Use of remote sensing in agriculture

Remote sensing studies in Virginia and Chesapeake Bay areas to investigate soil and plant conditions via remote sensing technology are reported ant the results given. Remote sensing techniques and interactions are also discussed. Specific studies on the effects of soil moisture and organic matter on energy reflection of extensively occurring Sassafras soils are discussed. Greenhouse and field studies investigating the effects of chlorophyll content of Irish potatoes on infrared reflection are presented. Selected ground truth and environmental monitoring data are shown in summary form. Practical demonstrations of remote sensing technology in agriculture are depicted and future use areas are delineated

Simultaneous Continuation of Infinitely Many Sinks Near a Quadratic Homoclinic Tangency

We prove that the $C^3$ diffeomorphisms on surfaces, exhibiting infinitely many sinksnear the generic unfolding of a quadratic homoclinic tangency of a dissipative saddle, can be perturbed along an infinite dimensional manifold of $C^3$ diffeomorphisms such that infinitely many sinks persist simultaneously. On the other hand, if they are perturbed along one-parameter families that unfold generically the quadratic tangencies, then at most a finite number of those sinks have continuation

Randomised feasibility study of a novel experience-based internet intervention to support self-management in chronic asthma.

ElectronicPeer reviewedPublisher PD

Communiqué No. 22: What Do Nonprofits Stand For? Renewing the Nonprofit Value Commitment

This report aims to determine the core values of the nonprofit sector. It found that a broad group of nonprofits are in agreement about these value attributes, but feel that key stakeholders in government, the media, and the general public do not understand them and the consequences could be harmful for the sector unless steps are taken to correct this. With bibliographical references

Infinitely Many Stochastically Stable Attractors

Let f be a diffeomorphism of a compact finite dimensional boundaryless manifold M exhibiting infinitely many coexisting attractors. Assume that each attractor supports a stochastically stable probability measure and that the union of the basins of attraction of each attractor covers Lebesgue almost all points of M. We prove that the time averages of almost all orbits under random perturbations are given by a finite number of probability measures. Moreover these probability measures are close to the probability measures supported by the attractors when the perturbations are close to the original map f.Comment: 14 pages, 2 figure

Random Noise Signal Processing

Pulse echo flaw detection systems have found extensive use in industry for quality control of many types of metal and ceramic components. The random signal flaw detection system described in this paper provides an increase in sensitivity of several orders of magnitude compared to conventional pulse echo systems. Following a review of the theory of system operation, we present some recently obtained results of our system on materials which are strongly sound absorbing, including ceramics, plastics and metals as well as material s which have large grains. In addition to detecting flaws in strongly absorbing materials we feel that this system might also be utilized as a way of estimating grain size, inclusion size or porosity

Speckle Reduction in Ultrasonic SAFT Images in Coarse Grained Material Through Split Spectrum Processing

Ultrasonic non-destructive testing (NDT) techniques are widely used to detect flaws or defects within structural and functional components, and to classify and characterize the defects by their size, shape, location, orientation etc. Techniques which have been used include: A-scan, B-scan and Synthetic Aperture Focusing Technique (SAFT). Of these, A-scan is difficult to interpret without extensive operator training, and may lead to unreliable inspections. B-scan is easy to interpret, but it also has some disadvantages, such as that forming a B-scan image with an unfocused transducer leads to poor lateral resolution, and if using a focused transducer, the dynamic focusing technique has to be used to obtain good lateral resolution in all the regions of interest. SAFT, on the other hand, can get an image with good lateral resolution in all the regions of interest. The basic principle of SAFT is to apply a signal processing algorithm to a collection of raw A-line data from different transducer positions. The algorithm allows each point within the inspected volume to be focused upon by mathematically simulating the action of a lens. This algorithm involves the summation of the raw RF data shifted by predicted time delay. SAFT has been used for the fine grained materials ultrasonic evaluation with excellent results [9] [10]. However, use of SAFT in coarse grained material results in an image which suffers from ultrasonic speckle. The presence of speckle reduces the detectability of targets. This problem is also encountered in ultrasonic A-scan and B-scan coarse grained material testing

On stochastic sea of the standard map

Consider a generic one-parameter unfolding of a homoclinic tangency of an area preserving surface diffeomorphism. We show that for many parameters (residual subset in an open set approaching the critical value) the corresponding diffeomorphism has a transitive invariant set $\Omega$ of full Hausdorff dimension. The set $\Omega$ is a topological limit of hyperbolic sets and is accumulated by elliptic islands. As an application we prove that stochastic sea of the standard map has full Hausdorff dimension for sufficiently large topologically generic parameters.Comment: 36 pages, 5 figure

Temperature dependence of interlayer coupling in perpendicular magnetic tunnel junctions with GdOx barriers

Perpendicular magnetic tunnel junctions with GdOX tunneling barriers have shown a unique voltage controllable interlayer magnetic coupling effect. Here we investigate the quality of the GdOX barrier and the coupling mechanism in these junctions by examining the temperature dependence of the tunneling magnetoresistance and the interlayer coupling from room temperature down to 11 K. The barrier is shown to be of good quality with the spin independent conductance only contributing a small portion, 14%, to the total room temperature conductance, similar to AlOX and MgO barriers. The interlayer coupling, however, shows an anomalously strong temperature dependence including sign changes below 80 K. This non-trivial temperature dependence is not described by previous models of interlayer coupling and may be due to the large induced magnetic moment of the Gd ions in the barrier.Comment: 14 pages, 4 figure