Development and testing of the infrared radiometer for the Mariner Venus/Mercury 1973 spacecraft

The science objectives, development history, functional description, and testing of the Mariner Venus/Mercury 1973 infrared radiometer are discussed. Included in the functional description section is a thorough discussion of the IRR optical system, electronic operation, and thermal control. Signal development and its conversion to engineering units is traced, starting with the radiant space object, passing through the IRR optics and electronics, and culminating with data number development and interpretation. The test program section includes discussion of IRR calibration and alignment verification. Finally, the problems and failures encountered by the IRR during the period of its development and testing are reviewed

An assessment of the impact of spacecraft glow on the Hubble space telescope. Summary of existing observations and theory

Visible spacecraft glow was first observed on the Atmospheric Explorer spacecraft (AE-E) and studied in some detail with the Visible Airglow Experiment (VAE). The AE-E was a spin-stabilized spacecraft without thrusters at an altitude of 140 to 280 km. The VAE contained six visible wavelength photometers that measured a glow spectrum which: (1) rose steeply in the red, (2) decreased with a cos cubed PH1 dependence from pointing into the ram direction of the spacecraft orbital motion, and (3) decreased in intensity with increasing altitude with the same dependence as the measured atomic oxygen number atmospheric density (O) and not with the measured molecular nitrogen density (N sub 2). It is proposed that the glow is produced by chemical reactions on the spacecraft surface as it sweeps through the atmospheric O, with roughly 5-8 eV per O atom available for excitation from the orbital motion of the spacecraft. This glow may in principal be produced by any of a number of species, including molecular band emission from OH, NO, and NO2. An attempt is made to scale the observed glow to the Hubble space telescope

Regularity for Lorentz Metrics under Curvature Bounds

Let (M, g) be an (n+1) dimensional space-time, with bounded curvature with respect to a bounded framing. If (M, g) is vacuum or satisfies a mild condition on the stress-energy tensor, then we show that (M, g) locally admits coordinate systems in which the Lorentz metric is well-controlled in the (space-time) Sobolev space L^{2,p}, for any finite p.Comment: 18p

The mathematics of functional differentiation under conservation constraint

The mathematics of K-conserving functional differentiation, with K being the integral of some invertible function of the functional variable, is clarified. The most general form for constrained functional derivatives is derived from the requirement that two functionals that are equal over a restricted domain have equal derivatives over that domain. It is shown that the K-conserving derivative formula is the one that yields no effect of K-conservation on the differentiation of K-independent functionals, which gives the basis for its generalization for multiple constraints. Connections with the derivative with respect to the shape of the functional variable and with the shape-conserving derivative, together with their use in the density-functional theory of many-electron systems, are discussed. Yielding an intuitive interpretation of K-conserving functional derivatives, it is also shown that K-conserving derivatives emerge as directional derivatives along K-conserving paths, which is achieved via a generalization of the Gateaux derivative for that kind of paths. These results constitute the background for the practical application of K-conserving differentiation.Comment: final version, published in J Math Chem; with an Appendix with the proof of (17) added, and some errata to [1] inserte

Statistical expansions and locally uniform Fréchet differentiability

Estimators which have locally uniform expansions are shown in this paper to be asymptotically equivalent to M-estimators. The M-functionals corresponding to these M-estimators are seen to be locally uniformly Fréchet differentiable. Other conditions for M-functionals to be locally uniformly Fréchet differentiable are given. An example of a commonly used estimator which is robust against outliers is given to illustrate that the locally uniform expansion need not be valid

The impacts for stone curlews of increased traffic on the A11. Model and predictions

Stone curlew nest density in the Breckland region of Eastern England was shown to be negatively related to ‘nearby’ housing density and ‘nearby’ trunk road traffic (based on new traffic data for the period 1988-2006). However, no statistically significant additional relationship with non-trunk A-road traffic could be detected. We recommend using the statistical modelling predictions in the report Table 5 as the best currently available estimates of the potential effect of a 70% increase in A11 average daily (March-August)two-way traffic above the average All traffic levels in 2002-06. The predicted effect of a 70% increase in A11 traffic is for a reduction from current observed nest numbers on suitable arable land of 3.7% with no changes in housing density or 4.9% when combined with the predicted effect of housing options. A reduction of 7.3% is predicted for semi-natural grassland and SSSI habitats. Taking both semi-natural grassland/SSSI and arable habitats together, the observed total average nest numbers for the period 2002-2006 was 221.4, and the prediction following a 70% increase in traffic on the A11 is 210.8, a reduction of 10.6 nests (4.8%)

An experimental investigation into the constant velocity water entry of wedge-shaped sections

Constant velocity water entry is important in understanding planing and slamming of marine vessels. A test rig has been developed that drives a wedge section with end plates down guides to enter the water vertically at near constant velocity. Entry force and velocity are measured. Analysis of the test data shows that the wetting factor is about 1.6 at low deadrise angles and reduces nearly linearly to 1.3 at 451 deadrise angle. The added mass increases quadratically with immersed depth until the chines become wetted. It then continues to increase at a reducing rate, reaching a maximum value between 20% and 80% greater than at chine immersion. The flow momentum drag coefficient is estimated from the results to be 0.78 at 51 deadrise angle reducing to 0.41 at 451 deadrise angles. Constant velocity exit tests show that the momentum of the added mass is expended in driving the water above the surface level and that exit forces are low and equivalent to a drag coefficient of about 1.0-1.3. Considerable dynamic noise limits the accuracy of the results, particularly after chine immersion

Synthesis towards the avermectins and milbemycins

Imperial Users onl

The Solent Disturbance & Mitigation Project. Phase II – results of the Solent household survey

This report sets out the results of the postal household survey component of the Solent Disturbance and Mitigation project. The work was commissioned by the Solent Forum in response to concerns over the impact of recreational pressure on features of the Solent SPA, SAC and Ramsar Sites. Of particular concern are the cumulative impacts of recreational use arising from potential new housing developments in Chichester District and South Hampshire. The household survey was distributed to 5000 households within 25km of the coastline between Hurst Castle, including the north shoreline of the Isle of Wight. The questionnaires and reminders were sent between October and December 2010. The household survey contained three sections which elicited information relating to general and specific visits to the coast and household demographics. A total of 1382 completed questionnaires were returned and 42% of these households had visited the coast the week prior to completing the survey. Only 4% of households (56) stated they never visited the coast. Households which did not visit the coast contained a lower number of people, lower number of dogs and a higher percentage did not have regular access to a private vehicle when compared to households that made regular coastal visits. Of the households which visited the coast, 50% visited at least once a week. A total of 55% of households visited the coast equally all year and an additional 39% of households made more visits in the summer. There was a significant difference in coastal visit frequency between households which owned a least one dog and non dog owning households, with dog owning households making more visits. There was no significant difference in visit frequency between households who had garden access or whether the household dwelling type was a flat or ‘non- flat’. The 1155 households providing full responses to the survey made an estimated annual total of 153,433 visits to the Solent coastline. The project and this survey divided the coastline into 103 numbered sections. Households made on average 133 annual coastal visits to 3.7 different sections of the coastline. On average each section received a total of 1490 annual visits but the number of coastal visits made to different sections was significantly different. The most frequently given activities undertaken during a coastal visit were walking (20% of all activity responses) and enjoying the scenery (20%), followed by being on the beach (11%) and meeting up with friends (11% of all activity responses). Households indicated where they undertook their activity during the coastal visit and for 47% of the visit responses the activity (walking, cycling, enjoying the scenery etc) was undertaken on the sea wall or the river bank. A further 39% of responses by households indicated they venture onto the beach/mudflat and 15% of responses actually took to the water. The majority (52%) of coastal visits by households were made by car with 39% made by foot, 4% by bicycle and 5% by public transport. Of the households which made visits by car, 50% travelled 9.5km or less by road to the section they visited and 90% travelled 29.0km or less to their visited section by road. Of the households who visited specific sections by foot half lived within 1.0km of the section (straight line distance from postcode to nearest point on section) and 90% lived within 4.0km of the visited section. Features that act as a deterrent for some households when selecting a coastal location to visit may also attract other households. For example, a requirement for dogs to be on leads and the presence of dog restrictions is rated as attractive to non dog owning households but as a deterrent by dog owning households. By far the most popular attractive feature when households choose which coastal location to visit was ‘sea views and attractive scenery’ followed by ‘feel safe’, ‘ability to do a range of different walks/routes ‘and the ‘presence of wildlife’. Predictions were derived by fitting formal statistical models to the observed (household survey) data. Specifically these models used observed visitor numbers per section per distance band and analysed these in relation to factors representing distance to section and section characteristics. Different models are presented within the report and separate models were generated for car and foot visitors, with each model showing a declining visitor rate with distance from the section – i.e. the further away people live the fewer visits they make. These models suggest some 52 million visits are made each year, by households within a 30km radius of the coastline between Hurst Castle to Chichester Harbour, including the north shore of the Isle of Wight. The models identify Portsmouth’s seafront (South Parade Pier to Fort Cumberland) as the most heavily visited coastal section, with over 3 million household visits per annum. These predictive visit models will be used alongside the bird models, commissioned separately and subject to a further report, to assess the impacts of disturbance to wintering birds under different housing scenarios. The use of the visitor models and how they will link to the bird models within the next stages of the Solent Disturbance and Mitigation Project are discussed

The Solent Disturbance & Mitigation Project Phase II – On-site visitor survey results from the Solent region

This report sets out the results of the on-site visitor survey component of the Solent Disturbance and Mitigation project. The work was commissioned by the Solent Forum in response to concerns over the impact of recreational pressure on features of the Solent SPA, SAC and Ramsar Sites. Of particular concern are the cumulative impacts of recreational use arising from potential new housing developments in the Chichester District and South Hampshire. The visitor surveys were conducted during the winter 2009/2010 to assess the level and type of visitor use at selected locations along the Solent coastline. Overall it is likely that the number of visitors interviewed and counted during the survey period was lower than would be normally be expected given the especially cold 2009/2010 winter. With that in mind, there is the potential that the monitoring could provide an underestimate of the absolute number visitors to the region. However, the interviews were designed to elicit generic and site specific details from visitors and although fewer individuals may have been recorded or interviewed because of the weather we can assume that the general winter visitation pattern remained similar and the results very useful in understanding who, where, when and why people use the coast. Counts of people and interviews were conducted at 20 locations around the Solent coastline (including the north shore of the Isle of Wight). A total of 16 hours of surveys were carried out at each location, split equally between weekend (8 hours) and a weekday (8 hours). A total of 784 interviews were conducted, accounting for 1,322 people and 550 dogs. The average group size was 1.7 people. There were differences in visitor numbers between survey locations, with the highest visitor numbers recorded at Emsworth (1088 visitors were recorded using the site over 16 hours) while Lymington (Boldre/Pylewell) was the least busy (33 visitors counted over 16 hours). Visitor numbers per day were typically highest on weekend compared to weekdays. Holiday makers accounted for 6% of the total number of visitors recorded (80 visitors). Visitors were undertook a wide range of activities, with walking (without a dog) and dog walking the two most frequently recorded activities (44% and 42% of interviews). Across all sites and activities, visits were typically short, with 89% lasting less than two hours. The main modes of transport used to reach sites were by car and on foot, with the proportion of people arriving by each mode varying between sites. Across all sites (and taking the data for non-holiday makers only), 51% of interviewees arrived by car and a further 46% arrived on foot. Home postcodes were used to identify the distance between interviewee’s home and the location where interviewed. Half of all visitors arriving on foot lived within 0.7km, while half of all visitors arriving by car lived more than 4km away. Only 9% of foot visitors lived more than 2km away compared to 80% of all car visitors. Linear regressions using housing numbers within different distance bands of a location as a predictor of visitor numbers for each location show a positive relationship between the number of houses within 1km, 3km and 5km and number of visitors entering each survey location. Car park capacity at the access points did not provide a good indication of the frequency of visitors arriving by car to each location. The relationship is more complex, future modelling of visitor rates travelling to locations by car should include potential road related parking (related to length of nearby roads around access points) in addition to official and off road car parking capacity around the access points. 2 Route data were also collected for each interview, with lines drawn directly on maps during the survey. These route data were analysed to determine which activities take place below Mean High Water Mark (MHWM) and how far different groups go out into the intertidal. Across all the interviews, 7% of the mapped routes did not go within 25m of MHWM and were therefore visitors who did not actually make it to the beach (in some locations the survey point was set inland, for example near to parking locations etc.). A further 78% were entirely within the band between 25m above and 25m below MHWM, indicating routes that remained at the top of the beach, on the seawall or similar. It was 14% of the mapped routes that went below 50m from MHWM, and these included a range of activities, for example bait diggers, dog walkers, joggers, cyclists and people out on a family outing. The implications of the results for further modelling and in relation to the disturbance of birds on the European Sites are discussed