment of new private forest consultants in the Tennessee Valley, a seven state region. The goal was to have new consultants work primarily with non-industrial private forest landowners as clients in private forestry development. A key to past success of the 18-year program has been the strong support of cooperators, and their ability to find new noncompetitive geographic areas, not near established consulting forestry operations. The opinions and support of these public and private foresters will likely determine the future role of the program regardless of past success. In 1987 an independent study was made by The University of Tennessee under contract with the ACF to evaluate the CFA program. Two mailed questionnaires were used to obtain opinions from both state service foresters and consulting foresters about the program. An attempt was made to obtain a balanced sample between ACF and non- ACF members for comparison purposes. The usable response rate of 72.4 percent was obtained from consulting foresters. All state foresters responded to a separate questionnaire. Generally, state service foresters (appointed by each State Forester) were not in support of continuing the program, with the exceptions of the State of Tennessee and the State of Alabama. Minor differences were found between the opinions of ACF and non-ACF members, with over 48 percent of both groups not supporting continuation of the program. Most respondents offered their ideas for either changing the program or suggesting alternatives in lieu of continuing the program. The general level of program awareness was very low, including ACF members. Consultants with high levels of knowledge about the program were, in general, more supportive of the program. This finding suggests that there is a need for better public relations information about the program in order to obtain continued professional support by all cooperating agencies

In-Flight Performance of the Terminator Tape End-of-Life Deorbit Module

The Terminator Tape™ is a passive deorbit module that utilizes both electrodynamic and aerodynamic drag effects to reduce spacecraft deorbit time. To date, three satellites have deployed Terminator Tapes, accumulating a total flight time of approximately thirty months. The first two deployments, on the NPSAT-1 and PROX-1 satellites, are starting multi-year deorbit profiles that will characterize Terminator Tape performance over a full solar cycle as they descend from altitudes above 700km. Additionally, the DRAGRACER mission recently demonstrated performance at lower altitudes, where aerodynamic drag becomes the dominant effect and has given insight into late-stage performance of the tape. Analysis of the impact of the drag tape solution on the overall probability of collision with active satellites indicates the Terminator Tape can significantly reduce collision risks relative to an unaided passive decay approach

Capillary force-induced structural instability in liquid infiltrated elastic circular tubes

The capillary-induced structural instability of an elastic circular tube partially filled by a liquid is studied by combining theoretical analysis and molecular dynamics simulations. The analysis shows that, associated with the instability, there is a well-defined length scale (elasto-capillary length), which exhibits a scaling relationship with the characteristic length of the tube, regardless of the interaction details. We validate this scaling relationship for a carbon nanotube partially filled by liquid iron. The capillary-induced structural transformation could have potential applications for nano-devices

MODIS information, data and control system (MIDACS) operations concepts

The MODIS Information, Data, and Control System (MIDACS) Operations Concepts Document provides a basis for the mutual understanding between the users and the designers of the MIDACS, including the requirements, operating environment, external interfaces, and development plan. In defining the concepts and scope of the system, how the MIDACS will operate as an element of the Earth Observing System (EOS) within the EosDIS environment is described. This version follows an earlier release of a preliminary draft version. The individual operations concepts for planning and scheduling, control and monitoring, data acquisition and processing, calibration and validation, data archive and distribution, and user access do not yet fully represent the requirements of the data system needed to achieve the scientific objectives of the MODIS instruments and science teams. The teams are not yet formed; however, it is possible to develop the operations concepts based on the present concept of EosDIS, the level 1 and level 2 Functional Requirements Documents, and through interviews and meetings with key members of the scientific community. The operations concepts were exercised through the application of representative scenarios