Critical Revaluation Research Articles

Coupling between a coherent structure and fine-scale turbulence.

Our direct numerical simulations show that a coherent structure (scrC) in an initially fine-scale homogeneous, isotropic turbulent field breeds secondary structures in its vicinity. These are organized. Shaped like concentric spiral threads perpendicular to the axis of scrC, each is found to be highly polarized with the azimuthal vorticity component being dominant. The threads occur in pairs, and the polarization typically alternates between adjacent threads. Above a critical value (\ensuremath{\approxeq}1000) of Re\ensuremath{\equiv}${\mathrm{\ensuremath{\Gamma}}}_{\mathit{s}\mathit{c}\mathit{r}\mathit{C}}$/\ensuremath{\nu} (${\mathrm{\ensuremath{\Gamma}}}_{\mathit{s}\mathit{c}\mathit{r}\mathit{C}}$ is circulation, \ensuremath{\nu} is kinematic viscosity) a small number of circulation-rich threads emerge as a result of the evolution. The secondary structures are of both practical and theoretical importance. For Reg${\mathrm{Re}}_{\mathrm{crit}}$, the strongest threads excite bending waves on the axis of scrC. For Re\ensuremath{\gg}${\mathrm{Re}}_{\mathrm{crit}}$, scrC is eventually destroyed. We believe that this feedback phenomenon is of critical importance for the rearrangement of coherent structures (CS) and transition to turbulence in shear flows such as plane, circular, and elliptic jets. Turbulent mixing near scrC is due to entrainment and ejection of fluid by the threads. Local isotropy assumption cannot be applied near a CS, because our results show anisotropy in a layer surrounding scrC. The threads are shown to be the combined result of three mechanisms: (1) azimuthal alignment of small-scale vorticity by the strain rate field of scrC; (2) merger (pairing) and axisymmetrization as in two-dimensional turbulent flows, enabled by the alignment; and (3) polarization by differential rotation.

International Studies In the USSR Under Perestroika

The years of perestroika that unleashed a real outburst of previously slumbering political consciousness have brought many new aspects to all areas of social life in the USSR. The new outlook has conquered a complexity of problems of social being, from purely material to socio‐political. The process of critical revaluation of soviet history, of the role the USSR plays in the modem world, impetuous and at the same time tormenting, is under way. Along with social thought, the reappraisal of foreign policy has started. In order to appreciate the scale of ongoing processes, it is first necessary to look back into history.

Revisionism and the Structure of Emersonian Action

Emerson and the Art of the Diary By Lawrence Rosenwald Oxford University Press 1988 American literary history has undergone a major revaluation in the 1980s. Although no period of American literature has been left untouched, the stakes have been highest and interest most pronounced in critical revaluation of the American Renaissance. The engine driving the recent revision of American literary history has been fueled by ideological analysis. Accordingly, revisionary critics have preoccupied themselves with the ways in which literature is transformed into history-the ways in which symbol, myth, and rhetoric dictate the shape and direction of social action. Most often revisionists have seen symbol, myth, and rhetoric as having a conservative influence, forestalling the possibility of truly oppositional or subversive action by upholding the ideology of reigning social and political institutions. In an influential formulation of the challenge that revisionism poses for traditional accounts of American literary history, Sacvan Bercovitch writes: will have to take the American Renaissance out of the realm of cultural schizophrenia which is the legacy of the old consensus and relocate firmly in history, which is to say, at the center of the antebellum movement toward industrialization, incorporation, and civil war. On some basic level, we will have to reconceive our socalled radical or subversive literary tradition as an insistent engagement with society, rather than a recurrent flight from it (642). Perhaps our most dominant cultural image of the man of letters in flight from society is Ralph Waldo Emerson, whose gospel of self-reliance has been understood to proclaim that all Americans could free themselves from their bondage to antebellum social and political institutions. As a result of the powerful hold exerted by Emersonian self-reliance on the American imagination, Emerson has proved somewhat recalcitrant to critical revaluation, and his texts remain something of an interpretive crux for the ongoing revision of American literary history-

The origin and subsequent development in space of Tollmien-Schlichting waves in a boundary layer

Two kinds of small-parameter expansions are used to derive a series of ordinary differential equations governing spatially growing or decaying disturbances of the travelling-wave type in non-parallel laminar boundary layers. Eigensolutions of the lowest-order equation are shown to tend to resemble eigensolutions of the unsteady boundary-layer equation as the Reynolds number Re decreases, and to the Tollmien-Schlichting wave solutions of the Orr-Sommerfeld equation as Re increases. Examination of the next-order approximation reveals that the unsteady boundary-layer equation has eigensolutions only if Re exceeds a critical value depending on the frequency of disturbances, while it remains a partial differential equation for lower Reynolds numbers. Thus the Tollmien-Schlichting wave may be considered to originate at the above critical value of Re. The subsequent development of the wave with fixed frequency can be followed by integrating the spatial growth rate of the eigensolutions with respect to the downstream distance. The amplitude is at first damped but grows even higher than its original value farther downstream, provided the frequency is less than a certain value.

Families and Cults: Familial Factors Related to Youth Leaving or Remaining in Deviant Religious Groups

Continuing debates and controversies center on the role offamily-relatedfactors inhibiting or contributing to youth involvement in cults. But empirical research has been scant and much of the debate is mired in polemical warfare. Therefore, a study of 90 former and current members of three highly controversial religious cults (Unification Church, Hare Krishna, and Children of God) was conducted in order to assess the extent of family influence upon decisions by youth to remain or withdraw. Some studies suggest that the participation of youth may be explained by family deprivation, but this relationship has not yet been fully explored in studies of cult disaffiliation. Our findings reveal a strong correlation between measures of family affinity and choices by cult devotees to leave or stay. Important differences between leavers and stayers are shown with regard to perceived parental attitudes toward involvement, prior familial closeness, and adolescent experiences with families. The results of this study suggest a critical revaluation of the alleged link between cult involvement and family deprivation.

On critical roughness Reynolds numbers of the atmospheric surface layer

Detailed features of drag coefficient (C10) varying with wind velocity (U10) are used to determine critical values of roughness Reynolds number (Re). Boundary‐layer regimes of the atmospheric surface layer are identified as aerodynamically smooth, Re<0.5 (U10<3 m s−1); transition, 0.5<Re<2 (3 m s−1<U10<7 m s−1); and aerodynamically rough Re>2 (U10>7 m s−1). Features of C10 varying with Re and determination of critical values of Re are also substantiated.

A laboratory model of the wind-driven ocean circulation

A simple laboratory model for the wind-driven ocean circulation is re-studied experimentally and theoretically. Introduced by Pedlosky & Greenspan (1967), the model consists of a rotating cylinder with sloping bottom, the fluid inside being driven by the steady relative rotation of the cylinder's lid. A linear theory is developed to illustrate the modification in the interior and Stewartson boundary layers caused by variation of the bottom slope from 0 to O(1); Stommel's (1948) model is obtained when the bottom slope tan α [Lt ] E¼, and the Munk & Carrier (1950) model is obtained for E¼ [Lt ] tan α [Lt ] 1 (E is the Ekman number). Measurements of the interior cross-contour ‘Sverdrup’ velocity agree well with theory when the Ekman-layer Reynolds number RE is ≈ 1 or less. The western boundarylayer azimuthal velocity agrees reasonably well with theory, although the observed variation with depth and bottom slope were not predicted. The western boundary layer shows downstream intensification when RE is increased from ≈ 1 until topographic Rossby waves appear in the transition region between western boundary layer and interior. The motion becomes unstable when a critical value of RE is reached, independent of the bottom slope, and a low-frequency two-dimensional flow oscillation is observed. A brief comparison is made with previous wind-driven ocean circulation studies.

Valle-Inclán and the art of the theatre

In spite of the recent critical revaluation of Valle-Inclan's work and the evidence of a number of successful productions, the question of the theatrical suitability of his plays remains an open one. Broadly speaking, critical opinion is divided between those connected with the practical theatre (in particular, the critics of the review Primer Acto) who have strongly supported Valle's claim as a dramatist and the authors of more general literary studies such as R. Sender and A. Risco who have concluded that the plays are ‘teatro para leer’ and basically unsuited to the stage.

Problems of Optimal Planning of the National Economy

The theoretical basis of the contemporary capitalist system of production management is a combination of econometrics and cybernetics. Official [sluzhebnye] groups of economists and mathematicians have staked a claim on monopolistic leadership and control in the field of optimal planning and management of the various production branches. In this connection we must draw a clear line between the principles of planning and management based on bourgeois econometrics and the principles based on the Marxist-Leninist science of economics. The automatic transposition of mathematical and cybernetic econometric methods to the system of planning and management of socialist enterprises without a proper critical revaluation may lead to major economic miscalculations.

The objective assessment of desensitization.

The impressive successes of early Behaviour Therapy are now being subjected to critical revaluation, whilst current work in the field employs more sophisticated methodology (Marks et al., 1965; Eysenck, 1964; Lazarus, 1961; Lang et al., 1963). The treatment is entirely symptom-centred and so its effects should be more easily assessable than those of other forms of psychotherapy. Yet results are still controversial, in spite of efforts to apply all the normal control measures.

The mechanochemistry of muscular contraction, a critical revaluation of In vivo studies

The mechanochemistry of muscular contraction, a critical revaluation of In vivo studies

The Dome of Sforzinda Cathedral

Whether he be considered an amusing fiddler, a romantic, a second-rate artist or a first-rate mind with second-rate hands, Filarete seems due for a critical revaluation.1 Anyone with the patience to plod through the arbitrary editing of von Oettingen's presentation of Filarete's treatise2 soon becomes aware that the text is less dull than Alberti and less detailed than Vitruvius, although the debt to both is considerable. The importance of Filarete's writings for the more obvious aspects of fifteenth century Italian art, everything from the continuation of Gothic traditions through systems of proportion to the uncritical taste of the times, are readily apparent in the only available edition of the text. The good things that Vasari claims to have found among so much foolishness3 emerge only after a critical reading of the text and its illustrations. One such example, the dome of Sforzinda cathedral, contains implications that merit special attention both for the history of Renaissance architecture and for ...

A Caveat on Crime Control

by similar conferences in various states including New York. Governor Lehman presented a legislative program emanating from his conference which purported to cover the field. A special prosecutor has been investigating racketeering in New York City and has obtained convictions. There has been ample publicity for all these activities. But none of the dilemmas which lie at the root of any effort to deal with crime by law has been exposed to public view. On the contrary, the crime conferences fostered the belief that because they were attended by scientists and experts any proposals made by them proceeded from a fund of knowledge adequate, or nearly adequate, to solve the practical problems of crime control. In addition, there has been an impressive series of newspaper and motion picture glorifications of the police work of Mr. J. Edgar Hoover and his Bureau and of the integrity and ability as prosecutors of men like Mr. Dewey in New York. As a result, the faith that crime programs of the Lehman type, police work of the Hoover type, and prosecution of the Dewey type will substantially eliminate crime is almost as widely held as the belief that the Bureau of Investigation fulfills the principal function of the Department of Justice of the United States. To attack this popular faith is a task which is unpleasant for several obvious reasons. The criminal law shares with the rest of our law the need of a careful and critical revaluation; the crime conferences were, potentially at least, a step in that direction and the crime programs, including Governor Lehman's, contain some useful measures which have often been insincerely criticized. Police organization and personnel in the major part of the United States are incredibly poor and the organization and personnel of the Bureau of Investigation constitute a genuine improvement. Prosecu-