Stable group delay cable

It was found that group delay is function of pressure in air dielectric coaxial cable. For example, 600-ft air dielectric cable will change phase 10 deg at 150 MHz when air pressure in cable changes from zero to 20 psi

Are some forecasters' probability assessments of macro variables better than those of others?

We apply the bootstrap test of DíAgostino et al. (2012) to determine whether some forecasters are able to make superior probability assessments to others. In contrast to the findings of DíAgostino et al. (2012) for point predictions, there is more evidence that some individuals really are better than others. The testing procedure controls for the different economic conditions the forecasters may face, given that each individual responds to only a subset of the surveys. One possible explanation for the different findings for point predictions and histograms is explored: that newcomers may make less accurate histogram forecasts than experienced respondents given the greater complexity of the task

University Scholar Series: Craig B. Clements

Groundbreaking Research on Wildfire Weather On November 28, 2012 Craig B. Clements spoke in the University Scholar Series hosted by Provost Ellen Junn at the Dr. Martin Luther King, Jr. Library. Craig Clements is an associate professor in the Department of Meteorology and Climate Science who received a $900,000 National Science Foundation CAREER grant for his work in tracking atmospheric conditions in and around wildfires. His work will better help predict wildfire behavior and conditions that could lead to increased wildfire danger.https://scholarworks.sjsu.edu/uss/1016/thumbnail.jp

System for stabilizing cable phase delay utilizing a coaxial cable under pressure

Stabilizing the phase delay of signals passing through a pressurizable coaxial cable is disclosed. Signals from an appropriate source at a selected frequency, e.g., 100 MHz, are sent through the controlled cable from a first cable end to a second cable end which, electrically, is open or heavily mismatched at 100 MHz, thereby reflecting 100 MHz signals back to the first cable end. Thereat, the phase difference between the reflected-back signals and the signals from the source is detected by a phase detector. The output of the latter is used to control the flow of gas to or from the cable, thereby controlling the cable pressure, which in turn affects the cable phase delay

Deconstructing the stereotypes: building mutual respect

Through a combination of a detailed literature review and structure online survey, the study seeks to establish the extent of interdisciplinary attitudes within built environment students at Kingston University, whilst building a picture of not only the stereotypes held amongst and between disciplines, but also the fundamental root of such perceptions

Mechanical characteristics of carbon fibre yacht masts

This paper provides a preliminary stress analysis of a carbon reinforced layered cylinder such as would be found in a yacht mast. The cylinder is subjected to a compressive load and both an analytical and numerical analysis of the resulting stress fields is obtained. Some conclusions are obtained regarding the failure mode for particular examples of such cylinders

Clover:cereal bi-cropping for organic farms (OF0173)

This is the final report of Defra project OF0173. The attached main report starts with a more detailed summary, from which this text is extracted. IGER, IACR and others developed a system for growing cereals, especially for whole crop silage, that enables either greatly reduced or zero levels of N fertilizer and agrochemicals to be used. The system is simple and straightforward and relies on direct drilling of the cereal into an established understorey of white clover. The white clover understorey becomes permanent and perennial and successive cereal crops are drilled into it, harvested and re-drilled each year. The clover provides N for the cereal crop and the gross changes in crop architecture that occur (a) encourage large populations of predatory invertebrates that devour pest species and hence obviate the need for insecticide use (b) frustrate the spread of fungal foliar diseases and remove the need to use fungicides and (c) suppress most weeds. Some of the advantages of the clover:cereal bi-cropping system that are especially relevant to organic farms are a) simultaneous cropping and fertility building rather than separate seasons for each b) effective nutrient cycling c) weeds replaced by clover; limitation of crop area requiring intensive weed control d) confusion of insect pests and habitat for beneficial insects, spiders etc. e) improved field access relative to bare soil The work investigated the agronomic viability and sustainability of bi-cropping for both silage and grain production in organic farming systems as specified under UKROFS. Experiments were carried out on three UKROF approved sites with contrasting soil types and environmental conditions. Randomised block, small-plot experiments evaluated the most satisfactory ways of modifying the IGER/IACR system for organic farming. The main point to emerge is that although the bi-crop system is well proven and developed for use in a non-organic system, grass weeds remain a problem in translating the system to organic farming as herbicides can not be used to control them. There are a number of strategies that emerged during the course of the present work that indicated ways in which the grass weed problem may be overcome in future. Firstly, oats seem to suppress grass weeds and growing this crop instead of wheat appeared to show considerable promise. Secondly strip drilling alternate 20 cm strips of cereal with 30 cm strips of clover allows separate management of the two crop components, facilitating weed control. The work confirmed that spring-sown cereals are not an option for bi-cropping as they are easily outcompeted by the clover. An important positive feature of all of the trials was the consistent absence or low levels of diseases and pests despite high levels of airborne pathogen inoculum in the trial area. It is difficult to gauge the relative contributions of the organic system as a whole and the bi-crop system in particular to this feature. There are certainly important theoretical reasons as to why the bi-crop system should help in this direction, including the restriction on spread of splash-borne diseases because of the presence of clover around the cereal plants, green background confusion of insect pests and the probable lack of surplus soluble nitrogen in the cereal plants. The more positive results in the absence of grass weeds were limited to a single year for cereals (and two seasons for vegetables in another related trial). However, in both cases, there were clear indications that, with a relatively small amount of fine tuning of the system, it should be possible to obtain highly acceptable results from both types of inter-cropping and, indeed, from rotational integration of the two. Further progress would certainly be worthwhile for the organic producer because it seems clear that a modest further adjustment of the competitive balance between crop and clover will lead to a clearer expression of all of the potential advantages of such systems, outlined above. Despite the difficulties encountered, progress was made and the list of advantages and potential advantages of bi-cropping for organic agriculture is so large and significant that further work should be done to capitalise on that completed to date