bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acoustically generated vorticity in an internal flow
Authors: ZHAO Q. , STAAB P. L. , KASSOY D. R. , KIRKKOPRU K. 
Published: July 2002

A mathematical model is formulated to describe the initiation and evolution of intense
unsteady vorticity in a low Mach number (M), weakly viscous internal flow sustained
by mass addition through the sidewall of a long, narrow cylinder. An O(M) axial
acoustic velocity disturbance, generated by a prescribed harmonic transient endwall
velocity, interacts with the basically inviscid rotational steady injected flow to generate
time-dependent vorticity at the sidewall. The steady radial velocity component convects
the vorticity into the flow. The axial velocity associated with the vorticity field
varies across the cylinder radius and in particular has an instantaneous oscillatory
spatial distribution with a characteristic wavelength O(M) smaller than the radius.
Weak viscous effects cause the vorticity to diffuse on the small radial length scale as
it is convected from the wall toward the axis. The magnitude of the transient vorticity
field is larger by O(M−1) than that in the steady flow.An initial-boundary-value formulation is employed to find nonlinear unsteady
solutions when a pressure node exists at the downstream exit of the cylinder. The complete
velocity consists of a superposition of the steady flow, an acoustic (irrotational) field
and the rotational component, all of the same magnitude.
The disappearance of laminar and turbulent wakes in complex flows
Authors: HUNT J. C. R. , EAMES I. 
Published: July 2002

The singular effects of steady large-scale external strain on the viscous wake generated
by a rigid body and the overall flow field are analysed. In an accelerating flow strained
at a positive rate, the vorticity field is annihilated owing to positive and negative
vorticity either side of the wake centreline diffusing into one another and the volume
flux in the wake decreases with downwind distance. Since the wake disappears, the
far-field flow changes from monopolar to dipolar. In this case, the force on the body
is no longer proportional to the strength of the monopole, but is proportional to the
strength of the far field dipole. These results are extended to the case of strained
turbulent wakes and this is verified against experimental wind tunnel measurements
of Keffer (1965) and Elliott & Townsend (1981) for positive and negative strains.
The analysis demonstrates why the total force acting on a body may be estimated by
adding the viscous drag and inviscid force due to the irrotational straining field.Applying the analysis to the wake region of a rigid body or a bubble shows that the
wake volume flux decreases even in uniform flows owing to the local straining flow in
the near-wake region. While the wake volume flux decreases by a small amount for
the flow over streamline and bluff bodies, for the case of a clean bubble the decrease
is so large as to render Betz's (1925) drag formula invalid.To show how these results may be applied to complex flows, the effects of a sequence
of positive and negative strains on the wake are considered. The average wake width
is much larger than in the absence of a strain field and this leads to diffusion of
vorticity between wakes and the cancellation of vorticity. The latter mechanism leads
to a net reduction in the volume flux deficit downstream which explains why in
calculations of the flow through groups of moving or stationary bodies the wakes
of upstream bodies may be ignored even though their drag and lift forces have a
significant effect on the overall flow field.
Spatial numerical simulation of boundary layer

transition: effects of a spherical particle
Authors: SAIKI E. M. , BIRINGEN S. 
Published: July 2002

In the present study, the effects of an isolated stationary

spherical particle on the transition process in a flat-plate boundary

layer are examined by a spatial direct numerical

simulation. The full three-dimensional time-dependent incompressible

Navier–Stokes

equations are integrated by a time-splitting method and discretized spatially
by a

high-order finite difference/spectral method. A virtual

boundary technique defining

the no-slip boundary of a sphere is implemented within the Cartesian geometry
of

the computational grid.Two numerical simulations which consider the effects of the sphere on
the boundary

layer are presented. The subcritical Reynolds number case reveals the appearance

of hairpin vortices shed into the sphere wake which decay as they are convected

downstream. The initial interaction of the sphere and the boundary layer
produces a

three-dimensional isolated disturbance comprising a wave part and a transient
part.

The decaying transient part is convected downstream at the local mean velocity,
while

the wave part induces a decaying Tollmien–Schlichting wave in the
flow field.In the second case, an increase in the Reynolds number results in a
wedge of

incipient turbulent flow downstream of the sphere. The development of the
wake of

the sphere is dominated by the appearance of an isolated disturbance which
rapidly

breaks down forming a structure resembling a turbulent spot. It is demonstrated
that

the transition induced by a sphere in the boundary layer is due to a mechanism

related to bypass transition.
Non-similarity solutions to the corner
boundary-layer equations
(and the effects of wall transpiration)
Authors: DUCK PETER W. , STOW SIMON R. , DHANAK MANHAR R. 
Published: July 2002

The incompressible boundary layer in the corner formed by two intersecting, semi-infinite planes is investigated, when the free-stream flow, aligned with the corner,
is taken to be of the form U∞F(x), x
representing the non-dimensional streamwise
distance from the leading edge. In Dhanak & Duck (1997) similarity solutions for
F(x) = xn were considered, and it was found that solutions exist for only a range
of values of n, whilst for ∞ > n > −0.018, approximately, two
solutions exist. In this paper, we extend the work of Dhanak & Duck to the case
of non-90° corner angles and allow for streamwise development of solutions. In addition,
the effect of transpiration at the walls of the corner is investigated. The governing equations
are of boundary-layer type and as such are parabolic in nature. Crucially, although the
leading-order pressure term is known a priori, the third-order pressure term is not,
but this is nonetheless present in the leading-order governing equations, together with
the transverse and crossflow viscous terms.Particular attention is paid to flows which develop spatially from similarity solutions.
It turns out that two scenarios are possible. In some cases the problem may
be treated in the usual parabolic sense, with standard numerical marching procedures
being entirely appropriate. In other cases standard marching procedures lead
to numerically inconsistent solutions. The source of this difficulty is linked to the
existence of eigensolutions emanating from the leading edge (which are not present in
flows appropriate to the first scenario), analogous to those found in the computation
of some two-dimensional hypersonic boundary layers (Neiland 1970; Mikhailov et
al. 1971; Brown & Stewartson 1975). In order to circumvent this difficulty, a different
numerical solution strategy is adopted, based on a global Newton iteration
procedure.A number of numerical solutions for the entire corner flow region are presented.
The role of dissipation and mixing in exchange
flow through a contracting channel
Authors: WINTERS KRAIG B. , SEIM HARVEY E. 
Published: July 2002

We investigate the transport of mass and momentum between layers in idealized
exchange flow through a contracting channel. Lock-exchange initial value problems
are run to approximately steady state using a three-dimensional, non-hydrostatic
numerical model. The numerical model resolves the large-scale exchange flow and
shear instabilities that form at the interface, parameterizing the effects of subgrid-scale turbulence. The closure scheme is based on an assumed steady, local balance of
turbulent production and dissipation in a density-stratified fluid.The simulated flows are analysed using a two-layer decomposition and compared
with predictions from two-layer hydraulic theory. Inter-layer transport leads to a
systematic deviation of the simulated maximal exchange flows from predictions. Relative
to predictions, the observed flows exhibit lower Froude numbers, larger transports
and wider regions of subcritical flow in the contraction. To describe entrainment
and mixing between layers, the computed solutions are decomposed into a three-layer
structure, with two bounding layers separated by an interfacial layer of finite thickness
and variable properties. Both bounding layers lose fluid to the interfacial layer which
carries a significant fraction of the horizontal transport. Entrainment is greatest from
the faster moving layer, occurring preferentially downstream of the contraction.Bottom friction exerts a drag on the lower layer, fundamentally altering the overall
dynamics of the exchange. An example where bed friction leads to a submaximal
exchange is discussed. The external forcing required to sustain a net transport is
significantly less than predicted in the absence of bottom stresses.
Technocrats and politicians in an authoritarian regime. The ‘ODEPLAN
Boys’ and the ‘Gremialists’ in Pinochet's Chile
Authors: HUNEEUS CARLOS 
Published: July 2002

This article analyses the role of the economic team known as the
‘Chicago Boys’ and of the main political faction in Pinochet's Chile, the
‘Gremialists’, founded by Jaime Guzmán in the Catholic University in 1966.
These two sectors of the elite had a common professional and political career and
were the principal civilian groups of the dictatorship who developed a long-term
political strategy that deeply influenced both the economic and political
orientation of the military regime. They shared a long-term power strategy, that
was basically defined by the ‘Gremialists’. The article focuses on the role played
by ODEPLAN in shaping the economic reforms. It demonstrates that the
coherence of the economic model inherent in the implementation of its policies
is to be found in the integration of the policies with a political project, articulated
by the ‘Gremialists’.I want to make it clear that I am convinced that the main responsibility for all
that is going on in Chile lies not with the military, but rather with the civilian
advisors and the whole climate of adulation and servilism that the economic
right has created around them, The ideology of the government was born in
the most traditional circles of the economic right, disguised under the sign of
‘nationalism’ and shielded behind ‘the courage to declare oneself anti-
Marxist’.
Preservation and minimality in loanword adaptation
Authors: PARADIS CAROLE , LACHARITÉ DARLENE 
Published: July 2002

Attractive as might seem the challenge to build a process or performance

model that can account for every behavioural decision, there are a number

of sound reasons to tackle first the still difficult (but hopefully manageable)

task of developing a competence model; of trying to find the underlying

system that informs and constrains (if it doesn't always actually
govern)

choice. (Spolsky 1988: 105)This article aims at showing the predictability of phonological adaptation,

segment

preservation and deletion in borrowings. It is shown that ill-formed segments
are

preserved and adapted in the vast majority of cases; segment deletion occurs
only

when an ill-formed segment is embedded within a higher level ill-formed
structure,

such as the syllable. This conclusion is based on the study of 15,686 segmental
and

syllabic malformations found in 11,348 loanword forms from five different
corpora

of loanwords. The analysis, which is set within the Theory of Constraints
and Repair

Strategies, is illustrated with the data from a corpus of 545 French loanwords

in Fula.
Laughter and Subjectivity: The Self-Ironical Tradition in Bengali Literature
Authors: Kaviraj Sudipta 
Published: July 2002

By the grace of the Almighty an extraordinary species of sentient life has been found on earth in the nineteenth century: they are known as modern Bengalis. After careful analysis zoological experts have found that this species displays the external bodily features of homo sapiens. They have five fingers on their hands and feet; they have no tails; and their bones and cranial structures are indeed similar to the human species. However as yet there is no comparable unanimity about their inner nature. Some believe that in their inner nature too they are similar to humans; others think that they are only externally human; in their inner nature they are in fact beasts.Which side do we support in this controversy? We believe in the theory which asserts the bestiality of Bengalis. We learnt this theory from English newspapers. According to some redbearded savants, just as the creator had taken atoms of beauty from all beautiful things to make Tilottama, in exactly the same way, by taking atoms of bestiality from all animals he has created the extraordinary character of the modern Bengali. Slyness from the fox, sycophancy and supplication from the dog, cowardliness from sheep, imitativeness from the ape and volubility from the ass—by a combination of these qualities He has made the modern Bengali rise in the firmament of history: a presence which illuminates the horizon, the centre of all of India's hopes and future prospects, and the great favourite of the savant Max Mueller.
Psychiatric bed utilization: 1896 and 1996 compared
Authors: HEALY D. , SAVAGE M. , MICHAEL P. , HARRIS M. , HIRST D. , CARTER M. , CATTELL D. , McMONAGLE T. , SOHLER N. , SUSSER E. 
Published: July 2002

Background. The 1896 and 1996 populations of North West Wales are similar in number, ethnic and social mix and rurality, enabling a study of the comparative incidence and prevalence of service utilization over the course of a century.Methods. We collected records on all psychiatric admissions from North-West Wales in 1894–1896 and 1996. These were assessed and diagnosed by the responsible sector area consultant.Results. The data reveal substantially more patients admitted for all diagnoses in 1996, even when comparisons are restricted to detained patients. The incidence of hospitalization by detention for schizophrenia is slightly lower 1996 than in 1896 but the incidence of hospitalization is higher now than in 1996. The incidence of hospitalization by detention for non-affective disorder psychoses is the same in both 1896 and 1996 but there is a doubling of incidence of hospitalization. The incidence of hospitalization for bipolar disorders is similar in the two periods. Modern mental health services admit large numbers of personality disordered patients, where none were admitted 100 years ago.Conclusions. Factors general to changing health care and expectations and others specific to mental health would appear to have led to the increase in rates of admissions observed in the modern period.
Effects of pregnancy and delivery on the availability of plasma tryptophan to the brain: relationships to delivery-induced immune activation and early post-partum anxiety and depression
Authors: MAES M. , OMBELET W. , VERKERK R. , BOSMANS E. , SCHARPÉ S. 
Published: July 2002

Background. There is now evidence that the availability of plasma tryptophan is decreased during pregnancy and the puerperium and also in patients with major depression and inflammation. The aims of the present study were to examine: (i) the effects of pregnancy and delivery on plasma tryptophan and the amino acids known to compete for the same cerebral uptake mechanism (CAAs), valine, leucine, tyrosine, phenylalanine and isoleucine; (ii) the relationships between the availability of plasma tryptophan and postpartum depression or anxiety; and (iii) the relationships between the availability of plasma tryptophan to the brain and inflammatory markers, such as serum interleukin-6 (IL-6), interleukin-1 receptor-antagonist (IL-1RA) and the leukaemia inhibitory factor receptor (LIF-R).Methods. The above variables were measured in 13 healthy non-pregnant and in 98 pregnant women 3 to 6 days before delivery and 1 and 3 days after delivery. On each occasion the parturient women completed the state version of Spielberger State–Trait Anxiety Inventory (STAI) and the Zung Depression Rating Scale (ZDS).Results. Plasma tryptophan and the tryptophan/CAA ratio were significantly lower at the end of term and after delivery than in the plasma of non-pregnant, healthy women. The tryptophan/CAA ratio was significantly lower in the early puerperium than at the end of term. There were no significant relationships between the availability of plasma tryptophan and either post-partum depression or changes in the STAI or ZDS scores in the early puerperium. The changes in the tryptophan/CAA ratio from the end of term to the early puerperium were significantly and inversely related to serum IL-6, IL-1RA and LIF-R.Conclusions. The results show that the reduction in the availability of plasma tryptophan from the end of term to the early puerperium is related to immune activation; and that the lowered availability of plasma tryptophan is not related either to depressive or anxiety symptoms in the early puerperium or to post-partum depression ensuing some months later.
The costs of community-based psychiatric care for

first-ever patients. A case register study
Authors: AMADDEO F. , BEECHAM J. , BONIZZATO P. , FENYO A. , TANSELLA M. , KNAPP M. 
Published: July 2002

Background. Analysing costs measures in conjunction with

psychiatric case register (PCR) data can

provide important epidemiologically-based information on resource

utilization. Costing the service

use patterns of first-ever patients can indicate the shape and likely

resource consequences for mental

health services operating within a community-based system of care.Methods. Yearly costs were calculated for the 299

first-ever patients and 768 longer-term patients

who contacted the South-Verona Psychiatric Case Register between 1

January 1992 and 31

December 1993. Bivariate and multivariate analyses were used to

compare costs between these

groups and to test the associations between costs and the sociodemographic

and diagnostic data recorded on the PCR.Results. For all diagnostic groups identified, first-ever

patients were found to be less costly to

support than longer-term patients, even after adjustment for

various factors, including whether

patients were single consulters. When multivariate analyses were

employed, between 20% and 69%

of the cost variation for first-ever patients could be explained by

patient and other characteristics,

and the effect of the contact (first or subsequent) variable was reduced.Conclusion. This study considered only the costs to the

specialist psychiatric services but the

methodology allows the likely annual resource implications of supporting

new patients to be

predicted from data collected at first contact. Such information can

help ensure that services are

adequately funded and that the resources are deployed appropriately

between client groups.
Decreased working memory and processing speed
mediate cognitive impairment in geriatric depression
Authors: NEBES R. D. , BUTTERS M. A. , MULSANT B. H. , POLLOCK B. G. , ZMUDA M. D. , HOUCK P. R. , REYNOLDS C. F. 
Published: July 2002

Background. While neuropsychological dysfunction is common in geriatric depression, not all
aspects of cognition are equally affected. It has been suggested that depressed patients are impaired
only in tasks that make heavy demands on processing resources and that a resource decrement
therefore underlies the neuropsychological decrements seen in geriatric depression. The present
study examined whether processing resources in the form of working memory and information
processing speed are decreased in depression and whether a decrease in these resources actually
mediates neuropsychological impairment.Methods. Measures of processing resources were administered to elderly depressed patients prior to
treatment and to age-matched controls. Patients whose depression remitted were retested as were
the controls. Subjects also received neuropsychological tests of episodic memory and visuospatial
performance.Results. Depressed patients performed significantly worse on measures of both processing speed
and working memory. While performance on these measures improved in patients whose depression
remitted, the amount of improvement was no greater than that seen in the controls with repeat
testing. Hierarchical regression analyses showed that depression explained a significant amount of
variance on the neuropsychological tasks. However, if the variance associated with processing
resources was removed first, depression no longer accounted for a significant amount of
neuropsychological variance.Conclusions. Processing resources are decreased in elderly depressed patients and this decrease in
resources appears to mediate impairments in several areas of neuropsychological functioning
including episodic memory and visuospatial performance. The resource decrement persists after
remission of the depression and thus may be a trait marker of geriatric depression.
Heterogeneity of cycloid psychoses: a latent class analysis
Authors: MOJTABAI RAMIN 
Published: July 2002

Background. Three hypotheses have been proposed in regard to the origin of cycloid psychoses: (1)
they are an independent nosological entity; (2) they are atypical cases of affective disorders; and (3)
they are a heterogeneous group of disorders. This study examined the heterogeneity hypothesis by
attempting to delineate distinct affective and non-affective subgroups.Methods. In 60 cases drawn from a classic study of cycloid psychoses by Perris (1974), latent class
analysis was used to delineate subgroups.Results. Two classes were identified in the analysis: one characterized by the convergence of
affective symptoms and family history of affective disorders and the other by the relative paucity
of such features.Conclusions. Cycloid psychoses are composed of at least two subgroups, distinguishable on the
basis of symptoms and family history.
Neuropsychological change in young people at high risk for schizophrenia: results from the first two neuropsychological assessments of the Edinburgh High Risk Study
Authors: COSWAY R. , BYRNE M. , CLAFFERTY R. , HODGES A. , GRANT E. , ABUKMEIL S. S. , LAWRIE S. M. , MILLER P. , JOHNSTONE E. C. 
Published: July 2002

Background. Studies of groups of individuals who have a genetically high risk of developing schizophrenia, have found neuropsychological impairments that highlight likely trait markers of the schizophrenic genotype. This paper describes the change in neuropsychological function and associations with psychiatric state of high risk participants during the first two assessments of the Edinburgh High Risk Study.Methods. Seventy-eight high risk participants and 22 normal controls, age and sex matched completed two neuropsychological assessments 18 months to 2 years apart. The areas of function assessed include intellectual function, executive function, learning and memory, and verbal ability and language.Results. The high risk participants performed significantly worse on particular tests of verbal memory and executive function over the two assessments than matched controls. Those high risk participants who experienced psychotic symptoms were found to exhibit a decline in IQ and perform worse on tests of verbal memory and executive function than those without symptoms. An increase in psychotic symptoms between the two assessments in the high risk group was found to
be associated with an apparent decline in IQ and memory.Conclusions. The results suggest that the development of psychotic symptoms is preceded by a decline in IQ and memory. This may reflect a general and a more specific disease process respectively.