bluuebunny/crossref_metadata_2025 huggingface dataset:
Sleep apnea as a comorbidity in obese psoriasis patients: a cross‐sectional study. Do psoriasis characteristics and metabolic parameters play a role?
Authors: Papadavid E. , Vlami K. , Dalamaga M. , Giatrakou S. , Theodoropoulos K. , Gyftopoulos S. , Stavrianeas N. , Papiris S. , Rigopoulos D.
Published: May 2012

Background  Psoriasis is associated with a variety of comorbidities such as obesity and cardiovascular disease.

Objective  In a cross‐sectional study, we explored whether obstructive sleep apnea and hypopnea syndrome (OSAHS) is associated with psoriasis characteristics and metabolic parameters.

Methods  Thirty‐five patients with chronic plaque psoriasis underwent a nocturnal polysomnography study and were analysed for Apnoea–Hypopnoea Index to assess OSAHS severity and Framigham score to predict the absolute risk of coronary artery disease at 10 years. The association of OSAHS with psoriasis was examined according to psoriasis characteristics (PASI and DLQI scores, disease duration and previous use of systemic treatments), metabolic parameters (Body Mass Index – BMI, waist to hip ratio – WHR, lipid profile) and other comorbidities (obesity, hypertension, arthritis and cardiovascular disease).

Results  There was no correlation between psoriasis characteristics and OSAHS. Psoriasis patients with OSAHS presented more frequent snoring and lower sleep quality compared with those without OSAHS. In univariate analyses, OSAHS was associated with increased BMI and hypertension in psoriasis patients. In multivariable logistic regression models, there was statistically significant evidence that only BMI and hypertension were associated with increased risk of OSAHS, adjusting for psoriasis characteristics, age and gender. Presence of metabolic syndrome, WHR, and smoking were not significant risk factors for OSAHS. In subgroup analyses, OSAHS correlated with duration of psoriasis (>8 years) in women (P = 0.021) and with Framigham score in men (P = 0.035).

Conclusion  OSAHS may be a comorbidity in obese psoriasis patients with hypertension. Treatment with continuous positive airway pressure and weight loss interventions should be initiated.
An autoethnographic approach to understanding Asperger's syndrome: a personal exploration of self‐identity through reflexive narratives
Authors: Hughes Paul
Published: May 2012

Accessible Summary

This article discusses how conceptual frameworks may be used to cope with Asperger's syndrome from a personal point of view.

The work encourages those with Asperger's syndrome to view the self in symbolic interactionism terms in which part of the self is projected as a thought out, projected self through reflective consideration of the ‘Other’.

Symbolic interactionism describes the way we act in social situations based on our interpretations of how we think others see us. Understanding the ‘self’ in symbolic interactionism terms can help us engage more effectively with the scenarios in which we find ourselves.

The work makes use of autoethnography, described as using autobiographical personal experiences to explore aspects of one's own life, to reflect on (i) personal journal narratives and (ii) experiences of school communication classes to help understand the Asperger's self in social situations.

This article makes use of autoethnography in which I, as researcher, explore my own awareness of Asperger's syndrome and how this, in turn, has helped me deal with many day to day situations I have encountered. The work illustrates how actively engaging with one's own life story narratives can help the Asperger's learner come to terms with his or her Asperger's self. The work makes use of symbolic interactionism to construct an outward image of the self and then use this projection to play out and engage with the social situations one encounters.

The article begins with a brief biographic picture of stages of my school and college journey. This places the work in context. It then discusses the autoethnography approach I use to examine aspects of myself, and how symbolic interactionism provides a framework with which to explore social action in the learning context. Examples from personal journals are used to illustrate aspects of my quest to understand the nature and essence of my Asperger's self.
Having friends – they help you when you are stuck from money, friends and making ends meet research group
Authors:   The Money, Friends and Making Ends Meet Research Group c/o Liz Tilly
Published: May 2012

Accessible Summary

We are people who do not get support from services and we have been doing some research about our lives, so we can share our stories about ‘money, friends and making ends meet’ with other people. We find it is hard to make ends meet and we do not know many people outside of our friends and family groups but we have each other, families and local groups such as churches for help and support.

This article is about the lived experiences and friendships of a small group of people with a learning disability who live without support in one of the most deprived areas in the UK. The findings are from an inclusive research project, that was named Money, Friends and Making Ends Meet and the participants who researched their own lives become known as the Money, Friends and Making Ends Meet research group. The group all experienced poverty, had limited social networks, many of whom are other people with a learning disability but did value the support they had from friends and family and local organisations.
Mechanisms of tracheal filling in insects
Authors: Förster Thomas D. , Woods H. Arthur
Published: May 2012

Insects exchange respiratory gases primarily using tracheal systems that are filled with gas. However, in different developmental and environmental circumstances, liquid can occupy the tracheal system, which can significantly impair its respiratory function. Insects therefore use a suite of mechanisms for tracheal filling, which is the process of replacing tracheal liquids with gas. We review these mechanisms for liquid removal and gas filling. By integrating recent molecular work with older physiological literature, we show that liquid removal likely involves active ion transport in the whole tracheal system. Gas filling reveals fascinating interactions between geometry, surface chemistry of the tracheal walls, the tracheal liquid, and dissolved gases. The temporal proximity to moulting allows for potentially complex interdependencies between gas filling, moult‐associated hormone signaling, and cuticle sclerotization. We propose a mechanistic model for tracheal filling. However, because the composition of the liquid is unknown, it remains hypothetical.
Discrepancies between elderly patient’s self‐reported and prescribed medications: a social investigation
Authors: Yasein Nada A. , Barghouti Farihan F. , Irshaid Yacoub M. , Suleiman Ahmad A.
Published: May 2012

Scand J Caring Sci; 2013; 27; 131–138

Discrepancies between elderly patient’s self‐reported and prescribed medications: a social investigation

Aims:  To study some characteristics of the elderly people attending the family practice clinic at the Jordan University Hospital (JUH) and to evaluate their knowledge of the prescribed drugs.

Methods:  A total of 400 elderly people (180 men and 220 women) aged 71 ± 5.8 years were studied regarding sociodemographic characteristics and the use of medicinal and nonmedicinal remedies. In addition, agreement between self‐reported drug information and information taken from the medical records was also evaluated.

Findings:  Almost one‐third of the patients had full agreement between their knowledge of total number of drugs they take and the numbers found in the medical records, whereas 43.4% underestimated and 21.8% overestimated these numbers. Five drugs/classes were accurately estimated by the patient (methyldopa, ezetimibe, warfarin, statins and antigout drugs). Underestimation was noticed in 17 drugs/classes and overestimation in 14. The significantly underestimated drug classes were biphoshponates, proton pump inhibitors, sulfonylureas and antiepileptic drugs.

Conclusion:  Some aspects of elderly people were evaluated regarding their medication knowledge. Almost two‐third of the patients did not take their drugs in the proper way. The results of the study highlight the importance of taking several actions by all healthcare workers and by the community to optimise health care provided for elderly people.
Paying for interviews? Negotiating ethics, power and expectation
Authors: Hammett Daniel , Sporton Deborah
Published: May 2012

The ethical dilemma of payment or compensation for participation in research remains a core concern for many scholars. Field class teaching is not exempt from these dilemmas and can provide subtly different challenges than those faced by the lone researcher, not least for work within the global South. Through reflections on two field class visits to Kenya, this paper explores issues of reciprocity, communication, trust, power and precedent in the negotiation of payment for participation. Critical reflections identify a number of weaknesses in the decisions made during field classes that are used to highlight the need to recognise and negotiate the tensions between collective and individual ethical negotiations within the context of conducting ethical research within a field class context.
A case for gender equity in governance of the Okavango Delta fisheries in Botswana
Authors: Ngwenya Barbara Ntombi , Mosepele Ketlhatlogile Keta , Magole Lapologang
Published: May 2012

Fish is a major source of livelihood for the majority of people living around the Okavango Delta in northwestern Botswana. Gender dynamics and governance regimes determine differential access to, and control of, resources between women and men in the area. The purpose of this case study is to critically assess the embeddedness of gendered inequities in the governance of Okavango Delta fishery. Primary data was collected through focus group discussions and face‐to‐face interviews of 96 basket fishers from five villages along the Panhandle area of the Okavango River. The study found that past and present Okavango Delta fishery policy and programme interventions tended to entrench rather than minimize gendered disparities between women and men fishers' access to and control over fish resources, asset accumulation and employment opportunities. Basket fishers have intimate knowledge of flood variability, fish migration and habitat and use this knowledge to make decisions about when and where to harvest what fish species. Women fishers' ecological knowledge, interests and concerns however, have been excluded from current zoning and closed season regulations and co‐management structures. The paper concludes that past and current development interventions as well as the regulatory framework continue to entrench pre‐existing gender relations in the fishery sector which excludes, disempowers and marginalizes women fishers. We recommend innovative co‐management and local based structures which recognize the diversity of interests and interest groups.
Water security: Old concepts, new package, what value?
Authors: Lautze Jonathan , Manthrithilake Herath
Published: May 2012

“Water security” has come to infiltrate prominent discourse in the international water and development community, and achieving it is often viewed as a new water sector target. Despite the elevated status that the concept has increasingly acquired, understandings of the term are murky and quantification is rare. To promote a more tangible understanding of the concept, this paper develops an index for evaluating water security at a country level. The index is comprised of indicators in five components considered to be critical to the concept: (i) basic needs; (ii) agricultural production; (iii) the environment; (iv) risk management; and (v) independence. Achieving water security in these components can be considered necessary but insufficient criteria to measure the achievement of security in related areas such as health, livelihoods, and industry. After populating indicators with data from Asia‐Pacific countries, results are interpreted and the viability of methods is discussed. This effort comprises an important first step for quantifying and assessing water security across countries, which should spur more concrete understanding of the term and discussion of its added value.
Defect Structure of Flash‐Sintered Strontium Titanate
Authors: Karakuscu Aylin , Cologna Marco , Yarotski Dmitry , Won Jonghan , Francis John S. C. , Raj Rishi , Uberuaga Blas P.
Published: May 2012

Flash sintering of strontium titanate (SrTiO3) is studied at different applied fields to understand its effect on density and grain growth. In particular, the defect structure is investigated by optical and structural analysis. SrTiO3 exhibited a trend in densification opposite that of ionically or electronically conductive ceramics: as the applied voltage decreased, the density increased. Abnormal grain growth in conventionally sintered SrTiO3 is arrested by flash sintering. Interestingly, undoped SrTiO3 behaved differently than undoped Al2O3, which did not exhibit any signs of flash sintering. Previous attempts at flash sintering could only be achieved in MgO‐doped Al2O3. We believe that non‐stoichiometric Ruddlesden‐Popper phases in SrTiO3, as indicated by ultrafast optical spectroscopy, X‐ray diffraction, conductivity measurements, and transmission electron microscopy, assist flash sintering by increasing local conductivity through enhanced defect content.
The Optimal Combination of Cartilage Source and Apparatus for Long‐TermIn VitroChondrocyte Viability Analysis
Authors: Alibegović Armin , Balažic Jože , Petrovič Danijel , Velikonja Nevenka Kregar , Blagus Rok , Šuput Dušan , Drobnič Matej
Published: May 2012

Abstract: Most studies of long‐term chondrocytes survival were for tissue banks. They showed a gradual reduction in the viable chondrocytes percentage as a function of time and ambient temperature, but the samples were harvested under optimal conditions. The aim of our study was to determine the most reliable combination of cartilage source and assay for thein vitropostmortem chondrocyte viability analysis in the conditions that imitate a dead body. Osteochondral cylinders were procured from femoral condyles and talar trochleas of three male donors and stored in the cell culture media at 4 ± 2°C and 23 ± 2°C. The samples were analyzed by a cell viability analyzer and a confocal laser scanning microscope (CLSM) initially 24–36 h after death and then in 4‐week intervals. The results reconfirmed the significant influence of time (p = 0.0002), but not of the temperature (p = 0.237). The largest reproducibility was presented for the knee joint and the CLSM.
Opening the Doors to the WTO Dispute Settlement: State Preferences on NGO Access as Amici
Authors: Squatrito Theresa
Published: May 2012

Abstract:  Greater access and inclusion of civil society is a possible means of increasing participation in international governing processes and thus enhancing the democratic legitimacy of global governance. Yet, opening the doors of an international organization to civil society is often controversial. At the core of such controversies are costs and benefits that may arise from the inclusion of civil society. The aim of this article is to explore the opening of international organizations’ doors to civil society actors, emphasizing state’s preferences. To explore state preferences on civil society’s access, this article looks at the WTO dispute settlement process and amici submissions, and asks: what factors shape states’ preferences to allow civil society actors access? Drawing from a unique dataset on state preferences on amici submissions to the WTO’s dispute settlement process, I argue that state preferences are shaped by the capacity to manage costs of civil society access.
Investigation of actual daily lifestyle leading to continuous self‐management after living‐donor liver transplantation: More than 5 years living with living‐donor liver transplantation and emotions of recipients
Authors: AKAZAWA Chiharu , NISHIZONO Teiko , YAMAMOTO Masae , TERAGUCHI Sayoko , HAYASHI Yuko
Published: May 2012

Aim:  This research aimed to investigate the actual daily lifestyle leading to continuous self‐management after living‐donor liver transplantation (LDLT), by interviewing more than 5 year survivors of transplantation on their lifestyles from various angles, such as meals, rests, and human relationships.

Method:  In this research, survivors of more than 5 years were interviewed about their daily lifestyle, and a qualitative inductive approach to the analysis of continuous self‐management was taken.

Results:  Interviews were conducted with 26 patients: 11 men and 15 women with an average age of 49 years (range, 22–76). Through analysis, 205 labels were extracted, which were aggregated into one core category, 13 categories and 68 subcategories. Differences in the three patterns of lifestyle –“the reflected lifestyle after operation”, “unchanged daily lifestyle”, and “self‐management eases along with recovery”– occurred owing to differences in changes in values through the transplantation experience. The changes in values were affected by realization of the experience and the action, which come from various internal and external influences during the process of recovery. All of the recipients used consulting behavior to complement self‐management after leaving hospital.

Conclusion:  The daily lifestyle of transplant recipients was clarified by the patterns of lifestyle. Differences in the three lifestyle types occurred owing to differences in changes in values though the transplantation experience.
Influence of Sildenafil on Genital Engorgement in Women with Female Sexual Arousal Disorder
Authors: Leddy Laura S. , Yang Claire C. , Stuckey Bronwyn G. , Sudworth Maria , Haughie Scott , Sultana Stefan , Maravilla Kenneth R.
Published: May 2012

Introduction

We previously described dynamic, noncontrast magnetic resonance imaging (MRI) of the female genitalia as a reproducible, nonintrusive, objective means of quantifying sexual arousal response in women without sexual difficulties. These studies showed an increase in clitoral engorgement ranging from 50 to 300% in healthy women during sexual arousal.

Aim

This study sought to evaluate the genital arousal response in women with female sexual arousal disorder (FSAD) after administration of sildenafil and placebo. We performed a multicenter, double-blind, placebo-controlled, cross-over study to assess the clitoral engorgement response using dynamic MRI in women with FSAD after administering sildenafil and placebo followed by audiovisual sexual stimulation (AVSS).

Methods

Nineteen premenopausal women with FSAD underwent two MRI sessions. Subjects were randomized to receive either (i) sildenafil 100 mg during the first session followed by placebo during the second session, or (ii) placebo followed by sildenafil. During each session, baseline MR images were obtained while subjects viewed a neutral video. Subjects then ingested sildenafil or placebo. After 30 minutes, a series of MRIs were obtained at 3-minute intervals for 10 time points while subjects viewed AVSS.

Main Outcome Measures

A positive sexual arousal response was achieved if clitoral volume increased ≥50% from baseline.

Results

Thirteen of 19 (68%) subjects achieved a ≥50% increase in clitoral engorgement from baseline when administered sildenafil or placebo 30 minutes after dose administration. At 60 minutes after administration, 17/19 (89%) subjects receiving sildenafil and 16/19 (84%) subjects receiving placebo had responded (P value 0.3173).

Conclusions

Sildenafil did not augment the genital response in women with FSAD. Secondarily, a majority of women in this study did not have impaired clitoral engorgement as measured by MRI, suggesting that FSAD is not predominantly a disorder of genital engorgement.
Adaptive strategies of overwintering adults: Reproductive diapause and mating behavior in a grasshopper, Stenocatantops splendens (Orthoptera: Catantopidae)
Authors: Zhu Dao‐Hong , Cui Shuang‐Shuang , Fan Yong‐Sheng , Liu Zhiwei
Published: May 2012

Abstract  To understand the adaptive strategies of the overwintering adults of Stenocatantops splendens, the mechanism of maintenance and termination of the reproductive diapause, the variation in mortality between overwintering females and males, and the mating strategy of the males were investigated. The results indicated that the adult reproductive diapause in natural conditions was mainly regulated by photoperiod in the fall – long photoperiods promoted reproductive development and short photoperiods maintained reproductive diapause, and the sensitivity of the overwintering adults to photoperiod was over before the end of the winter. When transferred from natural conditions to controlled laboratory conditions on dates from September through February, pre‐oviposition became increasingly shorter with increasingly deferred transfer dates regardless of photoperiod conditions. The adults treated with low temperature for 30 days in September through November had significantly shorter pre‐oviposition, suggesting that low temperatures in winter had an important role in the termination of reproductive diapause. The female had a significantly lower supercooling point than the male, which was related to their lower mortality after winter. In addition, observations of wild populations of the species indicated that mating behavior prior to winter and the duration of pre‐mating period were not affected by photoperiod; mating and sperm transfer were mostly completed by November. Compared with females only mating before winter, females mating in the spring had shorter life span, longer pre‐oviposition, lower hatching rate and laid fewer egg pods while showing no significant difference with regard to ovipositional interval, per pod number of eggs and nymph dry weight.
Irlen Colored Filters in the Classroom: A 1‐Year Follow‐Up
Authors: Ritchie Stuart J. , Della Sala Sergio , McIntosh Robert D.
Published: May 2012

Colored filters are used to treat Irlen syndrome (IS), a controversial disorder posited to be the cause of a substantial proportion of reading difficulties. Previously, we found that Irlen colored filters do not produce any short‐term alleviation of reading difficulties in schoolchildren aged 7–12. Here, we tested whether colored filters show benefits with longer‐term use, in a subset of the original sample. We measured reading rate with and without filters in 18 children diagnosed with IS, who had been using the filters for 1 year, and compared the progression of their reading ability across the year against 10 poor‐reader control children. The Irlen‐treatment group did not read any faster when using their colored filter, and showed no disproportionate gain in reading progress across the year compared to controls. We conclude that Irlen filters do not benefit reading, even after 1 year of use.
Clinical evaluation of diamine silver fluoride/potassium iodide as a dentine desensitizing agent. A pilot study
Authors: Craig GG , Knight GM , McIntyre JM
Published: May 2012

Background:  The aim of the present study was to compare the efficacy of an experimental diamine silver fluoride/potassium iodide product with an oxalic acid‐based preparation in reducing dentine hypersensitivity.

Methods:  The study was conducted as a double‐blind, randomized clinical trial. A total of 19 subjects with dentine hypersensitivity on both sides of their upper arch were selected. The most sensitive tooth in each quadrant was identified and received a cold stimulus. The response was recorded on a visual analogue scale (VAS). The tooth thus selected was treated with one of the treatment agents. One week later the level of dentine sensitivity was assessed. Participants were also asked for their subjective assessment of treatment effects.

Results:  The mean difference between VAS at baseline and seven days for teeth treated with diamine silver fluoride/potassium iodide was greater than that for teeth treated with the oxalic acid‐based preparation (p = 0.0134). The subjects’ subjective assessment of changes in dentine hypersensitivity indicated that more obtained relief with the diamine silver fluoride/potassium iodide treatment (p = 0.0129).

Conclusions:  It was concluded that an experimental diamine silver fluoride/potassium iodide product has potential as a treatment for dentine hypersensitivity.
Reactivity of nonsteroidal anti-inflammatory drugs with peroxidase: a classification of nonsteroidal anti-inflammatory drugs
Authors: Miura Toshiaki
Published: May 2012

Objectives

To improve understanding of the essential effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on prostaglandin H synthase (PGHS), the reactivity of NSAIDs with peroxidases and the tyrosyl radical derived from myoglobin was examined.

Methods

Horseradish peroxidase and myoglobin were used as models of peroxidase and cyclooxygenase of PGHS, respectively.

Key findings

From the results, a new classification of NSAIDs has been proposed. Class 1 includes the majority of NSAIDs, which reacted with horseradish peroxidase compound I, thus causing a spectral change by PGHS peroxidase and also including diminished electron spin resonance signals of the tyrosyl radical of myoglobin. They reduced compound I of horseradish peroxidase and scavenged the tyrosyl radical. The branched-chain mechanism by which the porphyrin radical is transferred to the tyrosine residue of the protein might be blocked by these NSAIDs. Class 2 includes salicylic acid derivatives that reacted only with the porphyrin radical and not with horseradish peroxidase compound II (oxoferryl species). Class 3 includes aspirin, nimesulide, tolmetin, and arylpropionic acid derivatives, including ibuprofen and the coxibs of celecoxib and rofecoxib, which are not substrates for horseradish peroxidase or PGHS peroxidase.

Conclusions

Understanding the essential mode of action of NSAIDs is particularly important for designing an effective therapeutic strategy against inflammatory diseases.
The Use of Perforated Damping Liners in Aero Gas Turbine Combustion Systems
Authors: Rupp Jochen , Carrotte Jon , Macquisten Michael
Published: May 2012

This paper considers the use of perforated porous liners for the absorption of acoustic energy within aero style gas turbine combustion systems. The overall combustion system pressure drop means that the porous liner (or “damping skin”) is typically combined with a metering skin. This enables most of the mean pressure drop, across the flame tube, to occur across the metering skin with the porous liner being exposed to a much smaller pressure drop. In this way porous liners can potentially be designed to provide significant levels of acoustic damping, but other requirements (e.g., cooling, available space envelope, etc) must also be considered as part of this design process. A passive damper assembly was incorporated within an experimental isothermal facility that simulated an aero-engine style flame tube geometry. The damper was therefore exposed to the complex flow field present within an engine environment (e.g., swirling efflux from a fuel injector, coolant film passing across the damper surface, etc.). In addition, plane acoustic waves were generated using loudspeakers so that the flow field was subjected to unsteady pressure fluctuations. This enabled the performance of the damper, in terms of its ability to absorb acoustic energy, to be evaluated. To complement the experimental investigation a simplified one-dimensional (1D) analytical model was also developed and validated against the experimental results. In this way not only was the performance of the acoustic damper evaluated, but also the fundamental processes responsible for this measured performance could be identified. Furthermore, the validated analytical model also enabled a wide range of damping geometry to be assessed for a range of operating conditions. In this way damper geometry can be optimized (e.g., for a given space envelope) while the onset of nonlinear absorption (and hence the potential to ingest hot gas) can also be identified.
Influence of Film Cooling Unsteadiness on Turbine Blade Leading Edge Heat Flux
Authors: Rutledge James L. , King Paul I. , Rivir Richard B.
Published: May 2012

Film cooling in the hot gas path of a gas turbine engine can protect components from the high temperature main flow, but it generally increases the heat transfer coefficient h partially offsetting the benefits in reduced adiabatic wall temperature. We are thus interested in adiabatic effectiveness η and h which are combined in a formulation called net heat flux reduction (NHFR). Unsteadiness in coolant flow may arise due to inherent unsteadiness in the external flow or be intentionally introduced for flow control. In previous work it has been suggested that pulsed cooling flow may, in fact, offer benefits over steady blowing in either improving NHFR or reducing the mass flow requirements for matched NHFR. In this paper we examine this hypothesis for a range of steady and pulsed blowing conditions. We use a new experimental technique to analyze unsteady film cooling on a semicircular cylinder simulating the leading edge of a turbine blade. The average NHFR with pulsed and steady film cooling is measured and compared for a single coolant hole located 21.5° downstream from the leading edge stagnation line, angled 20° to the surface and 90° to the streamwise direction. We show that for moderate blowing ratios at blade passing frequencies, steady film flow yields better NHFR. At higher coolant flow rates beyond the optimum steady blowing ratio, however, pulsed film cooling can be advantageous. We present and demonstrate a prediction technique for unsteady blowing at frequencies similar to the blade passing frequency that only requires the knowledge of steady flow behavior. With this important result, it is possible to predict when pulsing would be beneficial or detrimental.
An Experimental and Modeling-Based Study Into the Ignition Delay Characteristics of Diesel Surrogate Binary Blend Fuels
Authors: Carr Matthew A. , Caton Patrick A. , Hamilton Leonard J. , Cowart Jim S. , Mehl Marco , Pitz William J.
Published: May 2012

This study examines the combustion characteristics of a binary mixture surrogate for possible future diesel fuels using both a single-cylinder research engine and a homogeneous reactor model using detailed chemical reaction kinetics. Binary mixtures of a normal straight-chain alkane (pure n-hexadecane, also known as n-cetane, C16H34) and an alkyl aromatic (toluene, C7H8) were tested in a single-cylinder research engine. Pure n-hexadecane was tested as a baseline reference, followed by 50%, 70%, and 80% toluene in hexadecane blends. Testing was conducted at fixed engine speed and constant indicated load. As references, two conventional petroleum-based fuels (commercial diesel and U.S. Navy JP-5 jet fuel) and five synthetic Fischer-Tropsch-based fuels were also tested. The ignition delay of the binary mixture surrogate increased with increasing toluene fraction and ranged from approximately 1.3 ms (pure hexadecane) to 3.0 ms (80% toluene in hexadecane). While ignition delay changed substantially, the location of 50% mass fraction burned did not change as significantly due to a simultaneous change in the premixed combustion fraction. Detailed chemical reaction rate modeling using a constant pressure, adiabatic, homogeneous reactor model predicts a chemical ignition delay with a similar trend to the experimental results but shorter overall magnitude. The difference between this predicted homogeneous chemical ignition delay and the experimentally observed ignition delay is defined as the physical ignition delay due to processes such as spray formation, entrainment, mixing, and vaporization. On a relative basis, the addition of 70% toluene to hexadecane causes a nearly identical relative increase in both physical and chemical ignition delay of approximately 50%. The chemical kinetic model predicts that, even though the addition of toluene delays the global onset of ignition, the initial production of reactive precursors such as HO2 and H2O2 may be faster with toluene due to the weakly bound methyl group. However, this initial production is insufficient to lead to wide-scale chain branching and ignition. The model predicts that the straight-chain alkane component (hexadecane) ignites first, causing the aromatic component to be consumed shortly thereafter. Greater ignition delay observed with the high toluene fraction blends is due to consumption of OH radicals by toluene. Overall, the detailed kinetic model captures the experimentally observed trends well and may be able to provide insight as to the relationship between bulk properties and physical ignition delay.
The Effects of Fuel Characteristics on Stoichiometric Spark-Assisted HCCI
Authors: Weall Adam J. , Szybist James P.
Published: May 2012

The characteristics of fuel lean homogeneous charge compression ignition (HCCI) operation using a variety of fuels are well known and have been demonstrated using different engine concepts in the past. In contrast, stoichiometric operation of HCCI is less well documented. Recent studies have highlighted the benefits of operating at a stoichiometric condition in terms of load expansion combined with the applicability of three way catalyst technology to reduce NOx emissions. In this study the characterization of stoichiometric HCCI using gasoline-like fuels was undertaken. The fuels investigated are gasoline, a 50% volume blend of iso-butanol and gasoline (IB50), and an 85% volume blend of ethanol and gasoline (E85). A single cylinder engine operating with direct injection (DI) and spark assist combined with a fully variable hydraulic valve actuation system allowed a wide range of operating parameters to be studied. The resultant fuel properties, which differed in terms of octane rating, fuel oxygenation, and heat of vaporization, show that stoichiometric HCCI is possible using a range of fuels but that these fuel characteristics do have some effect on the combustion characteristics. How these fuel properties can enable an increased engine operating envelope to be achieved, in comparison with both fuel lean HCCI and conventional spark ignited combustion, is then discussed.
Thermophysical Phenomena Associated With Nano-Droplet Impingement on a Solid Surface
Authors: Haas Geoffrey M. , Wemhoff Aaron P.
Published: May 2012

The thermophysical properties pertaining to the impingement of a nano-droplet onto a solid surface were investigated using molecular dynamics (MD) simulations. The MD simulations used data collection for an entire group of molecules to investigate the propagation of energy in the system. Simulations of a moving nano-droplet colliding with a stationary solid were performed to determine the heat transfer between the droplet and the surface. It was discovered that the droplet-substrate collision caused the droplet temperature to rise significantly upon impact. The substrate also experiences a temperature jump with a slower response time. A theoretical relation for the substrate temperature jump is also developed that shows reasonable agreement with the MD simulations for small droplet diameters. Increasing the diameter of the droplet from 2.0 nm to 4.5 nm showed a gain in the total added substrate kinetic energy. Varying the initial speed of the droplet from 10 m/s to 40 m/s showed no significant difference in the applied kinetic energy onto the substrate, suggesting that the acceleration of the droplet toward the surface due to intermolecular interactions produces an impact speed relatively independent of the initial droplet bulk speed. These trends were also reflected in a thermodynamically based simple theoretical prediction of collision energy, which was shown to be accurate for droplet diameters up to 3.5 nm. The collision energy was estimated to be on the order of 1–10 eV, and the applied heat flux is on the order of GW/m2.
Real-time measurements of plasma photoresist modifications: The role of plasma vacuum ultraviolet radiation and ions
Authors: Weilnboeck F. , Kumar N. , Oehrlein G. S. , Chung T.-Y. , Graves D. , Li M. , Hudson E. A. , Benck E. C.
Published: May 2012

Plasma-induced roughness development of photoresist (PR) can be due to synergistic interactions of surface modifications introduced by ions, bulk material modifications by ultraviolet (UV)/vacuum ultraviolet (VUV) radiation, and increased temperature. While previous work identified the individual contributions of energetic ions and UV/VUV radiation, the dynamics of the concurrent modifications remained unclear. The authors studied the interactions of plasma radiation and ions with 193 nm PR and 248 nm PR in Ar plasma by in situ ellipsometry. Ellipsometry provides valuable information on changes in film thickness and material optical properties in real-time during plasma processing. MgF2, sapphire, and glass optical filters were used to reduce the plasma-material interactions to the radiation component of a selected wavelength range in the UV/VUV spectral region. Ar plasma radiation and its transmission through different optical filters were characterized by VUV spectroscopy. This characterization allowed for the identification of the relative contribution of specific wavelength ranges to the overall material modification in direct plasmas. Exposure of 193 nm PR to plasma UV/VUV radiation led to film thickness reduction and an increase in the refractive index (Ñ) which was enhanced for shorter wavelengths. For direct plasma exposure at low maximum ion energy (Eion ≤ 25 eV), radiation effects dominated and bulk material modifications saturated after ≈30 s. By comparison, for 248 nm PR film thickness reduction and increase of Ñ were modest and were only seen for UV/VUV exposure with wavelength lower than 142 nm. Both material surfaces remained relatively smooth during 60 s exposure to plasma radiation (0.3–0.6 nm RMS roughness) independent of radiation wavelengths used. For direct Ar plasma exposure involving energetic ion bombardment (Eion ≤ 125 eV), a graphitic surface layer was established within 3–5 s. During this time period ≈30% of the saturation UV/VUV modification in the material bulk of 193 nm PR were reached, which corresponds to a 60 nm thick soft layer underneath the ion crust. For 248 nm PR less than 20% of the bulk material modification that were established in 60 s were reached during formation of the ion-crust. This corresponds to a ≈4 nm thick hard layer underneath the ion-modified surface. This shows that for 193 nm PR, bulk material modifications by plasma UV/VUV radiation were fast and contributed significantly to the overall material modification in the first seconds of plasma exposure, whereas UV/VUV modifications of 248 nm PR were slow and small. This material specific difference in the dynamics of material modification was in good agreement with 193 nm PR developing much higher surface roughness (≈6.0 nm) than 248 nm PR (≈1.6 nm) during 60 s exposure to plasma exposures involving both UV/VUV radiation and energetic ion bombardment.
Oxidation resistance of quintuple Ti-Al-Si-C-N coatings and associated mechanism
Authors: Wu Guizhi , Ma Shengli , Xu Kewei , Ji Vincent , Chu Paul K.
Published: May 2012

The oxidation behavior of Ti-Al-Si-C-N hard coatings with different Al contents deposited on high-speed steel and Si substrates by hybrid arc-enhanced magnetron sputtering is investigated in the temperature range of 500 °C–1000 °C. The coating hardness is maintained at around 35 GPa, and the parabolic oxidation rate constant Kp at 1000 °C decreases to 3.36 × 10−10 kg2 m−4 s−1 when the Al concentration is increased to 30 at. %, indicating that Ti-Al-Si-C-N coatings with larger Al concentrations have better oxidation resistance. X-ray diffraction, cross-sectional scanning electron microscopy, and x-ray photoelectron spectroscopy reveal a protective surface layer consisting of Al2O3, TiO2, and SiO2 that retards inward oxygen diffusion. A mechanism is proposed to elucidate the oxide formation. As a consequence of the good oxidation resistance, the Ti-Al-Si-C-N coatings have a large potential in high-speed dry cutting as well as other high temperature applications.
The Motor Organization of Some Speech Gestures
Authors: Bell-Berti Fredericka , Harris Katherine Safford
Published: May 2012

EMG recordings from several muscles controlling tongue body movement for various VCV and VCCV utterances were examined to uncover the factors influencing the extent and direction of the coarticulatory reorganization of motor commands for speech gestures, and to reveal physiological correlates of syllable boundaries. The primary determiner of the direction of the reorganization appears to be the individual muscle's function in increasing or decreasing vocal tract constriction (closure and release). Muscles producing greater constrictions show anticipatory coarticulation while those producing greater openings show postcipatory coarticulation. Since consonants are produced with greater vocal tract constriction than are vowels, they limit the extent and direction of coarticulation. Thus, reorganization at the motor command level is shown for both anticipatory and postcipatory coarticulation. Syllabic units appear as VC sequences for muscles constricting the vocal tract and CV sequences for muscles expanding the vocal tract. [Supported by NIDR Grant DE01774.]
Factors Underlying the Articulatory and Acoustic Structure of Vowels
Authors: Harskman Richard , Ladefoged Peter , Goldstein Louis , DeClark Joseph
Published: May 2012

Three-mode (PARAFAC1) factor analysis was performed on the tongue shapes and mel formant values of ten English vowels as spoken by five subjects. Vocal tract cross-dimensions were measured from cine x rays, along lines perpendicular to the midline of the tract and spaced equidistantly at approximately 1-cm intervals. Deviations from “neutral” average-vowel values were computed for both formants and cross-dimensions. Only two factors were found, and these accounted for roughly 90% of the articulatory and 95% of the acoustic data variance. Factor 1 produces a predominately antisymmetric perturbation of the vocal tract and thus would have a greater acoustic effect on the unrounded vowels (since their vocal tract termination impedance is lower). It presumably is due to the position of the jaw and action of the genioglossus muscle. It mainly affects the second formant. Factor 2 is both less stable across analyses and less clearly defined. It produces a mainly symmetric perturbation and would thus be more effective during rounded vowels. It can be interpreted as resulting in part from the action of the styloglossus muscle. It affects both formant frequencies. PARAFAC1 analysis of formant data for Swedish, Danish, and Twi vowels shows similar factors, indicating a consistent pattern of interpersan variations along these two dimensions.
Introduction by Chairman
Authors: Siddon T. E.
Published: May 2012

A brief comment on the intended objectives of the session.
Cross-Correlation Analysis in Resonant Systems
Authors: Price A. J. , Wakefield C. W.
Published: May 2012

Cross-correlation analysis offers an opportunity to examine and possibly identify multiple acoustic transmission paths in building spaces and structures. Such paths might occur, for example, in the acoustic and structural transmission of energy between a pair of adjacent rooms. However, cross correlation between the outputs of a pair of transducers in a highly resonant system, such as a reverberant room or a structural element, often results in a correlogram exhibiting the system's strongest resonant modes rather than yielding useful time domain information on the separation of parallel transmission paths. In some such cases this model correlation effect can be eliminated by replacing the delayed transducer signal with the signal delivered directly to the system's excitation source. Once a transmission path has been so identified, its transfer function may then often be established by Fourier transformation. The limitations and possible sources of error involved in the use of this method are discussed, together with several practical examples of its application.
Binaural Interaction in Cat and Man. I. Signal Detection Lind Noise Cross Correlation
Authors: Langford Ted L. , Hoppe Susan A.
Published: May 2012

Theories of binaural hearing are usually based on human psychophysical data, while attempts to relate theory to physiology utilize data obtained primarily from the cat. In an attempt to better relate the two, a series of behavioral experiments is being conducted. The present study is addressed to the question of the time limits for binaural interaction in the cat as measured by the detection of tonal signals in a noise background. The signal was a 500-Hz tone, 1.5 sec in duration, and was always presented in phase. The interaural correlation of the noise was varied by delaying the noise to the right ear in steps of 1 msec from 0 to 5 msec. The signal and noise were presented to the animal by means of transducers held in place by leather helmets [Robinson and Wakeford, J. Acoust. Soc. Am. 53, 335 (A) (1973)]. The resulting data are compared with similar data for human subjects. [Supported in part by the National Science Foundation.]
Binaural Interaction in Cat and Man. II. Interaural Time and Intensity Relations
Authors: Langford Ted L. , Keramidas Sherry L.
Published: May 2012

For the reasons stated in the preceding paper, a study was undertaken to determine the degree of interaction between the interaural intensive and temporal cues used in lateralizing a sound image. Using apparatus and procedures similar to to reported by Wakeford and Robinson [J. Acoust. Soc. Am. 53, 336 (A) (1973)], cats were trained to respond to a change in a 500-Hz pulsed tone. The discrimination was based on a change from a temporal or intensive difference favoring one ear to an equivalent difference favoring the other ear. From these baseline conditions, combinations of the two cues were then varied. The resulting data are presented and the degree of correlation between the cues is compared with that of data obtained from the human. [Supported in part by the National Science Foundation.]
Cues for Auditory Localization in the Rat
Authors: Flammino F. , Clopton B. M.
Published: May 2012

Rats were trained to indicate the direction of a sound source under two conditions. The first task was set in an anechoic chamber with free-field stimuli. Tone bursts from 1 to 10 kHz were used. The relationship of mean correct responses to stimulus frequency was similar to those obtained with humans performing in localization studies. The rats showed a decrement in performance in the region of 5 kHz, suggesting that they utilize interaura] time cues for stimulus frequencies below S kHz and interaural intensity differences above about 6 kHz. In the second condition, time and intensity cues could be varied independently at each ear. The rats were able to lateralize the source when the stimulus at one ear led by 80 μsec (phaseshift equivalent) at 3 and 4 kHz. They were unable to do so at 5 and 7 kHz. The results indicate that despite their small head size rats are able to use both time and intensity cues in localizing the source of sounds. [Supported in part by NINDS Grant NS09551 and a General Research Grant, U.C. Academic Senate.]