Determining decay rates of polar cap plasma using bservations of polar cap patches

Polar cap patches are large scale structures occurring in the high-latitude ionosphere. They are regions of enhanced plasma density of at least twice the background density, and they are often observed in the polar cap region. The primary decay mechanism is via a two-step rearrangement and recombination reaction involving Oxygen and Nitrogen. Small scale structures within polar cap patches can result in scintillation of radio signals such as those used in Global Navigation Satellite Systems (GNSS). As such, quantifying the decay rate of the plasma is of importance if the effects on such communications are to be predicted. Observations were obtained during the Northern Deep Winter experiment, a series of incoherent scatter radar world days that took place in December 2014. Data from multiple incoherent scatter radars at high latitudes will be utilised to observe the same plasma at several locations as it is transported. From these observations, the decay of the plasma will be calculated and compared to the results of laboratory experiments

Simulations of satellite Doppler wind observations

This study will involve two objectives: (1) to develop, through computer simulations, optimal satellite-based sensor scanning techniques for direct measurement of tropospheric winds on the meso- and synoptic scales; and (2) to construct simulations of remotely measured wind fields for assessing impact of such fields on the diagnosis and prognosis of atmospheric phenomena through the use of Observing System Simulation Experiments (OSSE). Using the LAWS Simulation Model (LSM), various global coverage scenarios have been investigated as part of an effort to define the optimal orbit, configuration and sampling strategies for observations of winds for use in global circulation models. Simulated data sets have been provided to GSFC, FSU and several LAWS team members. Particular emphasis has been on providing realistic cloud cover, cirrus backscatter, aerosol distribution and wind variance on scales less than 600 km. Progress is currently being made to incorporate other remote sensors (AIRS/AMSU, STIKSCAT) into the global OSSEs

Two-dimensional polymer networks at a mixed boundary: Surface and wedge exponents

We provide general formulae for the configurational exponents of an arbitrary polymer network connected to the surface of an arbitrary wedge of the two-dimensional plane, where the surface is allowed to assume a general mixture of boundary conditions on either side of the wedge. We report on a comprehensive study of a linear chain by exact enumeration, with various attachments of the walk's ends to the surface, in wedges of angles $\pi/2$ and $\pi$, with general mixed boundary conditions.Comment: 4 pages, Latex2e, 3 figures, Eur. Phys. J. B macro

Nondestructive tests of regenerative chambers

The capabilities and limitations of nondestructive evaluation methods were studied to detect and locate bond deficiencies in regeneratively cooled thrust chambers for rocket engines. Flat test panels and a cylinder were produced to simulate regeneratively cooled thrust chamber walls. Planned defects with various bond integrities were produced in the panels to evaluate the sensitivity, accuracy, and limitations of nondestructive methods to define and locate bond anomalies. Holography, acoustic emission, and ultrasonic scan were found to yield sufficient data to discern bond quality when used in combination and in selected sequences. Bonding techniques included electroforming and brazing. Materials of construction included electroformed nickel bonded to Nickel 200 and OFHC copper, electroformed copper bonded to OFHC copper, and 300 series stainless steel brazed to OFHC copper. Variations in outer wall strength, wall thickness, and defect size were evaluated for nondestructive test response

Nondestructive tests of regenerative chambers, appendix

For abstract, see N75-12058

Use of glow discharge in fluidized beds

Static charges and agglomerization of particles in a fluidized bed systems are minimized by maintaining in at least part of the bed a radio frequency glow discharge. This approach is eminently suitable for processes in which the conventional charge removing agents, i.e., moisture or conductive particle coatings, cannot be used. The technique is applied here to the disproportionation of calcium peroxide diperoxyhydrate to yield calcium superoxide, an exceptionally water and heat sensitive reaction

Effects of composting manures and other organic wastes on soil processes and pest and disease interactions

Introduction Composts and manures are of major importance in providing fertility in organic farming systems, since synthetic fertilisers are prohibited. It is understood that composts have radically different nutrient release characteristics to those of uncomposted materials and manures, and it is believed that composting increases the beneficial effects of organic materials on soil health, soil quality, soil fertility and nutrient use efficiency. It has also been shown that some plant pests and diseases are suppressed through the application of composts and compost extracts to soils. There is considerable potential to use a wider range of feedstocks from on and off-farm sources and to improve the composting process and compost/manure application techniques. This review of scientific work to date was urgently required to help determine key research priorities to achieve this potential (Defra project OF0313). Project aims 1.To document the current standards, regulations and legislation relevant to recycling, compost/manure preparation and application and to review common UK practices relating to the preparation and application of uncomposted materials, manures, composts and compost extracts. 2. To review current scientific knowledge (from the literature) of the effects of different composting processes on chemical and biological parameters in the finished compost or compost extract. 3. To review (from the literature) the effects of uncomposted materials, manures and composts on soil health and quality, soil fertility and crop development and nutrition. 4. To review (from the literature) the effects of uncomposted materials, manures, composts and compost extracts on pest and disease incidence and severity in agricultural and horticultural crops. 5. To outline a proposed strategy for research which seeks to develop composting systems and compost/manure application protocols with a view to optimising soil fertility management and pest and disease control in organic agriculture and horticulture. Objective 1 - The current standards, regulations and legislation relevant to recycling, compost/manure preparation and application are documented in detail in the full report on Objective 1 (Appendix 2). Manures and uncomposted plant materials (e.g. green manures) are commonly used on UK organic farms. True composts (defined in the glossary, Appendix 1) are rarely prepared on UK organic farms, although there is increasing interest in their use, particularly on farms producing high value horticultural crops. An increasing number of companies are producing (or are interested in producing) composts suitable for use on organic farms as soil amendments or growing media. Objective 2 - The effects of different composting processes on chemical and biological parameters in the finished compost or compost extract are reviewed in detail in the full report on Objective 2 (Appendix 3). A short version of this review appears on pages 7-10 of this report. Objective 3 - The effects of uncomposted materials, manures and composts on soil health and quality, soil fertility and crop development and nutrition are reviewed in detail in the full report on Objective 3 (Appendix 4). A short version of this review appears on pages 10-13 of this report. Objective 4 - The effects of uncomposted materials, manures, composts and compost extracts on pest and disease incidence and severity in agricultural and horticultural crops are reviewed in detail in the full report on Objective 4 (Appendix 5). A short version of this review appears on pages 13-17 of this report. Objective 5 - A proposed strategy for research was outlined which seeks to develop composting systems and compost/manure application protocols with a view to optimising soil fertility management and pest/disease control in organic agriculture/horticulture Organic farming systems are by nature holistic. In other words, they function as a whole and all aspects of the system are interdependent on many other aspects of the system. It is essential therefore that research which is carried out to optimise the use of uncomposted plant residues, composts, manures and compost extracts is interdisciplinary; that is it must be carried out with reference to the organic farming system as a whole and not just a single aspect of it. Technology transfer and knowledge transfer are key elements to the proposed strategy for research. Seminars and conferences, farm walks, demonstration farms and a wide range of publishing formats must be used to ensure that end users have full access to the results of research carried out in the UK and abroad. The amount of information which is available for dissemination to those who wish to make or use composts will naturally depend on the amount of relevant research and development work which is going on in the UK, Europe and worldwide