The influence of erosion and wear on the accretion and adhesion of ice for nano reinforced polymetric composites used in aeronautics

The usage of polymeric matrix composites in aerospace applications has been significantly prevalent based on their desired material characteristics, which include higher strength, lower weight and heat resistance. With current advancements in nanotechnology, carbon nanotube reinforced polymeric matrix composites may enhance the operational usage of these advanced materials even further. In this study, a set of novel aerospace material candidates are characterized based on their mechanical properties, resilience to liquid erosion, wettability and ice adhesion. The experimental evaluations presented, allow for a preliminary ranking of the polymeric matrix composites and assessment of the influence of reinforcing carbon nanotubes. The role of erosion in particular is highlighted from both a historical viewpoint and based on empirical results for static and dynamic wettability and ice adhesion. Discussion of different ranking systems and fractography arising as a consequence of liquid impact are further addressed in this study. It is found that the candidate samples exhibit different physical parameters but nominally similar erosion resilience despite the presence of the reinforcing carbon nanotubes. The wettability of the experimental materials and their ice adhesion characteristics are further shown to be influenced by the presence of carbon nanotubes and largely dependent upon degradation of the material surfaces

The Political Economy of Iran: Development, Revolution and Political Violence

The book explores the relation between truth, trust and wealth in the modern history of Iran, and provides an up-to-date theoretical understanding of Iran and investigates the lack of stability, development and wealth creation in the country. Tragedy of confusion alongside unstable coalitions, frequent crises and socio-political violence result in an inability to build a solid foundation for the process of wealth creation via generation of trust in institutions. Drawing upon the latest research in economics, psychology, politics and philosophy, this study offers a new theoretical framework for interpretation of the Iranian modern history and its troubled experience of development. This monograph will appeal to researchers, scholars, graduate students, policy makers and anyone interested in the Middle Eastern politics, Iran, development studies and political economy

Tragedy of Confusion: The Political Economy of Truth in the modern history of Iran (A novel framework for the analysis of the enigma of socio-economic underdevelopment in the modern history of Iran)

This study entails a theoretical reading of the Iranian modern history and follows an interdisciplinary agenda at the intersection of philosophy, economics, and politics and intends to offer a novel framework for the analysis of socio-economic underdevelopment in Iran in the modern era. A brief review of Iranian modern history from the constitutional revolution, to the oil nationalization movement, the 1979 Islamic Revolution, and the recent Reformist and Green movements demonstrates that Iranian people travelled full circle. This historical experience of socio-economic underdevelopment revolving around the bitter question of “why are we backward?” and its manifestation in perpetual socio-political instability and violence is the subject matter of this study. Foucault’s conceived relation between the production of truth and production of wealth captures the essence of hypothesis offered in this study. Michel Foucault (1980: 93-4) maintains that “In the last analysis, we must produce truth as we must produce wealth, indeed we must produce truth in order to produce wealth in the first place”. Based on a hybrid methodology combining hermeneutics of understanding and hermeneutics of suspicion, this study proposes that the failure to produce wealth has had particular roots in the failure in the production of truth. At the heart of the proposed theoretical model is the following formula: The Iranian dasein’s confused preference structure culminates in the formation of unstable coalitions which in turn leads to institutional failure, creating a chaotic social order and a turbulent history as experienced by the Iranian nation in the modern era. The following set of interrelated propositions elaborate further on the core formula of the model: Each and every Iranian person and her subjectivity and preference structure is the site of three distinct warring regimes of truth and identity choice sets (identity markers) related to the ancient Persian empire (Persianism), Islam, and modernity. These three historical a priori and regimes of truth act as conditions of possibility for social interactions, and are unities in multiplicities. They, in their perpetual state of tension and conflict, constitute the mutually exclusive, contradictory, and confused dimensions of the prism of the Iranian dasein. The confused preference structure prevents Iranian people from organizing themselves in stable coalitions required for collective action to achieve the desired socio-economic change. The complex interplay between the state of inbetweenness and the state of belatedness makes it impossible to form stable coalitions in any areas of life, work, and language to achieve the desired social transformations, turning Iran into a country of unstable coalitions and alliances in macro, meso and micro levels. This in turn leads to failure in the construction of stable institutions (a social order based on rule of law or any other stable institutional structure becomes impossible) due to perpetual tension between alternative regimes of truth manifested in warring discursive formations, relations of power, and techniques of subjectification and their associated economies of affectivity. This in turn culminates in relations of power in all micro, meso, and macro levels to become discretionary, atomic, and unpredictable, producing perpetual tensions and social violence in almost all sites of social interactions, and generating small and large social earthquakes (crises, movements, and revolutions) as experienced by the Iranian people in their modern history. As such, the society oscillates between the chaotic states of socio-political anarchy emanating from irreconcilable differences between and within social assemblages and their affiliated hybrid forms of regimes of truth in the springs of freedom and repressive states of order in the winters of discontent. Each time, after the experience of chaos, the order is restored based on the emergence of a final arbiter (Iranian leviathan) as the evolved coping strategy for achieving conflict resolution. This highly volatile truth cycle produces the experience of socio-economic backwardness. The explanatory power of the theoretical framework offered in the study exploring the relation between the production of truth, trust and wealth is tested on three strong events of Iranian modern history: the Constitutional Revolution, the Oil-Nationalization Movement and the Islamic Revolution. The significant policy implications of the model are explored

A CONCEPTUAL DISASTER RISK REDUCTION FRAMEWORK FOR HEALTH AND SAFETY HAZARDS IN THE CONSTRUCTION INDUSTRY

The health and safety hazard status of construction workers is constantly challenged by the projects in the built environment. In this article, various aspects of health and safety hazards for construction workers have been reviewed and investigated through a disaster risk reduction prism. This approach has further led to the perception of glancing at the construction sector as an ongoing disaster zone and equally provides a new management perspective. From this perspective, the occurrence of a disaster within the construction sector corresponds to the temporary or permanent ill-health or death of a construction worker. Geographical location is one of the factors that play an important role in addressing the health and safety hazards for construction workers. In addition to the location, geographical considerations equally encapsulate regional, cultural, governmental and work ethical effects. These effects may potentially contribute to disparities in the construction sector. With an increasing level of understanding for health and safety hazards in the construction domain, more efficient prevention measures can be taken in order to enable a disaster management cycle, capable of responding to the rigorous demands of the construction sector

The influence of erosion and wear on the accretion and adhesion of ice for nano-reinforced polymetric composites used in aeronautics

The usage of polymeric matrix composites in aerospace applications has been significantly prevalent based on their desired material characteristics, which include higher strength, lower weight and heat resistance. With current advancements in nanotechnology, carbon nanotube reinforced polymeric matrix composites may enhance the operational usage of these advanced materials even further. In this study, a set of novel aerospace material candidates are characterized based on their mechanical properties, resilience to liquid erosion, wettability and ice adhesion. The experimental evaluations presented, allow for a preliminary ranking of the polymeric matrix composites and assessment of the influence of reinforcing carbon nanotubes. The role of erosion in particular is highlighted from both a historical viewpoint and based on empirical results for static and dynamic wettability and ice adhesion. Discussion of different ranking systems and fractography arising as a consequence of liquid impact are further addressed in this study. It is found that the candidate samples exhibit different physical parameters but nominally similar erosion resilience despite the presence of the reinforcing carbon nanotubes. The wettability of the experimental materials and their ice adhesion characteristics are further shown to be influenced by the presence of carbon nanotubes and largely dependent upon degradation of the material surfaces.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Effect of Coolant Ejection in Rectangular and Trapezoidal Trailing Edge Cooling Passages

ABSTRACT Heat transfer coefficients are experimentally determined in various trailing edge cooling channels. A rectangular channel (AR = 3:1) with fully developed flow is used as a baseline for the study with the Reynolds number varying from 20,000 to 80,000. The heat transfer coefficients in this channel are compared to those in a similar rectangular channel with coolant extraction, which would likely be encountered in a trailing edge cooling passage. The heat transfer trends in the rectangular channel are compared to those obtained in a passage with a trapezoidal (or wedgeshaped) cross-section. The heat transfer coefficients are also obtained in the channel without coolant extraction and with extraction from the narrow side of the channel. The effect of V-shaped rib turbulators is also considered in the rectangular and trapezoidal cooling passages. In addition, the effect of entrance condition is considered with the wedgeshaped channel. Heat transfer coefficients obtained with hydrodynamically developed flow are compared to those with flow through a contraction into the heated section of the channel. In the rectangular channel without ejection, the heat transfer coefficients are uniform across the span of the channel; however, with coolant ejection, the heat transfer coefficients increase near the ejection slots. In addition, in the trapezoidal channels, the heat transfer coefficients are uniform across the cross-section of the smooth channel. When coolant is extracted for trailing edge ejection, the outer surface sees the most significant heat transfer enhancement. The outer surface of the smooth, trapezoidal channel is most profoundly affected by the entrance condition, and the effect of the entrance condition is marginal in trapezoidal channels with ribs and ejection