Noise measurement evaluations of various takeoff-climbout profiles of a four-engine turbojet transport airplane

Noise measurement evaluations of various takeoff-climbout profiles of four engine turbojet transport airplan

Position indicating, rotating boom

Universal multiplanar position indicating, rotating boom for mounting various instruments or sensors is described. Boom is telescoping, and apparatus is capable of 3 types of rotation controlled by electric motors. Movement may be continuous or incremental

In-situ scanning probe microscopy of electrodeposited nickel.

The performance characteristics and material properties such as stress, microstructure, and composition of nickel coatings and electroformed components can be controlled over a wide range by the addition of small amounts of surface-active compounds to the electroplating bath. Saccharin is one compound that is widely utilized for its ability to reduce tensile stress and refine grain size in electrodeposited nickel. While the effects of saccharin on nickel electrodeposition have been studied by many authors in the past, there is still uncertainty over saccharin's mechanisms of incorporation, stress reduction, and grain refinement. In-situ scanning probe microscopy (SPM) is a tool that can be used to directly image the nucleation and growth of thin nickel films at nanometer length scales to help elucidate saccharin's role in the development and evolution of grain structure. In this study, in-situ atomic force microscopy (AFM) and scanning tunneling microscopy (STM) techniques are used to investigate the effects of saccharin on the morphological evolution of thin nickel films. By observing mono-atomic height nickel island growth with and without saccharin present we conclude that saccharin has little effect on the nickel surface mobility during deposition at low overpotentials where the growth occurs in a layer-by-layer mode. Saccharin was imaged on Au(l11) terraces as condensed patches without resolved packing structure. AFM measurements of the roughness evolution of nickel films up to 1200 nm thick on polycrystalline gold indicate that saccharin initially increases the roughness and surface skewness of the deposit that at greater thickness becomes smoother than films deposited without saccharin. Faceting of the deposit morphology decreases as saccharin concentration increases even for the thinnest films that have 3-D growth

The effect of the shear-thickening transition of model colloidal spheres on the sign of N1 and on the radial pressure profile in torsional shear flows

A novel rheometer plate was used to measure radial pressure profiles during cone-and-plate and parallel-plate shearing flows of a concentrated colloidal dispersion of polymethyl methacryalate spheres suspended in dioctyl phthalate. There is a long history of using suspensions of this type as a model rheological system. The measured pressure profile can be used to calculate N1 and N2, and also provides a check on the flow field in the rheometer. At shear rates just below onset of shear thickening, our measurements show that N1 is positive as predicted by Stokesian dynamics simulations of model Brownian hard spheres, but we are unable to determine the sign of N2. After the onset of thickening, we find that in both flow geometries the pressure increases sharply with radial position. This is in striking contrast to the pressure profiles ordinarily observed for viscoelastic liquids with the exception of certain liquid crystal polymers, for which the pressure decreases with radial position. Under these conditions, the apparent values of N1 and N2 are both negative with N2 N1, as predicted by the Stokesian dynamics simulations. However, the flow in the cone-and-plate rheometer may not be viscometric after the onset of shear thickening

Impact of Corporate Governance Practices on Firm Capital Structure and Profitability: A Study of Selected Hotels and Restaurant Companies in Sri Lanka.

Corporate governance issues have been a growing area of management research especially among large and listed firms. Good corporate governance practices are regarded as important in reducing risk for investors, attracting investment capital and improving the performance of companies. Companies need financial resources and better earnings to promote their objectives. Therefore, factorsmay affect the capital structure and profitability of companies should be considered carefully. The purpose of the present study is to investigate whether there is any relationship among some specific characters of corporate governance, capital structure and profitability of listedHotels &Restaurant companies in Colombo Stock Exchange (CSE). To do so, 18 companies were selected from those which were listed inCSE during the 2007-2012. The ‘Board Composition(BC)’, ‘Board Size (BS)’ and ‘CEOduality (CEOD)’ were considered as independent variables, whereas,’ Debt Ratio(DR)’,‘Debt-to-Equity Ratio(DER)’,‘Returns on Equity(ROE)’,and ‘Return on Assets(ROA)’ as dependent variable. The results indicate a positive relationship between ‘BS; BC; CEOD; ROE; ROA and DERwhereas negative relationship between BS; BID and DR.in addition CEOD have a positive relationship with DR.In addition, none of the variables have a significant relationship with capital structure and profitability. Key words: Corporate Governance; Capital Structure and Profitability

Major Fallacies Surrounding Stone Artifacts and Assemblages

While lithic objects can potentially inform us about past adaptations and behaviors, it is important to develop a comprehensive understanding of all of the various processes that influence what we recover from the archaeological record. We argue here that many assumptions used by archaeologists to derive behavioral inferences through the definition, conceptualization, and interpretation of both individual stone artifact forms and groups of artifacts identified as assemblages do not fit squarely with what we have learned from both ethnographic sources and analyses of archaeological materials. We discuss this in terms of two fallacies. The first is the fallacy of the “desired end product” in stone artifact manufacture, which also includes our ability to recognize such end products. The second fallacy has to do with the notions that lithic assemblages represent simple accumulations of contemporary behaviors and the degree to which the composition of the depositional units we study reliably match the kinds of activities that took place. Although it is beyond the scope of this paper to offer a comprehensive set of new methodologies and theoretical perspectives to solve these problems, our goal here is to stress the importance of rethinking some of our most basic assumptions regarding the nature of lithic objects and how they become part of the archaeological record. Such a revision is needed if we want to be able to develop research questions that can be addressed with the data we have available to us

The extracellular calcium-sensing receptor regulates human fetal lung development via CFTR

Optimal fetal lung growth requires anion-driven fluid secretion into the lumen of the developing organ. The fetus is hypercalcemic compared to the mother and here we show that in the developing human lung this hypercalcaemia acts on the extracellular calcium-sensing receptor, CaSR, to promote fluid-driven lung expansion through activation of the cystic fibrosis transmembrane conductance regulator, CFTR. Several chloride channels including TMEM16, bestrophin, CFTR, CLCN2 and CLCA1, are also expressed in the developing human fetal lung at gestational stages when CaSR expression is maximal. Measurements of Cl−-driven fluid secretion in organ explant cultures show that pharmacological CaSR activation by calcimimetics stimulates lung fluid secretion through CFTR, an effect which in humans, but not mice, was also mimicked by fetal hypercalcemic conditions, demonstrating that the physiological relevance of such a mechanism appears to be species-specific. Calcimimetics promote CFTR opening by activating adenylate cyclase and we show that Ca2+-stimulated type I adenylate cyclase is expressed in the developing human lung. Together, these observations suggest that physiological fetal hypercalcemia, acting on the CaSR, promotes human fetal lung development via cAMP-dependent opening of CFTR. Disturbances in this process would be expected to permanently impact lung structure and might predispose to certain postnatal respiratory disease

Sensitivity of natural gas HCCI combustion to fuel and operating parameters using detailed kinetic modeling

This paper uses the HCT (Hydrodynamics, Chemistry and Transport) chemical kinetics code to analyze natural gas HCCI combustion in an engine. The HCT code has been modified to better represent the conditions existing inside an engine, including a wall heat transfer correlation. Combustion control and low power output per displacement remain as two of the biggest challenges to obtaining satisfactory performance out of an HCCI engine, and these are addressed in this paper. The paper considers the effect of natural gas composition on HCCI combustion, and then explores three control strategies for HCCI engines: DME (dimethyl ether) addition, intake heating and hot EGR addition. The results show that HCCI combustion is sensitive to natural gas composition, and an active control may be required to compensate for possible changes in composition. The three control strategies being considered have a significant effect in changing the combustion parameters for the engine, and should be able to control HCCI combustion

Novel GPU Approach In Predicting The Directional Trend Of The S&P 500

Our goal is development of an algorithm capable of predicting the directional trend of the Standard and Poor’s 500 index (S&P 500). Extensive research has been published attempting to predict different financial markets using historical data testing on an in-sample and trend basis, with many authors employing excessively complex mathematical techniques. In reviewing and evaluating these in-sample methodologies, it became evident that this approach was unable to achieve sufficiently reliable prediction performance for commercial exploitation. For these reasons, we moved to an out-of-sample strategy based on linear regression analysis of an extensive set of financial data correlated with historical closing prices of the S&P 500. We are pleased to report a directional trend accuracy of greater than 55% for tomorrow (t+1) in predicting the S&P 500