bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymptomatic celiac sprue in juvenile rheumatic diseases children
Authors: GHEITA Tamer A. , FAWZY Samar M. , NOUR EL‐DIN Abeer M. , GOMAA Howaida E.
Published: October 2011

Background:  Celiac disease (CD) is the most frequent enteropathy in adults and its coexistence with other autoimmune diseases is frequent.

Objective:  To detect asymptomatic CD in children with rheumatic diseases by measuring tissue transglutaminase (tTG) antibodies and finding any relation to disease activity.

Patients and methods:  Setting and study design: The study included 60 children with juvenile rheumatic diseases consecutively from those attending the Rheumatology Clinics of Cairo University Hospitals: 30 juvenile rheumatoid arthritis (JRA), 10 juvenile systemic lupus erythematosus (SLE), 12 juvenile seronegative spondyloarthropathy and eight juvenile systemic sclerosis/polymyositis (SSc/PM) overlap syndrome were recruited during 2010. There were 22 male and 38 female patients. Thirty matched healthy controls were included. All children were subjected to thorough history taking, clinical examination and laboratory investigations. The body mass index (BMI) for age was used. All subjects had no gastrointestinal tract symptoms suggestive of CD and the tTG antibodies (IgA and IgG) were assessed.

Results:  The mean age of patients was 12.03 ± 3.3 years and disease duration 4.18 ± 3.24 years. The demographic, clinical and laboratory features of the children were studied and compared. The tTG was positive in 32 (53.3%) patients compared to 20% of the controls (P = 0.03), being higher in females. In tTG‐positive patients, the BMI was significantly lower, while white blood cell count, erythrocyte sedimentation rate and disease activity were significantly higher.

Conclusions:  tTG antibodies may be used as a screening test to identify asymptomatic CD associated with juvenile rheumatic diseases, especially those with active JRA or marked reduction in BMI.
The dentine remineralization activity of a desensitizing bioactive glass‐containing toothpaste: an in vitro study
Authors: Wang Z , Jiang T , Sauro S , Pashley DH , Toledano M , Osorio R , Liang S , Xing W , Sa Y , Wang Y
Published: October 2011

Background:  Dentine hypersensitivity occurs easily on exposed dentine. This study aimed to evaluate the effectiveness of a novel bioactive glass‐containing toothpaste on dentine permeability and remineralization.

Methods:  Thirty dentine discs were divided into three groups of 10 specimens each. The groups corresponded to the following brushing treatments: no brush, distilled water, and bioactive glass‐containing toothpaste (Novamin). The toothpaste was applied twice a day for 7 days. Dentine permeability was measured after ethylene‐diamine‐tetraacetic acid (EDTA) etching, initial application, 3‐day application, 7‐day application and citric acid challenge, respectively. The dentine morphology was investigated using scanning electron microscopy (SEM). Attenuated total reflection Fourier transform infrared (ATR/FTIR) spectroscopy was performed to monitor the mineral variation on demineralized dentine. Qualitative information of elemental variation before and after treatments on completely demineralized dentine was detected by energy dispersive X‐ray (EDX) analysis.

Results:  The bioactive glass‐containing toothpaste significantly reduced dentine permeability after the 7‐day treatment and showed, under SEM, excellent resistance to acid challenge compared to the other groups. ATR/FTIR and EDX revealed increased mineral content after treatment with Novamin.

Conclusions:  As the innovative bioactive glass‐containing toothpaste occlude dentinal tubules and resist acid challenge, it may be useful for the treatment of dentine hypersensitivity and dentine remineralization.
Geographic Variation in Roost‐Site Selection of Long‐Legged Myotis in the Pacific Northwest
Authors: LACKI MICHAEL J. , BAKER MICHAEL D. , JOHNSON JOSEPH S.
Published: October 2011

Abstract: Several species of bats in the Pacific Northwest of the United States, including long‐legged myotis (Myotis volans), are dependent on snags in coniferous forests during summer for roosting and rearing young. Thus, data on roosting preferences of this species are needed to integrate their habitat requirements into shifting plans for management of forests in this region. Therefore, from 2001 to 2006, we radiotracked adult female long‐legged myotis (n = 153) to day roosts (n = 395) across 6 watersheds in Washington, Oregon, and Idaho, USA, and compared characteristics associated with roosting sites to those of random snags (n = 260) sampled in the same watersheds using use‐availability logistic regression and an information‐theoretic approach. Model rankings varied among geographic locations, with quantity of stem surface for roosting the best model for explaining roost‐site selection of long‐legged myotis in both Washington and Oregon. Model rankings for populations of bats in Idaho found stand‐ and landscape‐scale features to be important in roost‐site selection, with a habitat fragmentation model and a foraging habitat quality model both demonstrating strong support as best model. Choice of day roosts by long‐legged myotis was associated with snags that were taller, intact at the top of the stem, possessing a greater amount of exfoliating bark, in stands with a larger basal area of dead stems, and in landscapes that were unfragmented (i.e., supporting lesser amounts of edge). Results indicate that roost‐site selection of bats in western coniferous forests, particularly long‐legged myotis, is likely to be region‐specific. We encourage land managers to consider importance of geographic variation in intraspecific habitat use in forest‐dwelling bats when implementing silvicultural systems to promote biological diversity in actively managed forests of the Pacific Northwest region.
Golden Eagle Indifference to Heli‐Skiing and Military Helicopters in Northern Utah
Authors: GRUBB TERYL G. , DELANEY DAVID K. , BOWERMAN WILLIAM W. , WIERDA MICHAEL R.
Published: October 2011

Abstract: In 2006‐2007, during Wasatch Powderbird Guides (WPG) permit renewal for heli‐skiing in the Tri‐Canyon Area (TCA) of the Wasatch Mountains, Utah, USA, we recorded 303 helicopter passes between 0 m and 3,000 m (horizontal distance) near ≥30 individual golden eagles (Aquila chrysaetos) in 22 nesting territories, through passive observation and active experimentation with civilian and military (Apache AH‐64) helicopters. Flight profiles included 800‐m, 400‐m, 200‐m, and 100‐m flybys (horizontal distance from cliff nest on parallel course), as well as approaches and popouts where helicopters flew toward, or popped out from behind, adult‐occupied cliff nests (0 m, horizontal distance). Between 1981 and 2007, during the only 8 years when nesting in the TCA was confirmed by presence of chicks, WPG annually flew 108–2,836 helicopter flights in the same drainages on 10–37 days between 15 December and 15 April, with no effect on early courtship, nest repair, or subsequent nesting success. Total WPG operating days (x̄ = 62.4) and helicopter hours (x̄ = 210.6) fluctuated annually but did not increase 1974–2007 (Cox‐Stuart trend test, P = 0.371, 0.393, respectively). Apache helicopter testing (227 passes) did not reduce golden eagle nesting success or productivity rates within the same year (t111, 96 = 0.495, 0.782, P = 0.622, 0.436, respectively), or rates of renewed nesting activity the following year, compared with 81–101 non‐manipulated nesting territories. We recorded no response during 66% and only watching during 30% of Apache passes at 0‐800 m from nesting golden eagles. No other reactions occurred until after hatching when ≤4 golden eagles accounted for 5 flatten and 3 fly behaviors at 3 nest sites. No responding pairs failed to fledge young because of testing. Limited fly responses suggested helicopters only precipitated an imminent departure, rather than causing startled, avoidance reactions. Responsiveness between test weeks 1 and 2 decreased (X22 = 32.167, P ≤ 0.001). Apache helicopters were twice as loud as WPG helicopters at comparable distances. Sound decreased with distance, most rapidly when flights were perpendicular to cliffs or ridges. Eagle ambient behaviors and watching the helicopter occurred randomly throughout recorded sound levels during helicopter testing (76.7–108.8 decibels, unweighted). Much helicopter sound energy is below golden eagles' auditory threshold, thus reducing potential impacts. Neither our observations nor our testing indicated special management restrictions are required for helicopters flying near nesting golden eagles in northern Utah. Our results underscore the necessity for circumstance‐specific research, as well as enlightened resource management to accommodate unexpected results.
Response of Reptiles and Amphibians to Repeated Fuel Reduction Treatments
Authors: MATTHEWS CHARLOTTE E. , MOORMAN CHRISTOPHER E. , GREENBERG CATHRYN H. , WALDROP THOMAS A.
Published: October 2011

Abstract:Recent use of prescribed fire and fire surrogates to reduce fuel hazards has spurred interest in their effects on wildlife. Studies of fire in the southern Appalachian Mountains (USA) have documented few effects on reptiles and amphibians. However, these studies were conducted after only one fire and for only a short time (1–3 yr) after the fire. From mid‐May to mid‐August 2006 and 2007, we used drift fences with pitfall and funnel traps to capture reptiles and amphibians in a control and 3 replicated fuel‐reduction treatments: 1) twice‐burned (2003 and 2006), 2) mechanical understory cut (2002), and 3) mechanical understory cut (2002) followed by 2 burns (2003 and 2006). We captured fewer salamanders in mechanical + twice‐burned treatment areas than in twice‐burned and control treatment areas, but we captured more lizards in mechanical + twice‐burned treatment areas than in other treatment areas. Higher lizard captures in mechanical + twice‐burned treatment areas likely was related to increased ground temperatures and greater thermoregulatory opportunities. Higher and more variable ground temperatures and faster drying of remaining litter and duff may have led to fewer salamander captures in mechanical + twice‐burned treatment areas. Our longer term results, after 2 prescribed burns, differ from shorter term results. After one prescribed burn at the same site, eastern fence lizard (Sceloporus undulatus) captures were greater in mechanical + burn treatment areas but salamander captures did not differ among treatment areas. Our results indicate that multiple (≥2) fuel‐reduction treatments that decrease canopy cover may benefit lizards but negatively affect salamanders.
Polymerase Chain Reaction‐Based Sex Identification in the Greater Roadrunner
Authors: SANTAMARIA CARLOS A. , KELLEY SAMUEL , SCHULZ GERRAL G. , RANSOM DEAN , HURTADO LUIS A.
Published: October 2011

Abstract: We determined a polymerase chain reaction (PCR)‐based method to identify the sex of greater roadrunners (Geococcyx californianus). We found that previously reported primer combinations used in other bird species did not work reliably in roadrunners. However, a novel primer combination (P2‐1237L) allowed for consistent and reliable sex identification of roadrunners. Conducting several PCR replicates per sample helped to identify occasional preferential amplification of the Z band that could occur in females (the heterogametic sex; i.e., WZ). Identifying the sex of individuals will allow for examination of sex‐associated differences in home range size and habitat use, population demographics, and parenting behavior, as well as for a better understanding of the social system of roadrunners.
Laboratory Efficacy of Chemical Repellents for Reducing Blackbird Damage in Rice and Sunflower Crops
Authors: WERNER SCOTT J. , LINZ GEORGE M. , TUPPER SHELAGH K. , CARLSON JAMES C.
Published: October 2011

Abstract: Nonlethal alternatives are needed to manage blackbird (Icterids) damage to rice and sunflower production in the United States. We evaluated 4 registered fungicides on rice seeds (i.e., Allegiance® FL, Thiram 42‐S, Trilex®, and Vitavax® 200 preplant seed treatments) and 2 foliar pesticides on sunflower seeds (Cobalt™ insecticide and Flock Buster bird repellent) as candidate blackbird repellents. Red‐winged blackbirds (Agelaius phoeniceus) preferred untreated rice relative to rice treated with Thiram (P < 0.001) and Vitavax (P < 0.001), and untreated sunflower relative to sunflower treated with Cobalt (P < 0.001). Blackbirds preferred untreated sunflower relative to sunflower treated with Flock Buster repellent on day 1 of a 4‐day preference test (P < 0.001). We observed no difference in consumption of treated versus untreated rice during the Allegiance preference test (P = 0.928), and blackbirds preferred rice treated with Trilex relative to untreated rice (P = 0.003). Although repellency was positively related to tested concentrations of Thiram (P = 0.010), Trilex (P = 0.026), and Vitavax (P < 0.001), maximum repellency was < 50% during our concentration‐response tests of these seed treatments. Repellency was also positively related to tested concentrations of Cobalt (P < 0.001), and we observed >80% repellency of sunflower treated with Cobalt at ≥50% of the label rate. We observed no concentration‐response relationship for the Allegiance seed treatment (P = 0.341) and Flock Buster repellent (P = 0.952). We recommend implementation of supplemental field studies to compare laboratory efficacy, repellency, and chemical residues of effective avian repellents throughout periods of needed crop protection.
Cougar Kill Rate and Prey Composition in a Multiprey System
Authors: KNOPFF KYLE H. , KNOPFF ALIAH ADAMS , KORTELLO ANDREA , BOYCE MARK S.
Published: October 2011

Abstract:Assessing the impact of large carnivores on ungulate prey has been challenging in part because even basic components of predation are difficult to measure. For cougars (Puma concolor), limited field data are available concerning fundamental aspects of predation, such as kill rate, or the influence of season, cougar demography, or prey vulnerability on predation, leading to uncertainty over how best to predict or interpret cougar‐ungulate dynamics. Global Positioning System (GPS) telemetry used to locate predation events in the field is an efficient way to monitor large numbers of cougars over long periods in all seasons. We applied GPS telemetry techniques combined with occasional snow‐tracking to locate 1,509 predation events for 53 marked and an unknown number of unmarked cougars and amassed 9,543 days of continuous predation monitoring for a subset of 42 GPS‐collared cougars in west‐central Alberta, Canada. Cougars killed ungulates at rates near the upper end of the previously recorded range, and demography substantially influenced annual kill rate in terms of both number of ungulates (subad F [SAF] = 24, subad M [SAM] = 31, ad M = 35, ad F = 42, ad F with kittens <6 months = 47, ad F with kittens <6 months = 67) and kg of prey (SAF = 1,441, SAM = 2,051, ad M = 4,708, ad F = 2,423, ad F with kittens <6 months = 2,794, ad F with kittens >6 months = 4,280). Demography also influenced prey composition; adult females subsisted primarily on deer (Odocoileusspp.), whereas adult males killed more large ungulates (e.g., moose [Alces alces]), and subadults incorporated the highest proportion of nonungulate prey. Predation patterns varied by season and cougars killed ungulates 1.5 times more frequently in summer when juveniles dominated the diet. Higher kill rate in summer appeared to be driven primarily by greater vulnerability of juvenile prey and secondarily by reduced handling time for smaller prey. Moreover, in accordance with predictions of the reproductive vulnerability hypothesis, female ungulates made up a higher proportion of cougar diet in spring just prior to and during the birthing period, whereas the proportion of males increased dramatically in autumn during the rut, supporting the notion that prey vulnerability influences cougar predation. Our results have implications for the impact cougars have on ungulate populations and have application for using cougar harvest to manage ungulates.
Fine‐Scale Habitat Associations of Red‐Backed Voles in Boreal Mixedwood Stands
Authors: VANDERWEL MARK C. , MALCOLM JAY R. , CASPERSEN JOHN P. , NEWMAN MARK A.
Published: October 2011

Abstract:To provide habitat for late‐successional wildlife species, new ecosystem‐based forest management practices aim to retain elements of complex stand structure, including live residual trees, dead wood legacies, and advanced regeneration, within managed stands. Predicting the effectiveness of these strategies is a challenge for species whose habitat relationships may involve multiple factors and can vary among sites. For 2 years, we live‐trapped a common, late‐successional microtine rodent, the southern red‐backed vole (Myodes[formerlyClethrionomys]gapperi), in 40 1.4‐ha boreal mixedwood sites in Ontario, Canada. Using a neighborhood‐scale modeling approach, we related red‐backed vole capture locations to spatially referenced measures of overstory trees, shrubs and saplings, downed woody debris (DWD), and forest floor substrate. We further assessed how associations with these features varied with availability of the features within a site and as a function of stand management history. In spring, red‐backed voles were associated with trap stations that had, within a 26‐m radius, a dense shrub layer, abundant late‐decay DWD, coniferous understory and litter, and possibly, understory vegetation associated with moist conditions. Positive associations with shrub cover, late‐decay DWD, and a moisture‐associated understory were most apparent in sites in which these elements were scarce (e.g., <1,500 stems/ha of hardwood saplings and short shrubs; <0.8% projected ground cover of late‐decay DWD). The importance of late‐decay DWD; shade‐tolerant, coniferous understory composition; and substrate varied depending on a site's management history, with each feature having a strong positive effect in 47–64‐year‐old stands that were harvested using horse skidding and weaker effects in both 31–40‐year‐old stands that were clearcut with mechanical skidding and >80‐year‐old fire‐origin stands. Our models of fine‐scale habitat relationships for red‐backed voles may be useful in establishing structural retention guidelines suitable for wildlife species dependent on late‐successional habitat structure. In this regard, retaining abundant DWD and 10–30% live trees at harvest may be effective management strategies for providing favorable habitat conditions at localized scales.
Efficacy and tolerability of vildagliptin in type 2 diabetic patients on hemodialysis
Authors: Kume Shinji , Uzu Takashi , Takagi Chieko , Kondo Morihiro , Okabe Tomoko , Araki Shin‐ichi , Isshiki Keiji , Takeda Naoko , Kondo Keiko , Haneda Masakazu , Koya Daisuke , Nishio Yoshihiko , Kashiwagi Atsunori , Maegawa Hiroshi
Published: October 2011

Anti‐diabetic agent‐related hypoglycemia is a serious complication in type 2 diabetic patients on hemodialysis. Therefore, we assessed the efficacy and tolerability of 24 weeks of monotherapy with vildagliptin, a dipeptidyl peptidase four inhibitor, which is a new class of antidiabetic agent. This open‐label, single‐arm clinical trial was performed on 26 patients on hemodialysis. The primary assessments were changes in postprandial glucose level and glycated albumin (GA). During the study, three patients dropped out, and data from 23 patients were analyzed. Significant reductions were seen in postprandial glucose (−2.60 ± 3.80 mmol/L, P < 0.001) and GA (−2.59 ± 2.33%, P < 0.001) levels. No serious drug‐related adverse events were observed. Vildagliptin monotherapy can be recommended for glycemic control in type 2 diabetic patients on hemodialysis. This trial was registered with the University Hospital Medical Information Network (no. UMIN000003661). (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00169.x, 2011)
Pharmaceutical care in a community-based practice setting in Jordan: where are we now with our attitudes and perceived barriers?
Authors: AbuRuz Salah , Al-Ghazawi Moatasem , Snyder Ann
Published: October 2011

Objectives

The objective of this study was to answer the following questions. How do community pharmacists in Jordan understand pharmaceutical care? What is the extent of pharmaceutical care practice in community pharmacies in Jordan? What are the main barriers to practising pharmaceutical care in Jordan? What is the attitude of community pharmacies in Jordan when considering provision of pharmaceutical care?

Method

A questionnaire was hand delivered to a random sample of 310 community pharmacists. The questionnaire was composed of six different sections including patient demographics, pharmacists' understanding of pharmaceutical care, frequencies of practice of pharmaceutical care, pharmacists' general attitudes about pharmaceutical care, pharmacists' intentions to provide specific pharmaceutical care activities and barriers to providing pharmaceutical care. Frequencies, percentages, means and standard deviations were used to describe pharmacists' responses. Chi-square and regression analysis were also conducted to identify important associations.

Key findings

More than 62% of respondents had a correct understanding of the basic concept of pharmaceutical care. The data show that the level of reported pharmaceutical care activities was limited. In general pharmacists have very good attitudes toward pharmaceutical care. Interestingly, more than 90% of respondents fully support the concept of pharmaceutical care. The need for pharmaceutical care training was found to be the top barrier to the provision of pharmaceutical care as indicated by more than 80% of pharmacists.

Conclusions

While pharmaceutical care provision is limited at this stage in Jordan, the responding pharmacists had a good understanding of pharmaceutical care. They expressed a willingness to implement pharmaceutical care practice but have identified a number of barriers to successful implementation. With the introduction of PharmD and Master of Clinical Pharmacy programmes, publication of the results of local studies on the benefit of pharmaceutical care, improved communications with physicians and modification of the current undergraduate pharmacy curriculum to include more focus on therapeutics and pharmaceutical care, many of these perceived barriers may be eliminated in the future.
How do pharmacy students learn professionalism?
Authors: Schafheutle Ellen I , Hassell Karen , Ashcroft Darren M , Hall Jason , Harrison Stephen
Published: October 2011

Objective

To understand and clarify how professionalism is learnt, cultivated and facilitated in pharmacy education.

Methods

Qualitative methodology involving three UK schools of pharmacy was used, including documentary analysis of course materials, interviews with seven teaching staff, six focus groups with 38 final-year pharmacy students and observation of professional pharmacy practice classes. We used a ‘curriculum mapping’ framework; analysis was thematic, with triangulation of methods and constant comparison between groups of participants and schools.

Key findings

Students and teachers found defining professionalism difficult, but they identified common attitudinal and behavioural attributes. These were predominantly based on students' work experience, and role models were identified as particularly influential. Professionalism learning needed to be grounded and longitudinal throughout the curriculum. Practical classes and the use of real-life examples and role plays were influential; and teacher practitioners appeared particularly valuable due to their dual base in practice. Explicit statements in year books and codes of conduct were valuable, especially if they were reinforced and carried through.

Conclusions

This study offers novel insights into professionalism learning during undergraduate education in the UK, by triangulating evidence from different sources and perspectives. It not only underpins the importance of professionalism learning but also highlights approaches which appeared valuable within the constraints of an otherwise artificial university environment.
Dynamic Mapping of the Structures of Content in Clinical Settings (DMSC). A new coding system for analysing the patient's narratives
Authors: Salvatore Sergio , Gennaro Alessandro , Auletta Andrea , Grassi Rossano , Rocco Diego
Published: October 2011

Objectives. The paper presents a method of content analysis framed within a semiotic and contextual model of the psychotherapy process as a situated dynamics of sensemaking: the Dynamic Mapping of the Structures of Content in Clinical Settings (DMSC).

Design. DMSC is a system of content analysis focused on a generalized level of meaning, concerning basic aspects of the patient's narrative (e.g., if the narrative concerns herself or other than herself).

Method. The paper presents the result of the application of DMSC to an intensive single‐case analysis (Katja). The method has been applied by judges to the transcripts of sessions and is aimed at identifying patterns of combinations (defined: Patterns of content) of the categories characterizing the patient's narratives (pattern analysis approach) as well as at mapping the transition among these patterns (sequential analysis approach).

Results. These results provide evidence of its construct validity. In accordance with the theoretical model grounding the method, we have found that: (a) DMSC provides a meaningful representation of the patient's narratives in terms of Patterns of content; (b) the probability of transition among the Patterns of content have proved to be significantly associated with the clinical quality of the sessions.

Conclusion. The DMSC has to be considered an attempt paving the way for further investigations aimed at developing a deeper understanding of the role played by the dynamics of sensemaking in the psychotherapy process.
The Effects of Fish Cages on Ambient Currents
Authors: Gansel Lars C. , McClimans Thomas A. , Myrhaug Dag
Published: October 2011

Experiments were carried out to measure forces on and wake characteristics downstream from fish cages. Cylinders made from metal mesh with porosities of 0%, 30%, 60%, 75%, 82%, and 90% were tested in a towing tank. The drag force was measured with strain gauges, and the flow field downstream from the models was analyzed using particle image velocimetry. The Reynolds numbers ranged from 1000–20,000 based on the model diameter and 15–300 based on the diameter of the strings of the mesh as an independent obstacle. High porosities (here, 82% and 90%) lead to low water blockage and allow a substantial amount of water to flow through the model. The data indicate that the wake characteristics change toward the wake characteristics of a solid cylinder at a porosity just below 75%. The drag force is highly dependent on the porosity for high porosities of a cylinder.
Comparative Abrasive Wear Study of HVOF Coatings Obtained by Spraying WC-17Co Microcrystalline and Duplex Near-Nanocrystalline Cermet Powders
Authors: Saha G. C. , Khan T. I.
Published: October 2011

High velocity oxy-fuel spraying was used to develop a near-nanocrystalline coating from a duplex Co coated WC-17Co powder feedstock. A microstructural and mechanical property characterization of the coating with a similar microcrystalline coating of the same composition was made. X-ray diffraction analysis showed less decarburization of the nanocrystalline coating and a more homogeneous coating structure than the microcrystalline coating produced under the same spraying conditions. The mechanical assessment of the coatings was performed using microhardness and indentation fracture toughness measurements. The abrasive wear resistance was determined using the ASTM G65-04 dry-sand rubber wheel test. The results showed that the hardness of the near-nanocrystalline coating was 25% greater than that of the microcrystalline coating and a sixfold increase in the abrasive wear resistance was also recorded for the near-nanocrystalline coating. Examination of the worn surfaces using atomic force microscopy after abrasive testing showed a smoother surface roughness in the near-nanocrystalline coating than that of the microcrystalline coating surface. The increase in fracture toughness of the near-nanocrystalline coating prevented brittle fracture of the coating surface.
Investigation of Self-Starting Capability of Vertical Axis Wind Turbines Using a Computational Fluid Dynamics Approach
Authors: Untaroiu Alexandrina , Wood Houston G. , Allaire Paul E. , Ribando Robert J.
Published: October 2011

Vertical axis wind turbines have always been a controversial technology; claims regarding their benefits and drawbacks have been debated since the initial patent in 1931. Despite this contention, very little systematic vertical axis wind turbine research has been accomplished. Experimental assessments remain prohibitively expensive, while analytical analyses are limited by the complexity of the system. Numerical methods can address both concerns, but inadequate computing power hampered this field. Instead, approximating models were developed which provided some basis for study; but all these exhibited high error margins when compared with actual turbine performance data and were only useful in some operating regimes. Modern computers are capable of more accurate computational fluid dynamics analysis, but most research has focused on horizontal axis configurations or modeling of single blades rather than full geometries. In order to address this research gap, a systematic review of vertical axis wind-power turbine (VAWT) was undertaken, starting with establishment of a methodology for vertical axis wind turbine simulation that is presented in this paper. Replicating the experimental prototype, both 2D and 3D models of a three-bladed vertical axis wind turbine were generated. Full transient computational fluid dynamics (CFD) simulations using mesh deformation capability available in ansys-CFX were run from turbine start-up to operating speed and compared with the experimental data in order to validate the technique. A circular inner domain, containing the blades and the rotor, was allowed to undergo mesh deformation with a rotational velocity that varied with torque generated by the incoming wind. Results have demonstrated that a transient CFD simulation using a two-dimensional computational model can accurately predict vertical axis wind turbine operating speed within 12% error, with the caveat that intermediate turbine performance is not accurately captured.
Analysis of sound propagation in an experimental model using a high resolution scanning system
Authors: Alamuru Aditya , Xiang Ning , Lee Joonhee
Published: October 2011

The aim of this work is to analyze low frequency and mid frequency sound propagation in a coupled volume system for different aperture configurations. The cross sectional areas of the primary room and the secondary room are scanned over high spatial resolution grids using an automated scanning system. This procedure is carried out systematically for different aperture configurations. A dedicated analysis algorithm converts experimentally measured room impulse response data at each grid point into energy distributions and instantaneous sound pressure levels as a function of time. The analysis algorithm provides streams of data for a selected frequency thereby creating an animation of sound propagating through the coupled volume system. This work will demonstrate wave phenomena for different aperture configurations at low frequencies and mid frequencies by using animations to analyze the experimentally measured data.
Temporal modeling of measurement conditions to enhance room acoustical parameter characterization
Authors: Roessner Stephen , Ren Gang , Bocko Mark F. , Headlam Dave
Published: October 2011

Forming statistical combinations of the results of repeated acoustical measurements taken under identical conditions is a common practice to reduce the effects of random noise. The most common method is to calculate the arithmetic mean of an ensemble of test results, which is based on the assumption that all experiments were conducted under identical noiseless test conditions. For most room acoustic measurement scenarios, this assumption is not valid, and non-stationary sources of noise often contaminate the results. Traditional statistical averaging methods can be improved by explicitly modeling the ambient interference and noise. Using a signal model for the noise and interference, the proposed parameter estimation procedure provides more accurate results than simple averaging in low signal to noise ratio test scenarios. This method, in which multiple, low volume measurements replace high volume test signals, provides a practical and cost-effective approach for characterizing acoustical spaces.
Benchmark measurements of noise, reverberation time, and an estimate of speech intelligibility in a representative operating room at Nationwide Children's Hospital in Columbus, Ohio
Authors: Godfrey Richard D. , Feth Lawrence L. , Winch Peter
Published: October 2011

Nationwide Children's Hospital was interested in understanding speech communications: in their operating rooms and between the parents/child and the doctor in pre-operative rooms. Long-term hearing loss of the staff was of secondary interest. Before a comprehensive project was proposed, data in a single OR to gain some experience was conducted. A SLM was programmed to measure the following during 15 s intervals: overall A-weighted equivalent energy sound level, A-weighted equivalent energy sound level in octave bands from 16 to 16 kHz, and peak un-weighted level during the interval. Reverberation was also measured by an impulsive method. Measurements were made for 23 consecutive hours. The data were downloaded for analysis. It was concluded that (1) adding some absorption around the top of the walls would improve SI, (2) good SI is only possible with a high vocal effort, and (3) long term hearing loss is very unlikely. Follow up topics before a comprehensive project is proposed were (1) try other reverberation methods, (2) study more rooms while a variety of surgical procedures are performed, (3) identify the source and duration of peaks levels, and (4) investigate other measures of SI.
Applications of a binaural model with contralateral inhibition in room acoustics analysis
Authors: Perez Timothy , Braasch Jonas , Xiang Ning
Published: October 2011

In many cases the conventional, monophonic measures used in analyzing room acoustics show little agreement with real listeners' responses; a binaural perspective provides much-needed spatial and perceptual information that is important in acoustical quality judgments. Traditionally, binaural models extracted information about location and intensity of sound through a relatively simple cross-correlation procedure. This paradigm was extended by Lindemann [J. Acoust. Soc. Am. 80, 1608–1630 (1986)] with the introduction of a contralateral inhibition process, which applies a time- and intensity-dependent weighting to a pair of binaural signals and accurately reproduces results from psychoacoustical tests where the traditional model fails, such as in the case of the Precedence effect. The model will be used to observe the broadening and splitting of auditory events based on the degree of interaural coherence, providing further validation of its adequacy. Then, applications in architectural acoustics will be investigated by processing binaural room impulse responses and producing a binaural activity pattern, which indicates the location and spatial extent of the resulting auditory events. These will be compared to visualizations drawn from spherical harmonic microphones. Implications of such a model on factors important in acoustical quality assessments, such as apparent source width and listener envelopment, will be discussed.
The audibility of direct sound as a key to measuring the clarity of speech and music
Authors: Griesinger David H.
Published: October 2011

Human ear/brain systems evolved to decode the direction, timbre, and distance of multiple sounds in a complex and noisy environment. In a reverberant space, this information is only available at the onset of a sound, before reflections overwhelm it. But since the time of Sabine acoustic science has concentrated on the decay of sound in a reverberant field, not on the audibility of the onset information. In addition, it is well known that the ability to separate multiple sound sources depends critically on pitch, but acoustic research studies only noise and impulses. This paper proposes that clarity requires the ability to separately analyze multiple sounds (the cocktail party effect) and that the cocktail party effect depends on phase relationships between harmonics of complex tones. These phase relationships are scrambled in predicable ways by reflections and reverberation. Well known properties of human hearing are used to develop both a physical model for the neurology of onset detection and an impulse response measure for localization and clarity in a reverberant field. A C language implementation of the physical model is capable of predicting and perhaps measuring the localizability of individual musicians in a binaural recording of live music.
On Van Holliday's shoulders
Authors: Diachok Orest
Published: October 2011

The year was 1992. The Cold War was over, and funding for resolving deep water issues was fading. I was at the NATO Undersea Research Centre, simultaneously searching for a new research challenge that I could sink my teeth into, and formulating a research program for the Centre, which would be appropriate for the post-Cold War era. I stumbled onto Van's classic paper on resonance scattering by fish, discussed it with him by telephone, and within an hour became a convert to marine bioacoustics. I became familiar with David Weston's work, discussed it with him, and soon thereafter started my research in bioacoustics. Van and David made important contributions to the design of my bioacoustics experiments. After I returned to the USA, I often met with Van to discuss a broad spectrum of fundamental and applied topics in bioacoustics. He was always generous with his time, knowledge, and insights. His explanations of seemingly complex phenomena were always readily understandable, concise, and precise. Standing on Van Holliday's shoulders, greatly expanded my vision of what is possible through technical innovation, interdisciplinary collaboration, dedication, and perseverance. I, along with many others, miss and will continue to miss this amazing and unique individual.
Zooplanktivory of fishes measured with a dual wide band sonar/optical imaging system
Authors: Genin Amatzia , Jaffe Jules , Lindemann Yoav , Roberts Paul , Guttel Yonathan
Published: October 2011

Recent experiments in several near shore habitats in Eilat, Israel, were performed to measure various aspects of predation on zooplankton. Toward this goal, two sets of (4) wide band echo-sounders that can identify echoes from individual sub-millimeter copepods in liter-sized volumes were deployed. The echo sounders were augmented with an underwater optical shadowgraph imaging system that concurrently imaged a 100 ml volume with 25 μm resolution that provided many usable in-situ images of the animals that were producing the acoustic reflections. Sonars were located both upstream and downstream from a group of zooplanktivorous fish, allowing measurement of zooplankton abundance in water parcels before and after they passed through the fish group. Information on fish abundance and movements was obtained with concurrent video records. Together with ancillary environmental measurements of flow rate and light level, zooplanktivory rates of: animals consumed per cubic meter per fish were computed from the differential concentration of animals as inferred from the two sets of four echo-sounders. The results permit the estimate of important environmental features of the ecosystem such as the dependence of predation rate on prey abundance, their size, and flow speed.
Overview of cumulative results of characterization studies of composites
Authors: Tittmann Bernhard R.
Published: October 2011

After an introduction into design concepts of composites, this paper presents a survey of material characterization investigations of a variety of composites ranging from graphite/epoxy, to metal-matrix, to carbon/carbon to CF/PEEK, and to biological material such as plant cell walls. Discussed are the results of a series of studies in anecdotal form, which include the characterization of soft-body impacts with gelatin projectiles as simulation due to bird strike, the healing of impact damage as imaged and followed by increasing temperature (5000 °C) in acoustic microscopy, finite element simulations of embedded piezoelectric element transducers, acoustic shear velocity measurements during the curing of graphite/epoxy; acoustic emissions during carbonization of carbon/carbon by the use of guided wave techniques inside an autoclave; and acoustic microscopy imaging in the characterization of metal-matrix composites. Always a factor is the resolution requirement. At the extreme end of the resolution capability of current instrumentation is the sub-nanometer resolution of the atomic force microscope which has been demonstrated by the imaging of plant cell walls (onion skin), which are a form of nature's composite structure. These topics have given insight into the many facets of problems as well as opportunities for the use of the characterization of composites.
Resonant frequencies of rectangular plates immersed in fluids
Authors: Li Kai Ming
Published: October 2011

The response of a fluid-loaded structure is a subject of considerable interests in many areas of engineering. This includes applications in aerospace industry for composite structures, design of offshore and building structures partially immersed in water, and the design of rectangular micro-plates for bio-sensing devices. For many decades, it has been well recognized that the resonant frequencies of structures in contact with fluid decrease significantly if the fluid-loading on the structure is very heavy. For somewhat lighter fluid-loading, the structural properties are important, and the in vacuo resonant frequencies are usually needed in determining the response due to an external driving force. This paper exploits a simple empirical model to estimate the effect of fluid-loading on the resonant frequency of a rectangular plate. Simple formulas were developed to rapidly compute the natural frequencies of rectangular plates loaded with different fluids on both sides. The rectangular plates with simply supported or clamped edges were considered in the present analysis. Particularly, a square plate with a general boundary condition varying from simply supported to clamped edges was examined. Empirical formulas were derived to calculate the change in the resonant frequencies for baffled plates in all cases.
Acoustic radiation from finite bilaminar submerged plates: Three-dimensional elasticity solution
Authors: Hayek Sabih I. , Boisvert Jeffrey E.
Published: October 2011

The vibration and radiation of a submerged baffled finite rectangular bilaminar plate is obtained analytically using the three-dimensional equations of elasticity. The plate is composed of two perfectly bonded finite layers of identical size. The boundary conditions on the perimeter of the plate are free of shear stresses and pinned on the in-plane displacements. The plate is coupled to acoustic media on both sides and is baffled by an infinite rigid plane. The solution for the vibration response due to normal surface forces is found in terms of the bilaminar plate eigenmodes. The vibratory response and the associated near- and far-field radiated acoustic pressures are computed for various ratios of thickness to plate dimensions over a broad frequency range. [Work supported by the ASEE Summer Faculty Research Program.]
Trans-dimensional strategies for geoacoustic posterior probability estimation
Authors: Dettmer Jan , Dosso Stan E.
Published: October 2011

Choosing appropriate model parametrizations is a fundamental aspect of Bayesian parameter inference. Trans-dimensional inference is based on a hierarchical Bayesian model, where the number of unknowns in the problem is itself unknown. The methodology extends the state-space to the union of subspaces of a group of models of interest. This allows the data to estimate the support for the parametrizations under consideration while accounting for the limited knowledge about the parametrization in the posterior probability density estimate. Algorithms, such as reversible-jump Markov chain Monte Carlo, can be used to sample from the trans-dimensional posterior by proposing and accepting/rejecting dimensional transitions (jumps) according to a generalized Metropolis-Hastings criterion. Several challenges exist for the efficient application of trans-dimensional methods to geoacoustic inference including defining proposal distributions for efficient transitions between dimensions and within dimensions, and specifying (or quantifying) data errors distributions (or statistics). Example1109; of applying the trans-dimensional approach are demonstrated for several geoacoustic inverse problems, using trans-dimensional partition modeling and hierarchical data-error models.
Time-domain finite element modeling of interaction of heterogeneous solids with acoustic waves
Authors: Krysl Petr
Published: October 2011

The vibroacoustic finite element toolkit (VATK) utilizes a Lagrangian finite element method specifically developed for analyzing the interaction of biosolids immersed in fluids with acoustic waves. It employs a superposition principle to separate the incident acoustic wave from the scattered and radiated waves in a displacement-based finite element model. An absorbing boundary condition is applied to the perturbation part of the displacement. Linear constitutive equation allows for inhomogeneous, anisotropic materials, both fluids and solids. Displacement-based finite elements are used for all materials in the computational volume, which can be fluids, solids, and voids in arbitrary combination. Robust performance for materials with limited compressibility is achieved using incompatible-mode brick elements. A centered-difference time-stepping algorithm is formulated to handle general damping accurately and efficiently. The VATK uses a voxel-based modeling scheme for complex geometries. The modeling methodology comes with some challenges. Here we discuss the issues of verification and validation, convergence and error control, and performance of the present technique in application areas for which it was not originally intended. [Work supported by the Office of Naval Research and the Chief of Naval Operations, Environmental Readiness Division.]
New strategies for full-wave simulations of large acoustic models
Authors: Huttunen Tomi
Published: October 2011

The simulation of large acoustic models using conventional low-order finite element or boundary element (BE) methods can be computationally demanding due to the requirement of wavelength dependent mesh density (5-10 elements per wavelength is a typical rule of thumb). A recent improvement of finite element type methods has focused on the efficient parallelization of problems to even thousands of processors. The discontinuous Galerkin (DG) methods, in time- and frequency-domain, have been particularly popular since DG methods retain the geometric flexibility of FE methods while allowing a more flexible choice of basis functions. The locality of DG basis makes them ideal for large-scale parallelization and the choice of basis can be easily extended to non-polynomial functions such as plane waves or Bessel functions. This study focuses on the three new strategies for solving large acoustic problems. First, the non-polynomial basis functions are used with the DG method in frequency-domain problems. Second, from element to element varying polynomial order is used for the wave equation in the time-domain. And third, cloud computing is utilized for efficient resource allocation with a fast multipole BE method for the acoustic Helmholtz equation.