scholarly journals Solid Particle Erosion Behaviour and Protective Coatings for Gas Turbine Compressor Blades—A Review

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 984
Author(s):  
Jasem Alqallaf ◽  
Naser Ali ◽  
Joao A. Teixeira ◽  
Abdulmajid Addali
Keyword(s):  
Gas Turbines ◽  
Protective Coatings ◽  
Theoretical Models ◽  
Research Direction ◽  
Solid Particles ◽  
Rotor Blades ◽  
Dust Particles ◽  
Future Research ◽  
Coating Materials ◽  
Surface Protection

Gas turbines (GTEs) are often utilised in harsh environments where the GT components, including compressor vanes and rotor blades, are subject to erosion damage by sand and dust particles. For instance, in a desert environment, the rate of damage made by solid particles erosion (SPE) becomes severe, and therefore results in degradation to the GTE parts, lowering the cycle efficiency, reducing the device lifetime, and increasing the overall cost of the operation. As such, understanding the erosion mechanism caused by solid particles and the effects associated with it is crucial for selecting the appropriate countermeasures and maintaining the system performance. This review paper provides a survey of the available studies on SPE effects on GTEs and surface protective coatings. Firstly, the ductile and brittle SPE mechanism is presented, as well as the ductile-brittle transition region. Then, an in-depth focus on the parameters associated with the SPE, such as particles properties and impingement conditions, is introduced. Furthermore, the existing theoretical models are shown and discussed. Afterwards, erosion resistant coating materials for surface protection and their selection criteria are covered in the review. Finally, the gap in knowledge and future research direction in the field of SPE on GTEs are provided.

Protective coatings on zirconium-based alloys as accident-tolerant fuel (ATF) claddings

2017 ◽  
Vol 35 (3) ◽  
pp. 141-165 ◽  
Author(s):  
Chongchong Tang ◽  
Michael Stueber ◽  
Hans Juergen Seifert ◽  
Martin Steinbrueck
Keyword(s):  
Protective Coatings ◽  
Future Research ◽  
Coating Materials ◽  
Research Activities ◽  
High Temperature Steam ◽  
Accident Scenarios ◽  
Accident Conditions ◽  
Surface Modified ◽  
Deposition Technology ◽  
Zr Alloy

AbstractSurface-modified zirconium (Zr)-based alloys, mainly by fabricating protective coatings, are being developed and evaluated as accident-tolerant fuel (ATF) claddings, aiming to improve fuel reliability and safety during normal operations, anticipated operational occurrences, and accident scenarios in water-cooled reactors. In this overview, the performance of Zr alloy claddings under normal and accident conditions is first briefly summarized. In evaluating previous studies, various coating concepts are highlighted based on coating materials, focusing on their performance in autoclave hydrothermal corrosion tests and high-temperature steam oxidation tests. The challenges for the utilization of coatings, including materials selection, deposition technology, and stability under various situations, are discussed to provide some valuable guidance to future research activities.

Washing Effectiveness Assessment of Different Cleaners on a Small-Scale Multistage Compressor

2021 ◽  
Author(s):  
Alessandro Vulpio ◽  
Alessio Suman ◽  
Nicola Casari ◽  
Michele Pinelli ◽  
Craig Appleby ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Axial Flow ◽  
Solid Particles ◽  
Rotor Blades ◽  
Small Scale ◽  
Internal Surfaces ◽  
Environmentally Sensitive ◽  
Flow Compressor ◽  
Processing Techniques ◽  
Effectiveness Assessment

Abstract Suspended micrometric particles are always present in the air swallowed by gas turbines. These solid particles can overpass the filters of heavy-duty gas turbines and deposit onto the internal surfaces of the compressor, leading to the overtime reduction of the machine performances, and, as a result, to the fuel consumption augmentation. A widely employed method to slow down the engine degradation is to wash the engine frequently. Over the years, the washing techniques have been continuously improved in order to reach the best compromise between low fluid consumption and high washing capabilities. In this work, an experimental campaign has been carried out to estimate the washing effectiveness on a multistage axial-flow compressor fouled with micrometric soot particles. The cleaning fluids tested in the present work were demineralized water and two cleaners provided by ZOK International Group ltd: a commercial cleaner available on the market (ZOK 27), and a new, under development, environmentally-sensitive formula. The fluids have been tested employing three droplet size distributions (with mean diameters of 20 μm, 50 μm, and 100 μm). The washing effectiveness has been assessed through image post-processing techniques by analyzing the pictures of the stator vanes and rotor blades taken in fouled and washed conditions. From the present investigation, two results arise. The finest droplets show a greater capability to remove soot deposits showing how, when the washing operation takes place during quasi-idle operating condition, the turbulent-driven motion spread smaller particles on a wider blade region. The second results is the demonstration how a environmentally-sensitive chemical formula allows the obtainment of good results in terms removal capability for the same amount of product. This finding could help the plant manager to operate the gas turbine with less constraints in terms of cost and rules.

Mixed Flow Turbine Research: A Review

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Srithar Rajoo ◽  
Ricardo Martinez-Botas
Keyword(s):  
Gas Turbines ◽  
Research Direction ◽  
Future Research ◽  
Mixed Flow ◽  
The Public ◽  
Performance Improvements ◽  
Rotor Design ◽  
Significant Performance ◽  
Increasing Demand ◽  
Initial Research

Research on mixed flow turbines spans over 50years with substantial literature available in the public domain. Mixed flow turbines were initially used as an alternative rotor design for gas turbines and later extended to automotive turbocharger applications. The characteristics of a mixed flow turbine resemble a radial turbine but with some significant performance improvements, giving this design an edge to satisfy the ever increasing demand in the automotive sector. The initial research focus was mainly experimental but in recent years, there have been significant contributions in computational analysis. This paper is intended to provide readers with a comprehensive review of the past and present research into the design, performance, and use of mixed flow turbines. Additionally, the future research direction of the mixed flow turbine is discussed in view of the current turbocharger and automotive demand.

ECONOMIC GROWTH ANALYSIS: A STUDY ON MALAYSIAN MARKET

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Suhaily Maizan Abdul Manaf ◽  
Shuhada Mohamed Hamidi ◽  
Nur Shafini Mohd Said ◽  
Siti Rapidah Omar Ali ◽  
Nur Dalila Adenan
Keyword(s):  
Economic Growth ◽  
Foreign Direct Investment ◽  
Direct Investment ◽  
Inflation Rate ◽  
Government Expenditure ◽  
Correlation Method ◽  
Research Direction ◽  
Least Square ◽  
Future Research ◽  
Internal And External Factors

Economic performance of a country is mostly determined by the growth and any other internal and external factors. In this study, researchers purposely focused on Malaysian market by examining the relationship between export, inflation rate, government expenditure and foreign direct investment towards economic growth in Malaysia by applying the yearly data of 47 years from 1970 to 2016 using descriptive statistics, regression model and correlation method analysis. By applying Ordinary Least Square (OLS) method, the result suggests that export, government expenditure and foreign direct investment are positively and significantly correlated with the economic growth. However, inflation rate has negative and insignificant relationship with the economic growth. The outcome of the study is suggested to be useful in providing the future research direction towards the economic growth in Malaysia. Keywords: economic growth; export; inflation rate; government expenditure

The Social Neuroscience of Cooperation

2018 ◽  
Author(s):  
Jay Joseph Van Bavel
Keyword(s):  
Theoretical Models ◽  
Brain Regions ◽  
Review Literature ◽  
Social Neuroscience ◽  
Future Research ◽  
A Value ◽  
Group Cooperation ◽  
Neural Processes ◽  
The Social ◽  
Cooperative Decision Making

We review literature from several fields to describe common experimental tasks used to measure human cooperation as well as the theoretical models that have been used to characterize cooperative decision-making, as well as brain regions implicated in cooperation. Building on work in neuroeconomics, we suggest a value-based account may provide the most powerful understanding the psychology and neuroscience of group cooperation. We also review the role of individual differences and social context in shaping the mental processes that underlie cooperation and consider gaps in the literature and potential directions for future research on the social neuroscience of cooperation. We suggest that this multi-level approach provides a more comprehensive understanding of the mental and neural processes that underlie the decision to cooperate with others.

Co-Enzyme Q10 to Treat Neurological Disorders: Basic Mechanisms, Clinical Outcomes, and Future Research Direction

2013 ◽  
Vol 12 (5) ◽  
pp. 641-664 ◽  
Author(s):  
Mohamed Salama ◽  
Ti-Fei Yuan ◽  
Sergio Machado ◽  
Eric Murillo-Rodriguez ◽  
Jose Vega ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Neurological Disorders ◽  
Research Direction ◽  
Future Research ◽  
Future Research Direction

Cancer and Cancer Treatment-Related Cognitive Impairment

2019 ◽  
pp. 60-83
Author(s):  
James C.  Root ◽  
Elizabeth Ryan ◽  
Tim A. Ahles
Keyword(s):  
Cancer Survivors ◽  
Cancer Treatment ◽  
Clinical Presentation ◽  
Functional Neuroimaging ◽  
Theoretical Models ◽  
Future Research ◽  
Cognitive Changes ◽  
Central Nervous System Cancer ◽  
Pharmacologic Treatments

As the population of cancer survivors has grown into the millions, there is increasing emphasis on understanding how late effects of treatment impact survivors’ ability return to work/school, ability to function and live independently, and overall quality of life. Cognitive changes are one of the most feared problems among cancer survivors. This chapter describes the growing literature examining cognitive changes associated with non-central nervous system cancer and cancer treatment. Typical elements of cancer treatment are discussed, followed by a description of clinical presentation, self-reported and objectively assessed cognitive findings, and results of structural and functional neuroimaging research. Genetic and other risk factors for cognitive decline following treatment are identified and discussed, together with biomarkers and animal models of treatment-related effects. This is followed by a discussion of behavioral and pharmacologic treatments. Finally, challenges and recommendations for future research are provided to help guide subsequent research and theoretical models.

Emerging Syndromes

2017 ◽  
Author(s):  
Kelly C. Allison ◽  
Jennifer D. Lundgren
Keyword(s):  
Empirical Studies ◽  
Theoretical Models ◽  
Future Research ◽  
Night Eating Syndrome ◽  
Statistical Manual ◽  
Night Eating ◽  
Diagnostic And Statistical Manual ◽  
Impairment In Functioning ◽  
Atypical Anorexia Nervosa ◽  
Comorbid Psychopathology

The Diagnostic and Statistical Manual, fifth edition, of the American Psychiatric Association (2013) has designated several disorders under the diagnosis of otherwise specified feeding and eating disorder (OSFED). This chapter evaluates three of these, night eating syndrome (NES), purging disorder (PD), and atypical anorexia nervosa (atypical AN). It also reviews orthorexia nervosa, which has been discussed in the clinical realm as well as the popular press. The history and definition for each is reviewed, relevant theoretical models are presented and compared, and evidence for the usefulness of the models is described. Empirical studies examining the disorders’ independence from other disorders, comorbid psychopathology, and, when available, medical comorbidities, are discussed. Distress and impairment in functioning seem comparable between at least three of these emerging disorders and threshold eating disorders. Finally, remaining questions for future research are summarized.

scholarly journals Structural and Functional Remodeling of Mitochondria in Cardiac Diseases

2021 ◽  
Vol 22 (8) ◽  
pp. 4167
Author(s):  
Xiaonan Sun ◽  
Jalen Alford ◽  
Hongyu Qiu
Keyword(s):  
Regulatory Network ◽  
Molecular Basis ◽  
Therapeutic Potential ◽  
Research Direction ◽  
Future Research ◽  
Cardiac Diseases ◽  
Functional Remodeling ◽  
Underlying Mechanisms ◽  
Mitochondrial Remodeling ◽  
Normal Cellular Function

Mitochondria undergo structural and functional remodeling to meet the cell demand in response to the intracellular and extracellular stimulations, playing an essential role in maintaining normal cellular function. Merging evidence demonstrated that dysregulation of mitochondrial remodeling is a fundamental driving force of complex human diseases, highlighting its crucial pathophysiological roles and therapeutic potential. In this review, we outlined the progress of the molecular basis of mitochondrial structural and functional remodeling and their regulatory network. In particular, we summarized the latest evidence of the fundamental association of impaired mitochondrial remodeling in developing diverse cardiac diseases and the underlying mechanisms. We also explored the therapeutic potential related to mitochondrial remodeling and future research direction. This updated information would improve our knowledge of mitochondrial biology and cardiac diseases’ pathogenesis, which would inspire new potential strategies for treating these diseases by targeting mitochondria remodeling.

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