Development of Three-Dimensional Flow Code Package to Predict Performance and Stability of Aircraft with Leading Edge Ice Contamination

In the work reported herein, a simplified, uncoupled, zonal procedure is utilized to assess the capability of numerically simulating icing effects on a Boeing 727-200 aircraft. The computational approach combines potential flow plus boundary layer simulations by VSAERO for the un-iced aircraft forces and moments with Navier-Stokes simulations by NPARC for the incremental forces and moments due to iced components. These are compared with wind tunnel force and moment data, supplied by the Boeing Company, examining longitudinal flight characteristics. Grid refinement improved the local flow features over previously reported work with no appreciable difference in the incremental ice effect. The computed lift curve slope with and without empennage ice matches the experimental value to within 1%, and the zero lift angle agrees to within 0.2 of a degree. The computed slope of the un-iced and iced aircraft longitudinal stability curve is within about 2% of the test data. This work demonstrates the feasibility of a zonal method for the icing analysis of complete aircraft or isolated components within the linear angle of attack range. In fact, this zonal technique has allowed for the viscous analysis of a complete aircraft with ice which is currently not otherwise considered tractable

Thermal and Cold Neutron Computed Tomography at the Los Alamos Neutron Scattering Center Using an Amorphous Silicon Detector Array

The use of the EG&G-Heimann RTM 128 [1] or dpiX FS20 [2] amorphous silicon (a-Si) detector array for thermal neutron radiography/computed tomography has proven to be a quick and efficient means of producing high quality digital radiographic images. The resolution, although not as good as film, is about 750 μm with the RTM and 127 μm with the dpiX array with a dynamic range in excess of 2800. In many respects using an amorphous silicon detector is an improvement over other techniques such as imaging with a CCD camera, using a storage phosphor plate or film radiography. Unlike a CCD camera, which is highly susceptible to radiation damage, a-Si detectors can be placed in the beam directly behind the object under examination and do not require any special optics or turning mirrors. The amorphous silicon detector also allows enough data to be acquired to construct a digital image in just a few seconds (minimum gate time 40 ms) whereas film or storage plate exposures can take many minutes and need to be digitized with a scanner. The flat panel can, therefore, acquire a complete 3D computed tomography data set in just a few tens of minutes. While a-Si detectors have been proposed for use in imaging neutron beams [3], this is the first reported implementation of such a detector for neutron imaging [4]

Geochemical applications in petroleum systems analysis: new constraints and the power of integration

This paper provides an overview of the role that geochemistry plays in petroleum systems analysis, and how this can be used to derive constraints on the key elements and processes that give rise to a successful petroleum system. We discuss the history of petroleum geochemistry before reflecting on the next frontier in geochemical applications in hydrocarbon systems. We then review the individual contributions to this Special Publication. These papers present new geochemical techniques that allow us to develop a more systematic understanding of critical petroleum system elements; including the temperature and timing of source-rock deposition and maturation, the mechanisms and timescales associated with hydrocarbon migration, trapping, storage and alteration, and the impact of fluid flow on reservoir properties. Finally, we provide a practical example of how these different geochemical techniques can be integrated to constrain and generate a robust understanding of the prolific Paleozoic petroleum system of the Bighorn Basin

Facial Fat Grafting (FFG): Worth the Risk? A Systematic Review of Complications and Critical Appraisal

Introduction: Autologous fat is ideal soft tissue filler. It is easily accessible, biocompatible, cheap, and it provides both volume augmentation and skin quality improvement. Fat grafting has been used since 1893, but it has only gained widespread popularity since the development of modern liposuction by Colemann and Illouz in the 1980s. Every year more than half a million facial fat grafting procedures are carried out worldwide and the trend is rapidly increasing. Overall, general complications associated with facial fat grafting are assumed to be around 2%. Is that true? Material and Methods: Until July 2021, a systematic search of the literature was performed interrogating PubMed search engines. The following algorithm was used for the research: (fat graft OR lipofilling) AND face AND complications. Exclusion criteria applied hierarchically were review articles, not reporting recipient site complications; not in English and paediatric population. Abstracts were manually screened by LS, GS, JM and PDS separately and subsequently matched for accuracy. Pertinent full-text articles were retrieved and analysed and data were extracted from the database. The flow chart of article selection is described following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Results: In total, 462 papers were identified by PubMed search. A total of 359 were excluded: 38 papers were not in English, 41 were review articles, 279 articles did not report recipient site complications and 1 was not on human subjects. Average complication rate ranged from 1.5% to 81.4%. A total of 298 adverse events were identified: 40 (13.4%) intravascular injections, 13 (4.3%) asymmetry, 57 (19.1%) irregularities, 22 (7.4%) graft hypertrophy, 21 (7%) fat necrosis, 73 (24.5%) prolonged oedema, 1 (0.3%) infection, 6 (2%) prolonged erythema, 15 (5%) telangiectasia and 50 (16.8%) cases of acne activation. Conclusions: FFG related side effects could be resumed in three categories: severe, moderate, and minor. Severe (13.4%) side effects such as intravascular injection or migration require neurological or neurosurgical management and often lead to permanent disability or death. Moderate (38.3%) side effects such as fat hypertrophy, necrosis, cyst formation, irregularities and asymmetries require a retouch operation. Minor (48.3%) side effects such as prolonged oedema or erythema require no surgical management. Despite the fact that the overall general complication rate of facial fat grafting is assumed to be around 2%, the real complication rate of facial fat grafting is unknown due to a lack of reporting and the absence of consensus on side effect definition and identification. More RCTs are necessary to further determine the real complication rate of this procedure

Impact of etiology leading to abdominoperineal resection with anterolateral thigh flap reconstruction: A retrospective cohort study.

Large and deep perineal defects following abdominal perineal resection (APR) are a challenge for reconstructive surgeons. Even if generally performed for oncological reasons, APR can be indicated as well in extended infection-related debridement for Hidradenitis suppurativa, Fournier's gangrene, or Crohn's disease. We aimed to compare the outcomes of two groups of patients with different indications for APR (infectious vs. oncological) after pedicled anterolateral thigh (ALT) flap coverage RESULTS: Forty-four consecutive pedicled ALT flap used for coverage after APR in 40 patients were analyzed. Twenty-seven patients (67.5%) underwent APR for oncological reasons and 13 patients (32.5%) for infectious reasons. The overall postoperative complications rate was significantly higher for infectious cases (76.5% vs. 40.7%, p = 0.0304). Major complications occurred in 52.9% of infectious cases versus 11.1% of oncological cases (p = 0.0045). Obesity and infectious etiology were independent risk factors for overall and major complications, respectively. Patients undergoing APR for acute or chronic infections had significantly more overall and major complications than patients having oncological APR. Modified care might be considered, especially in obese patients, in terms of surgical debridement, antibiotic treatment modalities, and postoperative management

User Guide for Luminescence Sampling in Archaeological and Geological Context

Luminescence dating provides a direct age estimate of the time of last exposure of quartz or feldspar minerals to light or heat and has been successfully applied to deposits, rock surfaces, and fired materials in a number of archaeological and geological settings. Sampling strategies are diverse and can be customized depending on local circumstances, although all sediment samples need to include a light-safe sample and material for dose-rate determination. The accuracy and precision of luminescence dating results are directly related to the type and quality of the material sampled and sample collection methods in the field. Selection of target material for dating should include considerations of adequacy of resetting of the luminescence signal (optical and thermal bleaching), the ability to characterize the radioactive environment surrounding the sample (dose rate), and the lack of evidence for post-depositional mixing (bioturbation in soils and sediment). Sample strategies for collection of samples from sedimentary settings and fired materials are discussed. This paper should be used as a guide for luminescence sampling and is meant to provide essential background information on how to properly collect samples and on the types of materials suitable for luminescence dating. La datación por luminiscencia proporciona una estimación directa de la edad del último momento en el que el cuarzo o los minerales de feldespato se expusieron a la luz o al calor y que se ha aplicado exitosamente a depósitos, superficies rocosas y materiales expuestos al fuego en distintos contextos arqueológicos y geológicos. Las estrategias de muestreo son diversas y pueden ser individualizadas dependiendo de las circunstancias locales, aunque todas las muestras de sedimentos deben incluir una muestra segura que no haya sido expuesta a la luz y material para calcular la tasa de la dosis. La exactitud y precisión de los resultados de la datación por luminiscencia están directamente relacionadas con el tipo y la calidad de los materiales muestreados y los métodos de recolección de muestras en el campo. La elección del material de estudio para su datación debe incluir las siguientes consideraciones en torno a la idoneidad de poder reposicionar la señal de luminiscencia (blanqueador óptico y térmico), la capacidad de caracterizar el ambiente radiactivo que rodea la muestra (la tasa de la dosis) y el que no exista evidencia de una alteración posdeposicional (bioperturbación en suelos y sedimentos). Se discuten las estrategias de muestreo para la recolección de muestras de contextos sedimentarios y de materiales expuestos al fuego. Este artículo debe utilizarse como una guía para el muestreo por luminiscencia y tiene la intención de proveer información básica de cómo recolectar muestras y sobre los tipos de materiales apropiados para la datación por luminiscencia

Anxiety-like behavior of prenatally stressed rats is associated with a selective reduction of glutamate release in the ventral hippocampus

Abnormalities of synaptic transmission and plasticity in the hippocampus represent an integral part of the altered programming triggered by early life stress. Prenatally restraint stressed (PRS) rats develop long-lasting biochemical and behavioral changes, which are the expression of an anxious/depressive-like phenotype. We report here that PRS rats showed a selective impairment of depolarization- or kainate-stimulated glutamate and 3HD-aspartate release in the ventral hippo campus, a region encoding memories related to stress and emotions. GABA release was un affected in PRS rats. As a consequence of reduced glutamate release, PRS rats were also highly resistant to kainate-induced seizures. Abnormalities of glutamate release were associated with large reductions in the levels of synaptic vesicle-related proteins, such as VAMP (synaptobrevin), syntaxin-1, synaptophysin, synapsin Ia/b and IIa, munc-18, and Rab3A in the ventral hippocampus of PRS rats. Anxiety-like behavior in male PRS (and control) rats was inversely related to the extent of depolarization-evoked glutamate release in the ventral hippocampus. A causal relationship between anxiety-like behavior and reduction in glutamate release was demonstrated usingamixtureofthemGlu2/3 receptor antagonist, LY341495, and the GABAB receptor antagonist, CGP52432, which was shown to amplify depolarization-evoked 3HD-aspartate release in the ventral hippocampus. Bilateral micro infusion of CGP52432 plus LY341495 in the ventral hippocampus abolished anxiety-like behavior in PRS rats. These findings indicate that an impairment of glutamate release in the ventral hippocampus is a key component of the neuro plastic program induced by PRS, and that strategies aimed at enhancing glutamate release in the ventral hippocampus correct the "anxious phenotype" caused by early life stress

Modeling acute health risks associated with accidental releases of toxic gases

CHEM{_}MACCS has been developed from the radiological accident consequence code, MACCS, to perform probabilistic calculations of potential off-site consequences of the accidental atmospheric release of hazardous chemicals. The principal phenomena considered in CHEM{_}MACCS are atmospheric transport, mitigative actions based on dose projection, dose accumulation by a number of pathways, and early and latent health effects. CHEM{_}MACCS provides the following capabilities: (1) statistical weather sampling data (8,760 hourly data points per year), (2) population dose and health effect risk calculations based on site-specific population data, (3) health effects calculations including the consideration of potential site specific mitigative actions (evacuation and shielding), and (4) modeling of multiple release segments. Three different sample problems are contained in this report to show how to use CHEM{_}MACCS. Three test problems are run to compare CHEM{_}MACCS and D2PC. The doses versus the downwind centerline distances from the source for the given doses are in very close agreement

5.9-keV Mn K-shell X-ray luminosity from the decay of Fe-55 in Type Ia supernova models

We show that the X-ray line flux of the Mn Kα line at 5.9 keV from the decay of 55Fe is a promising diagnostic to distinguish between Type Ia supernova (SN Ia) explosion models. Using radiation transport calculations, we compute the line flux for two three-dimensional explosion models: a near-Chandrasekhar mass delayed detonation and a violent merger of two (1.1 and 0.9 M⊙) white dwarfs. Both models are based on solar metallicity zero-age main-sequence progenitors. Due to explosive nuclear burning at higher density, the delayeddetonation model synthesizes ∼3.5 times more radioactive 55Fe than the merger model. As a result, we find that the peak Mn Kα line flux of the delayed-detonation model exceeds that of the merger model by a factor of ∼4.5. Since in both models the 5.9-keV X-ray flux peaks five to six years after the explosion, a single measurement of the X-ray line emission at this time can place a constraint on the explosion physics that is complementary to those derived from earlier phase optical spectra or light curves. We perform detector simulations of current and future X-ray telescopes to investigate the possibilities of detecting the X-ray line at 5.9 keV. Of the currently existing telescopes, XMM–Newton/pn is the best instrument for close (!1–2 Mpc), non-background limited SNe Ia because of its large effective area. Due to its low instrumental background, Chandra/ACIS is currently the best choice for SNe Ia at distances above ∼2 Mpc. For the delayed-detonation scenario, a line detection is feasible with Chandra up to ∼3 Mpc for an exposure time of 106 s. We find that it should be possible with currently existing X-ray instruments (with exposure times !5 × 105 s) to detect both of our models at sufficiently high S/N to distinguish between them for hypothetical events within the Local Group. The prospects for detection will be better with future missions. For example, the proposed Athena/X-IFU instrument could detect our delayed-detonation model out to a distance of ∼5 Mpc. This would make it possible to study future events occurring during its operational life at distances comparable to those of the recent supernovae SN 2011fe (∼6.4 Mpc) and SN 2014J (∼3.5 Mpc)