Medieval windmills to wind turbines: a history of theory and experiment

The wind industry is trying to find tools to accurately predict and know the reliability and availability of newly installed wind turbines. Failure modes, effects and criticality analysis (FMECA) is a technique used to determine critical subsystems, causes and consequences of wind turbines. FMECA has been widely used by manufacturers of wind turbine assemblies to analyze, evaluate and prioritize potential/known failure modes. However, its actual implementation in wind farms has some limitations. This paper aims to determine the most critical subsystems, causes and consequences of the wind turbines of the Moroccan wind farm of Amougdoul during the years 2010–2019 by applying the maintenance model (FMECA), which is an analysis of failure modes, effects and criticality based on a history of failure modes occurred by the SCADA system and proposing solutions and recommendations.

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Between Accuracy and Manageability: Computational Imperatives in Quantum Chemistry

Historical Studies in the Natural Sciences ◽

10.1525/hsns.2009.39.1.32 ◽

2009 ◽

Vol 39 (1) ◽

pp. 32-62 ◽

Cited By ~ 14

Author(s):

Buhm Soon Park

Keyword(s):

Quantum Chemistry ◽

Early Years ◽

Many Body ◽

Molecular Systems ◽

Technological Improvement ◽

Computational Work ◽

Human Labor ◽

History Of ◽

History Of Quantum Theory ◽

Theory And Experiment

This article explores the place of computation in the history of quantum theory by examining the development of several approximation methods to solve the Schröödinger equation without using empirical information, as these were worked out in the years from 1927 to 1933. These ab initio methods, as they became known, produced the results that helped validate the use of quantum mechanics in many-body atomic and molecular systems, but carrying out the computations became increasingly laborious and difficult as better agreement between theory and experiment was pursued and more complex systems were tackled. I argue that computational work in the early years of quantum chemistry shows an emerging practice of theory that required human labor, technological improvement (computers), and mathematical ingenuity.

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Wind power and real estate prices in Oklahoma

International Journal of Housing Markets and Analysis ◽

10.1108/ijhma-02-2018-0010 ◽

2018 ◽

Vol 11 (5) ◽

pp. 808-827 ◽

Cited By ~ 2

Author(s):

Becca Castleberry ◽

John Scott Greene

Keyword(s):

Real Estate ◽

Wind Turbines ◽

Property Values ◽

Wind Farms ◽

Land Values ◽

Content Type ◽

The Real Estate ◽

History Of ◽

Negative Impacts ◽

Real Estate Prices

PurposeOklahoma has seen rapid growth in the development of wind energy over the past decade. Residents are concerned about the negative impacts of turbines such as noise or their appearance. This has raised concerns about property values. Thus, this paper aims to examine and quantify the overall impact of wind turbines upon real estate prices in Western Oklahoma.Design/methodology/approachSales prices and the history of approximately 23,000 residential real estate records for both platted and unplatted properties in five counties were examined prior to the announcement of construction, after announcement and after construction. A hedonic analysis was undertaken to examine the real estate prices of the properties near wind farms.FindingsWhile there may be isolated instances of lower property values for homes near wind turbines, results show no significant decreases in property values over homes near wind farms in the study area. Similar results are found for the unplatted properties.Practical implicationsThis paper highlights that in spite of mixed attitudes toward wind farms and misconceptions regarding the link between turbines and property values, Oklahoma’s growing wind industry can continue to thrive without negatively impacting nearby home and land values and prices.Originality/valueAlthough there have been numerous studies examining the relationship between wind turbine locations and real estate prices, no study has combined the large quantity of records (over 23,000) as well as both platted and unplatted locations.

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QUARK MATTER AND NUCLEAR COLLISIONS A BRIEF HISTORY OF STRONG INTERACTION THERMODYNAMICS

International Journal of Modern Physics E ◽

10.1142/s0218301312300068 ◽

2012 ◽

Vol 21 (08) ◽

pp. 1230006 ◽

Cited By ~ 14

Author(s):

HELMUT SATZ

Keyword(s):

High Energy ◽

Big Bang ◽

Nuclear Collision ◽

Strong Interactions ◽

Extreme Temperatures ◽

Nuclear Collisions ◽

The Past ◽

History Of ◽

The Big Bang ◽

Theory And Experiment

The past 50 years have seen the emergence of a new field of research in physics, the study of matter at extreme temperatures and densities. The theory of strong interactions, quantum chromodynamics (QCD), predicts that in this limit, matter will become a plasma of deconfined quarks and gluons — the medium which made up the early universe in the first 10 microseconds after the Big Bang. High energy nuclear collisions are expected to produce short-lived bubbles of such a medium in the laboratory. I survey the merger of statistical QCD and nuclear collision studies for the analysis of strongly interacting matter in theory and experiment.

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Assessing the Factors Impacting on the Reliability of Wind Turbines via Survival Analysis—A Case Study

Energies ◽

10.3390/en11113034 ◽

2018 ◽

Vol 11 (11) ◽

pp. 3034 ◽

Cited By ~ 3

Author(s):

Samet Ozturk ◽

Vasilis Fthenakis ◽

Stefan Faulstich

Keyword(s):

Survival Analysis ◽

Wind Turbine ◽

Wind Turbines ◽

Direct Drive ◽

Maintenance Costs ◽

Electrical Systems ◽

Geographical Factors ◽

History Of ◽

Risk Rate

The failure of wind turbines is a multi-faceted problem and its monetary impact is often unpredictable. In this study, we present a novel application of survival analysis on wind turbine reliability, including accounting for previous failures and the history of scheduled maintenance. We investigated the operational, climatic and geographical factors that affect wind turbine failure and modeled the risk rate of wind turbine failure based on data from 109 turbines in Germany operating for a period of 19 years. Our analysis showed that adequately scheduled maintenance can increase the survival of wind turbine systems and electric subsystems up to 2.8 and 3.8 times, respectively, compared to the systems without scheduled maintenance. Geared-drive wind turbines and their electrical systems were observed to have 1.2- and 1.4- times higher survival, respectively, compared to direct-drive turbines and their electrical systems. It was also found that the survival of frequently-failing wind turbine components, such as switches, was worse in geared-drive than in direct-drive wind turbines. We show that survival analysis is a useful tool to guide the reduction of the operating and maintenance costs of wind turbines.

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The Strong and Weak Senses of Theory-Ladenness of Experimentation: Theory-Driven versus Exploratory Experiments in the History of High-Energy Particle Physics

Science in Context ◽

10.1017/s0269889712000300 ◽

2013 ◽

Vol 26 (1) ◽

pp. 93-136 ◽

Cited By ~ 20

Author(s):

Koray Karaca

Keyword(s):

Particle Physics ◽

Scientific Practice ◽

High Energy ◽

Coarse Grained ◽

High Energy Particle ◽

Inelastic Electron ◽

Energy Particle ◽

History Of ◽

Theory And Experiment ◽

Theory Ladenness

ArgumentIn the theory-dominated view of scientific experimentation, all relations of theory and experiment are taken on a par; namely, that experiments are performed solely to ascertain the conclusions of scientific theories. As a result, different aspects of experimentation and of the relations of theory to experiment remain undifferentiated. This in turn fosters a notion of theory-ladenness of experimentation (TLE) that is toocoarse-grainedto accurately describe the relations of theory and experiment in scientific practice. By contrast, in this article, I suggest that TLE should be understood as anumbrella conceptthat has different senses. To this end, I introduce a three-fold distinction among the theories of high-energy particle physics (HEP) as background theories, model theories, and phenomenological models. Drawing on this categorization, I contrast two types of experimentation, namely, “theory-driven” and “exploratory” experiments, and I distinguish between the “weak” and “strong” senses of TLE in the context of scattering experiments from the history of HEP. This distinction enables identifying the exploratory character of the deep-inelastic electron-proton scattering experiments – performed at the Stanford Linear Accelerator Center (SLAC) between the years 1967 and 1973 – thereby shedding light on a crucial phase of the history of HEP, namely, the discovery of “scaling,” which was the decisive step towards the construction of quantum chromo-dynamics as a gauge theory of strong interactions.

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Assessing Factors Impacting on Reliability of Wind Turbines by Use of Survival Analysis – A Case Study

10.20944/preprints201810.0438.v1 ◽

2018 ◽

Author(s):

Samet Ozturk ◽

Vasilis Fthenakis ◽

Stefan Faulstich

Keyword(s):

Survival Analysis ◽

Wind Turbine ◽

Wind Turbines ◽

Direct Drive ◽

Maintenance Costs ◽

Electrical Systems ◽

History Of ◽

Risk Rate ◽

Reliability Performance

Failure of wind turbines is a multi-faceted problem and its monetary impact is often unpredicted. In this study, we present a novel application of survival analysis on wind turbine reliability performance that includes accounting of previous failures and history of scheduled maintenance. We investigate the operational, climatic and geographical factors which affect wind turbine failures and model the risk rate of wind turbine failures based on data from 109 turbines in Germany operating during a period of 19 years.  Our analysis showed that adequately scheduled maintenance can increase the survivorship of wind turbine systems and electric subsystems up to 2.8 and 3.8 times, respectively compared to the ones without scheduled maintenance. Geared-drive wind turbines and their electrical systems were observed to have 1.2- and 1.4-times higher survivorship, respectively, compared to direct-drive turbines and their electrical systems. It is also found that survivorship of frequently-failed wind turbine components, such as switches, is worse in geared-drive than in direct-drive wind turbines. We show that survival analysis is a useful tool for guiding the reduction of operating and maintenance costs of wind turbines.

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MODELLING METHODS FOR SOIL-STRUCTURE INTERACTION APPLIED IN WIND TURBINE FOUNDATION DESIGN

Mathematical Modelling in Civil Engineering ◽

10.2478/mmce-2013-0015 ◽

2013 ◽

Vol 9 (4) ◽

pp. 23-32 ◽

Cited By ~ 2

Author(s):

George Catană ◽

Adrian-Alexandru Savu ◽

Ionuț Ealangi

Keyword(s):

Wind Turbines ◽

Soil Structure ◽

Soil Structure Interaction ◽

Foundation Design ◽

Important Conclusion ◽

Elastic Supports ◽

Structure Interaction ◽

Interaction Modelling ◽

History Of ◽

The Difference

Abstract The article presents a case study on soil-structure interaction modelling for Wind turbines. After a brief presentation on the history of wind turbines and their potential in Romania, the authors take on the task of modelling the soil-structure interaction for the raft and piles. Three models are chosen: in the first model the piles are fixed at foundation depth; in the second, elastic supports are modelled on the raft and the piles and in the third model both elastic supports and fixed supports are modelled. Several comparisons are made between the three cases referring to displacements, efforts and necessary reinforcement. Based on these comparisons, the most important conclusion drawn is that the modelling of the soil-structure interaction has an important effect on the final reinforcement of the raft and the piles, considering that the difference between the models reaches almost 18%, which in the case of really large foundations can draw the line between economic and non-economic design.

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Research about the Influence of Loading History on the Rock’s Thermal Cracking Fracture

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.631-632.740 ◽

2013 ◽

Vol 631-632 ◽

pp. 740-746

Author(s):

Wei Hong Xie ◽

Nan Zhou ◽

Hai Feng Shen ◽

Feng Zhang

Keyword(s):

Fatigue Testing ◽

Thermal Cracking ◽

Testing System ◽

Thermal Fracture ◽

Loading History ◽

Thermal Crack ◽

Damage And Fracture ◽

History Of ◽

Different Order ◽

Theory And Experiment

The research on the history of load and temperature to the influence of rock’s damage and fracture is rare. Commonly, it takes no account of the order of load and temperature and despite how the load’s history which arose its damage of thermal fracture is, the process of damage evolvement and the intensity of fracture is same as long as adds of carry is similar to temperature value. However, the thermal influenced by the history of adds of temperature and the result will be different under different order of adds of carry. This paper carries through meso-structure experiment of different order of adds of carry and temperature by the numbers, observe the process of limestone’s thermal crack damage under the different order of adds of temperature and carry on real time with instrument such as DaoJin High Temperature Fatigue Testing System with Scanning Electron Microscope. In the view of the rock’s tiny crack growth, compute its crack tip energy release rate under different order of adds of carry. The result of theory and experiment indicate that the fracture of rock’s thermal cracking are intensively influenced by the history of adds of carry.

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Practice, Reason, Context: The Dialogue Between Theory and Experiment

Science in Context ◽

10.1017/s0269889700000478 ◽

1988 ◽

Vol 2 (1) ◽

pp. 3-22 ◽

Cited By ~ 39

Author(s):

Timothy Lenoir

Keyword(s):

Philosophy Of Science ◽

Empirical Support ◽

The Body ◽

Logical Empiricist ◽

Technical Culture ◽

History Of ◽

Inductive Support ◽

Culture Of Science ◽

Theory And Experiment ◽

Theory Ladenness

Experiment, instrumentation, and procedures of measurement, the body of practices and technologies forming the technical culture of science, have received at most a cameo appearance in most histories. For the history of science is almost always written as the history of theory. Of course, the interpretation of science as dominated by theory was the main pillar of the critique, launched by Kuhn, Quine, Hanson, Feyerabend, and others, of the positivist and logical empiricist traditions in the philosophy of science. Against Carnap, Hempel, Nagel, and Popper, who accorded observation reports an independent status either as a source of inductive support or as a basis for the falsification of scientific theories, Hanson and Kuhn emphasized the theory-ladenness of observation. They made this central point – that all observation is shaped by reference to theory – the cornerstone of a full-blown philosophy of science by buttressing it with two additional lines of argument: First, theories are always underdetermined by the data, several theories being compatible with the same set of data. Hence, choice between theories is never a matter of empirical support, but always turns around conceptual issues. Second, statements derived from theory never confront nature alone; they are always clothed in a web of interrelated beliefs. Thus, theories, their associated observation languages, and the entire technical culture they support must be accepted or rejected as wholes.

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