On some numerical difficulties in integrating the equations for one-dimensional nonequilibrium nozzle flow

Numerical difficulties in integrating equations for one dimensional nonequilibrium nozzle flow of ga

An experimental evaluation of the use of Δ13C as a proxy for palaeoatmospheric CO2

Understanding changes in atmospheric CO2 over geological time via the development of well constrained and tested proxies is of increasing importance within the Earth sciences. Recently a new proxy (identified as the C3 proxy) has been proposed that is based on the relationship between CO2 and carbon isotope discrimination (Δ13C) of plant leaf tissue. Initial work suggests that this proxy has the capacity to deliver accurate and potentially precise palaeo-CO2 reconstructions through geological time since the origins of vascular plants (∼450 Mya). However, the proposed model has yet to be fully validated through independent experiments. Using the model plant Arabidopsis thaliana exposed to different watering regimes and grown over a wide range of CO2 concentrations (380, 400, 760, 1000, 1200, 1500, 2000 and 3000ppm) relevant to plant evolution we provide an experimental framework that allows for such validation. Our experiments show that a wide variation in Δ13C as a function of water availability is independent of CO2 treatment. Validation of the C3 proxy was undertaken by comparing growth CO2 to estimates of CO2 derived from Δ13C. Our results show significant differences between predicted and observed CO2 across all CO2 treatments and water availabilities, with a strong under prediction of CO2 in experiments designed to simulate Cenozoic and Mesozoic atmospheric conditions (≥1500ppm). Further assessment of Δ13C to predict CO2 was undertaken using Monte Carlo error propagation. This suite of analysis revealed a lack of convergence between predicted and observed CO2. Collectively these findings suggest that the relationship between Δ13C and CO2 is poorly constrained. Consequently the use of Δ13C as a proxy to reconstruct palaeoatmospheric CO2 is of limited use as the estimates of CO2 are not accurate when compared to known growth conditions

Generalized indical forces on deforming rectangular wings in supersonic flight

A method is presented for determining the time-dependent flow over a rectangular wing moving with a supersonic forward speed and undergoing small vertical distortions expressible as polynomials involving spanwise and chordwise distances. The solution for the velocity potential is presented in a form analogous to that for steady supersonic flow having the familiar "reflected area" concept discovered by Evvard. Particular attention is paid to indicial-type motions and results are expressed in terms of generalized indicial forces. Numerical results for Mach numbers equal to 1.1 and 1.2 are given for polynomials of the first and fifth degree in the chordwise and spanwise directions, respectively, on a wing having an aspect ratio of 4

Integrals and integral equations in linearized wing theory

The formulas of subsonic and supersonic wing theory for source, doublet, and vortex distributions are reviewed and a systematic presentation is provided which relates these distributions to the pressure and to the vertical induced velocity in the plane of the wing. It is shown that care must be used in treating the singularities involved in the analysis and that the order of integration is not always reversible. Concepts suggested by the irreversibility of order of integration are shown to be useful in the inversion of singular integral equations when operational techniques are used. A number of examples are given to illustrate the methods presented, attention being directed to supersonic flight speed

Two-and three-dimensional unsteady lift problems in high-speed flight

The problem of transient lift on two- and three-dimensional wings flying at high speeds is discussed as a boundary-value problem for the classical wave equation. Kirchoff's formula is applied so that the analysis is reduced, just as in the steady state, to an investigation of sources and doublets. The applications include the evaluation of indicial lift and pitching-moment curves for two-dimensional sinking and pitching wings flying at Mach numbers equal to 0, 0.8, 1.0, 1.2 and 2.0. Results for the sinking case are also given for a Mach number of 0.5. In addition, the indicial functions for supersonic-edged triangular wings in both forward and reverse flow are presented and compared with the two-dimensional values

Lanreotide extended-release aqueous-gel formulation, injected by patient, partner or healthcare provider in patients with acromegaly in the United States: 1-year data from the SODA registry

Lanreotide depot (LD; commercial name Somatuline® Depot) is an injectable, extended-release formulation of the synthetic somatostatin analog (SSA) lanreotide. In recent clinical trials, LD was found to be suitable for self or partner administration, avoiding the need to travel to a medical facility. The Somatuline® Depot for Acromegaly (SODA) study is an ongoing, multicenter, observational study in the US investigating the efficacy, safety, convenience and symptom relief provided by LD in patients with acromegaly. Sub-analyses explore outcomes according to who administered the injection: patient, partner, healthcare provider (HCP) or a combination. Data reported here reflect one year of patient experience. Patients are eligible for inclusion if they have a diagnosis of acromegaly, are treated with LD and can give signed informed consent. Baseline data include patient demographics, previous acromegaly treatment and investigations, GH and IGF-I levels, LD dose and dose adjustment frequency. Symptom frequency, injection pain and treatment convenience are assessed using patient-reported questionnaires. As of 18 April 2012, 166 patients had enrolled in SODA. Most (72 %) achieved normal IGF-I levels after 12 months of LD treatment. Disease control was similar in self or partner injectors and in patients who received injections from their HCP, although self or partner injecting was deemed more convenient. LD was well-tolerated irrespective of who performed the injection. Self injection led to more injection-site reactions, but this did not increase the rate of treatment interruption. Acromegaly symptoms remained stable. Biochemical, safety and convenience data support the clinical validity of injecting LD at home