EACH blade of an airscrew is submitted to an elementary static balance check after it has been completed. But this operation does not eliminate the necessity to carry out a…
Abstract
EACH blade of an airscrew is submitted to an elementary static balance check after it has been completed. But this operation does not eliminate the necessity to carry out a general balance of the complete airscrew. This is carried out statically, first of all for the hub alone, and then statically and dynamically for the completely assembled airscrew.
IN the construction of their airscrews the Hispano Suiza Company use principally aluminium alloys—duralumin, alfcrium, avional—with a mean density of 2·8, and with mechanical…
Abstract
IN the construction of their airscrews the Hispano Suiza Company use principally aluminium alloys—duralumin, alfcrium, avional—with a mean density of 2·8, and with mechanical properties equal to those of a half‐hard steel. They have been considering for some time the manufacture of blades of magnesium alloy, the mean density of which is 1·8, thereby offering considerable advantage over the aluminium alloys as regards weight, but, in this article, only aluminium alloy blades are dealt with.
The necessity for refinement of airscrew balance in order to eliminate destructive vibration from this source is due largely to the continuously improving standards of passenger…
Abstract
The necessity for refinement of airscrew balance in order to eliminate destructive vibration from this source is due largely to the continuously improving standards of passenger comfort of modern aeroplanes and to the operator's desire to extend the normal service life of the power plant and its accessories as well as that of the aeroplane structure. Power plant vibration already has been reduced to a degree where, in standard aeroplanes, there is no longer danger of major structural failure due to vibration originating from this source. Efforts to refine further the balance of engines and airscrews are directed mainly at increasing passenger comfort and extending the service life of aeroplane equipment.
Tri Sulistyaningsih, Mohammad Jafar Loilatu and Ali Roziqin
Smart urban governance research has progressed over the past few decades following changes and increasingly complicated city management difficulties. Therefore, the purpose of…
Abstract
Purpose
Smart urban governance research has progressed over the past few decades following changes and increasingly complicated city management difficulties. Therefore, the purpose of this paper is to use a scoping review and bibliometric analysis to examine all the publications on smart urban governance, especially in Asia.
Design/methodology/approach
A total of 1,900 smart urban governance articles indexed in the Scopus database was analyzed through scoping review and bibliometric analysis. The articles were analyzed by the number of publications per year, contributing countries, subject areas, authors, cited documents, related issues and cited papers. Furthermore, VOSviewer was used to provide a visual analysis of the co-occurrence of keywords.
Findings
This study indicated that urban smart governance publications continue to increase yearly. Even though the area of analysis is Asia, the USA and China seriously contributed to the analysis. Therefore, the topic of smart urban governance has become a discussion for scholars in the international. From the Scopus database analysis, the top three subject areas are social sciences (28%), environmental science (20%) and medicine (16%). The synthesis using bibliometric analysis by VOSviewer obtained 13 clusters.
Research limitations/implications
This study only focuses on the Scopus database and one specific topic, using one bibliometric analysis tool. Meanwhile, national and international index databases are not used.
Originality/value
This paper examined publication trends on smart urban governance. This paper provided a comprehensive analysis of topic-specific knowledge areas based on previous studies. Additionally, this paper suggested the direction of the development of smart urban governance in the future.
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Mohammad Saeid Aghighi, Christel Metivier and Sajad Fakhri
According to the research, viscoplastic fluids are sensitive to slipping. The purpose of this study is to determine whether slip affects the Rayleigh–Bénard convection of…
Abstract
Purpose
According to the research, viscoplastic fluids are sensitive to slipping. The purpose of this study is to determine whether slip affects the Rayleigh–Bénard convection of viscoplastic fluids in cavities and, if so, under what conditions.
Design/methodology/approach
The wall slip was evaluated using a model created for viscoplastic (Bingham) fluids. The coupled conservation equations were solved numerically using the finite element method. Simulations were performed for various parameters: the Rayleigh number, yield number, slip yield number and friction number.
Findings
Wall slip determines two essential yield stresses: a specific yield stress value beyond which wall slippage is impossible (S_Yc); and a maximum yield stress beyond which convective flow is impossible (Y_c). At low Rayleigh numbers, Y_c is smaller than S_Yc. Hence, the flow attained a stable (conduction) condition before achieving the no-slip condition. However, for more significant Rayleigh numbers Y_c exceeded S_Yc. Thus, the flow will slip at low yield numbers while remaining no-slip at high yield numbers. The possibility of slipping on the wall increases the buoyancy force, facilitating the onset of Rayleigh–Bénard convection.
Originality/value
An essential aspect of this study lies in its comprehensive examination of the effect of slippage on the natural convection flow of viscoplastic materials within a cavity, which has not been previously investigated. This research contributes to a new understanding of the viscoplastic fluid behavior resulting from slipping.
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M'Hamed El-Louh, Mohammed El Allali and Fatima Ezzaki
In this work, the authors are interested in the notion of vector valued and set valued Pettis integrable pramarts. The notion of pramart is more general than that of martingale…
Abstract
Purpose
In this work, the authors are interested in the notion of vector valued and set valued Pettis integrable pramarts. The notion of pramart is more general than that of martingale. Every martingale is a pramart, but the converse is not generally true.
Design/methodology/approach
In this work, the authors present several properties and convergence theorems for Pettis integrable pramarts with convex weakly compact values in a separable Banach space.
Findings
The existence of the conditional expectation of Pettis integrable mutifunctions indexed by bounded stopping times is provided. The authors prove the almost sure convergence in Mosco and linear topologies of Pettis integrable pramarts with values in (cwk(E)) the family of convex weakly compact subsets of a separable Banach space.
Originality/value
The purpose of the present paper is to present new properties and various new convergence results for convex weakly compact valued Pettis integrable pramarts in Banach space.
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This chapter provides a close reading and critical analysis of work by two New York City-based Afro-Dominican artists, Joiri Minaya (1990) and Josefina Báez (1960). The author…
Abstract
This chapter provides a close reading and critical analysis of work by two New York City-based Afro-Dominican artists, Joiri Minaya (1990) and Josefina Báez (1960). The author argues that Báez' “Carmen FotonovelARTE” (2020) and Minaya's “Containers” series (2015–2020) play with the trope of repose and mixed-race beauty to chart pathways of Afro-Latina representation that are shaped by yet that radically challenge the colonial script of the mulata. The artists create a space of refusal that transforms repose into a powerful site from which to articulate, problematize, and dismantle oppressive, reductive systems of representation.
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This chapter examines ways the Spanish Constitution of 1812, also known as the Constitution of Cádiz, has been viewed in historical and constitutional thought. The document is a…
Abstract
This chapter examines ways the Spanish Constitution of 1812, also known as the Constitution of Cádiz, has been viewed in historical and constitutional thought. The document is a liberal constitution establishing constitutional rights, a representative government, and a parliamentary monarchy. It influenced ideas of American equality within the Spanish Empire, and its traces are observed in the process of Latin American independence. To these accepted views, one must add that the Constitution was a lost moment in Latin American constitutional development. By the immediate politicization of constitutionalism after 1812, the document marks the beginning of constitutional difficulties in the region.
This chapter focuses on information efficiency as provided by fair value accounting (FVA) and corporate governance (CG) practices in an emerging market. Positive accounting theory…
Abstract
This chapter focuses on information efficiency as provided by fair value accounting (FVA) and corporate governance (CG) practices in an emerging market. Positive accounting theory was adopted as an empirical model to test the relationship between information efficiency and stock prices. Data for the period 2007–2020 from 576 listed firms on the Stock Exchange of Thailand were collected, tested, and analyzed using a fixed effect estimator. The results indicate that investors in the stock market trust the use of publicized efficient information as provided by FVA and CG practices in making their investment decisions, when FVA and CG proxies were found to significantly influence stock prices. Hence, this evidence implies that information efficiency leads to better firm values in an emerging market.
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The goal of this chapter is to discuss the foundations of ‘modern finance’, its paradigm and conceptual framework, its methods and tools, its practices and results, its governance…
Abstract
Purpose
The goal of this chapter is to discuss the foundations of ‘modern finance’, its paradigm and conceptual framework, its methods and tools, its practices and results, its governance and regulation.
Approach
The first part presents the characteristics of ‘modern finance’ and its negative effects. The second part analyses the efforts made to remedy those effects and argue about the need for a real reform.
Findings
Several aspects are pointed, for example an unreasonable ‘normality’, incentives that encourage excess, the spread of subprime crisis, etc. The contemporary finance is a ‘giant with clay feet’.
Originality/value
We need to proceed with a dual reembeddedness of finance in the economy and economy in society.