scholarly journals Introductory Chapter: An Introduction to the Optimization of Composite Structures

Author(s):  
Karam Maalawi
Keyword(s):  
Author(s):  
Frances M. Ross ◽  
Peter C. Searson

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.


2019 ◽  
Author(s):  
Curtis Hickmott ◽  
Alireza Forghani ◽  
Victoria Hutten ◽  
Evan Lorbiecki ◽  
Frank Palmieri ◽  
...  

Author(s):  
John Marmysz

This introductory chapter examines the “problem” of nihilism, beginning with its philosophical origins in the ideas of Plato, Immanuel Kant, Friedrich Nietzsche and Martin Heidegger. It is argued that film is an inherently nihilistic medium involving the evocation of illusory worlds cut loose from objective reality. This nihilism of film is distinguished from nihilism in film; the nihilistic content also present in some (but not all) movies. Criticisms of media nihilism by authors such as Thomas Hibbs and Darren Ambrose are examined. It is then argued, contrary to such critics, that cinematic nihilism is not necessarily degrading or destructive. Because the nihilism of film encourages audiences to linger in the presence of nihilism in film, cinematic nihilism potentially trains audiences to learn the positive lessons of nihilism while remaining safely detached from the sorts of dangers depicted on screen.


Author(s):  
Pål Kolstø ◽  
Helge Blakkisrud

Russian societal nationalism comes in various guises, both ethnic and imperialist. Also Putin’s rhetoric is marked by the tensions between ethnic and state-focused, imperialist thinking. Noting the complex interplay of state nationalism and societal nationalism, this introductory chapter examines the mental framework within which Russian politicians were acting prior to the decision to annex Crimea. The chapter develops a typology of Russian nationalisms, surveys recent developments, and presents the three-part structure of this book: official nationalism, radical and other societal nationalisms, and identities/otherings. It concludes that after the annexation of Crimea, when the state took over the agenda of both ethnic and imperialist nationalists in Russia, societal nationalism finds itself at low ebb.


1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.


Author(s):  
Nancy Woloch

This introductory chapter provides an overview of single-sex protective laws. The longevity of protective laws rests in part on reformers' bifocal defense. The goal of such laws, their proponents claimed, was to compensate for women's disadvantages in the labor market and to serve as the linchpin of a larger plan to achieve wage-and-hour standards for all employees. This double-planked rationale—though contradictory—proved versatile and enduring; it suited constituents with varied priorities. Protective laws' longevity also rested on effective social feminist organization and, after 1920, on the federal Women's Bureau. In retrospect, single-sex protective laws were an unwieldy means to achieve egalitarian ends—or what women reformers of the 1920s called “industrial equality.” However, critics charged that the laws failed to redress disadvantage and even compounded it. Protection's supporters also confronted developments they could not anticipate and shifts in attitude they could not foresee.


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