bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability limits of unsteady open capillary channel flow
Authors: GRAH ALEKSANDER , HAAKE DENNIS , ROSENDAHL UWE , KLATTE JÖRG , DREYER MICHAEL E. 
Published: March 2008

This paper is concerned with steady and unsteady flow rate limitations in open capillary channels under low-gravity conditions. Capillary channels are widely used in Space technology for liquid transportation and positioning, e.g. in fuel tanks and life support systems. The channel observed in this work consists of two parallel plates bounded by free liquid surfaces along the open sides. The capillary forces of the free surfaces prevent leaking of the liquid and gas ingestion into the flow.In the case of steady stable flow the capillary pressure balances the differential pressure between the liquid and the surrounding constant-pressure gas phase. Increasing the flow rate in small steps causes a decrease of the liquid pressure. A maximum steady flow rate is achieved when the flow rate exceeds a certain limit leading to a collapse of the free surfaces due to the choking effect. In the case of unsteady flow additional dynamic effects take place due to flow rate transition and liquid acceleration. The maximum flow rate is smaller than in the case of steady flow. On the other hand, the choking effect does not necessarily cause surface collapse and stable temporarily choked flow is possible under certain circumstances.To determine the limiting volumetric flow rate and stable flow dynamic properties, a new stability theory for both steady and unsteady flow is introduced. Subcritical and supercritical (choked) flow regimes are defined. Stability criteria are formulated for each flow type. The steady (subcritical) criterion corresponds to the speed index defined by the limiting longitudinal small-amplitude wave speed, similar to the Mach number. The unsteady (supercritical) criterion for choked flow is defined by a new characteristic number, the dynamic index. It is based on pressure balances and reaches unity at the stability limit.The unsteady model based on the Bernoulli equation and the mass balance equation is solved numerically for perfectly wetting incompressible liquids. The unsteady model and the stability theory are verified by comparison to results of a sounding rocket experiment (TEXUS 41) on capillary channel flows launched in December 2005 from ESRANGE in north Sweden. For a clear overview of subcritical, supercritical, and unstable flow, parametric studies and stability diagrams are shown and compared to experimental observations.
Mental–physical co-morbidity and its relationship with disability: results from the World Mental Health Surveys
Authors: Scott K. M. , Von Korff M. , Alonso J. , Angermeyer M. C. , Bromet E. , Fayyad J. , de Girolamo G. , Demyttenaere K. , Gasquet I. , Gureje O. , Haro J. M. , He Y. , Kessler R. C. , Levinson D. , Medina Mora M. E. , Oakley Browne M. , Ormel J. , Posada-Villa J. , Watanabe M. , Williams D. 
Published: March 2008

BackgroundThe relationship between mental and physical disorders is well established, but there is less consensus as to the nature of their joint association with disability, in part because additive and interactive models of co-morbidity have not always been clearly differentiated in prior research.MethodEighteen general population surveys were carried out among adults as part of the World Mental Health (WMH) Survey Initiative (n=42 697). DSM-IV disorders were assessed using face-to-face interviews with the Composite International Diagnostic Interview (CIDI 3.0). Chronic physical conditions (arthritis, heart disease, respiratory disease, chronic back/neck pain, chronic headache, and diabetes) were ascertained using a standard checklist. Severe disability was defined as on or above the 90th percentile of the WMH version of the World Health Organization Disability Assessment Schedule (WHODAS-II).ResultsThe odds of severe disability among those with both mental disorder and each of the physical conditions (with the exception of heart disease) were significantly greater than the sum of the odds of the single conditions. The evidence for synergy was model dependent: it was observed in the additive interaction models but not in models assessing multiplicative interactions. Mental disorders were more likely to be associated with severe disability than were the chronic physical conditions.ConclusionsThis first cross-national study of the joint effect of mental and physical conditions on the probability of severe disability finds that co-morbidity exerts modest synergistic effects. Clinicians need to accord both mental and physical conditions equal priority, in order for co-morbidity to be adequately managed and disability reduced.
The prevalence of premenstrual dysphoric disorder in a randomly selected group of urban and rural women
Authors: Gehlert S. , Song I. H. , Chang C.-H. , Hartlage S. A. 
Published: March 2008

BackgroundPremenstrual dysphoric disorder (PMDD) was included as a provisional diagnostic category in the appendices of Diagnostic and Statistical Manual of Mental Disorders (DSM)-III-R (then called late luteal phase dysphoric disorder) and remained as an appendix in DSM-IV. Our study aimed to determine the prevalence of PMDD using all four DSM-IV research diagnostic criteria in a representative sample of women of reproductive age in the United States.MethodData were collected in the homes of women between the ages of 13 and 55 years in two urban and two rural sites using a random sampling procedure developed by the National Opinion Research Center. Women completed daily symptom questionnaires and provided urine specimens each day for two consecutive ovulatory menstrual cycles (ovulation was estimated for women taking oral contraceptives) and were screened for psychiatric disorders by trained interviewers. Symptoms were counted toward a diagnosis of PMDD if they worsened significantly during the late luteal week during two consecutive ovulatory menstrual cycles, occurred on days in which women reported marked interference with functioning, and were not due to another mental disorder.ResultsIn the final analysis, 1246 women who had had at least one menstrual cycle and were neither naturally nor surgically menopausal nor pregnant were selected. Of the women in the study, 1.3% met criteria for the diagnosis as defined in DSM-IV.ConclusionsThe prevalence of PMDD is considerably lower than DSM-IV estimates and all but one of the estimates obtained from previous studies when all DSM-IV diagnostic criteria are considered. We suggest a new process for diagnosing PMDD based on our findings.
What Can Graph Theory Tell Us About Word Learning and Lexical Retrieval?
Authors: Vitevitch Michael S. 
Published: March 2008

Purpose
Graph theory and the new science of networks provide a mathematically rigorous approach to examine the development and organization of complex systems. These tools were applied to the mental lexicon to examine the organization of words in the lexicon and to explore how that structure might influence the acquisition and retrieval of phonological word-forms.

Method
Pajek, a program for large network analysis and visualization (V. Batagelj & A. Mvrar, 1998), was used to examine several characteristics of a network derived from a computerized database of the adult lexicon. Nodes in the network represented words, and a link connected two nodes if the words were phonological neighbors.

Results
The average path length and clustering coefficient suggest that the phonological network exhibits small-world characteristics. The degree distribution was fit better by an exponential rather than a power-law function. Finally, the network exhibited assortative mixing by degree. Some of these structural characteristics were also found in graphs that were formed by 2 simple stochastic processes suggesting that similar processes might influence the development of the lexicon.

Conclusions
The graph theoretic perspective may provide novel insights about the mental lexicon and lead to future studies that help us better understand language development and processing.
A Randomized Trial of Longitudinal Effects of Low-Intensity Responsivity Education/Prelinguistic Milieu Teaching
Authors: Warren Steven F. , Fey Marc E. , Finestack Lizbeth H. , Brady Nancy C. , Bredin-Oja Shelley L. , Fleming Kandace K. 
Published: March 2008

Purpose
To evaluate the longitudinal effects of a 6-month course of responsivity education (RE)/prelinguistic milieu teaching (PMT) for young children with developmental delay.

Method
Fifty-one children, age 24–33 months, with fewer than 10 expressive words were randomly assigned to early-treatment/no-treatment groups. All treatment was added as a supplement to services that the children received in the community. Follow-up data were collected 6 and 12 months after the conclusion of the initial 6-month treatment/no-treatment conditions.

Results
No effects of this treatment were detected 6 or 12 months after the conclusion of the initial treatment condition.

Conclusions
M. E. Fey et al. (2006) reported that 6 months of RE/PMT led to a significant treatment effect in the use of intentional communication in 1 of 2 communication sampling contexts. This finding, combined with evidence from other studies, suggests that RE/PMT may be applied clinically at low intensity with the expectation of medium-sized effects on children’s rate of intentional communication acts over the short term. The results of the present study, however, provide no evidence for the anticipated longer term benefits of this intervention. Further investigation of the approach at higher intensity levels and for longer periods of time is warranted.
The Effects of Hearing Aid Compression Parameters on the Short-Term Dynamic Range of Continuous Speech
Authors: Henning Rebecca L. Warner , Bentler Ruth A. 
Published: March 2008

Purpose
The purpose of this study was to evaluate and quantitatively model the independent and interactive effects of compression ratio, number of compression channels, and release time on the dynamic range of continuous speech.

Method

A CD of the Rainbow Passage (J. E. Bernthal & N. W. Bankson, 1993) was used. The hearing aid was a programmable, digital, wide dynamic range compression instrument. A fully crossed design and multiple regression analyses were used to evaluate and model the effects of release time (32, 128, and 1024 ms), compression ratio (1:1, 2:1, and 4:1), and number of compression channels (1, 2, and 4 channels) on the short-term octave-band dynamic range of speech.
Dynamic range of speech
was defined as the range between the 1% and 70% exceedance levels within each octave band.

Results
As the compression ratio and number of channels increased, and as the release time decreased, the dynamic range of speech decreased. The effects of channels and release time increased as the compression ratio increased. In all conditions, the amount of effective compression for speech was less than the nominal compression ratio.

Conclusion
A multiple regression model is provided that predicts the effects of various combinations of compression parameters on the dynamic range of speech.
Cognitive Maturation and the Use of Pitch and Rate Information in Making Similarity Judgments of a Single Talker
Authors: Petrini Karin , Tagliapietra Sara 
Published: March 2008

Purpose
This study examined age-related differences in speaker similarity judgments, in which acoustic cues known to be important in speaker and speech recognition and identification were varied.

Method
Four groups of listeners of 5- to 6-, 8- to 9-, 10- to 11-, and 25- to 30-year-olds were asked to judge the similarity between an original talker’s speech sample and 9 versions of a second speech sample from the same talker, obtained by manipulating the pitch and speech rate.

Results
Results showed that although pitch was used by all age groups as information to judge the similarity between the single talker speech samples, there was a significant age-related increase in the weight of speech rate attributed to similarity judgments. Furthermore, an age-related effect in accuracy was found, as was an effect of pitch level for the younger group.

Conclusion
The use of relevant acoustic features to discriminate a speaker changes with age, probably arising from a shift in cue weighting strategy as described by the developmental weighting strategy hypothesis (S. Nittrouer, C. Manning, & G. Meyer, 1993). Future studies should clarify whether the present findings can be extended to any pair of acoustic cues and should involve longitudinal methods to precisely detect when the strategy shift occurs.
Y Circulator
Authors: Chait Herman N. , Curry Thornton R. 
Published: March 2008

It is well known that the field distribution in a rectangular wave guide containing a magnetized ferrite can be asymmetrical even though the physical configuration is symmetrical. By properly choosing the ferrite, its shape, and location, it is possible to concentrate the energy on one side of the wave guide. Reversing the field or changing the direction of propagation will cause the energy to concentrate on the other side of the wave guide. This phenomenon has been utilized to construct a new type of circulator. A ferrite post has been placed at the junction of three wave guides intersecting at 120 degrees. The dc field is applied transverse to the broad side of the wave guide. Circulator action can be obtained by using a ferrite rod of the correct size and applying a dc field of the proper magnitude. Similar results have been obtained by using single and double slab configurations as well as with wedges.
A wave-guide switch can be obtained by reversing the direction of the applied field. Results to date indicate that it is possible to build this Y-type circulator with a loss less than 0.5 db and isolations and reflections of greater than 20 db over a 300-megacyle band at X band. A four-port junction operating on this same principle is also under investigation.
Strong Eddy-Current Applications of Permanent Magnets
Authors: Tendeloo K. 
Published: March 2008

Small eddy-current brakes for kwh meters have a practically linear torque-speed characteristic, because the induced current increases proportionally to the low relative speed between eddy-current disk and magnetic poles.
In bigger designs a considerable reaction of the induced-current field shifts the eddy-current paths in the direction of movement, so that the electrodynamic force between current and magnetic poles deviates from the linear relation, reaches a maximum at a critical speed, and decreases asymptotically to zero at infinite speed, whereas the dissipated power becomes a maximum.
Some investigations were made into the behavior of permanent magnets with a water-cooled setup with p.m. rotor and an air-cooled device with p.m. stator, both of cylindrical shape with 11.8 in. effective diameter and an axial length of 5.5 in. and 6 in., respectively. Maximum torques of 410 ft-lb and 304 ft-lb were obtained.
Pole pieces may sometimes increase the static flux, but do not always improve the dynamic behavior.
The ideal solution might be obtained with a high-induction magnet without pole pieces, but the induction in available materials is limited by the demagnetizing effect on the free pole top.
Possible applications could be found in a retarder for heavy trucks in mountainous districts and in a flexible coupling, slipping with decreasing torque when overloaded.
Magnetic Recording Head with dc Response
Authors: Fischell R. E. , Meehan S. J. 
Published: March 2008

A magnetic recording head has been developed to directly record and play back low-frequency signals, down to and including zero cps, without using amplitude, frequency, or pulse width modulation.
Two problems are encountered in dc magnetic recording. The more obvious problem is caused by the small voltage induced in the playback head when the flux changes at a very slow rate. At low frequencies, the output of a conventional playback head is proportional to the time rate of change of flux in the head; therefore, at dc the playback signal has zero amplitude. The second problem encountered in reproducing dc signals is the disappearance of the magnetic field at the gap of a ring-type head when wavelengths of considerable lengths are recorded on the tape. The magnetic field at the gap of a ring-type head becomes too small to be used when a recorded wavelength is longer than a few inches.
Combining a perpendicular head with flux sensitive playback has eliminated these two problems. A perpendicular head magnetizes the recording tape perpendicularly to the direction of tape motion, i.e., the tape is magnetized through its thickness. The pole pieces of the head are spring loaded and pressed against the tape to maintain consistent contact while the tape passes through the head. Vicalloy, in the form of a thin, homogeneous metal tape, was selected for this purpose because it contains many of the magnetic and physical characteristics desired, including a high coercive force, high remanence, and mechanical flexibility when it is rolled into a thin tape. A frequency response of dc (0 cps to 10 cps) is achieved at a tape speed of 0.027 in./sec. Pre-emphasis is not required in recording and equalization is not used during playback. Cross talk between adjacent heads in a multichannel system is below 50 db at moderate track separations.
On the Origin of Low Moments in Chromium-Containing Spinels
Authors: Baltzer Philip K. , Wojtowicz Peter J. 
Published: March 2008

The most commonly offered interpretation of the low magnetic moments of chromium-containing spinels has relied on the existence of the Yafet and Kittel ordering scheme. The experimental evidence for angular ordering schemes on the B lattice of spinels is, however, inconclusive and contradictory. Prince, for instance, has obtained neutron diffraction data on CuCr2O4 which is consistent with, but does not uniquely determine, the Yafet-Kittel scheme. Pickart, on the other hand, has found no evidence of the angular scheme in data on (MnFe2O4)1−x+(MnCr2O4)x and (NiFe2O4)1−x+(NiCr2O4)x, although he did establish that the moment of the B lattice was lower than expected on a simple Néel picture. In this report, we present a new approach to this problem which appears to lead to a reasonable, adequate, and consistent treatment of the moment data.
It is usually supposed that the spin of the Cr3+ ion in the octahedral environment of the spinel B site is 32 giving a moment of three Bohr magnetons. A consideration of the crystal field theory pertinent to Cr3+ shows, however, that if the B site is given a sufficient tetragonal or trigonal distortion, the doublet state, having a spin of 12 and a moment of one Bohr magneton, becomes the ground state. It is known further that the B sites can be distorted from regular octahedral symmetry by the presence of Jahn-Teller distortions in neighboring sites. For example, Ni2+ and Cu2+ cause distortions when on A sites, while Cu2+ and Mn3+ cause distortions when on the B sites. The process by which the moment of an ion is reduced in this way is called “spin quenching.”
We therefore propose that the origin of the low moments in the chromites is the spin-quenching effect imposed on the Cr3+ ions by the appropriate Jahn-Teller distortions of their neighbors. We also emphasize that a macroscopically distorted phase is not required for this effect. It is only necessary that a distribution of distorting neighbors be present, sufficient in number to alter the symmetry about (and hence spin quench) at least a fraction of the chromium ions. With the aid of these hypotheses it has proved possible to explain the moment data for many chromites in a consistent way. Of particular interest are the recently studied systems, (CuFe2O4)1−x+(CuCr2O4)x and (NiFe2O4)1−x+(NiCr2O4)x.
On the Magnetic Anisotropy in Manganese-Iron Spinels
Authors: Penoyer R. F. , Shafer M. W. 
Published: March 2008

The magnetic anisotropy energy is measured as a function of temperature in eleven single crystal compositions corresponding to MnxFe3−xO4, where x is varied from 0.00 to 1.90. The interesting features observed are as follows.
(1) Small manganese concentrations in magnetite (x=0) are shown to decrease the temperature of the “isotropy point” known to exist in magnetite at low temperatures.
(2) An unexpected variation in the temperature dependence and magnitude of the anisotropy energy in the x=0.4 to 1.0 composition region is shown.
(3) The anisotropy energy in the composition region between x=1.0 and 1.8 is semiquantitatively shown to be related to cubic crystalline field splitting of the energy levels of ferric ions.
(4) A large planar anisotropy is measured in a crystal composition given by x = 1.90 and is discussed in terms of the expected tetragonal nature of trivalent manganese.
(5) Finally, a minute magnetic annealing effect at a temperature of 370°K has been shown to exist in a crystal composition corresponding to x=0.40 and the magnitude of this effect is shown to be dependent on the direction relative to the crystal axes of the applied magnetic field during the annealing process.
Some Crystallographic and Magnetic Properties of Square-Loop Materials in Ferrite Systems Containing Copper
Authors: Greifer Aaron P. , Croft William J. 
Published: March 2008

Rectangular hysteresis loops have been found in ferrite systems containing copper during an investigation based on the proposal by Baltzer that a zero or near-zero value of the effective magnetocrystalline domain anisotropy is a necessary condition for loop squareness.
Data on hysteresis loop squareness of polycrystalline bodies as a function of composition, firing conditions and magnetostrictive effects are presented for the system: copper ferrite-magnesium ferrite. This system is characterized in general by large grains and long switching times. Abrupt flux changes occur in the hysteresis loop at low temperatures. Simultaneously, a decrease in the coercive force with decreasing temperature and squareness values approaching unity are observed. No crystallographic transitions were detected at low temperatures.
Magnetostrictive measurements do not unequivocally show whether anisotropy goes through zero at compositional region of maximum squareness. The saturation magnetostriction and probably the λ111 go through a minimum in this region.
Magnetic Properties of Nickel-Iron Ferrite
Authors: Menyuk N. , Dwight K. 
Published: March 2008

The magnetic anisotropy of a single crystal of nickel-iron ferrite with composition Fe1.003+[Ni0.792+Fe0.363+Fe0.903+]O4 is given between 450 and 4.2°K. At high temperatures the anistropy energy has cubic symmetry, and the absolute value of the first-order anisotropy constant is a maximum at ca 200°K. Below 200°K, |K1| decreases until 10°K, at which temperature there is an abrupt transition in the anisotropy characteristics. Below 10°K the anisotropy energy contains a uniaxial term of the form Εi αi2βi2 where αi and βi are the direction cosines of the magnetization at the measuring temperature and at the annealing temperature (10°K), respectively.
This low-temperature behavior has been explained on the basis of existent theory of magnetic annealing. The model used to explain the uniaxial anisotropy term given above is shown to be consistent with the noncubic anisotropy energy obtained upon cooling the sample through 10°K in the absence of an external field. The model is also shown to lead directly to a relaxation effect which contributes a term of the form K′(α12α22+α22α32+α32α12) to the anisotropy energy above 10°K and explains the observed maximum in |K1|.