Interactive analysis of a large aperture Earth observations satellite

A system level design and analysis has been conducted on an Earth Observation Satellite (EOS) system using the Interactive Design and Evaluation of Advanced Spacecraft (IDEAS) computer-aided design and analysis program. The IDEAS program consists of about 40 user-friendly technical modules and an interactive graphics display. The reflector support system and feed mast of the EOS spacecraft are constructed with box-truss structural concept, a lattice configuration which can be packaged for delivery in a single Shuttle flight and deployed in orbit. The deployed spacecraft consists of a 120-m by 60-m parabolic focal axis. The spacecraft was modeled for structural, thermal, and control systems analysis and structural elements were designed. On-orbit dynamic and thermal loading analyses were conducted; spacecraft weights and developmental and first unit costs were determined

Pension pots and how to survive them

Annuitising at retirement is not the best option. This new research report produced by Cass Business School argues that most people are better off drawing down, rather than annuitising. In 2014 the UK Government announced proposals to allow people to withdraw money from their pension pot from age 55, subject to their marginal rate of income tax in that year. This paper looks at how individuals can best use their pension pots. The research finds that with careful management, moderate sized pension pots of £100,000 or more should not run out until at least the age of 80 or even older. Using a flexible rather than fixed drawdown approach can reduce the risk of running out still further. The research recommends having a full financial ‘health check’ at the point of decision, and if drawdown is decided upon then the research recommends seeking regular independent professional advice thereafter

The effect of longevity drift and investment volatility on income sufficiency in retirement

In 2014 the Government announced radical proposals which now allow people to withdraw money from their pension pot from age 55, ‘how they want, subject to their marginal rate of income tax in that year’. The main effect of this change will be to put more onus on the individual to make sure they have sufficient resources to last for their retirement, but it also removes the obligation to annuitise their funds at any future age. This paper is concerned with how people can best use their pension pots by aligning them to their personal financial objectives and longevity risks. It finds that for most people annuitising is not the best option, except for a few circumstances, and that draw down is preferable, especially where there is a bequest motive and the individual has assets such as property to fall back on. These options are low risk if simple rules are followed but they are not a substitute for professional advice and should only be used in conjunction

Measurements of the structure and circulation of the stratosphere and mesosphere, 1971-2

Complete data from a total of 43 meteorological rocket soundings of the stratosphere and mesosphere conducted from Barrow, Alaska; Churchill, Canada; Wallops Island Va.; and Kourou, French Guiana are presented. These data consist of temperature, pressure, density, and wind profiles from 35 acoustic grenade soundings that cover the 30 to 90 km altitude range, and temperature, pressure, and density profiles from 8 pitot probe soundings that cover the 25 to 120 km altitude range. Errors for each of the 35 acoustic grenade soundings are also included

Optical photometric GTC/OSIRIS observations of the young massive association Cygnus OB2

In order to fully understand the gravitational collapse of molecular clouds, the star formation process and the evolution of circumstellar disks, these phenomena must be studied in different Galactic environments with a range of stellar contents and positions in the Galaxy. The young massive association Cygnus OB2, in the Cygnus-X region, is an unique target to study how star formation and the evolution of circumstellar disks proceed in the presence of a large number of massive stars. We present a catalog obtained with recent optical observations in r,i,z filters with OSIRIS, mounted on the $10.4\,m$ GTC telescope, which is the deepest optical catalog of Cyg OB2 to date. The catalog consist of 64157 sources down to M=0.15 solar masses at the adopted distance and age of Cyg OB2. A total of 38300 sources have good photometry in all three bands. We combined the optical catalog with existing X-ray data of this region, in order to define the cluster locus in the optical diagrams. The cluster locus in the r-i vs. i-z diagram is compatible with an extinction of the optically selected cluster members in the 2.64<AV<5.57 range. We derive an extinction map of the region, finding a median value of AV=4.33 in the center of the association, decreasing toward the north-west. In the color-magnitude diagrams, the shape of the distribution of main sequence stars is compatible with the presence of an obscuring cloud in the foreground at about 850+/-25 pc from the Sun.Comment: Accepted for publication ApJS 201

Exposure to nanomaterials in consumer spray products available in the UK

Products containing nanomaterials (NMs) (size < 100 nanometres) are rapidly entering the market, however little is known about inhalation exposures to NMs from their use. Here, we analysed representative consumer spray products available in the UK that claim (or are expected) to contain NMs, to assess potential NM exposure levels during use. In the absence of a UK-focused product inventory, we searched “The Nanodatabase” (nanodb.dk), which listed 269 (out of 3001) products for which inhalation was identified as an exposure pathway. None were available over-the-counter at large stores, but 40 were available on “.co.uk” websites (mainly Amazon). We obtained a representative sample (based on product type and claimed content e.g. silver, silica, gold) and found that 12 out of 16 products contained detectable NMs. We used a multi-method approach to characterise the NMs; inductively-coupled plasma mass spectrometry (ICP-MS), ultraviolet-visible spectroscopy and energy-dispersive x-ray spectroscopy to assess NM composition, and dynamic light scattering, nanoparticle tracking analysis, transmission electron microscopy and single particle ICP-MS to determine particle size and shape. The sizes of the airborne particles/droplets produced by spraying a sub-set (6) of these products were measured using aerodynamic and mobility particle sizers, demonstrating the presence of inhalable aerosols. Whilst 5 out of 6 products clearly contained NMs, only 3 produced aerosols in the nano-size range, suggesting that other constituents (e.g. solvent, fragrance) make up the bulk of the aerosol mass. Using the data generated, quantities of NMs inhaled when using these products can be estimated, which is important for appropriate risk characterisation

Group selection models in prebiotic evolution

The evolution of enzyme production is studied analytically using ideas of the group selection theory for the evolution of altruistic behavior. In particular, we argue that the mathematical formulation of Wilson's structured deme model ({\it The Evolution of Populations and Communities}, Benjamin/Cumings, Menlo Park, 1980) is a mean-field approach in which the actual environment that a particular individual experiences is replaced by an {\it average} environment. That formalism is further developed so as to avoid the mean-field approximation and then applied to the problem of enzyme production in the prebiotic context, where the enzyme producer molecules play the altruists role while the molecules that benefit from the catalyst without paying its production cost play the non-altruists role. The effects of synergism (i.e., division of labor) as well as of mutations are also considered and the results of the equilibrium analysis are summarized in phase diagrams showing the regions of the space of parameters where the altruistic, non-altruistic and the coexistence regimes are stable. In general, those regions are delimitated by discontinuous transition lines which end at critical points.Comment: 22 pages, 10 figure

Testing the circularity of PSR B0818-41's carousel

The phenomenon of sub-pulse drifting is an important single-pulse phenomenon that can potentially provide important insights into the elusive radio emission mechanism in pulsars. We analyze the frequency behaviour of the single pulses of B0818-41, observed from 300 to 500 MHz (Band 3 of the uGMRT), and compare it to the evolution of the average profile to place constraints on the geometry of the pulsar's emission beam. We show that a circular carousel of discrete beamlets, where each beamlet has radial symmetry, is not consistent with the observed behaviour, and describe an alternative, consistent range of possible elliptical carousel geometries. We also combine the uGMRT data with some archival MWA observations and several other published profiles to characterize the profile evolution across a frequency range spanning ~170 MHz to ~1.4 GHz

The Development and Application of High-Critical-Speed Nose Inlets

An analysis of the nose-inlet shapes developed in previous investigations to represent the optimum from the standpoint of critical speed has shown that marked similarity exists between the nondimensional profiles of inlets which have widely different proportions and critical speeds. With the nondimensional similarity of such profiles established, the large differences in the critical speeds of these nose inlets must be a function of their proportions. An investigation was undertaken in the Langley 8-foot high-speed tunnel to establish the effects of nose-inlet proportions on critical Mach number to develop a rational method for the design of high-critical-speed nose inlets to meet desired requirements. The test results data have been arranged in the form of design charts from NACA 1-series nose-inlet proportions and can be selected for given values of critical Mach number and airflow quantity. Examples of nose-inlet selections are presented for a typical jet-propulsion installation (critical Mach number of 0.83) and for two conventional radial-engine installations (critical Mach number of 0.76)

Investigation of Red-cockaded Woodpeckers within the Great Dismal Swamp National Wildlife Refuge: 2017 report

The Virginia population of red-cockaded woodpeckers is the northernmost throughout the species range and has been in eminent danger of extinction for more than 30 years. The single remaining population within the Piney Grove Preserve has responded to intensive management and is now approaching capacity but continues to be at risk to stochastic events such as hurricanes, tornadoes and disease. To offset this risk a three-phase conservation plan was developed that includes the establishment of additional breeding locations. The Great Dismal Swamp National Wildlife Refuge was identified as a high priority site for the establishment of a second population due to its capacity for habitat management and the similarity of habitat to non-typical red-cockaded woodpecker sites in nearby coastal North Carolina. In an effort to establish a population within the swamp, habitat management was initiated several years ago and translocation of birds into established recruitment clusters began in 2015. During the 2017 breeding season, the first breeding attempts were recorded and the first young were produced within the Great Dismal Swamp, NWR. By May the site supported two potential breeding groups. Both of these groups produced three-egg clutches. Three of the six eggs hatched and two of the three young fledged successfully resulting in a reproductive rate of 1±1.0 (mean±SE) young/breeding group. Both birds were females and both were still present within the site in December of 2017. During the calendar year of 2017, 17 individual red-cockaded woodpeckers were identified within the Great Dismal Swamp, NWR including three birds from the 2015 translocation cohort, two birds from the 2016 translocation cohort, ten birds from the 2017 translocation cohort and two birds produced within the refuge during the 2017 breeding season. Three birds were lost between the 2016 winter survey and the 2017 spring survey leaving only five birds moving into the breeding season. Two translocation events were executed during the fall of 2017 including a move of eight birds (4 females and 4 males) from Carolina Sandhills, NWR on 5 October and two birds (1 female and 1 male) from Piney Grove Preserve on 19 October. Eleven birds were detected during the 2017 winter survey. This compares to seven in 2015 and eight in 2016. A total of 62 woodpecker cavities had been created within the Great Dismal Swamp, NWR by the end of 2017. Three of these cavity trees were lost in October of 2016 during Hurricane Matthew. An additional six cavity trees were lost in March of 2017 during high-wind events. All of the trees lost in 2017 were snapped off at the insert location including two that were being used as roost trees. To compensate for losses, nine artificial cavities were installed during the late summer of 2017. The first natural cavity was discovered in a pond pine in December of 2017 (cluster S2-2). The primary objective of this ongoing project is to establish a breeding population of Red-cockaded Woodpeckers within the Great Dismal Swamp, NWR. A secondary objective is to collect information relevant to the continued management of birds and their habitat in Virginia. Specific objectives include: 1) To determine the number and identification of all birds resident within the Great Dismal Swamp, NWR during the 2017 calendar year. 2) To monitor breeding activity in order to document productivity and allow for the unique banding of all individuals within the population. 3) To determine fledging success for all breeding attempts. 4) To translocate birds from donor sites to the Great Dismal Swamp, NWR. 5) To monitor cavity tree and artificial cavity condition