V/STOL maneuverability and control

Maneuverability and control of V/STOL aircraft in powered-lift flight is studied with specific considerations of maneuvering in forward flight. A review of maneuverability for representative operational mission tasks is presented and covers takeoff, transition, hover, and landing flight phases. Maneuverability is described in terms of the ability to rotate and translate the aircraft and is specified in terms of angular and translational accelerations imposed on the aircraft. Characteristics of representative configurations are reviewed, including experience from past programs and expectations for future designs. The review of control covers the characteristics inherent in the basic airframe and propulsion system and the behavior associated with ontrol augmentation systems. Demands for augmented stability and control response to meet certain mission operational requirements are discussed. Experience from ground-based simulation and flight experiments that illustrates the impact of augmented stability and control on aircraft design is related by example

Physiographic constraints on the origin of lunar wrinkle ridges

Wrinkle ridges are linear asymmetric topographic highs with considerable morphologic complexity that are commonly found on the lunar maria and the smooth plains of Mars and Mercury. The origin of planetary wrinkle ridges has been a much argued and debated topic. Early ideas suggested that wrinkle ridges resulted from volcanic intrusion and extrusion of high viscosity lavas; these early ideas were countered with suggestions that wrinkle ridges formed from tectonic processes involving folding and faulting. Combined volcanic and tectonic mechanisms have also been suggested. The identification and analysis of a number of morphologically similar structures on the earth has helped in the recent interpretation of wrinkle ridges as thrust faults that deform surface rocks. Nevertheless, there remains the uncertainty of the dominant role of thrusting versus folding in the formation of planetary wrinkle ridges. Presented is a detailed physiographic analysis of lunar wrinkle ridges in an effort to help distinguish the dominant deformation mechanism. Results agree with the findings of the earth analog study and support the hypothesis that wrinkle ridges form from thrust faults that deform surface rocks

Modelled and measured strain in mascon basins on the moon

The close association of wrinkle ridges and grabens with mascon basins on the Moon has suggested that the responsible compression and extension resulted from basin subsidence and peripheral flexing of the lithosphere. The distribution of grabens and wrinkle ridges associated with mascon basins has been further used along with elastic plate bending models to constrain the thickness of the lithosphere at the time of their formation. Kinematic models for basin subsidence have also been developed and compared with strains inferred from grabens and wrinkle ridges. Note that kinematic models may be preferable to dynamic models because the strain associated with tectonic features can be compared directly with model predictions and because fewer assumptions are required for their calculations, such as perfect elasticity and specific values of the elastic moduli. Also, if the results from kinematic models compare favorably with the strain estimated across the tectonic features on the Moon, then a global strain field may not be necessary. Herein, the strain inferred for wrinkle ridges and grabens was compared to that calculated from a simple kinematic subsidence model for mascon basins on the Moon

Shortcuts to Spherically Symmetric Solutions: A Cautionary Note

Spherically symmetric solutions of generic gravitational models are optimally, and legitimately, obtained by expressing the action in terms of the two surviving metric components. This shortcut is not to be overdone, however: a one-function ansatz invalidates it, as illustrated by the incorrect solutions of [1].Comment: 2 pages. Amplified derivation, accepted for publication in Class Quant Gra

Unintentional injury prevention and the role of occupational therapy in the Solomon Islands: an integrative review

Introduction: Unintentional injuries (injuries for which there is no evidence of a predetermined intent) are one of the leading causes of death worldwide, particularly in low- and middle-income countries (LMICs). Although evidence demonstrates unintentional injuries are preventable it is a public health challenge for many LMICs such as the Solomon Islands. Occupational therapists are well placed to contribute to injury prevention, as they have specialised skills to analyse the accessibility and safety of the environments within which people conduct their daily occupations. While the role of occupational therapy in unintentional injury prevention is well known in high-income countries, it is unfamiliar in LMICs, especially in the Solomon Islands. This integrative review aimed to explore the incidence of common unintentional injuries, and the burden in the Solomon Islands; and explore the potential role of occupational therapy in unintentional injury prevention in the Solomon Islands, based on current activities in LMICs. Method: Articles were reviewed from six databases (Medline, CINAHL, OTDBase, OT Seeker, Scopus and PsychInfo). Five articles met the inclusion criteria for the first objective and 15 articles met the inclusion criteria for the second objective. These articles were thematically analysed where themes and codes associated with the research objectives were extracted and analysed. Results: Unintentional injuries in the Solomon Islands reported in the literature included ocular trauma, falls from fruit trees and coconut palms, and road traffic crashes. Burden of injury reported was mostly associated with loss of productivity. Occupational therapists undertook rehabilitative, biomechanical, neurodevelopmental and educational roles in LMIC, focusing on tertiary and secondary injury prevention. Conclusions: This integrative review suggests that there is limited information regarding injury in the Solomon Islands. However, evidence is available in LMICs to suggest that occupational therapy services can play a potential significant role in unintentional injury prevention, demonstrating a need for establishing injury prevention within the occupational therapy role in the Solomon Islands

Unintentional injury prevention and the role of occupational therapy in the Solomon Islands: an integrative review

Introduction: Unintentional injuries (injuries for which there is no evidence of a predetermined intent) are one of the leading causes of death worldwide, particularly in low- and middle-income countries (LMICs). Although evidence demonstrates unintentional injuries are preventable it is a public health challenge for many LMICs such as the Solomon Islands. Occupational therapists are well placed to contribute to injury prevention, as they have specialised skills to analyse the accessibility and safety of the environments within which people conduct their daily occupations. While the role of occupational therapy in unintentional injury prevention is well known in high-income countries, it is unfamiliar in LMICs, especially in the Solomon Islands. This integrative review aimed to explore the incidence of common unintentional injuries, and the burden in the Solomon Islands; and explore the potential role of occupational therapy in unintentional injury prevention in the Solomon Islands, based on current activities in LMICs. Method: Articles were reviewed from six databases (Medline, CINAHL, OTDBase, OT Seeker, Scopus and PsychInfo). Five articles met the inclusion criteria for the first objective and 15 articles met the inclusion criteria for the second objective. These articles were thematically analysed where themes and codes associated with the research objectives were extracted and analysed. Results: Unintentional injuries in the Solomon Islands reported in the literature included ocular trauma, falls from fruit trees and coconut palms, and road traffic crashes. Burden of injury reported was mostly associated with loss of productivity. Occupational therapists undertook rehabilitative, biomechanical, neurodevelopmental and educational roles in LMIC, focusing on tertiary and secondary injury prevention. Conclusions: This integrative review suggests that there is limited information regarding injury in the Solomon Islands. However, evidence is available in LMICs to suggest that occupational therapy services can play a potential significant role in unintentional injury prevention, demonstrating a need for establishing injury prevention within the occupational therapy role in the Solomon Islands

Chromatin meets RNA polymerase II

A report on the Cold Spring Harbor Laboratory meeting 'Mechanisms of eukaryotic transcription', Cold Spring Harbor, USA, 2 August-2 September 2007

Potential barrier lowering and electrical transport at the LaAlO3_{3}/SrTiO3_{3} heterointerface

Using a combination of vertical transport measurements across and lateral transport measurements along the LaAlO$_{3}$/SrTiO$_{3}$ heterointerface, we demonstrate that significant potential barrier lowering and band bending are the cause of interfacial metallicity. Barrier lowering and enhanced band bending extends over 2.5 nm into LaAlO$_{3}$ as well as SrTiO$_{3}$. We explain origins of high-temperature carrier saturation, lower carrier concentration, and higher mobility in the sample with the thinnest LaAlO$_{3}$ film on a SrTiO$_{3}$ substrate. Lateral transport results suggest that parasitic interface scattering centers limit the low-temperature lateral electron mobility of the metallic channel.Comment: 10 pages, 3 figures, and 1 tabl

Home range and habitat use by Kemp's Ridley turtles in West-Central Florida

The Kemp's ridley turtle (Lepidochelys kempii) is an endangered species whose recovery depends in part on the identification and protection of required habitats. We used radio and sonic telemetry on subadult Kemp's ridley turtles to investigate home-range size and habitat use in the coastal waters of west-central Florida from 1994 to 1996. We tracked 9 turtles during May-August up to 70 days after release and fou.ld they occupied 5-30 km2 foraging ranges. Compositional analyses indicated that turtles used rock outcroppings in their foraging ranges at a significantly higher proportion than expected. based on availability within the study area. Additionally. turtles used live bottom (e.g .• sessile invertebrates) and green macroalgae habitats significantly more than seagrass habitat. Similar studies are needed through'mt the Kemp's ridley turtles' range to investigate regional and stage-specific differences in habitat use. which can then be used to conserve important foraging areas

Intrinsic thermal vibrations of suspended doubly clamped single-wall carbon nanotubes

We report the observation of thermally driven mechanical vibrations of suspended doubly clamped carbon nanotubes, grown by chemical vapor deposition (CVD). Several experimental procedures are used to suspend carbon nanotubes. The vibration is observed as a blurring in images taken with a scanning electron microscope. The measured vibration amplitudes are compared with a model based on linear continuum mechanics.Comment: pdf including figures, see: http://www.unibas.ch/phys-meso/Research/Papers/2003/NT-Thermal-Vibrations.pd