Direct CFD Predictions of Low Frequency Sounds Generated by a Helicopter Main Rotor

The use of CFD to directly predict helicopter main rotor noise is shown to be quite promising as an alternative mean for low frequency source noise evaluation. Results using existing state-of-the-art grid structures and finite-difference schemes demonstrated that small perturbation pressures, associated with acoustics radiation, can be extracted with some degree of fidelity. Accuracy of the predictions are demonstrated via comparing to predictions from conventional acoustic analogy-based models, and with measurements obtained from wind tunnel and flight tests for the MD-902 helicopter at several operating conditions. Findings show that the direct CFD approach is quite successfully in yielding low frequency results due to thickness and steady loading noise mechanisms. Mid-to-high frequency contents, due to blade-vortex interactions, are not predicted due to CFD modeling and grid constraints

Report on the Joint Eglin Acoustic Week III

A series of three flight tests have been conducted at Eglin Air Force Base located in the Florida panhandle. The first was the Acoustics Week flight test conducted in September 2003. The second was the NASA Heavy Lift Rotorcraft Acoustic Flight Test conducted in October-November 2005. The most recent was the Eglin Acoustic Week III test conducted in August-September 2007. This series of tests have acquired acoustic data for a number of rotary and fixed wing aircraft that are used to generate noise semi-spheres used in predicting the acoustic footprint for prescribed flight operations. This extensive database can be used to determine the impact of flight operations on communities around a terminal area. Another valuable use of the semi-spheres is determining the long-range propagation of noise for civilian and military purposes. This paper will describe the third in this series of tests

The role of ECL2 in CGRP receptor activation: a combined modelling and experimental approach

The calcitonin gene-related peptide (CGRP) receptor is a complex of a calcitonin receptor-like receptor (CLR), which is a family B G-protein-coupled receptor (GPCR) and receptor activity modifying protein 1. The role of the second extracellular loop (ECL2) of CLR in binding CGRP and coupling to Gs was investigated using a combination of mutagenesis and modelling. An alanine scan of residues 271–294 of CLR showed that the ability of CGRP to produce cAMP was impaired by point mutations at 13 residues; most of these also impaired the response to adrenomedullin (AM). These data were used to select probable ECL2-modelled conformations that are involved in agonist binding, allowing the identification of the likely contacts between the peptide and receptor. The implications of the most likely structures for receptor activation are discussed.</jats:p

Joint Eglin Acoustic Week III Data Report

A series of three flight tests have been conducted at an Eglin Air Force Base remote test range located in the Florida panhandle. The first was the "Acoustics Week" flight test conducted in September 2003. The second was the NASA Heavy Lift Rotorcraft Acoustic Flight Test conducted in October-November 2005. The most recent was the Eglin Acoustic Week III test conducted in August-September 2007. This series of tests acquired acoustic data for a number of rotary and fixed wing aircraft and are used to generate noise semi-spheres used in predicting the acoustic footprint for prescribed flight operations. This extensive database can be used to determine the impact of flight operations on communities around a terminal area as well as for prediction code validations. Another valuable use of the semi-spheres is determining the long-range propagation of noise for civilian and military purposes. This paper describes the third test in this series. Data described in this report were acquired during testing of the MD-902 and Mi-8M aircraft. In addition, data acquired during a set of atmospheric propagation tests is also described

DEVELOPMENT OF BYPASSED OIL RESERVES USING BEHIND CASING RESISTIVITY MEASUREMENTS

Tubing and rods of the S.P. Pedro-Nepple No.1 well were pulled and the well was prepared for running of Schlumberger's Cased Hole Formation Resistivity Tool (CHFR) in selected intervals. The CHFR tool was successfully run and data was captured. The CHFR formation resistivity readings were compared to original open hole resistivity measurements. Separation between the original and CHFR resistivity curves indicate both swept and un-swept sand intervals. Both watered out sand intervals and those with higher remaining oil saturation have been identified. Due to the nature of these turbidite sands being stratigraphically continuous, both the swept and unswept layers have been correlated across to one of the four nearby offset shallow wells. As a result of the cased hole logging, one well was selected for a workover to recomplete high oil saturated shallow sand intervals. During the second report period, well S.P. Pedro-Nepple No.2 was plugged back with cement excluding the previously existing production interval, squeeze cemented behind casing, selectively perforated in the shallower ''Bell'' zone and placed on production to develop potential new oil reserves and increase overall well productivity. Prior workover production averaged 3.0 BOPD for the previous six-months. Post workover well production was marginally increased to 3.7 BOPD on average for the following six months

Pressure-Induced Insulator-to-Metal Transition in van der Waals compound CoPS3_3

We have studied the insulator-to-metal transition and crystal structure evolution under high pressure in the van der Waals compound CoPS$_3$ through $\textit{in-situ}$ electrical resistance, Hall resistance, magnetoresistance, X-ray diffraction, and Raman scattering measurements. CoPS$_3$ exhibits a $C2/m$ $\rightarrow$ $P\overline{3}$ structural transformation at 7 GPa accompanied by a 2.9$\%$ reduction in the volume per formula unit. Concomitantly, the electrical resistance decreases significantly, and CoPS$_3$ becomes metallic. This metallic CoPS$_3$ is a hole-dominant conductor with multiple conduction bands. The linear magnetoresistance and the small volume collapse at the metallization suggest the incomplete high-spin $\rightarrow$ low-spin transition in the metallic phase. Thus, the metallic CoPS$_3$ possibly possesses an inhomogeneous magnetic moment distribution and short-range magnetic ordering. This report summarizes the comprehensive phase diagram of $M$PS$_3$ ($M$ = V, Mn, Fe, Co, Ni, and Cd) that metalize under pressures.Comment: 14 pages, 6 figures, 1 tabl

Understanding the molecular functions of the second extracellular loop (ECL2) of the calcitonin gene-related peptide (CGRP) receptor using a comprehensive mutagenesis approach

The extracellular loop 2 (ECL2) region is the most conserved of the three ECL domains in family B G protein-coupled receptors (GPCRs) and has a fundamental role in ligand binding and activation across the receptor super-family. ECL2 is fundamental for ligand-induced activation of the calcitonin gene related peptide (CGRP) receptor, a family B GPCR implicated in migraine and heart disease. In this study we apply a comprehensive targeted non-alanine substitution analysis method and molecular modelling to the functionally important residues of ECL2 to reveal key molecular interactions. We identified an interaction network between R274/Y278/D280/W283. These amino acids had the biggest reduction in signalling following alanine substitution analysis and comprise a group of basic, acidic and aromatic residues conserved in the wider calcitonin family of class B GPCRs. This study identifies key and varied constraints at each locus, including diverse biochemical requirements for neighbouring tyrosine residues and a W283H substitution that recovered wild-type (WT) signalling, despite the strictly conserved nature of the central ECL2 tryptophan and the catastrophic effects on signalling of W283A substitution. In contrast, while the distal end of ECL2 requires strict conservation of hydrophobicity or polarity in each position, mutation of these residues never has a large effect. This approach has revealed linked networks of amino acids, consistent with structural models of ECL2 and likely to represent a shared structural framework at an important ligand-receptor interface that is present across the family B GPCRs

Fractional Synthetic Rate and Markers of Protein Turnover are Altered in the Diaphragms of Cachectic Mice

Cancer cachexia, a wasting syndrome characterized by rapid skeletal muscle wasting and fat loss, directly accounts for up to 20-40% of cancer-related deaths. All muscles, including respiratory muscles, are susceptible to atrophy because cancer cachexia is a systemic disease. Atrophy of the primary breathing muscle, the diaphragm, can lead to respiratory distress, which is commonly associated with a cachectic phenotype. Indeed, the diaphragm is more susceptible to atrophy in certain conditions, but little is known about the effects of cancer-cachexia on protein turnover in the diaphragm. Therefore, investigations into the alterations in protein turnover could provide insight to the molecular events and provide valuable information in the search for therapeutic targets. PURPOSE: The purpose of this study was to describe changes in diaphragmatic protein synthesis and molecular markers of synthesis and degradation during the progression of cancer cachexia. METHODS: C57BL6/J mice (8 wks old) were implanted with 1X106 Lewis Lung Carcinoma cells (LLC) or Phosphate-Buffered Saline (PBS, control). Tumors developed over a 1-4 wk time course and diaphragms were harvested at each time point (1, 2, 3, or 4 wks). Fractional synthetic rates (FSR) were determined using deuterium incorporation into muscle. Selected markers of protein synthesis and degradation pathways were analyzed by immunoblot analysis. One-Way ANOVA was used for statistical analyses, with significance set at pRESULTS: FSR trended downward over time, but did not reach significance. Similar to FSR, anabolic signaling markers (4EBP-1, ERK1/2, Deptor) did not demonstrate significant differences. p62, an autophagic degradation marker, was significantly less than PBS in 3 wk diaphragms (

Mitochondrial Dysfunction in Diaphragm Muscle Precedes the Cachectic Phenotype in LLC Tumor-Bearing Mice.

The defining feature of cancer cachexia is extensive weight loss and skeletal muscle atrophy. It is clinically important because cachexia reduces patient survival, results in functional impairment, and is estimated to be directly responsible for 20-40% of cancer deaths. Unfortunately, no clinical therapy exists and therefore, it is important to understand the molecular mechanisms responsible for rapid muscle wasting. Compared to limb muscles, the diaphragm is relatively understudied in cancer cachexia, but is likely to be adversely affected because cachexia is a systemic disease. Wasting of the primary inspiratory muscle may result in difficulty breathing and inability to adjust minute ventilation in response to a respiratory challenge. Based on emerging evidence, it is clear that oxidative stress is present in cachexia-induced wasting of the diaphragm; PURPOSE: we developed the hypothesis that mitochondrial dysfunction in the diaphragm precedes cachexia. METHODS: 1X106 Lewis Lung Carcinoma cells (LLC) or Phosphate-Buffered Saline (PBS, control) were implanted to the hind-flank of C57BL6/J mice at 8 wks of age. Tumors were allowed to develop for 1, 2, 3, or 4 wks. At designated time points diaphragms were collected and mitochondrial function was assessed by respiration and ROS production. RESULTS: Cancer cachexia was evident only at the 4 wk time point demonstrated by decrease in body mass and muscle atrophy in several limb muscles. Mitochondrial respiration, assessed by respiratory control ratio (state3/state 4 respiration), was significantly lower at 1 wk (pCONCLUSIONS:The molecular events that lead to muscle atrophy in cancer cachexia are unknown. We demonstrate that two hallmarks of mitochondrial dysfunction, altered respiration and ROS production, occur in the diaphragm well before the cancer cachexia phenotype is evident in the LLC model. These data suggest that the mitochondria are likely a suitable target to treat or prevent cancer cachexia-induced muscle wasting in the diaphragm

Joint Eglin Acoustics Week 2013 Data Report

Far-field acoustic measurements were obtained for the AH-64D, HH-60M and CV-22B at the Eglin AFB, Test Area C-72, in July/August 2013. The primary purpose for this flight test was to obtain a benchmark database of detailed acoustic source noise characteristics for the aircraft operating at typical mission gross weights over a range of typical mission operating conditions. Data were acquired for a range of steady-state level and descending flight conditions, hover, and a variety of unsteady maneuver conditions. Between 30 and 37 microphones were deployed during these tests. Vehicle position and state data, as well as weather data were acquired simultaneously with the acoustic data. This paper describes the test aircraft, onboard instrumentation, ground instrumentation, and the data acquired. Data from this test are available upon request and review