bluuebunny/crossref_metadata_2025 huggingface dataset:
New Destinations? Assessing the Post‐migration Social Mobility of Minority Ethnic Groups in England and Wales
Authors: Platt Lucinda
Published: October 2005

This paper considers the roles of migration and group‐specific ethnic penalties in minority groups’ life chances. In relation to existing knowledge of extensive diversity between ethnic groups, and outlining a range of frameworks within which to understand that diversity, the paper first explores the relationship of class origins to parental educational and economic assets for three groups of migrant parentage and a comparison white non‐migrant group. Second, the paper investigates for the different ethnic groups how the probability of having a professional or managerial class outcome is influenced by class origins and by the educational achievements of the “second generation”. Analysis is based on the ONS Longitudinal Study, which enables the study members to be tracked from 1971, when they were children living with their parents, to their own social class outcomes in 1991 and 2001. Because processes of occupational achievement may take different lengths of time for different groups, occupational outcomes are modelled in both 1991 and 2001, and also outcomes in 2001 conditional on position in 1991. The paper shows that there is evidence of differential processes operating for different ethnic groups that go beyond their class background, but which cannot be attributed to discrimination operating equally against all minority groups.
THE FIRST LAKE‐DWELLERS OF LITHUANIA: LATE BRONZE AGE PILE SETTLEMENTS ON LAKE LUOKESAS
Authors: MENOTTI F. , BAUBONIS Z. , BRAZAITIS D. , HIGHAM T. , KVEDARAVICIUS M. , LEWIS H. , MOTUZAITE G. , PRANCKENAITE E.
Published: October 2005

Summary.  Lake Luokesas in Lithuania has become the centre of attention in northern European wetland archaeological research after the discovery of two Late Bronze Age/Early Iron Age pile dwellings. Their unique location, chronology and building techniques have the potential to revolutionise our understanding of important aspects of wetland communities in later prehistoric Europe.
THE ORIENTATION OF ROMAN CAMPS AND FORTS
Authors: RICHARDSON A.
Published: October 2005

Summary.  The angles of orientation of 67 Roman camps were determined from their published plans. There was a marked tendency for them to be aligned close to the cardinal points but they were offset from those points by only 28 of a possible 45 angles and of these six occurred in 29 camps, probably because they were set out by making right‐angled triangles whose non‐hypotenuse sides were in whole number ratios. Twenty‐seven forts on the British frontier walls were similarly orientated by only 12 angles, one of which occurred six times. The apparent accuracy of the layouts suggested that the directions of the meridian and latitude were first carefully determined. The use of a limited number of offset angles was probably due to a religious regard for celestial geometry.
Reinventing Multiculturalism: Urban Citizenship and the Negotiation of Ethnic Diversity in Amsterdam
Authors: UITERMARK JUSTUS , ROSSI UGO , VAN HOUTUM HENK
Published: October 2005

A number of authors have recently suggested that cities are becoming increasingly important as sites for the negotiation of ethnic diversity. While multiculturalism has been declared ‘dead’ in many countries, cities are now experimenting with new ways to accommodate ethnic diversity. This article reports on research conducted in Amsterdam. In this city, a ‘minority policy’ has been replaced by a qualitatively different ‘diversity policy’. Even though the diversity policy meets many of the criticisms that have been made against multiculturalism, the new policy also generates its own forms of exclusion. It is concluded that the stress on intercultural interaction and an emphasis on high‐quality policies and projects can in practice produce results that run counter to the intentions of policymakers as well as critical theorists. Ironically, these two features of the diversity policy tend to depoliticize societal problems and frustrate political mobilization of some marginalized groups.

Dernièrement, plusieurs auteurs ont suggéré que les villes prennent une importance croissante en tant que lieux de négociation de la diversité ethnique. Alors qu’on a annoncé la mort du multiculturalisme dans bien des pays, les villes connaissent désormais de nouveaux modes d’accueil de la diversité ethnique. Cet article rend compte de recherches menées à Amsterdam. Une ‘politique des minorités’ y a été remplacée par une ‘politique de la diversité’ différente sur le plan qualitatif. Même si cette nouvelle politique répond à plusieurs des critiques formulées à l’encontre du multiculturalisme, elle génère aussi ses propres formes d’exclusion. On peut déduire que l’accent sur l’interaction interculturelle ainsi qu’une priorité aux politiques et projets de qualité peuvent, en pratique, produrie des résultats qui viennent s’opposer aux intentions des décideurs eux‐mêmes et des théoriciens détracteurs. Bizarrement, ces deux caractéristiques de la politique de la diversité tendent à dépolitiser les problèmes sociétaux et à contrarier la mobilisation politique de certains groupes marginalisés.
Colorimetric analysis of pigmented skin lesions: a pilot study with the Visi‐Chroma™ VC‐100 device
Authors: Vereecken P , Mommaerts M , Duez C , Petein M , Laporte M , Hubinon J‐L , Heenen M
Published: October 2005

Background  Definition of the colour of pigmented skin lesions (PSLs) with the naked eye remains subjective and may be influenced by lighting. This problem underlines the usefulness of instrumental assessments such as epiluminescence microscopy and colorimetric devices.

Objective and methods  We describe here a new method of colour analysis of PSLs with the Visi‐Chroma™ VC‐100 device, which illuminates the surface of the skin with white light‐emitting diodes (LEDs) and analyses the reflected light by a red–green–blue (RGB) charge‐coupled device (CCD) colour camera. Twenty‐one PSLs to be excised for cosmetic or medical reasons were analysed by this device with clinicopathological correlation.

Conclusions  This method is feasible and might be useful to assess the colour of PSLs and allow comparisons for changes over time. Further studies are needed to determine the usefulness of this device in clinical practice.
Quality of life and acne in Scottish adolescent schoolchildren: use of the Children's Dermatology Life Quality Index© (CDLQI) and the Cardiff Acne Disability Index© (CADI)
Authors: Walker N , Lewis‐Jones MS
Published: October 2005

Background  Acne vulgaris is known to adversely affect all aspects of quality of life. However, although acne is thought to occur in the majority of adolescents, there are few data currently available on the impact of acne in this age group.

Objectives  Measurement of the impairment of health‐related quality of life (HRQoL) in teenage Scottish schoolchildren in a comparative study using two HRQoL questionnaires. A secondary objective was to collect data on the use and perceived efficacy of medical and over‐the‐counter (OTC) preparations.

Study design  An anonymous cross‐sectional survey of 200 adolescent (15–18 years) Dundee schoolchildren was conducted by means of two self‐reported questionnaires: the Children's Dermatology Life Quality Index© (CDLQI) and the Cardiff Acne Disability Index© (CADI). Data on demographics and therapeutic modalities and their perceived efficacy were also collected.

Analysis  Statistical analysis was performed using the package Stata 7.0.

Results  Self‐reported acne was present in 83% of teenagers (147/178), with similar sex distribution (54% male, 46% female). The overall mean CDLQI score (max. 30) was low 1.7 {6% impairment} (CI −1 to 0), range 0–19. Nine pupils scored between 5 and 9 {17–30% impairment} suggesting moderate HRQoL impairment and three scored > 10 {> 33% impairment} indicating severe impairment. The overall mean CADI score (max. 15) of 1.9 {13% impairment}, CI 0 to 1 (range 0–15) was also low, but 12 pupils scored between 5 and 9 {33–60% impairment}, one scoring 10 + {> 67% impairment} and one scoring the maximum, 15 {100% impairment}. There was no significant difference in mean scores between the sexes in either questionnaire (P = 0.5). There was good correlation between the results from the two questionnaires (Spearman's rho = 0.62). Three‐quarters (75%) had used OTC products, of which only a third (33%) felt they helped ‘a lot’. Fifteen per cent were receiving prescribed treatment from their doctors of which 66% found it helpful.

Conclusions  Self‐reported acne occurred in 83% (147/178) of the Scottish teenagers involved in this study, which confirms previous reports of a high prevalence of acne in teenagers. Cross‐validation of the CLDQI and CADI demonstrated good correlation and both scales were easy to administer and identified 11% (16/147) of teenagers who perceive their lives to be significantly affected by their acne (8% moderately to severely, 3% severely). It is important to identify and treat such teenagers early to reduce the future socio‐economic burden of their acne.
The Long‐Term Use of a Low‐Phenylalanine Diet in Late‐Treated Phenylketonuria: A Single Case Report
Authors: Hewitt Philippa , Cottle Mandy , Coleman Carol
Published: October 2005

Background  When phenylketonuria (PKU) is not diagnosed and long‐term treatment commenced within the first few weeks of life, permanent brain damage will occur. There is some evidence to show that late diagnosed or untreated people with PKU who have severe challenging behaviours may benefit from a low phenylalanine diet [Harper & Reid (1987)Journal of Mental Deficiency Research vol. 31, pp. 209–212; Hoskins et al. (1992)Journal of Intellectual Disability Research vol. 36, pp. 183–191; Baumeister & Baumeister (1998) Clinical Neuropharmacology vol. 21, pp. 18–27; Fitzgerald et al. (2000)Journal of Intellectual Disability Research vol. 44, pp. 53–59].

Method  In the light of this evidence, a woman with late‐diagnosed PKU was treated with a low‐phenylalanine diet in an attempt to reduce her severe challenging behaviour.

Results  A reduction in challenging behaviours was observed when phenylalanine levels were maintained within a specific narrow range. Data are reported over a 2‐year period. A dramatic rise in severe challenging behaviour was noticed when her blood phenylalanine levels fell below a certain level.

Conclusions  This case report suggests that blood phenylalanine levels need to be maintained within a specific range for maximum benefit.
Isolation and characterization of seven polymorphic microsatellite loci in the box jellyfish (Chironex fleckeri, Cubozoa, Cnidaria)
Authors: COUGHLAN J. P. , SEYMOUR J. , CROSS T. F.
Published: October 2005

Population structure and migration patterns for the highly venomous cubozoan box jellyfish (Chironex fleckeri) are unknown. We describe the development of seven polymorphic microsatellites for this species, the first such loci to be characterized for any cubozoan or indeed cnidarian species other than some corals. These markers will be suitable for use in population and behavioural genetic studies.
Short microsatellite DNA markers for the red fox (Vulpes vulpes)
Authors: WANDELER P. , FUNK S. M.
Published: October 2005

Seven short microsatellite loci (< 165 bp) were characterized for red foxes for the amplification of degraded DNA extracted from historical samples. Following polymerase chain reaction (PCR) using primers developed in the domestic dog, red fox‐specific primers were designed within the flanking regions. The number of detected alleles ranged between six and 15 alleles and the expected heterozygosities ranged between 0.67 and 0.92. No deviations from Hardy–Weinberg equilibrium were detected for any of the markers.
Six microsatellite loci in forest musk deer, Moschus berezovskii
Authors: XIA SHAN , ZOU FANGDONG , YUE BISONG
Published: October 2005

Through an improved enrichment protocol, 20 microsatellite loci were isolated and characterized in an endangered animal, forest musk deer (Moschus berezovskii). In which, six loci showed high polymorphism with five to 13 alleles in 48 sampled individuals. The observed and expected heterozygosities were 0.362–0.955 and 0.784–0.906, respectively. The average polymorphism information content (PIC) was 0.8108 in these six microsatellites and they could be the valuable genetic markers for further investigation of forest musk deer species.
Eight new microsatellite loci for the critically endangered fire‐bellied toad Bombina bombina and their cross‐species applicability among anurans
Authors: STUCKAS H. , TIEDEMANN R.
Published: October 2005

We describe eight new microsatellite loci for the critically endangered fire‐bellied toad, Bombina bombina. Seven of them are polymorphic with two to seven alleles per locus, an expected heterozygosity between 0.41 and 0.8, and an observed heterozygosity between 0.27 and 0.7. The yield of new loci was relatively low, presumably due to mildly repetitive sequence motifs in microsatellite flanking regions. As typical for anurans, cross‐species amplification was limited (here, to congeners Bombina orientalis and Bombina variegata). Combining these new loci with those already available provides a reasonable number of loci for population studies and pedigree analysis in Bombina.
Isolation and characterization of microsatellite loci in Eurycorymbus cavaleriei, a dioecious endemic tree species in China
Authors: CHEN J. , WANG Y. , KANG M. , ZHOU J. , HUANG H.
Published: October 2005

Eleven dinucleotide microsatellites were developed and characterized for Eurycorymbus cavaleriei, a dioecious, rare and endemic tree species in China. A genomic DNA enrichment protocol was used to isolate microsatellite loci and polymorphism was explored using 30 trees from two natural populations. The observed heterozygosity (HO) ranged from 0.379 to 0.931, with an average of 0.625. These markers provide powerful tools for the ongoing population and conservation genetics studies of E. cavaleriei.
CHEMICAL CHARACTERIZATION AND STATISTICAL MULTIVARIATE ANALYSIS OF ANCIENT POTTERY FROM MESSINA, CATANIA, LENTINI AND SIRACUSA (SICILY)*
Authors: BARONE G. , LO GIUDICE A. , MAZZOLENI P. , PEZZINO A. , BARILARO D. , CRUPI V. , TRISCARI M.
Published: October 2005

This paper presents the chemical characterization of 79 fragments of Archaic and Hellenistic fine‐grained pottery from archaeological sites in Messina, Catania, Lentini and Siracusa (Sicily). The sherds were classified as ‘calcidian’, ‘banded’, ‘unvarnished’ and ‘black varnished’ pottery. The major and trace elements identified by X‐ray fluorescence (XRF) were statistically elaborated using the method proposed by J. Aitchinson in 1986 for the analysis of compositional data. From cluster analyses using element/SiO2 log‐ratios, it was possible to group the pottery found in Catania, Lentini and Siracusa into highly linked clusters. Conversely, the Messina pottery was divided into two clearly distinct groups. With the aim of identifying any possible mineralogical differences between the two Messina groups, Fourier transform infrared (FT–IR) absorption measurements were made, showing only quantitative differences in plagioclase and muscovite. The specific groups of pottery with restricted chemical compositions are considered to be of local production, also on the basis of archaeological and petrographic evidence.
So Many Civilizations, So Few Pages: A Review Essay*
Authors: Rothman Hal
Published: October 2005

Books reviewed in this article:

Christian JoppkeSelecting by Origin: Ethnic Migration in the Liberal State

Douglas S. Massey and J. Edward Taylor (EDS.) International Migration: Prospects and Policies in a Global Market

United Nations Research Institute For Social DevelopmentGender Equality: Striving for Justice in an Unequal World

International Organization For MigrationArab Migration in a Globalized World
Accuracy of Random Groups Equating with Very Small Samples
Authors: Skaggs Gary
Published: October 2005

This study investigated the effectiveness of equating with very small samples using the random groups design. Of particular interest was equating accuracy at specific scores where performance standards might be set. Two sets of simulations were carried out, one in which the two forms were identical and one in which they differed by a tenth of a standard deviation in overall difficulty. These forms were equated using mean equating, linear equating, unsmoothed equipercentile equating, and equipercentile equating using two through six moments of log‐linear presmoothing with samples of 25, 50, 75, 100, 150, and 200. The results indicated that identity equating was preferable to any equating method when samples were as small as 25. For samples of 50 and above, the choice of an equating method over identity equating depended on the location of the passing score relative to examinee performance. If passing scores were located below the mean, where data were sparser, mean equating produced the smallest percentage of misclassified examinees. For passing scores near the mean, all methods produced similar results with linear equating being the most accurate. For passing scores above the mean, equipercentile equating with 2‐ and 3‐moment presmoothing were the best equating methods. Higher levels of presmoothing did not improve the results.
MATHEMATICAL MODEL FOR THE SURVIVAL OF LISTERIA MONOCYTOGENES IN MEXICAN‐STYLE SAUSAGE
Authors: HAJMEER M.N. , BASHEER I.A. , CLIVER D.O.
Published: October 2005

Survival of Listeria monocytogenes in chorizos (Mexican‐style sausages) was modeled in relation to initial water activity (aw0) and storage conditions using the Weibull cumulative distribution function. Twenty survival curves were generated from chorizos formulated at aw0 = 0.85–0.97 then stored under four temperature (T) and air inflow velocity (F) conditions. The Weibull model parameters (α and β) were determined for every curve. Predicted survival curves agreed with experimental curves with R2 = 0.945–0.992. Regression models (R2 = 0.981–0.984) were developed to relate α and β to operating conditions. The times to one‐ and two‐log reduction in count (t1D and t2D) were derived from the Weibull model in terms of α and β. A parametric study revealed that L. monocytogenes survival was most sensitive to aw0 between 0.90 and 0.95. The inactivation of L. monocytogenes could be maximized with higher T and lower aw0; however, F did not significantly influence survival.
PUBLIC UNDERSTANDING OF FOOD RISK ISSUES AND FOOD RISK MESSAGES ON THE ISLAND OF IRELAND: THE VIEWS OF FOOD SAFETY EXPERTS
Authors: DE BOER MARTINE , MCCARTHY MARY , BRENNAN MARY , KELLY ALAN L. , RITSON CHRISTOPHER
Published: October 2005

Food safety experts have a key role in constructing food risk messages and thus their perceptions will influence how food risk issues are communicated to the public. This research examined the perceptions of food safety experts regarding public understanding of food risk issues and food risk messages on the island of Ireland. It also looked into expert views of the barriers to effective food risk communication and how to improve food risk messages. One hundred and forty‐three experts, working in areas related to food safety, completed an online questionnaire. Questionnaire and statement design was guided by the results of four in‐depth interviews with food safety experts. The findings indicate that most experts surveyed have little confidence in the public's understanding of food risk issues, their assessment of food risks, their ability to deal with scientific information and their food safety practices. Experts are of the view that the public under‐assesses the risk associated with some microbiological hazards and over‐assesses the risk associated with other hazards such as genetically modified organisms (GMOs) and bovine spongiform encephalopathy. The opinion of experts with regard to GMOs is not supported by previous consumer research. Experts noted that the level of education and age were important determinants for the level of understanding of food risk issues and messages. Experts were of the view that early intervention via school curricula was the best method to improve public understanding of food risk messages in the long term. Furthermore, experts are of the view that the media have the ability to improve awareness and knowledge about food risk issues but believe that the media tend to communicate information that is misleading. The majority of experts also believe that they should communicate uncertainty but are not confident that the public is able to cope with this uncertainty. Many of the experts also indicated a desire for training on how to interact with the media. The results may be used by those experts who are involved in the construction of food risk messages to improve the design and communication of food risk messages.
THERMAL RESISTANCE OF ANTIBIOTIC‐RESISTANT AND ANTIBIOTIC‐SENSITIVE SALMONELLA SPP. ON CHICKEN MEAT
Authors: WALSH C. , DUFFY G. , SHERIDAN J.J. , FANNING S. , BLAIR I.S. , MCDOWELL D.A.
Published: October 2005

The aim of this research was to investigate the potential relationship, if any, between the acquisition/possession of antibiotic resistance genes in strains of Salmonella and its resistance to heat stress. Chicken pieces were inoculated with antibiotic sensitive (AS) strains of S. Enteritidis and S. Typhimurium, its laboratory‐acquired antibiotic‐resistant (AR) mutant strains (nalidixic acid and streptomycin), or a multiresistant strain of S. Typhimurium DT104. Half of these samples were heat‐shocked (48C for 30 min) and all were heat‐challenged at 55C for up to 30 min. Samples were then plated on xylose lysine desoxycholate (XLD) and tryptone soya agar (TSA) overpoured with XLD. Heat‐shocked cultures of S. Typhimurium DT104 had significantly higher D‐values (the time required for a 1 log reduction in the number of bacteria) than their non‐heat‐shocked counterparts (P < 0.05). No significant differences were observed between AR and their AS. However, the D‐values for S. Typhimurium DT104 were significantly higher than the D‐values for S. Typhimurium (AS) and S. Enteritidis (AS) (P < 0.05). This study concluded that laboratory‐acquired antibiotic‐resistant mutation did not affect heat resistance of the Salmonella strains studied and suggested a potential link between multiantibiotic resistance and heat resistance in S. Typhimurium DT104.
BIOFILM FORMATION BY SALMONELLA SPP. ON CANTALOUPE MELONS**
Authors: ANNOUS BASSAM A. , SOLOMON ETHAN B. , COOKE PETER H. , BURKE ANGELA
Published: October 2005

The ability of two strains of Salmonella to form biofilms on whole cantaloupe melons was investigated. Ten microliters of bacterial suspensions was spot‐inoculated onto cantaloupe melon rinds in pre‐marked areas, and the cantaloupe melons were held at either 10 or 20C. Biofilm formation was monitored using scanning electron microscopy on excised portions of the cantaloupe melon rind at 2, 24, 48, 72 and 144 h postinoculation. Micrographs indicated that biofilm formation occurred rapidly following introduction of cells (2 h at 20C) onto the cantaloupe melon rind. A fibrillar material was visible after just 2 h at 20C, and cells were embedded in extracellular polymeric material after 24 h at either temperature. These results indicate that a human pathogen is capable of forming a biofilm on plant tissue and that biofilm formation may be responsible for the increased recalcitrance of bacteria to aqueous sanitizers.
Acoustical and planning considerations for home theater and multichannel music playback systems
Authors: Horrall Thomas R.
Published: October 2005

Optimum multichannel sound playback in the home environment requires different room acoustical characteristics than traditional two channel playback. In particular, room surfaces should be acoustically more absorptive in order to avoid masking of later arriving reflections encoded in the software, and the availability of more than two channel playback permits such room design while preserving and enhancing the listener’s sense of immersion in the sound field. Newer recorded five and six channel transmission systems employing a dedicated low-frequency effects channel require careful consideration of the type and placement of low-frequency loudspeakers. The optimum location and directional and other characteristics of loudspeakers intended for existing home theater audio formats are often considered different than those for music playback, but multichannel transmission formats for both video and music-only playback may impact these requirements. Layout requirements of the room, including screen size and placement, are reviewed in light of the coming availability of high resolution video formats such as the digital video disc (DVD). Finally, some measurements of acoustical performance in the author’s home playback facility are presented.
Measurements of airborne and impact sound through floors—A new project
Authors: Warnock Alf C. C.
Published: October 2005

A comprehensive project to study all aspects of sound transmission through floors has just been initiated at the National Research Council of Canada. As well as airborne sound transmission, measurements will include: impact sound transmission using a standard tapping machine, a special rubber ball, a walker, and a tire machine meeting the relevant Japanese standard. As well as these measurements on complete floor systems, all material properties will be measured to provide a complete characterization of the floor systems. Vibration measurements to determine modal characteristics and damping will also be made. These measurements will be made in the new floor facility at NRC which has been found to give more reliable results than the old facility, which is no longer in use. Floors in the new facility measure 3.8 × 4.7 m, a more realistic size than the 2.4 × 2.4 m floor in the obsolete facility. An outline of the project will be given. Initial measurements on wood joist floors to look at the effects of methods of attaching the floor and ceiling layers will be presented.
Acoustic visualization of zooplankton and micronekton patchiness in oceanic ecosystems
Authors: Greene Charles H. , Wiebe Peter H.
Published: October 2005

Acoustic visualization combines the techniques of acoustic remote sensing and scientific data visualization. It provides scientists with the means for interactively exploring three-dimensional data sets collected acoustically. In this presentation, field investigations will be presented in which acoustic visualization has provided unique insights into the three-dimensional patchiness of zooplankton and micronekton distributions. The steps involved with survey design as well as data analysis and interpretation will be discussed along with a video presentation. Details will be given of attempts to derive quantitative, objective inferences from irregualrly spaced and temporally inconsistent data collected during acoustic surveys of patchily distributed animals in an advective flow field. [Work supported by ONR, NSF, and NOAA.]
Acoustic backscattering by complex zooplankton assemblages on Georges Bank
Authors: Wiebe Peter H. , Stanton Timothy K. , Greene Charles H.
Published: October 2005

High-frequency (420 kHz) sound was used to study the volume backscattering from plankton and micronekton over Georges Bank as part of a study designed to understand the relationship between volume backscattering and the composition of the plankton. Volume backscattering levels at stratified sites were factors of 4 to 7 times higher than at a well mixed site. However, there was no significant difference in MOCNESS sampled biomass between the locations and the regression between volume backscattering and total biovolume was not significant. The difference in volume backscattering is due to differences in the acoustic scattering properties of zooplankton taxa and the fact that the taxonomic composition of the plankton differed between the sites. When taxa-specific model predictions of acoustic backscattering cross section were used with field size and abundance data to predict measured volume backscattering data, a highly significant relationship between observed and predicted volume backscattering was obtained. [Work supported by ONR, NSF, and NOAA.]
Analysis of rather high-frequency sound echoes from ensembles of fish
Authors: Clay C. S. , Horne John K.
Published: October 2005

At rather high frequencies, fish length/wavelength ratios are in the range 1 to 20 and the majority of scattered sound originates at the swimbladder. The sonar frequency, shape, and tilt of the swimbladder affect echo amplitudes. Echo amplitudes also depend on the position of a fish in the sonar beam. Echo emplitudes can be corrected for range and position in the sonar beam, but are still dependent on sonar frequency and swimbladder orientation relative to the soundwave front. Acoustic fish models were used to examine the dependence of echo amplitudes on frequency and swimbladder orientation [C. S. Clay and J. K. Horne, J. Acoust. Soc. Am. 96, 1661–1669 (1994)]. Probability density functions (PDF) of echo amplitudes were computed for sets of fish orientation angles. The PDFs of single and ensembles of fish were sensitive to sonar frequency and fish orientation. These PDFs are more interesting than those of Rayleigh and Rice and give additional data to characterize fish targets. [Work supported in part by the NSF (OCE-8817171, OCE-9115740) and Office of Naval Research (N-00014-89-J-1515).]
A micromachined silicon condenser microphone and its potential for hearing aid applications.
Authors: Bernstein Jonathan J.
Published: October 2005

Draper Laboratory has fabricated and tested several generations of micromachined silicon microphones. These monolithic microphones include on-chip JFET buffer amplifiers, providing a complete microphone plus electronics on a single silicon chip. Recent test data will be presented showing sensitivities as high as 40 mV/Pa (−48 dB re: 1 V/μBar), with routine sensitivity of 15 mV/Pa (−57 dB re: 1 V/μBar) and bandwidth of 70 Hz to 20 kHz. The particular constraints resulting from use as a hearing aid microphone are the available bias voltage (one volt at end of battery life) and the small package volume. An analysis of the theoretical attainable sensitivity of a micromachined microphone will be presented. This analysis shows that useful sensitivities (15 mV/Pa) can be attained with a 1-V bias in a small (15 mm3) internal package volume. [Work supported by Noise Cancellation Technologies, Inc.]
Temporal amplitude modulation processing for phonetic ‘‘edge enhancement’’ for otopathologic listeners
Authors: Mortz Margaret , Schweitzer Christopher , Terry Mark
Published: October 2005

This research attempts to address the problem of hearing in noise by hearing-impaired listeners with digital algorithms motivated by the results of Carrell and Opie, 1992, who showed that temporal amplitude modulations helped normal-hearing listeners form auditory objects when exposed to time-varying sinusoidal sentences. The current processing algorithms involved segmenting speech materials into spectral bands and extracting a signed envelope from each band. The envelope in each band was then normalized and either directly added back to the normalized signal or ‘‘edge enhanced’’ with a derivative operator before recombination with the normalized signal. A compression algorithm using a hyperbolic tangent was used to compress the enhanced speech before renormalizing to the same power (rms) as the original speech. Processing variations included applying coherence rules across bands to ascertain when it was ‘‘appropriate’’ to modulate the signal with this technique. Standardized (BKB) sentences were scored for seven hearing-impaired listeners with and without the modulation processing. As a further control, preemphasized treble-enhanced samples were also compared. The same materials were used for subjective judgments on scaled perceptual difference measures, again comparing processed versus the unprocessed speech samples. Both types of measures produced encouraging results.
Recent developments in computational aeroacoustics
Authors: Long Lyle N.
Published: October 2005

There is renewed interest in predicting aeroacoustic noise, especially for jets, rotating blades, and shock waves. These flows involve nonlinear, three-dimensional, turbulent phenomena, and nonuniform free streams. Simulating these flows requires algorithms quite different than those traditionally used in computational fluid dynamics (CFD). The time-dependent nature of aeroacoustic problems requires the algorithm to correctly simulate the dispersion and dissipation features of the flow. Good CFD algorithms usually rapidly damp out all but the steady-state portion of the flow, and are inappropriate for aeroacoustics. Computational aeroacoustics schemes have more in common with large eddy simulation (LES) algorithms than those used in CFD. Recent progress in higher-order algorithms for supersonic jets [T. S. Chyczewski and L. N. Long, 16th AIAA Aeroacoustics Conference, Paper 95-011 (1995)] and fan noise [Y. Ozyoruk and L. N. Long, 16th AIAA Aeroacoustics Conference, Paper 95-063 (1995)] illustrates that quite complicated aeroacoustic problems can be simulated. These algorithms require roughly 5-10 grid points per wavelength. The large demand on computer memory and speed requires that one use modern parallel computers, such as the IBM SP2 and the TMC CM-5. One must be careful to properly load balance the scheme and to minimize interprocessor communication. Kirchhoff surfaces are very effective in predicting the far-field solution.
An analytical and statistical examination of the low-wave-number region of the turbulent boundary layer wall pressure
Authors: Hwang Y. F.
Published: October 2005

The underlying physical mechanisms that generate the low-wave-number pressure components of the turbulent boundary layer wall pressure are examined based on a solution of linearized Navier-Stokes equations in the viscous sublayer with no-slip wall condition. The result indicates that the predominant low-wave-number pressure components are generated by viscous diffusion of shear stress fluctuations at the no-slip wall. These random pressure components have a wave-number spectrum spanning from zero wave number to well beyond the convective wave number. However, their contribution to the convective ridge of the wall pressure spectrum is negligible compared to those of other sources. In the low-wave-number limit, we reach the same conclusion reached by Chase [J. Fluid Mech. 225, 545–555 (1991)], i.e., the wave number spectral density does not vanish as the streamwise wave number approaches zero. The reasons for nonvanishing wave-number spectral density as k→0, for both shear stress and wall pressure, are established analytically. A statistical model is derived based on a probabilistic area-averaging on an assumed random process which is capable of producing the measured two-point correlation functions. The result is a space-time autocorrelation function that yields the experimental low-wave-number data. [Work supported by NSWC ILIR Program and ONR.]
Pressure mapping under an operating lawn mower deck
Authors: Giordano Jeffery A.
Published: October 2005

The use of relatively quiet engines and electric motors on lawn mowers has shifted much of the emphasis on noise reduction to the under deck flow-induced noise sources. However, the environment under an operating mower deck makes it difficult to either model or directly measure the pressure field. This presentation will detail a rather simple scheme which was used to first measure, then animate the pressure field in a plane directly below an operating deck, using an inertial frame of reference. Time synchronous averaging was employed to collect the data at discrete sample points. Individual data planes were then reconstructed representing all the sample points at specific blade locations. The measurement planes were contoured and used as separate frames in a slow-motion animation of the pressure field.
Active control of axial-flow fan noise
Authors: MacGillivray John R. , Lauchle Gerald C. , Swanson David C.
Published: October 2005

An investigation was conducted using active noise control to reduce noise from small axial-flow fan units commonly found in computers and printers. The fan unit itself was used as the cancellation source in the active noise control scheme, achieved by axially modulating the unit with a shaker. Feasibility studies which looked at radiation efficiency and transfer function data identified fan units which would adequately perform as efficient, undistorted sources of noise when driven by particular shakers. Once a suitable shaker and fan combination was discovered, simulations of active noise control were conducted in MATLAB which utilized the measured error path impulse response (representing the system which defines the output voltage response of a microphone near the fan to an input voltage supplied to the shaker). Results from the simulation showed that an experiment could be constructed which would effectively reduce the tonal components from the fan unit. An experimental demonstration was constructed, results from which show a 20-dB reduction in sound-pressure level for the blade passage tone, a 15-dB reduction for the second harmonic, and a 7- to 8-dB reduction for the third harmonic. [Work supported by IBM through Shared University Research Program.]
Numerical simulation of aerosound from airfoils and exhaust jets using Lighthill theory with k-ε turbulence model and large eddy simulation
Authors: Huang Wei-Jen , Schein David B. , Meecham William C.
Published: October 2005

Far-field noise from turbulence near an NACA 0012 airfoil and potential core of a high-speed (subsonic) jet engine exhaust have been computed using the ANSWER computational fluid dynamics code of Runchal and Caretto [Intl. J. Num. Methods Eng. 24 (1990)] and Lighthill’s acoustic analogy. The k-ε turbulence model which is part of ANSWER is used to compute Reynolds stress from two ‘‘side’’ equations in addition to continuity, Navier–Stokes, and for high-speed flow, the energy equation. Three-dimensional turbulence intensities are obtained from the stress. Fluctuations are needed to calculate aerosound, while k-ε only produces averages. Thus the time derivative form of Lighthill’s analogy is used to calculate the sound. Time derivatives must be estimated; the characteristic time L/u′, as calculated by k-ε, is used. ANSWER modified to perform Large Eddy Simulation is used for the free jet, employing a hybrid subgrid scale model previously developed for application to a low-speed jet by Lee [UCLA dissertation (1992)] which combines the conventional Smagorinsky formulation with a deductive model formed by taking a Taylor series expansion of the flow field and using the first terms to give the fluctuations. Preliminary results are compared with jet noise measurements.
The intake and exhaust noise control by influence on manifolds of vehicle engine
Authors: Starobinski Roudolf , Kergomard Jean
Published: October 2005

Excitation of eigenmodes in intake and exhaust manifolds of multi- cylinder internal combustion engine is investigated. It is shown that some of the eigenmodes do not depend very much on the intake, and exhaust systems are jointing behind the manifold. The sound increase (particularly for an asymmetrical excitation) caused by these modes depends on the degree of the asymmetry of the manifold and on sound energy dissipation in the manifold. Under some conditions this increase is the reason for resonance sound radiation. The tendency for resonance excitation at the branch of intake (exhaust) pipes with mufflers is considered to be one of the criteria in assessing the quality of manifold construction. Special attention is paid to the asymmetrical exhaust and intake manifolds of trucks. It is shown that the influence of the manifolds design of their engines allows a decrease truck intake and exhaust noise in a wide range of crankshaft RPM.
Estimation of stress-induced velocity anisotropy using finite-deformation theory
Authors: Liu Xingzhou , Nur Amos
Published: October 2005

Murnaghan’s second-order elasticity theory is applied to studying the directional- and stress-dependence of elastic wave velocities in intrinsically isotropic rocks. At any stress within the ‘‘perfectly’’ elastic range, the velocity change with stress (slope) and direction is determined by three third-order elastic (TOE) constants. However, the three TOE constants are not all independent for most rock samples measured in this study. This observation reduces the number of independent TOE constants from three to two, which allows the prediction of stress-induced velocity anisotropy from P- and S-wave velocity measurements under hydrostatic pressures. Compared with the approach that adopts linear stress-strain relation but allows stress-dependent elastic constants (second-order), this method avoids the modeling of rock pore compressibilities and has a clearer physical meaning. The origin of the elastic nonlinearity in rocks is shown to be the prevalence of compliant pore space in rocks, with geometries ranging from thin cracks in igneous rocks to cemented grain contacts in granular sedimentary rocks undergoing diagenesis. By using elastic solutions for cracks, contacts, and cemented contacts and assuming a mixture of these different types of pores, it is shown that the TOE constants of rocks can be related to their textural or petrographical properties.
Nonlinear acoustics of rocks and other hard subjects
Authors: Breazeale M. A.
Published: October 2005

With single crystals, an acceptable approximation is achieved with only the first nonlinear term in the wave equation. With such crystals and weakly nonlinear solids, one can define a nonlinearity parameter β as the negative ratio of the coefficients of the nonlinear and the linear terms. Values of β between 3 and 15 have been observed for single crystals. It appears that the approximation no longer is adequate when β becomes larger. Values of β between 80 and 1000 have been observed for rocks. A value of β=1500 has been observed for PZT at the Curie temperature. In addition, frequency dispersion of the nonlinearity has been observed in PZT, and the third harmonic is much larger than expected from an extrapolation of second harmonic data. Since the approximate theory no longer is adequate, terms have been added to the nonlinear equation. The nonlinear equation required to fit data on PZT has been determined. The next step is to explain this mathematical success in physical terms. This will involve the effect of grain boundaries. Then the results can be applied to rocks, which are more complicated.
Borehole propagation in berea sandstone: Stress-induced dipole anisotropy
Authors: Sinha Bikash , Plona Thomas J. , Winkler Kenneth , D’Angelo Ralph
Published: October 2005

Stress-induced dipole anisotropy exhibits a crossover in the principal flexural wave slowness dispersions oriented parallel and perpendicular to the farfield uniaxial compressive stress direction. This crossover phenomena is a result of borehole stress concentrations and can be used as a new technique for distinguishing stress-induced anisotropy from intrinsic anisotropy. Theoretical modeling (based on third-order elasticity) and laboratory measurements (from 10 to 60 kHz) have been made on a large block of berea sandstone subject to a uniaxial stress of up to 5 MPa. The two flexural mode dispersions are obtained by Prony’s processing of an array of measured waveforms for dipole orientations parallel and perpendicular to the stress direction. The theoretical dispersions in the presence of biasing stresses are obtained from the solution of equations of motion for small dynamic fields superimposed on a static bias. Good agreement has been obtained between theory and experiment including a dispersion crossover phenomena unique to stress-induced anisotropy.
Recent advances in computer-aided design of loudspeakers
Authors: Dickason Vance
Published: October 2005

Although successful CAE software that allows the accurate simulation and development of loudspeaker enclosures and crossover networks has been available for professional design work for several years, a number of loudspeaker industry practitioners still persist in using traditional methods of ‘‘cut and try.’’ This presentation outlines a computer-aided loudspeaker development case study of a commercial three-way loudspeaker using a vented enclosure and a crossover network that incorporated fourth-order acoustic slopes. Measurement of the resulting prototype showed close agreement, within 0.5–1 dB, with the computer simulation. Time required for the development of the fairly complex crossover network determined for this loudspeaker was less than 1.5 h, substantially less than what is generally expected of ‘‘cut and try’’ methods. Key to the resulting accuracy using this type of computer software is the correct portrayal of interdriver time delay and driver phase. Driver phase for this project was derived from the driver magnitude using a highly sophisticated phase calculation methodology, as opposed to being directly measured with a two-port analyzer. Other criteria responsible for the success of the loudspeaker modeling portrayed in this case study are the ability to predetermine the group delay performance of the enclosure design, and the ability to examine crossover network transfer function during the design process.
A new family of rotary loudspeaker transducers
Authors: Danley Thomas J.
Published: October 2005

A technical overview will be provided for a new electromagnetic transducer concept that employs rotary motion rather than rectilinear piston motion. The differences in the physical rules that govern the distribution of force and mass in the rotary and rectilinear systems will be explored. These relationships have permitted the construction of a new category of transducer which offers solutions to some of the seemingly insurmountable design constraints inherent in conventional coil/cone driver systems. One of the transducers examined is a high-output, full-range (40 Hz to 20 kHz) rotary loudspeaker which produces low-distortion, minimum-phase acoustic output with a radiation pattern resembling that of a line source.
Design considerations for an application-specific loudspeaker
Authors: Mitchell James E.
Published: October 2005

The design of a proprietary loudspeaker for use in IMAX theaters posed some unusual problems while offering a unique opportunity: that of optimizing a loudspeaker design for a predetermined and relatively narrowly defined set of acoustic, geometric, and mechanical conditions. Requirements unique to the application, a specialty cinema format which employs six discrete audio signal channels and makes substantial demands on sound system bandwidth and acoustic output, are explained. Methods used to arrive at the final loudspeaker design are presented. Sound system coverage prediction software was utilized in a novel fashion, significantly reducing the time required to complete the development of the loudspeaker. Investigation of IMAX theater geometries indicated that a vertically asymmetric radiation pattern was highly desirable. Optimum loudspeaker directivity criteria were established, and horns were developed with these criteria in mind. Testing of prototypes indicated that the criteria had been substantially met. Predictive work was verified with insitu testing of prototype systems.