The Development of a Second Generation of Controlled Diffusion Airfoils for Multistage Compressors

1986 ◽  
Vol 108 (1) ◽  
pp. 32-40 ◽  
Author(s):  
R. F. Behlke
Keyword(s):  
Large Scale ◽  
First Generation ◽  
Second Generation ◽  
Flow Region ◽  
Operating Conditions ◽  
Design Model ◽  
Controlled Diffusion ◽  
Percent Increase ◽  
Significant Performance ◽  
High Mach

The evolution of Controlled Diffusion Airfoils is traced from inception of the theoretical design model to demonstration of significant performance gains at engine operating conditions in a multistage compressor rig. The proven aerodynamic benefits and versatility of first-generation Controlled Diffusion Airfoil blade elements are extended to the endwall flow region using an Integrated Core/Endwall Vortex design model to produce a new full-span optimized second-generation Controlled Diffusion design. Highlighted are the essential roles of extensive cascade, low-speed, large-scale, and high Mach number compressor rig testing in developing and substantiating the second-generation Controlled Diffusion technology resulting in a 1.5 percent increase in efficiency and 30 percent increase in surge-free operation relative to first-generation Controlled Diffusion Airfoils.

scholarly journals The Development of a Second-Generation of Controlled Diffusion Airfoils for Multistage Compressors

1985 ◽  
Author(s):  
R. F. Behlke
Keyword(s):  
Large Scale ◽  
First Generation ◽  
Second Generation ◽  
Flow Region ◽  
Operating Conditions ◽  
Design Model ◽  
Controlled Diffusion ◽  
Significant Performance ◽  
Multistage Compressors ◽  
High Mach

The evolution of Controlled Diffusion Airfoils is traced from inception of the theoretical design model to demonstration of significant performance gains at engine operating conditions in a multistage compressor rig. The proven aerodynamic benefits and versatility of first-generation Controlled Diffusion Airfoil blade elements are extended to the endwall flow region using an Integrated Core/Endwall Vortex design model to produce a new full span optimized second-generation Controlled Diffusion design. Highlighted are the essential roles of extensive cascade, low speed, large scale and high Mach number compressor rig testing in developing and substantiating the second generation Controlled Diffusion technology resulting in a 1.5% increase in efficiency and 30% increase in surge-free operation relative to first-generation Controlled Diffusion Airfoils.

Investigation of the Role of Droplet Transport in Mitigating Top of the Line Corrosion

CORROSION ◽  
10.5006/2764 ◽  
2018 ◽  
Vol 74 (8) ◽  
pp. 873-885
Author(s):  
Nicolas Jauseau ◽  
Fernando Farelas ◽  
Marc Singer ◽  
Srdjan Nešić
Keyword(s):  
Large Scale ◽  
Flow Region ◽  
Limited Range ◽  
Operating Conditions ◽  
Experimental Methodology ◽  
Liquid Droplets ◽  
Flow Loop ◽  
Droplet Entrainment ◽  
Droplet Transport ◽  
Large Scale Flow

The entrainment of liquid droplets, occurring in a limited range of gas and liquid flow conditions within the stratified flow region, could represent an effective way to transport a non-volatile liquid corrosion inhibitor through the gas phase and combat top of the line corrosion (TLC). However, such an approach is only viable if the inhibitor can reach the top of the pipe and deposit at a rate higher than the local rate of condensing water can dilute it. This work presents a combined modeling and experimental methodology to determine the onset of droplet entrainment from the bottom and deposition at the top of the line. A modeling approach predicting the droplet entrainment onset is proposed and validated against new multiphase flow data recorded in a large scale flow loop, at operating conditions similar to those encountered in gas-condensate production facilities. Additionally, TLC experiments were performed in the same flow loop under simulated water condensation conditions to measure the actual corrosion at different rates of inhibiting droplet deposition. The results confirm that the droplet entrainment/deposition can effectively mitigate TLC when operating parameters are accurately controlled.

A PERFORMANCE EVALUATION OF THE NEHALEM QUAD-CORE PROCESSOR FOR SCIENTIFIC COMPUTING

2008 ◽  
Vol 18 (04) ◽  
pp. 453-469 ◽  
Author(s):  
KEVIN J. BARKER ◽  
KEI DAVIS ◽  
ADOLFY HOISIE ◽  
DARREN J. KERBYSON ◽  
MIKE LANG ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Large Scale ◽  
Scientific Computing ◽  
First Generation ◽  
Second Generation ◽  
Building Blocks ◽  
Simultaneous Multithreading ◽  
Scientific Applications ◽  
Memory Controller ◽  
A Performance

In this work we present an initial performance evaluation of Intel's latest, second-generation quad-core processor, Nehalem, and provide a comparison to first-generation AMD and Intel quad-core processors Barcelona and Tigerton. Nehalem is the first Intel processor to implement a NUMA architecture incorporating QuickPath Interconnect for interconnecting processors within a node, and the first to incorporate an integrated memory controller. We evaluate the suitability of these processors in quad-socket compute nodes as building blocks for large-scale scientific computing clusters. Our analysis of intra-processor and intra-node scalability of microbenchmarks, and a range of large-scale scientific applications, indicates that quad-core processors can deliver an improvement in performance of up to 4x over a single core depending on the workload being processed. However, scalability can be less when considering a full node. We show that Nehalem outperforms Barcelona on memory-intensive codes by a factor of two for a Nehalem node with 8 cores and a Barcelona node containing 16 cores. Further optimizations are possible with Nehalem, including the use of Simultaneous Multithreading, which improves the performance of some applications by up to 50%.

scholarly journals Transitioning from a First Generation to Second Generation Large-Scale Agile Development Method: Towards Understanding Implications for Coordination

2020 ◽  
pp. 84-91
Author(s):  
Finn Olav Bjørnson ◽  
Torgeir Dingsøyr
Keyword(s):  
Large Scale ◽  
First Generation ◽  
Second Generation ◽  
Development Project ◽  
Agile Development ◽  
Public Organization ◽  
Longitudinal Case Study ◽  
Development Method ◽  
Development Methodology

Abstract This paper reports our initial findings from a longitudinal case study within a large development project in a public organization in Scandinavia. We focus on changes in coordination practices as the development project moved from a 1st to a 2nd generation large-scale agile development methodology. Building on four theories of coordination from different fields, we investigate how each theory illuminates our case and what insight they might provide. We find that two of the theories are well suited to characterizing each phase, providing answer to how coordination was done. While two other theories can provide answers to why these changes occurred.

Do remittances differ depending on migration pathway and length of stay?

2016 ◽  
Vol 1 (1) ◽  
pp. 105-118
Author(s):  
Anita Pugliese ◽  
Julie Ray ◽  
Neli Esipova
Keyword(s):  
Length Of Stay ◽  
First Generation ◽  
Second Generation ◽  
Global Analysis ◽  
Large Sample ◽  
Migration Pathway ◽  
First Generation Migrants ◽  
Second Generation Migrants

This paper reports the results from Gallup’s global analysis of the likelihood of first-generation migrants, second-generation migrants and the native-born to send financial help in the form of money or goods to others inside or outside their respective country of residence. The findings in this paper are based on more than 450,000 interviews conducted through Gallup’s World Poll in 157 countries in 2012, 2013 and 2014. The sample includes more than 26,000 first-generation migrants and more than 20,000 second-generation migrants. The large sample enables Gallup to analyze first-generation migrants by the duration of their stay in their adopted country and compare their remittance behaviors with second-generation migrants and the native-born.

Marcuse and Habermas's Political Ideas in English

2019 ◽  
pp. 215
Author(s):  
Asaad Abdullwahab AbdulKarim ◽  
Waleed Massaher Hamad ◽  
Salah Ibrahim Hamadi
Keyword(s):  
First Generation ◽  
Second Generation ◽  
Frankfurt School ◽  
Western Thought ◽  
Political Ideas ◽  
Important Impact

Abstract     The Frankfurt School is characterized by its critical nature and it is the result of the Marxist socialist thought as it contributed to the development of the German thought in particular and the Western thought in general through important ideas put forward by a number of pioneers in the various generations of the school and most notably through the leading pioneer in the first generation, Marcuse, and the leading pioneer of the second  generation, Habermas, whose political ideas had an important impact on global thinking and later became the basis of the attic of many critical ideas. In spite of the belief of the school members in the idea of the criticism of power and community, each had his own ideas that distinguish him from the others.

Adsorption Isotherm Predictions for Multiple Molecules in MOFs Using the Same Deep Learning Model

2019 ◽  
Author(s):  
Ryther Anderson ◽  
Achay Biong ◽  
Diego Gómez-Gualdrón
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Molecular Simulation ◽  
Large Scale ◽  
Learning Model ◽  
Operating Conditions ◽  
Small Subset ◽  
Screening Methods ◽  
Large Set ◽  
Metal Organic

<div>Tailoring the structure and chemistry of metal-organic frameworks (MOFs) enables the manipulation of their adsorption properties to suit specific energy and environmental applications. As there are millions of possible MOFs (with tens of thousands already synthesized), molecular simulation, such as grand canonical Monte Carlo (GCMC), has frequently been used to rapidly evaluate the adsorption performance of a large set of MOFs. This allows subsequent experiments to focus only on a small subset of the most promising MOFs. In many instances, however, even molecular simulation becomes prohibitively time consuming, underscoring the need for alternative screening methods, such as machine learning, to precede molecular simulation efforts. In this study, as a proof of concept, we trained a neural network as the first example of a machine learning model capable of predicting full adsorption isotherms of different molecules not included in the training of the model. To achieve this, we trained our neural network only on alchemical species, represented only by their geometry and force field parameters, and used this neural network to predict the loadings of real adsorbates. We focused on predicting room temperature adsorption of small (one- and two-atom) molecules relevant to chemical separations. Namely, argon, krypton, xenon, methane, ethane, and nitrogen. However, we also observed surprisingly promising predictions for more complex molecules, whose properties are outside the range spanned by the alchemical adsorbates. Prediction accuracies suitable for large-scale screening were achieved using simple MOF (e.g. geometric properties and chemical moieties), and adsorbate (e.g. forcefield parameters and geometry) descriptors. Our results illustrate a new philosophy of training that opens the path towards development of machine learning models that can predict the adsorption loading of any new adsorbate at any new operating conditions in any new MOF.</div>

Pharmakotherapie update

2020 ◽  
Vol 25 (1) ◽  
pp. 23-32
Author(s):  
Gerd Laux
Keyword(s):  
First Generation ◽  
Second Generation ◽  
Therapeutische Maßnahmen ◽  
Second Generation Antipsychotics

Für die Therapie schizophrener Erkrankungen sind seit fast 60 Jahren Antipsychotika/Neuroleptika aufgrund ihrer antipsychotischen Wirkung von zentraler Bedeutung. Die Einteilung kann unter verschiedenen Gesichtspunkten erfolgen (chemische Struktur, neuroleptische Potenz, Rezeptorprofil), heute werden üblicherweise unterschieden typische (traditionelle, klassische, konventionelle) Antipsychotika der ersten Generation ‒ »First Generation Antipsychotics« (FGA) ‒ und sog. atypische (»neuere«) Neuroleptika bzw. Antipsychotika der zweiten Generation ‒»Second Generation Antipsychotics« (SGA). Hierzu zählen Aripiprazol, Asenapin, Cariprazin, Clozapin, Olanzapin, Quetiapin, Risperidon, Sertindol und Ziprasidon. Hierbei handelt es sich um keine homogene Gruppe – sowohl neuropharmakologisch (Wirkmechanismus), als auch hinsichtlich klinischem Wirkprofil und dem Nebenwirkungsspektrum bestehen z. T. erhebliche Unterschiede. Neben der Akut-Medikation ist eine Langzeitmedikation bzw. Rezidivprophylaxe mit Antipsychotika für die Rehabilitation vieler schizophrener Patienten im Sinne eines »Stresspuffers« von grundlegender Bedeutung. In Placebo-kontrollierten Studien trat bei Patienten, die über ein Jahr behandelt wurden, bei etwa 30% unter Neuroleptika ein Rezidiv auf, unter Placebo bei mehr als 70%. Für die Langzeitbehandlung bietet sich der Einsatz von Depot-Neuroleptika an, neu entwickelt wurden Langzeit-Depot-Injektionen mit Intervallen von bis zu 3 Monaten. Grundsätzlich ist die niedrigstmögliche (wirksame) Dosis zu verwenden. Im Zentrum der Nebenwirkungen (UAW) standen lange Zeit extrapyramidal-motorische Bewegungsstörungen (EPMS), mit der Einführung von Clozapin und anderen atypischen Antipsychotika der zweiten Generation gewannen andere Nebenwirkungen an Bedeutung. Hierzu zählen Gewichtszunahme, Störungen metabolischer Parameter und ein erhöhtes Risiko für Mortalität und zerebrovaskuläre Ereignisse bei älteren Patienten mit Demenz. Entsprechende Kontrolluntersuchungen sind erforderlich, für Clozapin gibt es aufgrund seines Agranulozytose-Risikos Sonderbestimmungen. Immer sollte ein Gesamtbehandlungsplan orientiert an der neuen S3-Praxisleitlinie Schizophrenie der DGPPN aufgestellt werden, der psychologische und milieu-/sozial-therapeutische Maßnahmen einschließt. Standard ist heute auch eine sog. Psychoedukation, für Psychopharmaka liegen bewährte Patienten-Ratgeber vor.

Molecular Epidemiology and Biomarkers in Etiologic Cancer Research: The New in Light of the Old

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Gene Expression ◽  
Cancer Research ◽  
Molecular Epidemiology ◽  
Exposure Assessment ◽  
Large Scale ◽  
First Generation ◽  
Cancer Epidemiology ◽  
Policy Changes ◽  
The Past ◽  
New Generation

The purpose of this review is to evaluate progress inmolecular epidemiology over the past 24 years in canceretiology and prevention to draw lessons for futureresearch incorporating the new generation of biomarkers.Molecular epidemiology was introduced inthe study of cancer in the early 1980s, with theexpectation that it would help overcome some majorlimitations of epidemiology and facilitate cancerprevention. The expectation was that biomarkerswould improve exposure assessment, document earlychanges preceding disease, and identify subgroupsin the population with greater susceptibility to cancer,thereby increasing the ability of epidemiologic studiesto identify causes and elucidate mechanisms incarcinogenesis. The first generation of biomarkers hasindeed contributed to our understanding of riskandsusceptibility related largely to genotoxic carcinogens.Consequently, interventions and policy changes havebeen mounted to reduce riskfrom several importantenvironmental carcinogens. Several new and promisingbiomarkers are now becoming available for epidemiologicstudies, thanks to the development of highthroughputtechnologies and theoretical advances inbiology. These include toxicogenomics, alterations ingene methylation and gene expression, proteomics, andmetabonomics, which allow large-scale studies, includingdiscovery-oriented as well as hypothesis-testinginvestigations. However, most of these newer biomarkershave not been adequately validated, and theirrole in the causal paradigm is not clear. There is a needfor their systematic validation using principles andcriteria established over the past several decades inmolecular cancer epidemiology.

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