Slug to annular flow transition of microgravity two-phase flow

A new model is developed for predicting the transition from the slug to annular flow of adiabatic two-phase gas/liquid flow in microgravity (mu g) environment. This model is based on the analyses of the effects of the surface tension and the gas inertia in a sense of more physical approach. The drift-flux model is applied to determine the gas void fraction near the transition region. The new model is compared with previous models and experimental data, and the results show the improvement in explanation of the experimental results.

Distribution, stability, bifurcations and catastrophe of steady rotation of a symmetrical heavy gyroscope with viscous-liquid-filled cavity

The number, the angles of orientation and the stability in Rumyantsev Movchan's sense of oblique steady rotations of a symmetric heavy gyroscope with a cavity completely filled with a uniform viscous liquid, possessing a fixed point 0 on its symmetric axis. are given for various values of the parameters. By taking the square of the upright component of the angular momentum M2 as a control parameter, three types of bifurcation diagrams of the steady rotations, two types of jumps and two kinds of local catastrophes, one being the symmetric reduced cusp type and the other being of the symmetric reduced butterfly type, are obtained. By taking account of the M2-damping owing to the moment of unavoidable faint friction, two different modes for the gyroscope, initially in a stable quasi-steady upright rotation with a nutation angle theta(s) equal to zero, to topple over are found.

Visual impact assessment of small dock & piers: Theory and practice

From a manager’s perspective, oftentimes the publicly held concerns related to small docks and piers are not really related to the environment. They may be more related to visual impacts and aesthetic concerns, a sense of over-development of the shore, or simply change. While individuals may hold personal aesthetic values related to small docks in general or an individual structure in particular, techniques have evolved that appear to provide reproducible, predictive assessments of the visual impacts and aesthetic values of an area and how those might change with development, including an increase in numbers of small docks. These assessments may be used to develop regulatory or non-regulatory methods for the management of small docks based on state or community standards. Visual impact assessments are increasingly used in the regulatory review of proposed development—although this process is still in its infancy as regards small docks and piers. Some political jurisdictions have established visual impact or aesthetic standards as relate to docks and others are in the process of investigating how to go about such an effort. (PDF contains 42 pages)

Analysis of Spanish text-thesaurus as a complex network

[EN]Based on the theoretical tools of Complex Networks, this work provides a basic descriptive study of a synonyms dictionary, the Spanish Open Thesaurus represented as a graph. We study the main structural measures of the network compared with those of a random graph. Numerical results show that Open-Thesaurus is a graph whose topological properties approximate a scale-free network, but seems not to present the small-world property because of its sparse structure. We also found that the words of highest betweenness centrality are terms that suggest the vocabulary of psychoanalysis: placer (pleasure), ayudante (in the sense of assistant or worker), and regular (to regulate).

Projections in a normed linear space and a generalization of the pseudo-inverse

The concept of a "projection function" in a finite-dimensional real or complex normed linear space H (the function P_M which carries every element into the closest element of a given subspace M) is set forth and examined.

If dim M = dim H - 1, then P_M is linear. If P_N is linear for all k-dimensional subspaces N, where 1 ≤ k < dim M, then P_M is linear.

The projective bound Q, defined to be the supremum of the operator norm of P_M for all subspaces, is in the range 1 ≤ Q < 2, and these limits are the best possible. For norms with Q = 1, P_M is always linear, and a characterization of those norms is given.

If H also has an inner product (defined independently of the norm), so that a dual norm can be defined, then when P_M is linear its adjoint P_M^H is the projection on (kernel P_M)^⊥ by the dual norm. The projective bounds of a norm and its dual are equal.

The notion of a pseudo-inverse F⁺ of a linear transformation F is extended to non-Euclidean norms. The distance from F to the set of linear transformations G of lower rank (in the sense of the operator norm ∥F - G∥) is c/∥F⁺∥, where c = 1 if the range of F fills its space, and 1 ≤ c < Q otherwise. The norms on both domain and range spaces have Q = 1 if and only if (F⁺)⁺ = F for every F. This condition is also sufficient to prove that we have (F⁺)^H = (F^H)⁺, where the latter pseudo-inverse is taken using dual norms.

In all results, the real and complex cases are handled in a completely parallel fashion.

How far from Jerusalem? Tropical customs and the question of race in the Book of John Mandeville

The Book of John Mandeville, while ostensibly a pilgrimage guide documenting an English knight’s journey into the East, is an ideal text in which to study the developing concept of race in the European Middle Ages. The Mandeville-author’s sense of place and morality are inextricably linked to each other: Jerusalem is the center of his world, which necessarily forces Africa and Asia to occupy the spiritual periphery. Most inhabitants of Mandeville’s landscapes are not monsters in the physical sense, but at once startlingly human and irreconcilably alien in their customs. Their religious heresies, disordered sexual appetites, and monstrous acts of cannibalism label them as fallen state of the European Christian self. Mandeville’s monstrosities lie not in the fantastical, but the disturbingly familiar, coupling recognizable humans with a miscarriage of natural law. In using real people to illustrate the moral degeneracy of the tropics, Mandeville’s ethnography helps shed light on the missing link between medieval monsters and modern race theory.

Stability of parametrically excited differential equations

Sufficient stability criteria for classes of parametrically excited differential equations are developed and applied to example problems of a dynamical nature.

Stability requirements are presented in terms of 1) the modulus of the amplitude of the parametric terms, 2) the modulus of the integral of the parametric terms and 3) the modulus of the derivative of the parametric terms.

The methods employed to show stability are Liapunov’s Direct Method and the Gronwall Lemma. The type of stability is generally referred to as asymptotic stability in the sense of Liapunov.

The results indicate that if the equation of the system with the parametric terms set equal to zero exhibits stability and possesses bounded operators, then the system will be stable under sufficiently small modulus of the parametric terms or sufficiently small modulus of the integral of the parametric terms (high frequency). On the other hand, if the equation of the system exhibits individual stability for all values that the parameter assumes in the time interval, then the actual system will be stable under sufficiently small modulus of the derivative of the parametric terms (slowly varying).

Nature of the radical intermediates in a substituted cyclopropylcarbiny-allylcarbinyl system

We have sought to determine the nature of the free-radical precursors to ring-opened hydrocarbon 5 and ring-closed hydrocarbon 6. Reasonable alternative formulations involve the postulation of hydrogen abstraction (a) by a pair of rapidly equilibrating classical radicals (the ring-opened allylcarbinyl-type radical 3 and the ring-closed cyclopropylcarbinyl-type 4), or (b) by a nonclassical radical such as homoallylic radical 7.

[Figure not reproduced.]

Entry to the radical system is gained via degassed thermal decomposition of peresters having the ring-opened and the ring-closed structures. The ratio of 6:5 is essentially independent of the hydrogen donor concentration for decomposition of the former at 125° in the presence of triethyltin hydrdride. A deuterium labeling study showed that the α and β methylene groups in 3 (or the equivalent) are rapidly interchanged under these conditions.

Existence of two (or more) product-forming intermediates is indicated (a) by dependence of the ratio 6:5 on the tin hydride concentration for decomposition of the ring-closed perester at 10 and 35°, and (b) by formation of cage products having largely or wholly the structure (ring-opened or ring-closed) of the starting perester.

Relative rates of hydrogen abstraction by 3 could be inferred by comparison of ratios of rate constants for hydrogen abstraction and ortho-ring cyclization:

[Figure not reproduced.]

At 100° values of k_a/k_r are 0.14 for hydrogen abstraction from 1,4-cyclohexadiene and 7 for abstraction from triethyltin hydride. The ratio 6:5 at the same temperature is ~0.0035 for hydrogen abstraction from 1,4-cyclohexadiene, ~0.078 for abstraction from the tin hydride, and ≥ 5 for abstraction from cyclohexadienyl radicals. These data indicate that abstraction of hydrogen from triethyltin hydride is more rapid than from 1,4-cyclohexadiene by a factor of ~1000 for 4, but only ~50 for 3.

Measurements of product ratios at several temperatures allowed the construction of an approximate energy-level scheme. A major inference is that isomerization of 3 to 4 is exothermic by 8 ± 3 kcal/mole, in good agreement with expectations based on bond dissociation energies. Absolute rate-constant estimates are also given.

The results are nicely compatible with a classical-radical mechanism, but attempted interpretation in terms of a nonclassical radical precursor of product ratios formed even from equilibrated radical intermediates leads, it is argued, to serious difficulties.

The roles played by hydrogen abstraction from 1,4,-cyclohexadiene and from the derived cyclohexadienyl radicals were probed by fitting observed ratios of 6:5 and 5:10 in the sense of least-squares to expressions derived for a complex mechanistic scheme. Some 30 to 40 measurements on each product ratio, obtained under a variety of experimental conditions, could be fit with an average deviation of ~6%. Significant systematic deviations were found, but these could largely be redressed by assuming (a) that the rate constant for reaction of 4 with cyclohexadienyl radical is inversely proportional to the viscosity of the medium (i.e., is diffusion-controlled), and (b) that k_a/k_r for hydrogen abstraction from 1,4-cyclohexadiene depends slightly on the composition of the medium. An average deviation of 4.4% was thereby attained.

Degassed thermal decomposition of the ring-opened perester in the presence of the triethyltin hydride occurs primarily by attack on perester of triethyltin radicals, presumably at the –O-O- bond, even at 0.01 M tin hydride at 100 and 125°. Tin ester and tin ether are apparently formed in closely similar amounts under these conditions, but the tin ester predominates at room temperature in the companion air-induced decomposition, indicating that attack on perester to give the tin ether requires an activation energy approximately 5 kcal/mole in excess of that for the formation of tin ester.

Teatro e identidade nacional: as representações das alteridades na obra dramática de José de Alencar

O século XIX, no Brasil, foi marcado por uma tentativa de construção de uma identidade nacional e cultural num país pós-independência. Neste panorama, José de Alencar destaca-se, entre outros papéis que exerceu, como significativo romancista e contribui para a formação de um sistema literário em nosso país. Porém, é na obra dramática alencariana que também podemos identificar uma proposta discursiva da possível identidade do homem no Brasil a partir de suas relações contraditórias e problemáticas com os "outros" aqui presentes: o português, o índio, o negro, e o francês representações estas capazes de dar ao homem uma ideia de pertencimento cultural, através de uma seleção do que deve ou não servir para representar sua identidade e a de seu povo

Tipografía Popular Urbana: Los rótulos del pequeño negocio en el paisaje de Bilbao

419 páginas. 561 fotografías originales.

Co-management of beach seine fisheries in Mozambique: a case study

In Mozambique, compliance with regulations in beach seines fishery is improved when the fishers themselves choose the season the government will declare closed. Beneficial side effects of co-management include a stronger sense of community and individual responsibility toward the common good. This article reports on a case study of fisheries co-management in the community of Inhassoro in the northern part of the province of Inhambane, about 800 km north of the capital of Mozambique, Maputo.

Compulsory heterosexuality and Caribbean queer identities: an investigation of Achy Obejas's Memory mambo and Shani Mootoo's Valmiki's daughter

Esta dissertação pretende investigar de que forma idéias construídas socialmente impõem a heterossexualidade e afetam indivíduos não heterosexuais das ilhas Caribenhas, conforme ilustrado nos romances Memory Mambo, da Cubana-Americana Achy Obejas e Valmikis Daughters, da Trinitária-Canadense Shani Mootoo. Este trabalho se concentra na análise de políticas sexuais ligadas à homossexualidade tanto nas ilhas do Caribe quanto nos Estados Unidos da América. Em Memory Mambo, a protagonista Juani Casas deseja entender como sua condição de exilada cubana molda sua identidade sexual e como seu lesbianismo afeta seus relacionamentos familiares e amorosos. Reconstruindo sua história através de uma memória não confiável, Juani procura descobrir como sua sexualidade e sua nacionalidade estão ligadas, para que ela possa conciliar as duas. Em Valmikis Daughter, Viveka Krishnu e seu pai Valmiki Krishnu tentam esconder seus verdadeiros desejos por causa dos comportamentos supostamente corretos que foram designados tanto para homens quanto para mulheres em Trinidad, e mais especificamente na sociedade indo-caribenha. Pai e filha sofrem com a opressão e tentam não se tornarem vítimas de homofobia constante, ele escondendo sua sexualidade e ela deixando a ilha. Assim, através da representação literária, Obejas e Mootoo participam de uma discussão necessária sobre as consequencias das políticas sexuais na construção identitária de Caribenhos que vivem nas ilhas ou em destinos diaspóricos

Maracanazo e Mineiratzen: Imprensa e Representação da Seleção Brasileira nas Copas do Mundo de 1950 e 2014.

O esporte, entre as suas diversas variantes, é meio de expressão das construções acerca da identidade nacional. O futebol atua como um elemento aglutinador de etnias e classes e é uma importante maneira de influenciar a visão que o brasileiro tem de si próprio. No Brasil, a Seleção funciona como instrumento unificador de nação, representante da cultura nacional. Ao representar os atletas e equipe, os meios de comunicação acabam por construir imagens que influenciam nos sentidos de pertencimento em relação ao objeto retratado. Por meio dos discursos adotados pela imprensa, atribuímos valores simbólicos que geram identificação. A disputa de uma Copa do Mundo FIFA é um momento em que o sentimento de nacionalidade é avivado diante da competição entre times de futebol que correspondem a Estados-nação. No entanto, os últimos anos teriam demonstrado uma queda de interesse do torcedor nacional pelo selecionado. O Brasil, por duas oportunidades, foi sede de um Mundial. E, nas duas ocasiões, a Seleção Brasileira sofreu derrotas e não conseguiu conquistar o título jogando em seu território. O trabalho, um estudo sobre Comunicação e Esporte, é uma análise dos textos dos jornais impressos O Globo e Folha na cobertura das Copas do Mundo de 1950 e 2014. Busca-se, uma vez que se percebera o vínculo simbólico entre o conceito de nação e o desempenho da Seleção nacional de futebol, entender como foram construídas as representações da equipe e, consequentemente, dos seus jogadores e quais amostras que podem identificar a relação de aproximação ou afastamento com os torcedores, nas competições que marcaram as duas principais derrotas da Seleção em cem anos de história.

Managing without measuring: A study of an electricity distribution company

Purpose: The purpose of this paper is to present an exception to the common belief "If you can't measure it, you can't manage it". It aims to show how in certain situations particular practices, attitudes and cultures can remove the need for individual performance measurement. Design/methodology/approach: First, the paper identifies the usual roles of performance measurement in managing individual employees as described by control and motivation theorists. Second, it identifies a market-leading organisation where managers deliberately refuse to use their top-level performance measurement system to manage the performance of individual employees. A case study is carried out to test what non-measurement mechanisms fulfil the roles of individual performance measurement in this organisation. Findings: Building on situations observed at this company, a set of possible characteristics of companies that do not require formalised individual performance measurement systems in order to achieve high performance standards is put forward. Practical implications: Managers should not always assume that individual performance measurement is the only way to achieve excellent performance. This study shows that, by granting responsibilities and providing appropriate support, managers can channel workers' enhanced motivation towards meeting wider organisational goals. Originality/value: This work broadens the understanding of how excellent performance can be achieved. It shows that excellence can be achieved through practices based on shared values linked to motivation, trust, and a common sense of mission, without the need to install individual performance measurement systems based on cybernetic principles. © Emerald Group Publishing Limited.

I did that! Measuring users' experience of agency in their own actions

Cognitive neuroscience defines the sense of agency as the experience of controlling one's own actions and, through this control, affecting the external world. We believe that the sense of personal agency is a key factor in how people experience interactions with technology. This paper draws on theoretical perspectives in cognitive neuroscience and describes two implicit methods through which personal agency can be empirically investigated. We report two experiments applying these methods to HCI problems. One shows that a new input modality - skin-based interaction - can substantially increase users' sense of agency. The second demonstrates that variations in the parameters of assistance techniques such as predictive mouse acceleration can have a significant impact on users' sense of agency. The methods presented provide designers with new ways of evaluating and refining empowering interaction techniques and interfaces, in which users experience an instinctive sense of control and ownership over their actions. Copyright 2012 ACM.