Independent Orbiter Assessment (IOA): Analysis of the landing/deceleration subsystem

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Landing/Deceleration Subsystem hardware. The Landing/Deceleration Subsystem is utilized to allow the Orbiter to perform a safe landing, allowing for landing-gear deploy activities, steering and braking control throughout the landing rollout to wheel-stop, and to allow for ground-handling capability during the ground-processing phase of the flight cycle. Specifically, the Landing/Deceleration hardware consists of the following components: Nose Landing Gear (NLG); Main Landing Gear (MLG); Brake and Antiskid (B and AS) Electrical Power Distribution and Controls (EPD and C); Nose Wheel Steering (NWS); and Hydraulics Actuators. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Due to the lack of redundancy in the Landing/Deceleration Subsystems there is a high number of critical items

Results from a three year testing project of new strawberry cultivars in Verticillium infested soils and under organic farming conditions

As part of a research project 13 cultivars were planted in 2005 at 11 sites on 9 farms in 5 different Austrian regions. The aim was to find new cultivars tolerant to soil-borne pathogens and leaf/fruit diseases, with high yield, winter hardness and good fruit quality, to serve as alternative to the highly susceptible cultivar ‘Elsanta’, regarding soil-borne diseases. Plant vigour and infestation with Verticillium dahliae and leaf diseases were evaluated in 2005 und 2006 at 7 sites and in 2007 at 3 sites. In addition, following parameters were assessed on 2 organically managed sites in 2006 and 2007: marketable yield, percentage of different categories of unmarketable fruits and incidence of the blossom weevil. In 2006 fruit characteristics and consumer acceptance were studied. ‘Elsanta’ showed the highest infestation with V. dahliae whereas ‘Salsa’, ‘Daroyal’ and ‘Alice’ were most tolerant. ‘Dora’, ‘Eva’, ‘Queen Elisa’ and ‘Daroyal’ recorded significantly higher losses by the blossom weevil than ‘Alice’. ‘Alba’ and ‘Divine’ were the earliest cultivars in ripening time. Highest marketable yield per plant had the late ripening cultivars, particularly ‘Salsa’ and ‘Sonata’. Of all early ripening cultivars tested, ‘Elsanta’ showed the highest productivity, followed by 'Alba', ‘Darselect’, ‘Daroyal’ and ‘Eva’. Regarding fruit firmness, content of ascorbic acid, shelf life and appearance, ‘Alba’, ’Clery’, ‘Eva’ and ‘Queen Elisa’ were most convincing. The best tasting cultivars were ‘Clery’, ‘Daroyal’ and ‘Divine’. Summing up all the results, ‘Alba’, ‘Alice’ and ‘Salsa’ can be recommended for organic production, whereas ‘Clery’, ‘Daroyal’, ‘Darselect’, ‘Elsanta’, ‘Eva’, ‘Queen Elisa’ and ‘Sonata’ are classified as suitable for only a limited extent. ‘Elsanta’, ‘Divine’, ‘Dora’ and ‘Sonata’ are particularly unsuitable for growing in Verticillium infested soils. ‘Divine’, ‘Dora’, and ‘Record’ cannot be recommended for organic production at all

Effect of dynamic stall on the aerodynamics of vertical-axis wind turbines

Accurate simulations of the aerodynamic performance of vertical-axis wind turbines pose a significant challenge for computational fluid dynamics methods. The aerodynamic interaction between the blades of the rotor and the wake that is produced by the blades requires a high-fidelity representation of the convection of vorticity within the wake. In addition, the cyclic motion of the blades induces large variations in the angle of attack on the blades that can manifest as dynamic stall. The present paper describes the application of a numerical model that is based on the vorticity transport formulation of the Navier–Stokes equations, to the prediction of the aerodynamics of a verticalaxis wind turbine that consists of three curved rotor blades that are twisted helically around the rotational axis of the rotor. The predicted variation of the power coefficient with tip speed ratio compares very favorably with experimental measurements. It is demonstrated that helical blade twist reduces the oscillation of the power coefficient that is an inherent feature of turbines with non-twisted blade configurations

Disease classification from capillary electrophoresis: mass spectrometry

We investigate the possibility of using pattern recognition techniques to classify various disease types using data produced by a new form of rapid Mass Spectrometry. The data format has several advantages over other high-throughput technologies and as such could become a useful diagnostic tool. We investigate the binary and multi-class performances obtained using standard classifiers as the number of features is varied and conclude that there is potential in this technique and suggest research directions that would improve performance

Practical Implementation of a General Numerical Lifting-Line Method

A general numerical lifting-line method provides corrections to overcome the singularities inherent in the lifting-line downwash integrals in certain cases. These singularities have previously limited the scope of lifting-line theory to straight wings not in sideslip; in all other cases, more traditional numerical approaches to solving Prandtl\u27s hypothesis fail to grid converge. However, this general numerical lifting-line method grid converges even for swept wings and wings in sideslip. In the current work, we apply the general numerical lifting-line method to any number of wings with arbitrary geometry. We also provide a dimensional derivation of the basic general numerical lifting-line equations and discuss how airfoil section properties can be corrected for sweep. We develop a linearized system of equations and a nonlinear improvement method to solve the general numerical lifting-line equations. Results show that placing the lifting-line on the wing locus of aerodynamic centers, as done by others, may not yield the most accurate results. Comparisons with published data reveal that the general numerical lifting-line method can accurately predict the lift distribution for swept wings

Vegetation response to invasive Tamarix control in southwestern U.S. rivers: a collaborative study including 416 sites

Most studies assessing vegetation response following control of invasive Tamarix trees along southwestern U.S. rivers have been small in scale (e.g., river reach), or at a regional scale but with poor spatial-temporal replication, and most have not included testing the effects of a now widely used biological control. We monitored plant composition following Tamarix control along hydrologic, soil, and climatic gradients in 244 treated and 172 reference sites across six U.S. states. This represents the largest comprehensive assessment to date on the vegetation response to the four most common Tamarix control treatments. Biocontrol by a defoliating beetle (treatment 1) reduced the abundance of Tamarix less than active removal by mechanically using hand and chain-saws (2), heavy machinery (3) or burning (4). Tamarix abundance also decreased with lower temperatures, higher precipitation, and follow-up treatments for Tamarix resprouting. Native cover generally increased over time in active Tamarix removal sites, however, the increases observed were small and was not consistently increased by active revegetation. Overall, native cover was correlated to permanent stream flow, lower grazing pressure, lower soil salinity and temperatures, and higher precipitation. Species diversity also increased where Tamarix was removed. However, Tamarix treatments, especially those generating the highest disturbance (burning and heavy machinery), also often promoted secondary invasions of exotic forbs. The abundance of hydrophytic species was much lower in treated than in reference sites, suggesting that management of southwestern U.S. rivers has focused too much on weed control, overlooking restoration of fluvial processes that provide habitat for hydrophytic and floodplain vegetation. These results can help inform future management of Tamarix-infested rivers to restore hydrogeomorphic processes, increase native biodiversity and reduce abundance of noxious species

Changes in gene expression patterns in the tumor microenvironment of head and neck squamous cell carcinoma under chemoradiotherapy depend on response

Chemoradiotherapy (CRT) is a standard treatment for advanced head and neck squamous cell carcinoma (HNSCC). Unfortunately, not all patients respond to this therapy and require further treatment, either salvage surgery or palliative therapy. The addition of immunotherapy to CRT is currently being investigated and early results describe a mixed response. Therefore, it is important to understand the impact of CRT on the tumor microenvironment (TME) to be able to interpret the results of the clinical trials. Paired biopsies from 30 HNSCC patients were collected before and three months after completion of primary CRT and interrogated for the expression of 1392 immune- and cancer-related genes. There was a relevant difference in the number of differentially expressed genes between the total cohort and patients with residual disease. Genes involved in T cell activation showed significantly reduced expression in these tumors after therapy. Furthermore, gene enrichment for several T cell subsets confirmed this observation. The analysis of tissue resident memory T cells (TRM) did not show a clear association with impaired response to therapy. CRT seems to lead to a loss of T cells in patients with incomplete response that needs to be reversed. It is not clear whether the addition of anti-PD-1 antibodies alone to CRT can prevent treatment failure, as no upregulation of the targets was measurable in the TME