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Sample records for irreversible hearing disorders

  1. Hearing Disorders and Deafness

    Science.gov (United States)

    ... enough to enjoy talking with friends or family. Hearing disorders make it hard, but not impossible, to ... often be helped. Deafness can keep you from hearing sound at all. What causes hearing loss? Some ...

  2. Assessment of hearing and hearing disorders in rock/jazz musicians.

    Science.gov (United States)

    Kähärit, Kim; Zachau, Gunilla; Eklöf, Mats; Sandsjö, Leif; Möller, Claes

    2003-07-01

    The aim of this study was to assess hearing and hearing disorders among rock/jazz musicians. One hundred and thirty-nine (43 women and 96 men) musicians participated. The results are based on pure-tone audiometry and questionnaire responses. According to our definition of hearing loss, tinnitus, hyperacusis, distortion and/or diplacusis as hearing disorders, we found disorders in 74%, of the rock/jazz musicians studied. Hearing loss, tinnitus and hyperacusis were most common, and the latter two were found significantly more frequently than in different reference populations. The women showed bilateral, significantly better hearing thresholds at 3-6 kHz than the men. Hyperacusis, and the combination of both hyperacusis and tinnitus, were found to be significantly more frequent among women than among men. Hearing loss and tinnitus were significantly more common among men than among women. It is important to evaluate all kinds of hearing problems (other than hearing loss) in musicians, since they represent an occupational group especially dependent on optimal, functional hearing. On the basis of our results, we suggest that hearing problems such as tinnitus, hyperacusis, distortion and/or diplacusis should, in addition to hearing loss, be defined as hearing disorders.

  3. Progressive irreversible hearing loss is caused by stria vascularis degeneration in an Slc26a4-insufficient mouse model of large vestibular aqueduct syndrome.

    Science.gov (United States)

    Ito, T; Nishio, A; Wangemann, P; Griffith, A J

    2015-12-03

    Hearing loss of patients with enlargement of the vestibular aqueduct (EVA) can fluctuate or progress, with overall downward progression. The most common detectable cause of EVA is mutations of SLC26A4. We previously described a transgenic Slc26a4-insufficient mouse model of EVA in which Slc26a4 expression is controlled by doxycycline administration. Mice that received doxycycline from conception until embryonic day 17.5 (DE17.5; doxycycline discontinued at embryonic day 17.5) had fluctuating hearing loss between 1 and 6 months of age with an overall downward progression after 6 months of age. In this study, we characterized the cochlear functional and structural changes underlying irreversible hearing loss in DE17.5 mice at 12 months of age. The endocochlear potential was decreased and inversely correlated with auditory brainstem response thresholds. The stria vascularis was thickened and edematous in ears with less severe hearing loss, and thinned and atrophic in ears with more severe hearing loss. There were pathologic changes in marginal cell morphology and gene expression that were not observed at 3 months. We conclude that strial dysfunction and degeneration are the primary causes of irreversible progressive hearing loss in our Slc26a4-insufficient mouse model of EVA. This model of primary strial atrophy may be used to explore the mechanisms of progressive hearing loss due to strial dysfunction. Published by Elsevier Ltd.

  4. Acute auditory agnosia as the presenting hearing disorder in MELAS.

    Science.gov (United States)

    Miceli, Gabriele; Conti, Guido; Cianfoni, Alessandro; Di Giacopo, Raffaella; Zampetti, Patrizia; Servidei, Serenella

    2008-12-01

    MELAS is commonly associated with peripheral hearing loss. Auditory agnosia is a rare cortical auditory impairment, usually due to bilateral temporal damage. We document, for the first time, auditory agnosia as the presenting hearing disorder in MELAS. A young woman with MELAS (A3243G mtDNA mutation) suffered from acute cortical hearing damage following a single stroke-like episode, in the absence of previous hearing deficits. Audiometric testing showed marked central hearing impairment and very mild sensorineural hearing loss. MRI documented bilateral, acute lesions to superior temporal regions. Neuropsychological tests demonstrated auditory agnosia without aphasia. Our data and a review of published reports show that cortical auditory disorders are relatively frequent in MELAS, probably due to the strikingly high incidence of bilateral and symmetric damage following stroke-like episodes. Acute auditory agnosia can be the presenting hearing deficit in MELAS and, conversely, MELAS should be suspected in young adults with sudden hearing loss.

  5. A Survey of Relationship between Rheumatoid Arthritis and Hearing Disorders

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    Mohammad Hossein Baradaranfar

    2010-12-01

    Full Text Available RA (rheumatoid arthritis is a chronic multisystem disease with a variety of systemic manifestations. One of these manifestations, is hearing disorder, so study of the relation between RA and hearing disorders is seem important. This was a case-control study which has done from December 2004 to August 2006. This study compared 50 patients with RA, with age, sex and job-matched as control. Audiometric tests in different frequencies show that hearing threshold in high frequencies specially in 8000 Hz had a significant difference between two groups, also acoustic reflexes were absent in case groups and had significant difference between two groups too. The evaluation of sensory neural hearing loss showed that this hearing loss is sensory not neural. Based on this study, frequent evaluation of audiometric tests is recommended for controlling hearing disorders by therapeutic and rehabilitation procedures in RA patients.

  6. Characterizing Time Irreversibility in Disordered Fermionic Systems by the Effect of Local Perturbations

    Science.gov (United States)

    Vardhan, Shreya; De Tomasi, Giuseppe; Heyl, Markus; Heller, Eric J.; Pollmann, Frank

    2017-07-01

    We study the effects of local perturbations on the dynamics of disordered fermionic systems in order to characterize time irreversibility. We focus on three different systems: the noninteracting Anderson and Aubry-André-Harper (AAH) models and the interacting spinless disordered t -V chain. First, we consider the effect on the full many-body wave functions by measuring the Loschmidt echo (LE). We show that in the extended or ergodic phase the LE decays exponentially fast with time, while in the localized phase the decay is algebraic. We demonstrate that the exponent of the decay of the LE in the localized phase diverges proportionally to the single-particle localization length as we approach the metal-insulator transition in the AAH model. Second, we probe different phases of disordered systems by studying the time expectation value of local observables evolved with two Hamiltonians that differ by a spatially local perturbation. Remarkably, we find that many-body localized systems could lose memory of the initial state in the long-time limit, in contrast to the noninteracting localized phase where some memory is always preserved.

  7. Music exposure and hearing disorders: an overview.

    Science.gov (United States)

    Zhao, Fei; Manchaiah, Vinaya K C; French, David; Price, Sharon M

    2010-01-01

    It has been generally accepted that excessive exposure to loud music causes various hearing symptoms (e.g. tinnitus) and consequently leads to a risk of permanent hearing damage, known as noise-induced hearing loss (NIHL). Such potential risk of NIHL due to loud music exposure has been widely investigated in musicians and people working in music venues. With advancements in sound technology and rapid developments in the music industry, increasing numbers of people, particularly adolescents and young adults, are exposing themselves to music on a voluntary basis at potentially harmful levels, and over a substantial period of time, which can also cause NIHL. However, because of insufficient audiometric evidence of hearing loss caused purely by music exposure, there is still disagreement and speculation about the risk of hearing loss from music exposure alone. Many studies have suggested using advanced audiological measurements as more sensitive and efficient tools to monitor hearing status as early indicators of cochlear dysfunction. The purpose of this review is to provide further insight into the potential risk of hearing loss caused by exposure to loud music, and thus contribute to further raising awareness of music induced hearing loss.

  8. [Fall prevention counselling for patients with hearing and balance disorders].

    Science.gov (United States)

    Ptok, M; Ptok, A; Jungheim, M; Kühn, D; Miller, S

    2014-09-01

    Otolaryngologists caring for patients with hearing and balance disorders are also responsible for advising patients about their increased risk of falling and informing them of fall prevention measures. This review will give a brief overview of appropriate programs. This systematic review is based on a selective literature search. Intrinsic and extrinsic fall risk factors can be distinguished. The former include not only hearing and balance disorders, but also increasing age, nocturia, dementia, limited mobility and poor nutritional status. Extrinsic factors include, for example, unfixed carpet edges, poor lighting and poor footwear. Fall prevention can be achieved through appropriate counselling about risk factors and fall prevention courses. The frequency of falls--with potentially very adverse consequences--increases continuously beyond the age of 60 years. Furthermore, the risk of falling is significantly increased in patients with hearing and balance disorders. Otolaryngologists caring for this patient group should inform them about their fall risk and advise appropriate countermeasures during counselling. A basal knowledge of fall prevention measures is therefore helpful.

  9. Daily Stress, Hearing-Specific Stress and Coping: Self-Reports from Deaf or Hard of Hearing Children and Children with Auditory Processing Disorder

    Science.gov (United States)

    Eschenbeck, Heike; Gillé, Vera; Heim-Dreger, Uwe; Schock, Alexandra; Schott, Andrea

    2017-01-01

    This study evaluated stressors and coping strategies in 70 children who are deaf or hard of hearing (D/HH) or with auditory processing disorder (APD) attending Grades 5 and 6 of a school for deaf and hard-of-hearing children. Everyday general stressors and more hearing-specific stressors were examined in a hearing-specific modified stress and…

  10. Hearing, speech, language, and vestibular disorders in the fetal alcohol syndrome: a literature review.

    Science.gov (United States)

    Church, M W; Kaltenbach, J A

    1997-05-01

    Fetal alcohol syndrome (FAS) is characterized in part by mental impairment, as well as craniofacial and ocular anomalies. These conditions are traditionally associated with childhood hearing disorders, because they all have a common embryonic origin in malformations of the first and second branchial arches, and have similar critical periods of vulnerability to toxic insult. A review of human and animal research indicates that there are four types of hearing disorders associated with FAS. These are: (1) a developmental delay in auditory maturation, (2) sensorineural hearing loss, (3) intermittent conductive hearing loss due to recurrent serous otitis media, and (4) central hearing loss. The auditory and vestibular systems share the same peripheral apparatuses (the inner ear and eighth cranial nerve) and are embryologically and structurally similar. Consequently, vestibular disorders in FAS children might be expected. The evidence for vestibular dysfunction in FAS is ambiguous, however. Like other syndromes associated with craniofacial anomalies, hearing disorders, and mental impairment, FAS is also characterized by a high prevalence of speech and language pathology. Hearing disorders are a form of sensory deprivation. If present during early childhood, they can result in permanent hearing, language, and mental impairment. Early identification and intervention to treat hearing, language, and speech disorders could therefore result in improved outcome for the FAS child. Specific recommendations are made for intervention and future research.

  11. Reversible and irreversible changes of surface morphology by order-disorder transition in CuAu alloy

    International Nuclear Information System (INIS)

    Sachl, Jindrich; Sima, Vladimir; Pfeiler, Wolfgang

    2004-01-01

    The change of symmetry from the disordered fcc structure to tetragonal or orthorhombic structure is accompanied in CuAu alloy by anisotropy of lattice parameters and also by local generation of c-variants of structural antiphase domains. Macroscopic results of these processes can be observed as a dynamic change of the surface morphology. Some surface changes are reversible, on the other hand the internal stresses connected with the order-disorder transformation are also responsible for irreversible surface deformation effects. The domain structure formation can be influenced by external load and a shape memory effect can be observed at special conditions in CuAu. A combination of in-situ microscopic video cinematography and post-mortem 3-D atomic force microscopy (AFM) has been used for the surface study. The AFM images have enabled a detailed analysis of the surface morphology and the cinematography has given an in-situ information dealing with conditions and kinetics of observed surface changes. Measurements on CuAu single- and poly-crystalline samples have been made for a wide variety of experimental conditions (heating/cooling rates, external load, thermal history of the sample)

  12. Reversible and irreversible changes of surface morphology by order-disorder transition in CuAu alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sachl, Jindrich; Sima, Vladimir; Pfeiler, Wolfgang

    2004-09-22

    The change of symmetry from the disordered fcc structure to tetragonal or orthorhombic structure is accompanied in CuAu alloy by anisotropy of lattice parameters and also by local generation of c-variants of structural antiphase domains. Macroscopic results of these processes can be observed as a dynamic change of the surface morphology. Some surface changes are reversible, on the other hand the internal stresses connected with the order-disorder transformation are also responsible for irreversible surface deformation effects. The domain structure formation can be influenced by external load and a shape memory effect can be observed at special conditions in CuAu. A combination of in-situ microscopic video cinematography and post-mortem 3-D atomic force microscopy (AFM) has been used for the surface study. The AFM images have enabled a detailed analysis of the surface morphology and the cinematography has given an in-situ information dealing with conditions and kinetics of observed surface changes. Measurements on CuAu single- and poly-crystalline samples have been made for a wide variety of experimental conditions (heating/cooling rates, external load, thermal history of the sample)

  13. Prevalence of Hearing disorders in 3-6 year old Children of Kindergartens in Yazd City

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    Z Jafari

    2009-01-01

    Full Text Available Introduction: A hearing– impaired patient is defined as one with abnormal or reduced function in hearing resulting from an auditory disorder. The goal of any preschool and schools screening program should be to accurately indentify those children whose hearing has been impaired due to conductive and / or sensory– neural pathology. Methods: This cross– sectional descriptive study was done on 577 children (299 girls and 278 boys aged between 3–6 years at kindergartens of Yazd city from September 2005 to January 2006. The otoscopy examination, pure-tone screening and impedance study was conducted after completion of awareness form of the hearing loss existence by the parents. Results: In this study, there were 12.6% abnormal conditions of external ear canal, 34.2% abnormal tympanic membrane, 35.9% abnormal tympanograms and 13.4% hearing loss including 11.5% conductive hearing loss, 1.5% sensory-neural hearing loss and 0.5% mixed hearing loss. Conclusion: With respect to the high prevalence and negative effects of middle ear disorders in learning of preschool children, and also due to the importance of early identification and intervention of hearing loss in aural rehabilitation programs, increasing the awareness and education of people, especially parents about the effects of hearing disorders and its prevention and identification is very important

  14. Order-disorder criticality, wetting, and morphological phase transitions in the irreversible growth of far-from-equilibrium magnetic films

    International Nuclear Information System (INIS)

    Candia, J.Julian; Albano, E.V.Ezequiel V.

    2003-01-01

    An exhaustive numerical investigation of the growth of magnetic films in confined (d+1)-dimensional stripped geometries (d=1,2) is carried out by means of extensive Monte Carlo simulations. Films in contact with a thermal bath at temperature T, are grown by adding spins having two possible orientations and considering ferromagnetic (nearest-neighbor) interactions. At low temperatures, thin films of thickness L are constituted by a sequence of well-ordered domains of average length l D >>L. These domains have opposite magnetization. So, the films exhibit 'spontaneous magnetization reversal' during the growth process. Such reversal occurs within a short characteristic length l R , such that l D >>l R ∼L. Furthermore, it is found that for d=1 the system is non-critical, while a continuous order-disorder phase transition at finite temperature takes place in the d=2 case. Using standard finite-size scaling procedures, the critical temperature and some relevant critical exponents are determined. Finally, the growth of magnetic films in (2+1) dimensions with competing short-range magnetic fields acting along the confinement walls is studied. Due to the antisymmetric condition considered, an interface between domains with spins having opposite orientation develops along the growing direction. Such an interface undergoes a localization-delocalization transition that is the precursor of a wetting transition in the thermodynamic limit. Furthermore, the growing interface also undergoes morphological transitions in the growth mode. A comparison between the well-studied equilibrium Ising model and the studied irreversible magnetic growth model is performed throughout. Although valuable analogies are encountered, it is found that the non-equilibrium nature of the latter introduces new and rich physical features of interest

  15. The importance of retesting the hearing screening as an indicator of the real early hearing disorder

    OpenAIRE

    Silva,Daniela Polo Camargo da; Lopez,Priscila Suman; Ribeiro,Georgea Espíndola; Luna,Marcos Otávio de Mesquita; Lyra,João César; Montovani,Jair Cortez

    2015-01-01

    INTRODUCTION: Early diagnosis of hearing loss minimizes its impact on child development. We studied factors that influence the effectiveness of screening programs.OBJECTIVE: To investigate the relationship between gender, weight at birth, gestational age, risk factors for hearing loss, venue for newborn hearing screening and "pass" and "fail" results in the retest.METHODS: Prospective cohort study was carried out in a tertiary referral hospital. The screening was performed in 565 newborns thr...

  16. STUDY ABOUT THE INCIDENCE OF HEARING-SPEAKING DISORDERS IN A POPULATION WITH MENTAL DEFICIENCY

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    Ioana Mihaela Tomulescu

    2003-01-01

    Full Text Available This study is about the incidence of hearing-speaking disorders in a population with mental deficiency. We studied 596 children interned in Neurology and Psychiatry Clinical Hospital of Oradea during the 1999 - 2001 period. In 596 children, 393 presented different types of mental deficiency. The most frequent disorders observed are hearing loss or deafness, deaf-mutism, mutism and speaking retardation. Also, we related an increased frequency in rural area and in group of children with severe mental deficiency.

  17. The importance of retesting the hearing screening as an indicator of the real early hearing disorder

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    Daniela Polo Camargo da Silva

    2015-08-01

    Full Text Available INTRODUCTION: Early diagnosis of hearing loss minimizes its impact on child development. We studied factors that influence the effectiveness of screening programs.OBJECTIVE: To investigate the relationship between gender, weight at birth, gestational age, risk factors for hearing loss, venue for newborn hearing screening and "pass" and "fail" results in the retest.METHODS: Prospective cohort study was carried out in a tertiary referral hospital. The screening was performed in 565 newborns through transient evoked otoacoustic emissions in three admission units before hospital discharge and retest in the outpatient clinic. Gender, weight at birth, gestational age, presence of risk indicators for hearing loss and venue for newborn hearing screening were considered.RESULTS: Full-term infants comprised 86% of the cases, preterm 14%, and risk factors for hearing loss were identified in 11%. Considering the 165 newborns retested, only the venue for screening, Intermediate Care Unit, was related to "fail" result in the retest.CONCLUSIONS: Gender, weight at birth, gestational age and presence of risk factors for hearing loss were not related to "pass" and/or "fail" results in the retest. The screening performed in intermediate care units increases the chance of continued "fail" result in the Transient Otoacoustic Evoked Emissions test.

  18. Effect of Workplace Noise on Hearing Ability in Tile and Ceramic Industry Workers in Iran: A 2-Year Follow-Up Study

    OpenAIRE

    Mostaghaci, Mehrdad; Mirmohammadi, Seyyed Jalil; Mehrparvar, Amir Houshang; Bahaloo, Maryam; Mollasadeghi, Abolfazl; Davari, Mohammad Hossein

    2013-01-01

    Introduction. Noise as a common physical hazard may lead to noise-induced hearing loss, an irreversible but preventable disorder. Annual audiometric evaluations help detect changes in hearing status before clinically significant hearing loss develops. This study was designed to track hearing threshold changes during 2-year follow-up among tile and ceramic workers. Methods. This follow-up study was conducted on 555 workers (totally 1110 ears). Subjects were divided into four groups according t...

  19. Examination of characteristics and management of children with hearing loss and autism spectrum disorders.

    Science.gov (United States)

    Fitzpatrick, Elizabeth M; Lambert, Linda; Whittingham, JoAnne; Leblanc, Emma

    2014-09-01

    Up to 40% of children with hearing loss present with other developmental disabilities. The purpose of this study was to document the prevalence of autism spectrum disorders (ASD) in children with permanent hearing loss, to describe the audiologic characteristics, and to examine clinical management. Prospective data related to clinical characteristics of children identified with hearing loss and ASD were examined. A retrospective chart review was also conducted to explore clinical management and uptake of amplification. The study included all children in one Canadian region identified with permanent hearing loss and followed from 2002-2010. Of a total of 785 children with permanent hearing loss, 2.2% (n = 17) also received a diagnosis of ASD. The 13 boys and 4 girls presented with a range of audiologic profiles from unilateral to profound bilateral hearing loss. Four of five children with unilateral hearing loss experienced progression to bilateral loss. Amplification was recommended for all but one child and 9 of 16 children continued to use their hearing devices. The higher prevalence rate of ASD in this clinical population is consistent with previous reports. Our findings suggest that some children with autism can derive benefits from the use of amplification.

  20. Acoustic Reflex Screening of Conductive Hearing Loss for Third Window Disorders.

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    Hong, Robert S; Metz, Christopher M; Bojrab, Dennis I; Babu, Seilesh C; Zappia, John; Sargent, Eric W; Chan, Eleanor Y; Naumann, Ilka C; LaRouere, Michael J

    2016-02-01

    This study examines the effectiveness of acoustic reflexes in screening for third window disorders (eg, superior semicircular canal dehiscence) prior to middle ear exploration for conductive hearing loss. Case series with chart review. Outpatient tertiary otology center. A review was performed of 212 ears with acoustic reflexes, performed as part of the evaluation of conductive hearing loss in patients without evidence of chronic otitis media. The etiology of hearing loss was determined from intraoperative findings and computed tomography imaging. The relationship between acoustic reflexes and conductive hearing loss etiology was assessed. Eighty-eight percent of ears (166 of 189) demonstrating absence of all acoustic reflexes had an ossicular etiology of conductive hearing loss. Fifty-two percent of ears (12 of 23) with at least 1 detectable acoustic reflex had a nonossicular etiology. The positive and negative predictive values for an ossicular etiology were 89% and 57% when acoustic reflexes were used alone for screening, 89% and 39% when third window symptoms were used alone, and 94% and 71% when reflexes and symptoms were used together, respectively. Acoustic reflex testing is an effective means of screening for third window disorders in patients with a conductive hearing loss. Questioning for third window symptoms should complement screening. The detection of even 1 acoustic reflex or third window symptom (regardless of reflex status) should prompt further workup prior to middle ear exploration. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  1. Frequency Distribution of Hearing Disorders Among the Student of Public Elementary School in Neishaboor

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    Dr. Mohammad Kamali

    2000-05-01

    Full Text Available Objectives: determining the frequency distribution of hearing disorders among the student of public elementary school by Otoscopy, Puretone Audiometry, Impedance Audiometiy and questionnaires. Methods and Materials: This study was carried out in a cross - sectional descriptive survey - on 1200 students (600 girls and 600 boys among the student of primary school of Neishabbor, academic year 1376-77 Results: 1- Otoscopy examination; abnormal conditions of external ear canal was found in 14.1% of cases; mostly impacted ceruman (13.6%; Abnormal conditions of tympanic membrane (0.4% and foreign body 0.16%. Abnormal conditions of external ear canal was statistically unmeaningful. (P V=0 .8 2- Impedance Audiometiy: 5. 75% Abnormal tympanograms were observed, mostly type C (3.15% 3- Pure Tone Audiometry: An overall 5.5% hearing loss was found in this population including 3% bilateral and 1.25% unilateral hearing loss. Only conductive hearing loss was found in this population (2.7% in right ear and 3.5% in left ear, PV=0.9. Hearing loss observed mostly in girls but the difference was slight. Family background showed no effects on the hearing disorders.9.8% of cases were in need of medical care and 0.3% were in need of rehabilitation services. Only 28.8% of parents, 36.3% of teachers and 40.9% of afflicted students were aware of the problem.

  2. Classification of Hearing Loss Disorders Using Teoae-Based Descriptors

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    Hatzopoulos, Stavros Dimitris

    Transiently Evoked Otoacoustic Emissions (TEOAE) are signals produced by the cochlea upon stimulation by an acoustic click. Within the context of this dissertation, it was hypothesized that the relationship between the TEOAEs and the functional status of the OHCs provided an opportunity for designing a TEOAE-based clinical procedure that could be used to assess cochlear function. To understand the nature of the TEOAE signals in the time and the frequency domain several different analyses were performed. Using normative Input-Output (IO) curves, short-time FFT analyses and cochlear computer simulations, it was found that for optimization of the hearing loss classification it is necessary to use a complete 20 ms TEOAE segment. It was also determined that various 2-D filtering methods (median and averaging filtering masks, LP-FFT) used to enhance of the TEOAE S/N offered minimal improvement (less than 6 dB per stimulus level). Higher S/N improvements resulted in TEOAE sequences that were over-smoothed. The final classification algorithm was based on a statistical analysis of raw FFT data and when applied to a sample set of clinically obtained TEOAE recordings (from 56 normal and 66 hearing-loss subjects) correctly identified 94.3% of the normal and 90% of the hearing loss subjects, at the 80 dB SPL stimulus level. To enhance the discrimination between the conductive and the sensorineural populations, data from the 68 dB SPL stimulus level were used, which yielded a normal classification of 90.2%, a hearing loss classification of 87.5% and a conductive-sensorineural classification of 87%. Among the hearing-loss populations the best discrimination was obtained in the group of otosclerosis and the worst in the group of acute acoustic trauma.

  3. Neurodevelopmental Disorders in Children with Severe to Profound Sensorineural Hearing Loss: A Clinical Study

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    Chilosi, Anna M.; Comparini, Alessandro; Scusa, Maria F.; Berrettini, Stefano; Forli, Francesca; Battini, Roberta; Cipriani, Paola; Cioni, Giovanni

    2010-01-01

    Aim: The effects of sensorineural hearing loss (SNHL) are often complicated by additional disabilities, but the epidemiology of associated disorders is not clearly defined. The aim of this study was to evaluate the frequency and type of additional neurodevelopmental disabilities in a sample of children with SNHL and to investigate the relation…

  4. Metabolic disorders in vertigo, tinnitus, and hearing loss.

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    Kaźmierczak, H; Doroszewska, G

    2001-01-01

    Vertigo, tinnitus, and hearing loss are common complaints among populations of industrial countries, especially in persons older than 40 years. Numerous agents are known to incite vertigo, tinnitus, and hearing loss, among them hyperinsulinemia, diabetes mellitus, and hyperlipidemia. In this study, we proposed to assess the occurrence of hyperinsulinemia, diabetes mellitus, and hyperlipidemia in patients suffering from vertigo, tinnitus, or hearing loss of unknown origin. Results of various tests in 48 patients were compared to those in 31 control subjects. Assessments of body mass index, blood pressure, and laryngological, audiometric, and electronystagmographic parameters were performed in all study participants. An oral glucose tolerance test was used to evaluate insulin levels, and lipoprotein phenotyping served to determine cholesterol, triglyceride, and lipoprotein levels. Patients were found to be significantly more overweight (on the basis of body mass index) than were the control subjects. Hypertension was more common among patients than controls, but the difference was significant only between the men in the two groups. Disturbances of glucose metabolism were found in 27.1% of patients but in only 9.7% of controls. Diabetes mellitus was not present in any controls but was identified in four patients. Hyperinsulinemia was almost twice as common in patients as in controls. Only the occurrence of hyperlipoproteinemia seemed not to differ between patients and control subjects. We conclude that such disturbances of glucose metabolism as diabetes mellitus and hyperinsulinemia may be responsible for inner ear diseases, whereas the role of disturbances of lipid metabolism remains vague.

  5. Prevalence of language and hearing disorders in children

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    Augusto Muñoz-Caicedo

    2012-12-01

    Full Text Available Objective: to establish the prevalence institutional alterations in hearing and languaje in children aged 4 and 5 years, attending the Growth and Development program at the Social Institution of Popayan in 2012. Methodology: We performed a cross-sectional study in sample of 96 children who attended four points ESE Care Popayan, during the months of december 2011 and January 2012. Were evaluated by Fonoaudiología, who applied the Reynell test to assess languaje and tone audiometry and otoacoustic emissions to assess hearing. Results: the mean age of the population was 59.34 months, while 50% was made up of men. The 78.1% had alterations in expressive language and 41.7% in language understanding, 29.2% showed changes of left ear as otoacoustic emissions and according to tone audiometry, high frequency of right are the most affected. Conclusions: the high prevalence of alterations in speech and hearing in children found to initiate processes that are more complex as the acquisition of reading and writing, could trigger negative consequences such as poor school performance and even dropouts.

  6. Irreversible social change

    NARCIS (Netherlands)

    Pols, A.J.K.; Romijn, H.A.; Collste, G.; Reuter, L.

    2014-01-01

    In this paper we evaluate how irreversible social change should be evaluated from an ethical perspective. First; we analyse the notion of irreversibility in general terms. We define a general notion of what makes a change irreversible; drawing on discussions in ecology and economics. This notion is

  7. Classification of voice disorder in children with cochlear implantation and hearing aid using multiple classifier fusion

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    Tayarani Hamid

    2011-01-01

    Full Text Available Abstract Background Speech production and speech phonetic features gradually improve in children by obtaining audio feedback after cochlear implantation or using hearing aids. The aim of this study was to develop and evaluate automated classification of voice disorder in children with cochlear implantation and hearing aids. Methods We considered 4 disorder categories in children's voice using the following definitions: Level_1: Children who produce spontaneous phonation and use words spontaneously and imitatively. Level_2: Children, who produce spontaneous phonation, use words spontaneously and make short sentences imitatively. Level_3: Children, who produce spontaneous phonations, use words and arbitrary sentences spontaneously. Level_4: Normal children without any hearing loss background. Thirty Persian children participated in the study, including six children in each level from one to three and 12 children in level four. Voice samples of five isolated Persian words "mashin", "mar", "moosh", "gav" and "mouz" were analyzed. Four levels of the voice quality were considered, the higher the level the less significant the speech disorder. "Frame-based" and "word-based" features were extracted from voice signals. The frame-based features include intensity, fundamental frequency, formants, nasality and approximate entropy and word-based features include phase space features and wavelet coefficients. For frame-based features, hidden Markov models were used as classifiers and for word-based features, neural network was used. Results After Classifiers fusion with three methods: Majority Voting Rule, Linear Combination and Stacked fusion, the best classification rates were obtained using frame-based and word-based features with MVR rule (level 1:100%, level 2: 93.75%, level 3: 100%, level 4: 94%. Conclusions Result of this study may help speech pathologists follow up voice disorder recovery in children with cochlear implantation or hearing aid who are

  8. Audiometric Profiles in Autism Spectrum Disorders: Does Subclinical Hearing Loss Impact Communication?

    Science.gov (United States)

    Demopoulos, Carly; Lewine, Jeffrey David

    2016-01-01

    Rates of hearing impairment in individuals with Autism Spectrum Disorders (ASD) are higher than those reported in the general population. Although ASD is not caused by hearing impairment, it may exacerbate symptomatology. Participants with ASD (N = 60) and typically developing peers (N = 16) aged 5-18 years underwent a comprehensive audiological screening (pure tone audiometry, uncomfortable loudness level, tympanometry, acoustic reflexes, distortion product otoacoustic emissions, and auditory brainstem response) and assessment of communication abilities (expressive/receptive language, articulation, phonological awareness, and vocal affect recognition). Incidence of abnormal findings on at least one measure of audiological functioning was higher for the ASD group (55%) than controls (14.9%) or the general population estimate (6%). The presence of sound sensitivity was also considerably higher for the ASD group (37%) compared with controls (0%) or general population estimates (8-15%). When participants with ASD were dichotomized into groups with and without evidence of clinical audiological abnormality, no significant differences were identified on measures of communication; however, results of correlational analyses indicated that variability in hearing thresholds at middle range frequencies (2000 Hz) was significantly related to performance on all measures of speech articulation and language after correction for multiple comparisons (r = -0.48 to r = -0.53, P <  0.0045). These findings suggest that dichotomized classification of clinical audiology may not be sufficient to understand the role of subclinical hearing loss in ASD symptomatology and that treatment studies for mild/subclinical hearing loss in this population may be worthwhile. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

  9. Questionnaire investigation of musicians’ use of hearing protectors, self reported hearing disorders and their experience of their working environment

    DEFF Research Database (Denmark)

    Laitinen, Heli; Poulsen, Torben

    2008-01-01

    Musicians in symphony orchestras are exposed to harmful sound levels. Although research shows that industrial workers have a higher propensity to noise induced hearing loss, musicians can also develop a hearing loss from noise exposure. Furthermore, musicians can suffer from tinnitus, hyperacusis...

  10. Irreversible processes kinetic theory

    CERN Document Server

    Brush, Stephen G

    2013-01-01

    Kinetic Theory, Volume 2: Irreversible Processes deals with the kinetic theory of gases and the irreversible processes they undergo. It includes the two papers by James Clerk Maxwell and Ludwig Boltzmann in which the basic equations for transport processes in gases are formulated, together with the first derivation of Boltzmann's ""H-theorem"" and a discussion of this theorem, along with the problem of irreversibility.Comprised of 10 chapters, this volume begins with an introduction to the fundamental nature of heat and of gases, along with Boltzmann's work on the kinetic theory of gases and s

  11. Prevalence and characteristics of self-reported physical and mental disorders among adults with hearing loss in Denmark: a national survey

    DEFF Research Database (Denmark)

    Dammeyer, Jesper; Chapman, Madeleine

    2017-01-01

    Purpose Existing research shows that people with hearing loss have a high risk of additional physical and mental disorders. However, only a few population-based studies have been conducted. This study assesses the prevalence and characteristics of additional disorders among adults with hearing loss...

  12. Do Communication Disorders Extend to Musical Messages?: An Answer from Children with Hearing Loss or Autism Spectrum Disorders

    Science.gov (United States)

    Whipple, Christina M.; Gfeller, Kate; Driscoll, Virginia; Oleson, Jacob; McGregor, Karla

    2014-01-01

    Background Effective musical communication requires conveyance of the intended message in a manner perceptible to the receiver. Communication disorders that impair transmitting or decoding of structural features of music (e.g., pitch, timbre) and/or symbolic representation may result in atypical musical communication, which can have a negative impact on music therapy interventions. Objective This study compared recognition of symbolic representation of emotions or movements in music by two groups of children with different communicative characteristics: severe to profound hearing loss (using cochlear implants [CI]) and autism spectrum disorder (ASD). Their responses were compared to those of children with typical-development and normal hearing (TD-NH). Accuracy was examined as a function of communicative status, emotional or movement category, and individual characteristics. Methods Participants listened to recorded musical excerpts conveying emotions or movements and matched them with labels. Measures relevant to auditory and/or language function were also gathered. Results There was no significant difference between the ASD and TD-NH groups in identification of musical emotions or movements. However, the CI group was significantly less accurate than the other two groups in identification of both emotions and movements. Mixed effects logistic regression revealed different patterns of accuracy for specific emotions as a function of group. Conclusion Conveyance of emotions or movements through music may be decoded differently by persons with different types of communication disorders. Because music is the primary therapeutic tool in music therapy sessions, clinicians should consider these differential abilities when selecting music for clinical interventions focusing on emotions or movement. PMID:25691513

  13. Do communication disorders extend to musical messages? An answer from children with hearing loss or autism spectrum disorders.

    Science.gov (United States)

    Whipple, Christina M; Gfeller, Kate; Driscoll, Virginia; Oleson, Jacob; McGregor, Karla

    2015-01-01

    Effective musical communication requires conveyance of the intended message in a manner perceptible to the receiver. Communication disorders that impair transmitting or decoding of structural features of music (e.g., pitch, timbre) and/or symbolic representation may result in atypical musical communication, which can have a negative impact on music therapy interventions. This study compared recognition of symbolic representation of emotions or movements in music by two groups of children with different communicative characteristics: severe to profound hearing loss (using cochlear implants [CI]) and autism spectrum disorder (ASD). Their responses were compared to those of children with typical-development and normal hearing (TD-NH). Accuracy was examined as a function of communicative status, emotional or movement category, and individual characteristics. Participants listened to recorded musical excerpts conveying emotions or movements and matched them with labels. Measures relevant to auditory and/or language function were also gathered. There was no significant difference between the ASD and TD-NH groups in identification of musical emotions or movements. However, the CI group was significantly less accurate than the other two groups in identification of both emotions and movements. Mixed effects logistic regression revealed different patterns of accuracy for specific emotions as a function of group. Conveyance of emotions or movements through music may be decoded differently by persons with different types of communication disorders. Because music is the primary therapeutic tool in music therapy sessions, clinicians should consider these differential abilities when selecting music for clinical interventions focusing on emotions or movement. © the American Music Therapy Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Advances in the neurobiology of hearing disorders : Recent developments regarding the basis of tinnitus and hyperacusis

    NARCIS (Netherlands)

    Knipper, Marlies; Van Dijk, Pim; Nunes, Isidro; Rüttiger, Lukas; Zimmermann, Ulrike

    2013-01-01

    The prevalence of hearing problems in the Western world has, due to aging of the population, doubled over the past 30 years. Thereby, noise-induced hearing loss is an important factor that worsens over time in addition to age-related hearing loss. Hearing loss is usually measured as an elevation of

  15. The role of speech therapy in the therapy of children with central hearing disorders

    Directory of Open Access Journals (Sweden)

    Agnieszka Kasperczuk-Bajda

    2017-09-01

    Full Text Available Central disorders of hearing processing are one of the main causes of school difficulties among children. CAPD is described as incapability of using auditory acoustic sounds with its correct perception within ambit structures. The disorder is often accompanied by such difficulties as dyslexia, specific learning problems or subnormal speech development. Early diagnose of the  disorder and commencing a therapy allows a child a better adjustment to expectations which he or she is exposed to by its environment. The aim of this work is indicating the role and abilities of a speech therapist while treating CAPD children. Aural training is adequate for children with central auditory disorders and in order to be effective it should be long lasting, intensive and adjusted to a child’s individual abilities. Therapy should include both passive listening of sounds and exercises in which the child can actively participate. The aim of speech therapy is to develop auditory skills, speaking, communication and stimulating cognitive potential of a child. Among the auditory exercises conducted by the speech therapist are understanding distorted speech exercises, understanding distorted speech in the presence of a jamming signal, separation and integration of information exercises. localization and lateralization exercises, recognizing sound patterns exercises, recognizing sound sequences exercises, differentiating nonverbal stimuli and phonemes exercises and prosodic training. Therapeutic auditory training that is carried out systematically develops aural and linguistic competences.

  16. Managing Behavior by Managing the Classroom: Making Learning Accessible for Deaf and Hard of Hearing Students with Autism Spectrum Disorders

    Science.gov (United States)

    Szymanski, Christen A.

    2012-01-01

    The prevalence of Autism Spectrum Disorders (ASD)--a group of developmental disabilities that cause severe problems with socialization, behavior, and communication--continues to grow. In 2008, the year that "Odyssey" focused on autism, the estimated prevalence of ASD for hearing children was 1 in 150 (CDC, 2007), while today estimates suggest…

  17. Hear, Hear!

    Science.gov (United States)

    Rittner-Heir, Robbin

    2000-01-01

    Examines the problem of acoustics in school classrooms; the problems it creates for student learning, particularly for students with hearing problems; and the impediments to achieving acceptable acoustical levels for school classrooms. Acoustic guidelines are explored and some remedies for fixing sound problems are highlighted. (GR)

  18. Hearing Aids: MedlinePlus Health Topic

    Science.gov (United States)

    ... for hearing loss (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Hearing Aids updates ... MEDICAL ENCYCLOPEDIA Devices for hearing loss Related Health Topics Cochlear Implants Hearing Disorders and Deafness National Institutes ...

  19. Stochastic dynamics and irreversibility

    CERN Document Server

    Tomé, Tânia

    2015-01-01

    This textbook presents an exposition of stochastic dynamics and irreversibility. It comprises the principles of probability theory and the stochastic dynamics in continuous spaces, described by Langevin and Fokker-Planck equations, and in discrete spaces, described by Markov chains and master equations. Special concern is given to the study of irreversibility, both in systems that evolve to equilibrium and in nonequilibrium stationary states. Attention is also given to the study of models displaying phase transitions and critical phenomema both in thermodynamic equilibrium and out of equilibrium. These models include the linear Glauber model, the Glauber-Ising model, lattice models with absorbing states such as the contact process and those used in population dynamic and spreading of epidemic, probabilistic cellular automata, reaction-diffusion processes, random sequential adsorption and dynamic percolation. A stochastic approach to chemical reaction is also presented.The textbook is intended for students of ...

  20. Extended Irreversible Thermodynamics

    CERN Document Server

    Jou, David

    2010-01-01

    This is the 4th edition of the highly acclaimed monograph on Extended Irreversible Thermodynamics, a theory that goes beyond the classical theory of irreversible processes. In contrast to the classical approach, the basic variables describing the system are complemented by non-equilibrium quantities. The claims made for extended thermodynamics are confirmed by the kinetic theory of gases and statistical mechanics. The book covers a wide spectrum of applications, and also contains a thorough discussion of the foundations and the scope of the current theories on non-equilibrium thermodynamics. For this new edition, the authors critically revised existing material while taking into account the most recent developments in fast moving fields such as heat transport in micro- and nanosystems or fast solidification fronts in materials sciences. Several fundamental chapters have been revisited emphasizing physics and applications over mathematical derivations. Also, fundamental questions on the definition of non-equil...

  1. Relationship between changes in the cochlear blood flow and disorder of hearing function induced by blast injury in guinea pigs.

    Science.gov (United States)

    Chen, Wei; Wang, Jianmin; Chen, Jing; Chen, Jichuan; Chen, Zhiqiang

    2013-01-01

    The auditory system is the most susceptible to damages from blast waves. Blast injuries always lead to varying degrees of hearing impairment. Although a disorder of the cochlear blood flow (CoBF) has been considered to be related to many pathological processes of the auditory system and to contribute to various types of hearing loss, changes in the CoBF induced by blast waves and the relationship between such changes and hearing impairment are undefined. To observe the changes in the cochlear microcirculation after exposure to an explosion blast, investigate the relationship between changes in the CoBF and hearing impairment and subsequently explore the mechanism responsible for the changes in the CoBF, we detected the perfusion of the cochlear microcirculation and hearing threshold shift after exposure to an explosion blast. Then, an N-nitro-L-arginine-methyl ester (L-NAME, NO synthase inhibitor) solution and artificial perilymph were applied to the round window (RW) of the cochlea before the blast exposure, followed by an evaluation of the CoBF and hearing function. The results indicated that the changes in the CoBF were correlated to the strength of the blast wave. The cochlear blood flow significantly increased when the peak value of the blast overpressure was greater than approximately 45 kPa, and there was no significant change in the cochlear blood flow when the peak value of the blast overpressure was less than approximately 35 kPa. Following local administration of the NO synthase inhibitor L-NAME, the increase in the CoBF induced by the blast was inhibited, and this reduction was significantly associated with the hearing threshold.

  2. The Prevalence of Hearing Disorders among the 3-6 Years Old Children of Kindergartens in Welfare Organization of Tehran Province

    Directory of Open Access Journals (Sweden)

    Younes Lotfi

    2001-06-01

    Full Text Available Objective: A “hearing-impaired is defined as abnormal or reduced function in hearing resulting from auditory disorder” (Stach,1997. The goal of any preschool and school screening program should be to accurately identify those children whose hearing has impaired resulting from either conductive and / or sensory - neural pathology. Although some ear pathologies (e.g., middle ear effusion might not produce a significant hearing loss, screening for these pathologies should be a part of the screening program because they may influence the potential to learn. Materials & Methods: This research was carried out in a cross-sectional descriptive study on 577 children (278 girls and 299 boys among the 3-6 years old children of kindergartens in Welfare Organization of the Tehran Province from March to June 2001. The otoscopy examination, pure-tone screening and impedance screening was conducted after completion the parents awareness form of the hearing loss existence. Results: In this study, there were 12.58% abnormal conditions of external ear canal, 23.7% abnormal tympanic membrane, 34.3% abnormal tympanograms, 35% no acoustic reflex, 12.6% hearing loss including 9.7% bilateral and 2.9% unilateral hearing loss (12.0% conductive hearing loss, 0.64% sensory-neural hearing loss and 0.36% mixed hearing loss, higher prevalence of left ear disorders and statistically meaning difference between two ears (P<0.05 in all of studied items, except of acoustic reflex condition. Conclusion: With respect to high prevalence of need to medical care and the negative effects of middle ear disorders in learning of preschool children, and also due to the importance of early identification and intervention of hearing loss in aural rehabilitation programs, awaring and teaching the people about the effects of hearing disorders and it's prevention and identification are very important.

  3. Association of tinnitus and hearing loss in otological disorders: a decade-long epidemiological study in a South Indian population

    Directory of Open Access Journals (Sweden)

    Santoshi Kumari Manche

    Full Text Available Abstract Introduction: Tinnitus is a common disorder that occurs frequently across all strata of population and has an important health concern. Tinnitus is often associated with different forms of hearing loss of varying severity. Objective: The present study aimed to identify the association of tinnitus with hearing loss in various otological disorders of a South Indian population. Methods: A total of 3255 subjects referred to the MAA ENT Hospital, Hyderabad, from 2004 to 2014, affected with various otological diseases have been included in the present cross-sectional study. Diagnosis of the diseases was confirmed by an ear, nose, and throat (ENT specialist using detailed medical and clinical examination. Statistical analysis was performed using the χ 2 test and binary logistic regression. Results: Tinnitus was observed in 29.3% (956 of the total study subjects that showed an increased prevalence in greater than 40 years of age. There was a significant increase in risk of tinnitus with middle (OR = 1.79, 95% CI = 1.02-3.16 and inner (OR = 3.00, 95% CI = 1.65-5.45 inner ear diseases. It was noted that 96.9% (n = 927 of the tinnitus subjects was associated with hearing loss. Otitis media (60.9%, presbycusis (16.6% and otosclerosis (14.3% are the very common otological disorders leading to tinnitus. Tinnitus was significantly associated with higher degree of hearing loss in chronic suppurative otitis media (CSOM subjects. Conclusion: The present study could identify the most prevalent otological risk factors leading to development of tinnitus with hearing loss in a South Indian population.

  4. Frequency Distribution of Hearing Disorders Among the Student of Public Elementary school in EslamAbad Gharb

    Directory of Open Access Journals (Sweden)

    Dr. Abdollah Mousavi

    2000-05-01

    Full Text Available Objects Determining the frequency distribution of hearing disorders among the student of public elementary school by Otoscopy, Puretone Audiometry, impedance Audiometry and questionnaires. Methods and Materials: This study was can-led out in a cross - sectional descriptive survey - on 1000 students (500 girls and 500 boys among the student of primary school of EslamAhad Gharh, academic year 1376-77 Results: 1- Otoscopy examination; abnormal conditions of external ear canal was found in 13.65% of cases; mostly impacted ceruman (13.3%. Abnormal conditions of external ear canal was more prevalent in girls than boys and the difference was statistically meaningful in the right (P V=0 .012 and left (PV=0.043 ear. Abnormal tympanic membrane was seen in 6.75% of cases; mostly retraction (295%. "n2- Impedance Audiometry: 11.05% abnormal tympanograms were observed, mostly type C (4.1%. 3- Pure Tone Audiometry: An overall 9.7% hearing loss was found in this population including 3.5% bilateral and 6.2% unilateral hearing loss. 4.15% of population suffered from SNHL observed mostly in boys and conductive. Hearing loss mostly in girls and the difference was statistically meaning in the left ear (PV=0.03. (l.e 0.6% were in need of rehabilitation services. Family background showed on effects on the hearing disorders. Only 11. 4% of parents, 13.4% of teachers and 14.4% of afflicted students were aware of the problem.

  5. Irreversibility and conditional probability

    International Nuclear Information System (INIS)

    Stuart, C.I.J.M.

    1989-01-01

    The mathematical entropy - unlike physical entropy - is simply a measure of uniformity for probability distributions in general. So understood, conditional entropies have the same logical structure as conditional probabilities. If, as is sometimes supposed, conditional probabilities are time-reversible, then so are conditional entropies and, paradoxically, both then share this symmetry with physical equations of motion. The paradox is, of course that probabilities yield a direction to time both in statistical mechanics and quantum mechanics, while the equations of motion do not. The supposed time-reversibility of both conditionals seems also to involve a form of retrocausality that is related to, but possibly not the same as, that described by Costa de Beaurgard. The retrocausality is paradoxically at odds with the generally presumed irreversibility of the quantum mechanical measurement process. Further paradox emerges if the supposed time-reversibility of the conditionals is linked with the idea that the thermodynamic entropy is the same thing as 'missing information' since this confounds the thermodynamic and mathematical entropies. However, it is shown that irreversibility is a formal consequence of conditional entropies and, hence, of conditional probabilities also. 8 refs. (Author)

  6. Hearing Loss due to Carbon Monoxide Poisoning

    DEFF Research Database (Denmark)

    Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl

    2013-01-01

    Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker a...

  7. Nonequilibrium and irreversibility

    CERN Document Server

    Gallavotti, Giovanni

    2014-01-01

    This book concentrates on the properties of the stationary states in chaotic systems of particles or fluids, leaving aside the theory of the way they can be reached. The stationary states of particles or of fluids (understood as probability distributions on microscopic configurations or on the fields describing continua) have received important new ideas and data from numerical simulations and reviews are needed. The starting point is to find out which time invariant distributions come into play in physics. A special feature of this book is the historical approach. To identify the problems the author analyzes the papers of the founding fathers Boltzmann, Clausius and Maxwell including translations of the relevant (parts of ) historical documents. He also establishes a close link between treatment of irreversible phenomena in statistical mechanics and the theory of chaotic systems at and beyond the onset of turbulence as developed by Sinai, Ruelle, Bowen (SRB) and others: the author gives arguments intending t...

  8. High-frequency audiometry: A means for early diagnosis of noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    Amir H Mehrparvar

    2011-01-01

    Full Text Available Noise-induced hearing loss (NIHL, an irreversible disorder, is a common problem in industrial settings. Early diagnosis of NIHL can help prevent the progression of hearing loss, especially in speech frequencies. For early diagnosis of NIHL, audiometry is performed routinely in conventional frequencies. We designed this study to compare the effect of noise on high-frequency audiometry (HFA and conventional audiometry. In a historical cohort study, we compared hearing threshold and prevalence of hearing loss in conventional and high frequencies of audiometry among textile workers divided into two groups: With and without exposure to noise more than 85 dB. The highest hearing threshold was observed at 4000 Hz, 6000 Hz and 16000 Hz in conventional right ear audiometry, conventional left ear audiometry and HFA in each ear, respectively. The hearing threshold was significantly higher at 16000 Hz compared to 4000. Hearing loss was more common in HFA than conventional audiometry. HFA is more sensitive to detect NIHL than conventional audiometry. It can be useful for early diagnosis of hearing sensitivity to noise, and thus preventing hearing loss in lower frequencies especially speech frequencies.

  9. Hearing Loss due to Carbon Monoxide Poisoning

    DEFF Research Database (Denmark)

    Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl

    2013-01-01

    Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker...... after an acute exposure to carbon monoxide. This complication was diagnosed by pure-tone audiometry and confirmed by transient evoked otoacoustic emissions. Hearing loss has not improved after 3 months of followup....

  10. A case law review of the individuals with disabilities education act for children with hearing loss or auditory processing disorders.

    Science.gov (United States)

    Kreisman, Brian M; John, Andrew B

    2010-01-01

    In 1975, Congress passed the Education for All Handicapped Children Act (Public Law 94-142), and it has been revised and modified several times. At the time of this writing, this law was most recently amended by the Individuals with Disabilities Education Improvement Act (Pub. L. No. 108-446, 118 Stat. 2647, December 3, 2004), which took effect on July 1, 2005. Colloquially the law is still referred to as the Individuals with Disabilities Education Act (IDEA). Children with hearing loss or auditory processing disorder (APD) may qualify for services under IDEA. However, a review of the literature found no review of case law for such children. This article provides a comprehensive review of case law involving the IDEA and children with hearing loss or APD from the U.S. Supreme Court and U.S. courts of appeals. We conducted a systematic review of case law. A LexisNexis search for cases involving IDEA and children with hearing loss or APDs was conducted. For the purpose of the present case review, all appellate decisions (cases accepted by the U.S. courts of appeals or the U.S. Supreme Court) were included if they found that the child had hearing loss or APD, regardless of the reason for the appeal under IDEA. In the instance of multiple cases that involved the same two parties, these cases are summarized together to provide the legal context. Brief explanations of IDEA and the federal judicial process as it pertains to IDEA disputes are presented. Following these explanations, a chronological review of IDEA appellate cases concerning students with hearing loss or APD is provided. The IDEA cases reviewed focus on three main issues: placement of the child, methodology of teaching, and the provision of services. This case law review provides a helpful summary of higher court cases for educational audiologists and parents of children with hearing loss or APDs, as well as educators, individualized education program team members, school administrators, and legal

  11. Irreversibility in quantum mechanics

    International Nuclear Information System (INIS)

    Kadomtsev, Boris B

    2003-01-01

    From the Editorial Board. November 9, 2003 would have marked the seventy-fifth birthday of Boris Borisovich Kadomtsev, were he alive. An outstanding theoretical physicist, teacher, and enlightener, a prominent scientist in plasma physics and controlled nuclear fusion, Kadomtsev was also actively involved in science organization activities. In particular, from 1976 until his untimely death on August 19, 1998, Kadomtsev was the Editor-in-Chief of Physics-Uspekhi, and it is owing to his efforts that the journal improved notably during his tenure. Now, the Editorial Board, with gratitude and sorrow, would like to celebrate his birthday and to honor his blessed memory in these pages. There is, however, a rule - indeed an immutable tradition - in the journal that, except for the Personalia section, no anniversary can be marked in any way other than in a scientific publication. This rule was strictly observed under Kadomtsev, and certainly should not be violated now, even when honoring his memory. Fortunately, there is a video which remained of a lecture on modern problems of quantum physics that Kadomtsev delivered on May 12, 1997. Prepared for publication by M B Kadomtsev, the lecture allows the reader to revisit the heritage of B B Kadomtsev, to appreciate his logic in treating this very difficult area of physics, to hear his voice as it were, to recall Boris Borisovich Kadomtsev and to honor his memory. (methodological notes)

  12. Hereditary Hearing Loss.

    Science.gov (United States)

    Tran, LenhAnh P.; Grundfast, Kenneth M.

    1997-01-01

    This article discusses inheritance patterns in hearing loss, epidemiology, clues to genetic causes, locating genes that cause hereditary disorders, genes related to hearing loss disorders in individuals with Usher syndrome, Waardenburg syndrome, Treacher-Collins syndrome, Branchio-oto-renal and Pendred syndromes, and the significance of finding…

  13. Assistive Devices for People with Hearing, Voice, Speech, or Language Disorders

    Science.gov (United States)

    ... the person with hearing loss. With today’s new electronic communication devices, however, TTY machines have almost become a thing of the past. People can place phone calls through the telecommunications relay service using almost any device with a keypad, ...

  14. EchoScan: A new system to objectively assess peripheral hearing disorders

    Directory of Open Access Journals (Sweden)

    Thomas Venet

    2012-01-01

    Full Text Available Pure-tone air-conduction audiometry (PTA is the reference clinical test used in Europe and the United States to measure the extent of hearing loss. It is a subjective, behavioral test, which measures thresholds of hearing sensations and perceptions based on patient responses to frequency-specific pure-tone stimuli. PTA can detect hearing problems due to cochlear or retro-cochlear impairment, without identifying the source of the problem. In contrast, cubic distortion product otoacoustic emissions (DPOAEs detect inner-ear dysfunctions, particularly those involving the outer hair cells sensitive to noise and ototoxicants. Recently, ototoxicants were shown to have an action on the central nuclei driving the middle-ear acoustic reflex. Therefore, a new device, called EchoScan, was conceived to collect and measure performance both in the middle- and inner-ear. Its originality: the use of a battery of DPOAE measurements associated with contra-lateral acoustic stimulation. Changes in DPOAE amplitude due to ageing and gender were incidentally detected and EchoScan was more sensitive than impedancemetry to detect the stapedial reflex. EchoScan can be used both in clinical investigations and in occupational medicine, especially for the auditory follow-up of people exposed to noise or ototoxic agents. EchoScan could be promising to assess early detection in programs to prevent hearing loss.

  15. Hearing loss

    Science.gov (United States)

    Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss; Sensorineural hearing loss; Presbycusis ... Symptoms of hearing loss may include: Certain sounds seeming too loud Difficulty following conversations when two or more people are talking ...

  16. About Hearing

    Science.gov (United States)

    ... Info to Go » Hearing-Related » About Hearing About Hearing Each child who is deaf or hard of ... the ear to the brain. Implications: When the hearing mechanism is not functioning Hearing may be impacted ...

  17. Inter-trial coherence as a marker of cortical phase synchrony in children with sensorineural hearing loss and auditory neuropathy spectrum disorder fitted with hearing aids and cochlear implants

    Science.gov (United States)

    Nash-Kille, Amy; Sharma, Anu

    2014-01-01

    Objective Although brainstem dys-synchrony is a hallmark of children with auditory neuropathy spectrum disorder (ANSD), little is known about how the lack of neural synchrony manifests at more central levels. We used time-frequency single-trial EEG analyses (i.e., inter-trial coherence; ITC), to examine cortical phase synchrony in children with normal hearing (NH), sensorineural hearing loss (SNHL) and ANSD. Methods Single trial time-frequency analyses were performed on cortical auditory evoked responses from 41 NH children, 91 children with ANSD and 50 children with SNHL. The latter two groups included children who received intervention via hearing aids and cochlear implants. ITC measures were compared between groups as a function of hearing loss, intervention type, and cortical maturational status. Results In children with SNHL, ITC decreased as severity of hearing loss increased. Children with ANSD revealed lower levels of ITC relative to children with NH or SNHL, regardless of intervention. Children with ANSD who received cochlear implants showed significant improvements in ITC with increasing experience with their implants. Conclusions Cortical phase coherence is significantly reduced as a result of both severe-to-profound SNHL and ANSD. Significance ITC provides a window into the brain oscillations underlying the averaged cortical auditory evoked response. Our results provide a first description of deficits in cortical phase synchrony in children with SNHL and ANSD. PMID:24360131

  18. Central auditory processing disorder (CAPD tests in a school-age hearing screening programme – analysis of 76,429 children

    Directory of Open Access Journals (Sweden)

    Piotr H. Skarzynski

    2015-02-01

    Full Text Available [b]Introduction and objective[/b]. Hearing disorders among school-age children are a current concern. Continuing studies have been performed in Poland since 2008, and on 2 December 2011 the EU Council adopted Conclusions on the Early Detection and Treatment of Communication Disorders in Children, Including the Use of e-Health Tools and innovative Solutions. The discussion now focuses not only on the efficacy of hearing screening programmes in schoolchildren, but what should be its general aim and what tests it should include? This paper makes the case that it is important to include central auditory processing disorder (CAPD tests. One such test is the dichotic digits test (DDT. The aim of the presented study was to evaluate the usefulness of the DDT in detecting central hearing disorders in school-age children. [b]Materials and methods[/b]. During hearing screening programmes conducted in Poland in 2008–2010, exactly 235,664 children (7–12-years-old were screened in 9,325 schools. Of this number, 7,642 were examined using the DDT test for CAPD. Screening programmes were conducted using the Sense Examination Platform. [b]Results.[/b] With the cut-off criterion set at the 5th percentile, results for the DDT applied in a divided attention mode were 11.4% positive for 7-year-olds and 11.3% for 12-year-olds. In the focused attention mode, the comparable result for 12-year-olds was 9.7%. There was a clear right ear advantage. In children with positive DDT results, a higher incidence of other disorders, such as dyslexia, was observed. [b]Conclusions[/b]. A test for CAPD should be included in the hearing screening of school-age children. The results of this study form the basis for developing Polish standards in this area.

  19. Effect of Workplace Noise on Hearing Ability in Tile and Ceramic Industry Workers in Iran: A 2-Year Follow-Up Study

    Directory of Open Access Journals (Sweden)

    Mehrdad Mostaghaci

    2013-01-01

    Full Text Available Introduction. Noise as a common physical hazard may lead to noise-induced hearing loss, an irreversible but preventable disorder. Annual audiometric evaluations help detect changes in hearing status before clinically significant hearing loss develops. This study was designed to track hearing threshold changes during 2-year follow-up among tile and ceramic workers. Methods. This follow-up study was conducted on 555 workers (totally 1110 ears. Subjects were divided into four groups according to the level of noise exposure. Hearing threshold in conventional audiometric frequencies was measured and standard threshold shift was calculated for each ear. Results. Hearing threshold was increased during 2 years of follow-up. Increased hearing threshold was most frequently observed at 4000, 6000, and 3000 Hz. Standard threshold shift was observed in 13 (2.34%, 49 (8.83%, 22 (3.96%, and 63 (11.35% subjects in the first and second years of follow-up in the right and left ears, respectively. Conclusions. This study has documented a high incidence of noise-induced hearing loss in tile and ceramic workers that would put stress on the importance of using hearing protection devices.

  20. Effect of workplace noise on hearing ability in tile and ceramic industry workers in Iran: a 2-year follow-up study.

    Science.gov (United States)

    Mostaghaci, Mehrdad; Mirmohammadi, Seyyed Jalil; Mehrparvar, Amir Houshang; Bahaloo, Maryam; Mollasadeghi, Abolfazl; Davari, Mohammad Hossein

    2013-01-01

    Noise as a common physical hazard may lead to noise-induced hearing loss, an irreversible but preventable disorder. Annual audiometric evaluations help detect changes in hearing status before clinically significant hearing loss develops. This study was designed to track hearing threshold changes during 2-year follow-up among tile and ceramic workers. This follow-up study was conducted on 555 workers (totally 1110 ears). Subjects were divided into four groups according to the level of noise exposure. Hearing threshold in conventional audiometric frequencies was measured and standard threshold shift was calculated for each ear. Hearing threshold was increased during 2 years of follow-up. Increased hearing threshold was most frequently observed at 4000, 6000, and 3000 Hz. Standard threshold shift was observed in 13 (2.34%), 49 (8.83%), 22 (3.96%), and 63 (11.35%) subjects in the first and second years of follow-up in the right and left ears, respectively. This study has documented a high incidence of noise-induced hearing loss in tile and ceramic workers that would put stress on the importance of using hearing protection devices.

  1. Intrinsic irreversibility in quantum theory

    International Nuclear Information System (INIS)

    Prigogine, I.; Petrosky, T.Y.

    1987-01-01

    Quantum theory has a dual structure: while solutions of the Schroedinger equation evolve in a deterministic and time reversible way, measurement introduces irreversibility and stochasticity. This presents a contrast to Bohr-Sommerfeld-Einstein theory, in which transitions between quantum states are associated with spontaneous and induced transitions, defined in terms of stochastic processes. A new form of quantum theory is presented here, which contains an intrinsic form of irreversibility, independent of observation. This new form applies to situations corresponding to a continuous spectrum and to quantum states with finite life time. The usual non-commutative algebra associated to quantum theory is replaced by more general algebra, in which operators are also non-distributive. Our approach leads to a number of predictions, which hopefully may be verified or refuted in the next years. (orig.)

  2. Extremum principles for irreversible processes

    International Nuclear Information System (INIS)

    Hillert, M.; Agren, J.

    2006-01-01

    Hamilton's extremum principle is a powerful mathematical tool in classical mechanics. Onsager's extremum principle may play a similar role in irreversible thermodynamics and may also become a valuable tool. His principle may formally be regarded as a principle of maximum rate of entropy production but does not have a clear physical interpretation. Prigogine's principle of minimum rate of entropy production has a physical interpretation when it applies, but is not strictly valid except for a very special case

  3. Irreversible stochastic processes on lattices

    International Nuclear Information System (INIS)

    Nord, R.S.

    1986-01-01

    Models for irreversible random or cooperative filling of lattices are required to describe many processes in chemistry and physics. Since the filling is assumed to be irreversible, even the stationary, saturation state is not in equilibrium. The kinetics and statistics of these processes are described by recasting the master equations in infinite hierarchical form. Solutions can be obtained by implementing various techniques: refinements in these solution techniques are presented. Programs considered include random dimer, trimer, and tetramer filling of 2D lattices, random dimer filling of a cubic lattice, competitive filling of two or more species, and the effect of a random distribution of inactive sites on the filling. Also considered is monomer filling of a linear lattice with nearest neighbor cooperative effects and solve for the exact cluster-size distribution for cluster sizes up to the asymptotic regime. Additionally, a technique is developed to directly determine the asymptotic properties of the cluster size distribution. Finally cluster growth is considered via irreversible aggregation involving random walkers. In particular, explicit results are provided for the large-lattice-size asymptotic behavior of trapping probabilities and average walk lengths for a single walker on a lattice with multiple traps. Procedures for exact calculation of these quantities on finite lattices are also developed

  4. Ecological optimization for generalized irreversible Carnot refrigerators

    International Nuclear Information System (INIS)

    Chen Lingen; Zhu Xiaoqin; Sun Fengrui; Wu Chih

    2005-01-01

    The optimal ecological performance of a Newton's law generalized irreversible Carnot refrigerator with the losses of heat resistance, heat leakage and internal irreversibility is derived by taking an ecological optimization criterion as the objective, which consists of maximizing a function representing the best compromise between the exergy output rate and exergy loss rate (entropy production rate) of the refrigerator. Numerical examples are given to show the effects of heat leakage and internal irreversibility on the optimal performance of generalized irreversible refrigerators

  5. Inclusion of Children with Autism Spectrum Disorders: Listening and Hearing to Voices from the Grassroots

    Science.gov (United States)

    Majoko, Tawanda

    2016-01-01

    The current significantly high prevalence rates of autism spectrum disorder (ASD) coupled with the paradigm shift from exclusive to inclusive education warrants research on inclusion of children with ASD in mainstream classrooms in Zimbabwe. A qualitative methodology was used to interview 21 regular primary school teachers regarding social…

  6. Is Hearing Impairment Associated with Rheumatoid Arthritis?

    DEFF Research Database (Denmark)

    Emamifar, Amir; Bjoerndal, Kristine; Jensen Hansen, Inger Marie

    2016-01-01

    BACKGROUND: Rheumatoid arthritis (RA) is a systemic, inflammatory disease that affects 1% of the population. The auditory system may be involved during the course of disease; however the association of RA and hearing impairment has not been clearly defined. OBJECTIVE: The objective of this review...... is to evaluate published clinical reports related to hearing impairment in patients with RA. Furthermore, we discuss possible pathologies and associated factors as well as new treatment modalities. METHOD: A thorough literature search was performed using available databases including Pubmed, Embase, Cochrane...... and ComDisDome to cover all relative reports. The following keywords were used: hearing loss, hearing difficulties, hearing disorders, hearing impairment, sensorineural hearing loss, conductive hearing loss, mixed hearing loss, autoimmune hearing loss, drug ototoxicity, drug-induced hearing loss, hearing...

  7. Antibiotic use for irreversible pulpitis.

    Science.gov (United States)

    Agnihotry, Anirudha; Fedorowicz, Zbys; van Zuuren, Esther J; Farman, Allan G; Al-Langawi, Jassim Hasan

    2016-02-17

    Irreversible pulpitis, which is characterised by acute and intense pain, is one of the most frequent reasons that patients attend for emergency dental care. Apart from removal of the tooth, the customary way of relieving the pain of irreversible pulpitis is by drilling into the tooth, removing the inflamed pulp (nerve) and cleaning the root canal. However, a significant number of dentists continue to prescribe antibiotics to stop the pain of irreversible pulpitis.This review updates the previous version published in 2013. To assess the effects of systemic antibiotics for irreversible pulpitis. We searched the Cochrane Oral Health Group's Trials Register (to 27 January 2016); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015, Issue 12); MEDLINE via Ovid (1946 to 27 January 2016); EMBASE via Ovid (1980 to 27 January 2016), ClinicalTrials.gov (to 27 January 2016) and the WHO International Clinical Trials Registry Platform (to 27 January 2016). There were no language restrictions in the searches of the electronic databases. Randomised controlled trials which compared pain relief with systemic antibiotics and analgesics, against placebo and analgesics in the acute preoperative phase of irreversible pulpitis. Two review authors screened studies and extracted data independently. We assessed the quality of the evidence of included studies using GRADEpro software. Pooling of data was not possible and a descriptive summary is presented. One trial assessed at low risk of bias, involving 40 participants was included in this update of the review. The quality of the body of evidence was rated low for the different outcomes. There was a close parallel distribution of the pain ratings in both the intervention and placebo groups over the seven-day study period. There was insufficient evidence to claim or refute a benefit for penicillin for pain intensity. There was no significant difference in the mean total number of ibuprofen tablets over the

  8. Establishment of mouse model of MYH9 disorders: heterozygous R702C mutation provokes macrothrombocytopenia with leukocyte inclusion bodies, renal glomerulosclerosis and hearing disability.

    Science.gov (United States)

    Suzuki, Nobuaki; Kunishima, Shinji; Ikejiri, Makoto; Maruyama, Shoichi; Sone, Michihiko; Takagi, Akira; Ikawa, Masahito; Okabe, Masaru; Kojima, Tetsuhito; Saito, Hidehiko; Naoe, Tomoki; Matsushita, Tadashi

    2013-01-01

    Nonmuscle myosin heavy chain IIA (NMMHCIIA) encoded by MYH9 is associated with autosomal dominantly inherited diseases called MYH9 disorders. MYH9 disorders are characterized by macrothrombocytopenia and very characteristic inclusion bodies in granulocytes. MYH9 disorders frequently cause nephritis, sensorineural hearing disability and cataracts. One of the most common and deleterious mutations causing these disorders is the R702C missense mutation. We generated knock-in mice expressing the Myh9 R702C mutation. R702C knock-in hetero mice (R702C+/- mice) showed macrothrombocytopenia. We studied megakaryopoiesis of cultured fetal liver cells of R702C+/- mice and found that proplatelet formation was impaired: the number of proplatelet tips was decreased, proplatelet size was increased, and proplatelet shafts were short and enlarged. Although granulocyte inclusion bodies were not visible by May-Grünwald Giemsa staining, immunofluorescence analysis indicated that NMMHCIIA proteins aggregated and accumulated in the granulocyte cytoplasm. In other organs, R702C+/- mice displayed albuminuria which increased with age. Renal pathology examination revealed glomerulosclerosis. Sensory hearing loss was indicated by lowered auditory brainstem response. These findings indicate that Myh9 R702C knock-in mice mirror features of human MYH9 disorders arising from the R702C mutation.

  9. Quantum mechanical irreversibility and measurement

    CERN Document Server

    Grigolini, P

    1993-01-01

    This book is intended as a tutorial approach to some of the techniques used to deal with quantum dissipation and irreversibility, with special focus on their applications to the theory of measurements. The main purpose is to provide readers without a deep expertise in quantum statistical mechanics with the basic tools to develop a critical judgement on whether the major achievements in this field have to be considered a satisfactory solution of quantum paradox, or rather this ambitious achievement has to be postponed to when a new physics, more general than quantum and classical physics, will

  10. Seeing to hear? Patterns of gaze to speaking faces in children with autism spectrum disorders.

    Directory of Open Access Journals (Sweden)

    Julia eIrwin

    2014-05-01

    Full Text Available Using eye-tracking methodology, gaze to a speaking face was compared in a group of children with autism spectrum disorders (ASD and those with typical development (TD. Patterns of gaze were observed under three conditions: audiovisual (AV speech in auditory noise, visual only speech and an AV non-face, non-speech control. Children with ASD looked less to the face of the speaker and fixated less on the speakers’ mouth than TD controls. No differences in gaze were reported for the non-face, non-speech control task. Since the mouth holds much of the articulatory information available on the face, these findings suggest that children with ASD may have reduced access to critical linguistic information. This reduced access to visible articulatory information could be a contributor to the communication and language problems exhibited by children with ASD.

  11. Eating Disorders: The Impact on Children and Families. Hearing before the Select Committee on Children, Youth, and Families. House of Representatives, One Hundredth Congress, First Session (San Francisco, CA, July 31, 1987).

    Science.gov (United States)

    Congress of the U.S., Washington, DC. House Select Committee on Children, Youth, and Families.

    The text of a Congressional hearing to examine the impact of eating disorders on children and families is presented in this document. Testimony by the following witnesses is included: (1) Krista Brown, eating disorder victim, and her mother, Susan Brown; (2) Robert B. Duncan, a hospital president; (3) Patricia Fallon, a clinical psychogist; (4)…

  12. Hearing Screening

    Science.gov (United States)

    Johnson-Curiskis, Nanette

    2012-01-01

    Hearing levels are threatened by modern life--headsets for music, rock concerts, traffic noises, etc. It is crucial we know our hearing levels so that we can draw attention to potential problems. This exercise requires that students receive a hearing screening for their benefit as well as for making the connection of hearing to listening.

  13. Video modeling for children with dual diagnosis of deafness or hard of hearing and autism spectrum disorder to promote peer interaction.

    Science.gov (United States)

    Thrasher, Amy

    2014-11-01

    This article describes an intervention program offered at the University of Colorado Boulder that supports peer interaction among young children with autism spectrum disorders and their typical peers using a multicomponent approach, including video modeling. Characteristics of autism that may interfere with the development of peer interaction in young children will be discussed. Components of the approach will be described and the evidence base for the application of these components examined in regards to children with autism and for the potential application to children with the dual diagnosis of autism and deafness or hard of hearing. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  14. Children with Auditory Neuropathy Spectrum Disorder Fitted with Hearing Aids Applying the American Academy of Audiology Pediatric Amplification Guideline: Current Practice and Outcomes.

    Science.gov (United States)

    Walker, Elizabeth; McCreery, Ryan; Spratford, Meredith; Roush, Patricia

    2016-03-01

    Up to 15% of children with permanent hearing loss (HL) have auditory neuropathy spectrum disorder (ANSD), which involves normal outer hair cell function and disordered afferent neural activity in the auditory nerve or brainstem. Given the varying presentations of ANSD in children, there is a need for more evidence-based research on appropriate clinical interventions for this population. This study compared the speech production, speech perception, and language outcomes of children with ANSD, who are hard of hearing, to children with similar degrees of mild-to-moderately severe sensorineural hearing loss (SNHL), all of whom were fitted with bilateral hearing aids (HAs) based on the American Academy of Audiology pediatric amplification guidelines. Speech perception and communication outcomes data were gathered in a prospective accelerated longitudinal design, with entry into the study between six mo and seven yr of age. Three sites were involved in participant recruitment: Boys Town National Research Hospital, the University of North Carolina at Chapel Hill, and the University of Iowa. The sample consisted of 12 children with ANSD and 22 children with SNHL. The groups were matched based on better-ear pure-tone average, better-ear aided speech intelligibility index, gender, maternal education level, and newborn hearing screening result (i.e., pass or refer). Children and their families participated in an initial baseline visit, followed by visits twice a year for children 2 yr of age. Paired-sample t-tests were used to compare children with ANSD to children with SNHL. Paired t-tests indicated no significant differences between the ANSD and SNHL groups on language and articulation measures. Children with ANSD displayed functional speech perception skills in quiet. Although the number of participants was too small to conduct statistical analyses for speech perception testing, there appeared to be a trend in which the ANSD group performed more poorly in background noise

  15. Anomalies, Unitarity and Quantum Irreversibility

    CERN Document Server

    Anselmi, D

    1999-01-01

    The trace anomaly in external gravity is the sum of three terms at criticality: the square of the Weyl tensor, the Euler density and Box R, with coefficients, properly normalized, called c, a and a', the latter being ambiguously defined by an additive constant. Unitarity and positivity properties of the induced actions allow us to show that the total RG flows of a and a' are equal and therefore the a'-ambiguity can be consistently removed through the identification a'=a. The picture that emerges clarifies several long-standing issues. The interplay between unitarity and renormalization implies that the flux of the renormalization group is irreversible. A monotonically decreasing a-function interpolating between the appropriate values is naturally provided by a'. The total a-flow is expressed non-perturbatively as the invariant (i.e. scheme-independent) area of the graph of the beta function between the fixed points. We test this prediction to the fourth loop order in perturbation theory, in QCD with Nf ~< ...

  16. Examination of various postulates of irreversibility

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, J [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)

    1977-01-01

    Firstly, it is shown that it is necessary to break the reversible character of the B.B.G.K.Y. system of equations by means of a postulate of irreversibility to obtain a kinetic equation compatible with the second principle of thermodynamics. Next, three postulates of irreversibility are examined: that of molecular chaos, that of linear relaxation and, finally, that of superposition. Then the corresponding kinetic equations and the expressions for the viscosity coefficient to which they lead are determined. Comparison with experiment is made each time. Lastly, an attempt to obtain an irreversible kinetic equation without introducing a postulate of irreversibility in the B.B.G.K.Y. system is realized. This consists in adding a complementary irreversible term to the fundamental equation of the dynamics of a particle. The suggested term is of quantum origin and leads to a kinetic equation of the Fokker-Planck type.

  17. [Presbycusis - Age Related Hearing Loss].

    Science.gov (United States)

    Fischer, N; Weber, B; Riechelmann, H

    2016-07-01

    Presbycusis or age related hearing loss can be defined as a progressive, bilateral and symmetrical sensorineural hearing loss due to age related degeneration of inner ear structures. It can be considered a multifactorial complex disorder with environmental and genetic factors. The molecular, electrophysiological and histological damage at different levels of the inner ear cause a progressive hearing loss, which usually affects the high frequencies of hearing. The resulting poor speech recognition has a negative impact on cognitive, emotional and social function in older adults. Recent investigations revealed an association between hearing impairment and social isolation, anxiety, depression and cognitive decline in elderly. These findings emphasize the importance of diagnosis and treating hearing loss in the elderly population. Hearing aids are the most commonly used devices for treating presbycusis. The technical progress of implantable hearing devices allows an effective hearing rehabilitation even in elderly with severe hearing loss. However, most people with hearing impairments are not treated adequately. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Hearing Aids

    Science.gov (United States)

    ... primarily useful in improving the hearing and speech comprehension of people who have hearing loss that results ... and you can change the program for different listening environments—from a small, quiet room to a ...

  19. Hear, hear, what, what

    Energy Technology Data Exchange (ETDEWEB)

    1985-02-01

    Noise is now the most serious health hazard in industry. People risk suffering severe damage to their hearing and health generally through exposure to noise levels which exceed the risk limit of 95-90 dB(A). Stress related problems are often directly the result of exposure to noise. Furthermore, noise leads to reduced productivity, increased absenteeism and compensation claims. In a series of eight reports, Bilson technologists detail the specific noise problems commonly encountered in each of the major areas of industry. These range from the concrete and construction industry through sawmilling, wood working, mining and mechanical engineering, to textile and food manufacture. This report discusses the noise in mining, considering drills, load haul dump machines, surface mines, earth moving equipment, treatment plants, frequency spectra of noise, and finally, choice of hearing protection.

  20. Hearing Problems

    Science.gov (United States)

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Hearing ProblemsLoss in the ability to hear or discriminate ... This flow chart will help direct you if hearing loss is a problem for you or a ...

  1. Optimization of an irreversible Stirling regenerative cycle

    International Nuclear Information System (INIS)

    Aragón-González, G; Cano-Bianco, M; León-Galicia, A; Rivera-Camacho, J M

    2015-01-01

    In this work a Stirling regenerative cycle with some irreversibilities is analyzed. The analyzed irreversibilities are located at the heat exchangers. They receive a finite amount of heat and heat leakage occurs between both reservoirs. Using this model, power and the efficiency at maximum power are obtained. Some optimal design parameters for the exchanger heat areas and thermal conductances are presented. The relation between the power, efficiency and the results obtained are shown graphically

  2. Irreversible thermodynamics of Poisson processes with reaction.

    Science.gov (United States)

    Méndez, V; Fort, J

    1999-11-01

    A kinetic model is derived to study the successive movements of particles, described by a Poisson process, as well as their generation. The irreversible thermodynamics of this system is also studied from the kinetic model. This makes it possible to evaluate the differences between thermodynamical quantities computed exactly and up to second-order. Such differences determine the range of validity of the second-order approximation to extended irreversible thermodynamics.

  3. Occupational hearing loss of market mill workers in the city of Accra, Ghana

    OpenAIRE

    Emmanuel D Kitcher; Grace Ocansey; Benjamin Abaidoo; Alidu Atule

    2014-01-01

    Noise induced hearing loss (NIHL) is an irreversible sensorineural hearing loss associated with exposure to high levels of excessive noise. Prevention measures are not well established in developing countries. This comparative cross sectional study aims to determine the prevalence of hearing loss in both a group of high risk workers and a control group and to assess their knowledge of the effects of noise on hearing health. A total of 101 market mill workers and 103 controls employed within m...

  4. Irreversibility and self-organization in spin glasses. 1. Origin of irreversibility in spin glasses

    International Nuclear Information System (INIS)

    Kovrov, V.P.; Kurbatov, A.M.

    1989-05-01

    The origin of irreversibility in spin glasses is found out on the basis of the analytical study of the well-known TAP equations. Connection between irreversible jumpwise transitions and a positive feedback in spin glasses is discussed. (author). 7 refs, 4 figs

  5. Do Hearing Protectors Protect Hearing?

    Science.gov (United States)

    Groenewold, Matthew R.; Masterson, Elizabeth A.; Themann, Christa L.; Davis, Rickie R.

    2015-01-01

    Background We examined the association between self-reported hearing protection use at work and incidence of hearing shifts over a 5-year period. Methods Audiometric data from 19,911 workers were analyzed. Two hearing shift measures—OSHA standard threshold shift (OSTS) and high-frequency threshold shift (HFTS)—were used to identify incident shifts in hearing between workers’ 2005 and 2009 audiograms. Adjusted odds ratios were generated using multivariable logistic regression with multi-level modeling. Results The odds ratio for hearing shift for workers who reported never versus always wearing hearing protection was nonsignificant for OSTS (OR 1.23, 95% CI 0.92–1.64) and marginally significant for HFTS (OR 1.26, 95% CI 1.00–1.59). A significant linear trend towards increased risk of HFTS with decreased use of hearing protection was observed (P = 0.02). Conclusion The study raises concern about the effectiveness of hearing protection as a substitute for noise control to prevent noise-induced hearing loss in the workplace. Am. J. Ind. Med. 57:1001–1010, 2014. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. PMID:24700499

  6. Absorption media for irreversibly gettering thionyl chloride

    Science.gov (United States)

    Buffleben, George; Goods, Steven H.; Shepodd, Timothy; Wheeler, David R.; Whinnery, Jr., LeRoy

    2002-01-01

    Thionyl chloride is a hazardous and reactive chemical used as the liquid cathode in commercial primary batteries. Contrary to previous thinking, ASZM-TEDA.RTM. carbon (Calgon Corporation) reversibly absorbs thionyl chloride. Thus, several candidate materials were examined as irreversible getters for thionyl chloride. The capacity, rate and effect of temperature were also explored. A wide variety of likely materials were investigated through screening experiments focusing on the degree of heat generated by the reaction as well as the material absorption capacity and irreversibility, in order to help narrow the group of possible getter choices. More thorough, quantitative measurements were performed on promising materials. The best performing getter was a mixture of ZnO and ASZM-TEDA.RTM. carbon. In this example, the ZnO reacts with thionyl chloride to form ZnCl.sub.2 and SO.sub.2. The SO.sub.2 is then irreversibly gettered by ASZM-TEDA.RTM. carbon. This combination of ZnO and carbon has a high capacity, is irreversible and functions effectively above -20.degree. C.

  7. Risk Aversion, Price Uncertainty and Irreversible Investments

    NARCIS (Netherlands)

    van den Goorbergh, R.W.J.; Huisman, K.J.M.; Kort, P.M.

    2003-01-01

    This paper generalizes the theory of irreversible investment under uncertainty by allowing for risk averse investors in the absence of com-plete markets.Until now this theory has only been developed in the cases of risk neutrality, or risk aversion in combination with complete markets.Within a

  8. Port contact systems for irreversible thermodynamical systems

    NARCIS (Netherlands)

    Eberard, D.; Maschke, B.M.; Schaft, A.J. van der

    2005-01-01

    In this paper we propose a definition of control contact systems, generalizing input-output Hamiltonian systems, to cope with models arising from irreversible Thermodynamics. We exhibit a particular subclass of these systems, called conservative, that leaves invariant some Legendre submanifold (the

  9. Onsager's reciprocity theorem in extended irreversible thermodynamics

    International Nuclear Information System (INIS)

    Garcia-Colin, L.S.; Velasco, R.M.

    1992-01-01

    In this paper we shall discuss the Onsager relations for the transport coefficients in a dilute monatomic gas described by the extended irreversible thermodynamics. Our discussion is based on a 26 variables description of the system and its corresponding comparison with the kinetic reciprocity between coefficients is shown (Author)

  10. A kinetic equation for irreversible aggregation

    International Nuclear Information System (INIS)

    Zanette, D.H.

    1990-09-01

    We introduce a kinetic equation for describing irreversible aggregation in the ballistic regime, including velocity distributions. The associated evolution for the macroscopic quantities is studied, and the general solution for Maxwell interaction models is obtained in the Fourier representation. (author). 23 refs

  11. Alterações auditivas e fenilcetonúria: uma revisão sistemática Hearing disorders and phenylketonuria: a systematic review

    Directory of Open Access Journals (Sweden)

    Patrícia Cotta Mancini

    2010-02-01

    in individuals with phenylketonuria. Essentially, a dietary treatment should be implemented in the first weeks of life in order to avoid clinical and biochemical manifestations of the disease. When diet is continually maintained, children with phenylketonuria show normal development. However, deficits in executive functions, interhemispherical interaction, language and memory have been observed even in children with early treatment and appropriate diet. Some researches were carried out for investigating the relationship between phenylketonuria and alterations in the hearing function. PURPOSE: to systematically review articles dedicated to the research of relationship between hearing disorders and hyperphenylalaninaemias, highlighting the classic phenylketonuria. The bibliographical references were obtained through research in the databases: Lilacs, Medline, Cochrane Library and Scielo and through search in the reference list of the identified and selected articles. CONCLUSION: the relationship among hyperphenylalaninaemias, including phenylketonuria, and hearing alterations is still controversial in the literature. It is suggested that more investigations as for the hearing function are necessary on those individuals in order to elucidate this possible relationship.

  12. Hearing Impairment

    Science.gov (United States)

    ... Ear Hears Think about how you can feel speakers vibrate on your sound system or feel your throat vibrate when you speak. Sound, which is made up of invisible waves of energy, causes these vibrations. Hearing begins when sound waves that travel through ...

  13. Lungfish Hearing

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Madsen, Peter Teglberg; Christensen-Dalsgaard, Jakob

    Recent research has shown that tympanic middle ears evolved independently in the major vertebrate groups and represent independent experiments in terrestrial hearing. Furthermore, the tympanic ear emerged quite late – ap - proximately 120 mya after the origin of the tetrapods and approximately 70...... my after the first truly terrestrial tetrapods emerged. One of the major challenges is to understand the transitional stages from tetrapod ancestors to the tympanic tetrapod ear, for example how a non-tympanic ear functions in terrestrial hearing. Lungfish are the closest living relatives...... and urodeles. Based on ABR and vibration measurements also on amphib - ians, lizards, snakes and alligators we can outline scenarios for the initial adaptations of the middle ear to non-tympanic hearing and assess the selection pressures later adapting the middle ear for tympanic hearing. Hearing by bone...

  14. The influence of music and stress on musicians' hearing

    Science.gov (United States)

    Kähäri, Kim; Zachau, Gunilla; Eklöf, Mats; Möller, Claes

    2004-10-01

    Hearing and hearing disorders among classical and rock/jazz musicians was investigated. Pure tone audiometry was done in 140 classical and 139 rock/jazz musicians. The rock/jazz musicians answered a questionnaire concerning hearing disorders and psychosocial exposure. All results were compared to age appropriate reference materials. Hearing thresholds showed a notch configuration in both classical and rock/jazz musicians indicating the inclusion of high sound levels but an overall well-preserved hearing thresholds. Female musicians had significantly better hearing thresholds in the high-frequency area than males. Rock/jazz musicians showed slight worse hearing thresholds as compared to classical musicians. When assessing hearing disorders, a large number of rock/jazz musicians suffered from different hearing disorders (74%). Hearing loss, tinnitus and hyperacusis were the most common disorders and were significantly more frequent in comparison with different reference populations. Among classical musicians, no extended negative progress of the pure tone hearing threshold values was found in spite of the continued 16 years of musical noise exposure. In rock/jazz musicians, there was no relationships between psychosocial factors at work and hearing disorders. The rock/jazz musicians reported low stress and high degree of energy. On the average, the rock/jazz musicians reported higher control, lower stress and higher energy than a reference material of white-collar workers.

  15. Definition of fluctuant hearing loss.

    Science.gov (United States)

    Shea, J J

    1975-06-01

    In summary, fluctuant hearing loss is defined as a disorder of the inner ear characterized by fullness, roaring tinnitus, and fluctuations in hearing. It is believed to be caused by an inadequate absorption of endolymph from the endolymphatic sac, with or without one or more metabolic disorders, that interferes with the delicate balance between the production and absorption of endolymph and thus produces cochlear hydrops. This triad of fullness, roaring tinnitus, and fluctuant hearing loss resulting from cochlear hydrops is much more common than the quadrad of true turning vertigo, fullness, roaring tinnitus, and fluctuant hearing loss due to vestibular and cochlear hydrops known as Meniere's disease. Although patients with fluctuant hearing loss only may eventually develop vertigo as the chief complaint and then be said to have Meniere's disease, it is remarkable how many patients continue to suffer mainly from cochlear symptoms at all times. It would appear, because of the greater frequency of fluctuant hearing loss than in Meniere's disease, that the cochlear labyrinth is more susceptible to hydrops than the vestibular labyrinth. For the purposes of diagnosis and treatment it is very useful to separate patients into those with fluctuant hearing loss and those with Meniere's disease.

  16. Irreversibility and self-organization in spin glasses. 2. Irreversibility and the problem of configuration averaging

    International Nuclear Information System (INIS)

    Kovrov, V.P.; Kurbatov, A.M.

    1989-05-01

    The generalization of a configuration averaging to a system displaying irreversible effects is suggested. The properties of the ''pathological'' equilibrium state at low temperatures are determined and discussed. (author). 16 refs, 3 figs

  17. Hearing loss and speech perception in noise difficulties in Fanconi anemia

    NARCIS (Netherlands)

    Verheij, Emmy; Oomen, Karin P.Q.; Smetsers, Stephanie E.; van Zanten, Gijsbert A.; Speleman, Lucienne

    2017-01-01

    Objectives/Hypothesis: Fanconi anemia is a hereditary chromosomal instability disorder. Hearing loss and ear abnormalities are among the many manifestations reported in this disorder. In addition, Fanconi anemia patients often complain about hearing difficulties in situations with background noise

  18. Hearing loss in fibromyalgia? Somatic sensory and non-sensory symptoms in patients with fibromyalgia and other rheumatic disorders

    NARCIS (Netherlands)

    Wolfe, Frederick; Rasker, Johannes J.; Häuser, W.

    2012-01-01

    OBJECTIVES: It has been proposed that fibromyalgia can be understood as a disorder of central sensitisation and dysregulation (CD) and that characteristic somatic symptoms are the result of `central augmentation`. We examined this hypothesis by analysing sensory and non-sensory variables in the

  19. Optima and bounds for irreversible thermodynamic processes

    International Nuclear Information System (INIS)

    Hoffmann, K.H.

    1990-01-01

    In this paper bounds and optima for irreversible thermodynamic processes and their application in different fields are discussed. The tools of finite time thermodynamics are presented and especially optimal control theory is introduced. These methods are applied to heat engines, including models of the Diesel engine and a light-driven engine. Further bounds for irreversible processes are introduced, discussing work deficiency and its relation to thermodynamic length. Moreover the problem of dissipation in systems composed of several subsystems is studied. Finally, the methods of finite time thermodynamics are applied to thermodynamic processes described on a more microscopic level. The process used as an example is simulated annealing. It is shown how optimal control theory is applied to find the optimal cooling schedule for this important stochastic optimization method

  20. Time in Science: Reversibility vs. Irreversibility

    Science.gov (United States)

    Pomeau, Yves

    To discuss properly the question of irreversibility one needs to make a careful distinction between reversibility of the equations of motion and the choice of the initial conditions. This is also relevant for the rather confuse philosophy of the wave packet reduction in quantum mechanics. The explanation of this reduction requires also to make precise assumptions on what initial data are accessible in our world. Finally I discuss how a given (and long) time record can be shown in an objective way to record an irreversible or reversible process. Or: can a direction of time be derived from its analysis? This leads quite naturally to examine if there is a possible spontaneous breaking of the time reversal symmetry in many body systems, a symmetry breaking that would be put in evidence objectively by looking at certain specific time correlations.

  1. Mathematical models and equilibrium in irreversible microeconomics

    Directory of Open Access Journals (Sweden)

    Anatoly M. Tsirlin

    2010-07-01

    Full Text Available A set of equilibrium states in a system consisting of economic agents, economic reservoirs, and firms is considered. Methods of irreversible microeconomics are used. We show that direct sale/purchase leads to an equilibrium state which depends upon the coefficients of supply/demand functions. To reach the unique equilibrium state it is necessary to add either monetary exchange or an intermediate firm.

  2. Hearing Aids

    Science.gov (United States)

    ... listen to TV or your music player, play videogames, or use your phone. Talk to your audiologist ... your audiologist several times, but it's worth the benefit of being able to hear your friends and ...

  3. Bonebridge Implantation for Conductive Hearing Loss in a Patient with Oval Window Atresia.

    Science.gov (United States)

    Kim, Minbum

    2015-08-01

    The occurrence of oval window atresia is a rare anomaly with conductive hearing loss. Traditional atresia surgeries involve challenging surgical techniques with risks of irreversible inner ear damage. Recent reports on Bonebridge (Medel, Innsbruck, Austria), a novel implantable bone conduction hearing aid system, assert that the device is safe and effective for conductive hearing loss. We present a case of Bonebridge implantation in an eight-year-old girl with bilateral oval window atresia.

  4. Trends in incidence of occupational asthma, contact dermatitis, noise-induced hearing loss, carpal tunnel syndrome and upper limb musculoskeletal disorders in European countries from 2000 to 2012.

    Science.gov (United States)

    Stocks, S Jill; McNamee, Roseanne; van der Molen, Henk F; Paris, Christophe; Urban, Pavel; Campo, Giuseppe; Sauni, Riitta; Martínez Jarreta, Begoña; Valenty, Madeleine; Godderis, Lode; Miedinger, David; Jacquetin, Pascal; Gravseth, Hans M; Bonneterre, Vincent; Telle-Lamberton, Maylis; Bensefa-Colas, Lynda; Faye, Serge; Mylle, Godewina; Wannag, Axel; Samant, Yogindra; Pal, Teake; Scholz-Odermatt, Stefan; Papale, Adriano; Schouteden, Martijn; Colosio, Claudio; Mattioli, Stefano; Agius, Raymond

    2015-04-01

    The European Union (EU) strategy for health and safety at work underlines the need to reduce the incidence of occupational diseases (OD), but European statistics to evaluate this common goal are scarce. We aim to estimate and compare changes in incidence over time for occupational asthma, contact dermatitis, noise-induced hearing loss (NIHL), carpal tunnel syndrome (CTS) and upper limb musculoskeletal disorders across 10 European countries. OD surveillance systems that potentially reflected nationally representative trends in incidence within Belgium, the Czech Republic, Finland, France, Italy, the Netherlands, Norway, Spain, Switzerland and the UK provided data. Case counts were analysed using a negative binomial regression model with year as the main covariate. Many systems collected data from networks of 'centres', requiring the use of a multilevel negative binomial model. Some models made allowance for changes in compensation or reporting rules. Reports of contact dermatitis and asthma, conditions with shorter time between exposure to causal substances and OD, were consistently declining with only a few exceptions. For OD with physical causal exposures there was more variation between countries. Reported NIHL was increasing in Belgium, Spain, Switzerland and the Netherlands and decreasing elsewhere. Trends in CTS and upper limb musculoskeletal disorders varied widely within and between countries. This is the first direct comparison of trends in OD within Europe and is consistent with a positive impact of European initiatives addressing exposures relevant to asthma and contact dermatitis. Taking a more flexible approach allowed comparisons of surveillance data between and within countries without harmonisation of data collection methods. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. Irreversible properties of YBCO coated conductors

    International Nuclear Information System (INIS)

    Vostner, A.

    2001-02-01

    Over the past few years substantial efforts were made to optimize the fabrication techniques of various high temperature superconductors for commercial applications. In addition to Bi-2223 tapes, Y-123 coated conductors have the potential for large-scale production and are considered as the second generation of superconducting 'wires' for high current applications. This work reports on magnetic and transport current investigations of Y-123 thick films deposited on either single crystalline substrates by liquid phase epitaxy (LPE) or on metallic substrates by pulsed laser deposition (PLD). At the beginning, a short introduction of the general idea of a coated conductor and of the different production techniques is presented, followed by a description of the different experimental set-ups and the evaluation methods. The main part starts with the results obtained from SQUID magnetometry and ac-susceptibility measurements including the transition temperatures T c , the field dependence of the magnetic critical current densities and the irreversibility lines. In addition, some issues concerning the granular structure and the inter- and intragranular current distribution of the superconducting films are discussed. The investigations by transport currents are focused on the behavior of the application relevant irreversible parameters. These are the angular and the field dependence of the critical transport current densities at 77 and 60 K, as well as the temperature dependence of the irreversibility fields up to 6 T. To gain more insight into the defect structure of the films, neutron irradiation studies were performed on some samples. The introduction of these artificial pinning centers causes large enhancements of the magnetic J c in LPE specimens for the field parallel to the c-axis (H//c) at higher temperatures and magnetic fields. The granular structure of the samples does not change up to the highest neutron fluences. However, the enhancements of the transport J c

  6. Advertising and Irreversible Opinion Spreading in Complex Social Networks

    Science.gov (United States)

    Candia, Julián

    Irreversible opinion spreading phenomena are studied on small-world and scale-free networks by means of the magnetic Eden model, a nonequilibrium kinetic model for the growth of binary mixtures in contact with a thermal bath. In this model, the opinion of an individual is affected by those of their acquaintances, but opinion changes (analogous to spin flips in an Ising-like model) are not allowed. We focus on the influence of advertising, which is represented by external magnetic fields. The interplay and competition between temperature and fields lead to order-disorder transitions, which are found to also depend on the link density and the topology of the complex network substrate. The effects of advertising campaigns with variable duration, as well as the best cost-effective strategies to achieve consensus within different scenarios, are also discussed.

  7. Occupational hearing loss in Korea.

    Science.gov (United States)

    Kim, Kyoo Sang

    2010-12-01

    In this article, current status of noise exposure in workplaces, trend of workers with noise-induced hearing loss (NIHL), and prevalence of NIHL in workers by industry and job category in Korea were reviewed. In addition, trends of research on the audiological effects such as hearing loss from noise and occupational hearing loss from non-noise in Korea were addressed through reports in industrial audiology. Though noise exposure level has improved, noise still shows the highest rate of cases exceeding exposure limit among workplace hazards. NIHL is the most common occupational disease except work-related disease such as musculoskeletal disorders and cerebrovascular diseases, and NIHL prevalence is thought to be much higher than reported in official publications. Noise affecting hearing comes from various sources such as workplaces, military settings, areas with exposure to high noise, and specific noise sources. There is also occupational hearing loss by non-noise including chemicals such as organic solvents and heavy metals, barotrauma, and trauma due to welding spark. Noise affects daily life through audiological effects such as hearing loss and tinnitus, non-audiological physical effects (e.g., cardiovascular), and psychosocial and behavioral effects. Development of systematic and comprehensive hearing conservation programs for lowering the noise level in workplaces and preventing the NIHL, and preparation of technological, administrative system for its settlement at workplace are urgently needed.

  8. Elucidation of the Molecular Genetic Basis of Inherited Hearing Impairment.

    NARCIS (Netherlands)

    Luijendijk, M.W.J.

    2006-01-01

    Hearing loss is the most common sensory disorder in the human population. It affects 0.1% of all young children and by the age of 70, 30% of the population suffers from hearing loss greater than 40 dB. When early onset hearing loss is inherited, 70% is classified as nonsyndromic and 30% as

  9. Statistical mechanics out of equilibrium the irreversibility

    International Nuclear Information System (INIS)

    Alvarez Estrada, R. F.

    2001-01-01

    A Round Table about the issue of Irreversibility and related matters has taken place during the last (20th) Statistical Mechanics Conference, held in Paris (July 1998). This article tries to provide a view (necessarily limited, and hence, uncompleted) of some approaches to the subject: the one based upon deterministic chaos (which is currently giving rise to a very active research) and the classical interpretation due to Boltzmann. An attempt has been made to write this article in a self-contained way, and to avoid a technical presentation wherever possible. (Author) 29 refs

  10. Congenital hearing loss. Is CT enough?

    African Journals Online (AJOL)

    Mahmoud Agha

    2014-01-24

    Jan 24, 2014 ... Congenital hearing loss is one of the developmental disorders that may be not clearly .... Alport syndrome, Klippel-Feil, Norrie disease and Waarden- .... Bismuth eye shield was routinely used for all patients (AttenuRad;.

  11. Irreversible electroporation: state of the art

    Directory of Open Access Journals (Sweden)

    Wagstaff PGK

    2016-04-01

    Full Text Available Peter GK Wagstaff,1 Mara Buijs,1 Willemien van den Bos,1 Daniel M de Bruin,2 Patricia J Zondervan,1 Jean JMCH de la Rosette,1 M Pilar Laguna Pes1 1Department of Urology, 2Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the Netherlands Abstract: The field of focal ablative therapy for the treatment of cancer is characterized by abundance of thermal ablative techniques that provide a minimally invasive treatment option in selected tumors. However, the unselective destruction inflicted by thermal ablation modalities can result in damage to vital structures in the vicinity of the tumor. Furthermore, the efficacy of thermal ablation intensity can be impaired due to thermal sink caused by large blood vessels in the proximity of the tumor. Irreversible electroporation (IRE is a novel ablation modality based on the principle of electroporation or electropermeabilization, in which electric pulses are used to create nanoscale defects in the cell membrane. In theory, IRE has the potential of overcoming the aforementioned limitations of thermal ablation techniques. This review provides a description of the principle of IRE, combined with an overview of in vivo research performed to date in the liver, pancreas, kidney, and prostate. Keywords: irreversible electroporation, IRE, tumor, ablation, focal therapy, cancer

  12. Trends in the prevalence of autism spectrum disorder, cerebral palsy, hearing loss, intellectual disability, and vision impairment, metropolitan atlanta, 1991-2010.

    Directory of Open Access Journals (Sweden)

    Kim Van Naarden Braun

    Full Text Available This study examined the prevalence and characteristics of autism spectrum disorder (ASD, cerebral palsy (CP, hearing loss (HL, intellectual disability (ID, and vision impairment (VI over a 15-20 year time period, with specific focus on concurrent changes in ASD and ID prevalence. We used data from a population-based developmental disabilities surveillance program for 8-year-olds in metropolitan Atlanta. From 1991-2010, prevalence estimates of ID and HL were stable with slight increases in VI prevalence. CP prevalence was constant from 1993-2010. The average annual increase in ASD prevalence was 9.3% per year from 1996-2010, with a 269% increase from 4.2 per 1,000 in 1996 to 15.5 per 1,000 in 2010. From 2000-2010, the prevalence of ID without ASD was stable; during the same time, the prevalence of ASD with and without co-occurring ID increased by an average of 6.6% and 9.6% per year, respectively. ASD prevalence increases were found among both males and females, and among nearly all racial/ethnic subgroups and levels of intellectual ability. Average annual prevalence estimates from 1991-2010 underscore the significant community resources needed to provide early intervention and ongoing supports for children with ID (13.0 per 1,000, CP, (3.5 per 1,000, HL (1.4 per 1,000 and VI (1.3 in 1,000, with a growing urgency for children with ASD.

  13. Autophagy is essential for hearing in mice.

    Science.gov (United States)

    Fujimoto, Chisato; Iwasaki, Shinichi; Urata, Shinji; Morishita, Hideaki; Sakamaki, Yuriko; Fujioka, Masato; Kondo, Kenji; Mizushima, Noboru; Yamasoba, Tatsuya

    2017-05-11

    Hearing loss is the most frequent sensory disorder in humans. Auditory hair cells (HCs) are postmitotic at late-embryonic differentiation and postnatal stages, and their damage is the major cause of hearing loss. There is no measurable HC regeneration in the mammalian cochlea, and the maintenance of cell function is crucial for preservation of hearing. Here we generated mice deficient in autophagy-related 5 (Atg5), a gene essential for autophagy, in the HCs to investigate the effect of basal autophagy on hearing acuity. Deletion of Atg5 resulted in HC degeneration and profound congenital hearing loss. In autophagy-deficient HCs, polyubiquitinated proteins and p62/SQSTM1, an autophagy substrate, accumulated as inclusion bodies during the first postnatal week, and these aggregates increased in number. These findings revealed that basal autophagy has an important role in maintenance of HC morphology and hearing acuity.

  14. The Value of Fighting Irreversible Demise by Softening the Irreversible Cost

    NARCIS (Netherlands)

    Magis, P.; Sbuelz, A.

    2005-01-01

    We study a novel issue in the real-options-based technology innovation literature by means of double barrier contingent claims analysis.We show how much a ¯rm with the monopoly over a project is willing to spend in investment technology innovation that softens the irreversible cost of accessing the

  15. Educating Children Who Are Deaf or Hard of Hearing: Overview. ERIC Digest #E549.

    Science.gov (United States)

    Easterbrooks, Susan

    This digest discusses hearing loss in children. Topics covered include: (1) the causes of hearing loss and the three major types of hearing losses, conductive loss, sensorineural loss, and central auditory processing disorder; (2) the federal definitions of "deaf" (hearing loss which adversely affects educational performance and which is…

  16. Anistropically varying conductivity in irreversible electroporation simulations.

    Science.gov (United States)

    Labarbera, Nicholas; Drapaca, Corina

    2017-11-01

    One recent area of cancer research is irreversible electroporation (IRE). Irreversible electroporation is a minimally invasive procedure where needle electrodes are inserted into the body to ablate tumor cells with electricity. The aim of this paper is to propose a mathematical model that incorporates a tissue's conductivity increasing more in the direction of the electrical field as this has been shown to occur in experiments. It was necessary to mathematically derive a valid form of the conductivity tensor such that it is dependent on the electrical field direction and can be easily implemented into numerical software. The derivation of a conductivity tensor that can take arbitrary functions for the conductivity in the directions tangent and normal to the electrical field is the main contribution of this paper. Numerical simulations were performed for isotropic-varying and anisotropic-varying conductivities to evaluate the importance of including the electrical field's direction in the formulation for conductivity. By starting from previously published experimental results, this paper derived a general formulation for an anistropic-varying tensor for implementation into irreversible electroporation modeling software. The anistropic-varying tensor formulation allows the conductivity to take into consideration both electrical field direction and magnitude, as opposed to previous published works that only took into account electrical field magnitude. The anisotropic formulation predicts roughly a five percent decrease in ablation size for the monopolar simulation and approximately a ten percent decrease in ablation size for the bipolar simulations. This is a positive result as previously reported results found the isotropic formulation to overpredict ablation size for both monopolar and bipolar simulations. Furthermore, it was also reported that the isotropic formulation overpredicts the ablation size more for the bipolar case than the monopolar case. Thus, our

  17. Basic quantum irreversibility in neutron interferometry

    International Nuclear Information System (INIS)

    Rauch, H

    2009-01-01

    The transition between the quantum and classical world is a topical problem in quantum physics, which can be investigated by neutron interferometric methods. Here we discuss unavoidable quantum losses as they appear in neutron phase-echo and spin rotation experiments and we show how entanglement effects in a single-particle system demonstrate quantum contextuality, i.e. an entanglement between external and internal degrees of freedom in single-particle systems. This contextuality phenomenon also shows that a quantum system carries much more information than usually extracted. In all cases of an interaction, parasitic beams are produced which cannot be recombined completely with the original beam. This means that a complete reconstruction of the original state is, in principle, impossible which causes a kind of intrinsic irreversibility. Even small interaction potentials can have huge effects when they are applied in quantum Zeno-like experiments. The path towards advanced neutron quantum optics will be discussed.

  18. Competing irreversible cooperative reactions on polymer chains

    International Nuclear Information System (INIS)

    Evans, J.W.; Hoffman, D.K.; Burgess, D.R.

    1984-01-01

    We analyze model processes involving competition between several irreversible reactions at the sites of a 1D, infinite, uniform polymer chain. These reactions can be cooperative, i.e., the corresponding rates depend on the state of the surrounding sites. An infinite hierarchy of rate equations is readily derived for the probabilities of various subconfigurations. By exploiting a shielding property of suitable blocks of unreacted sites, we show how exact hierarchy truncation and solution is sometimes possible. The behavior of solutions is illustrated in several cases by plotting families of ''reaction trajectories'' for varying ratios of reactant concentrations. As a specific application, we consider competition between coordination of ZnCl 2 to pairs of oxygen atoms and to single oxygen atoms in poly(propylene oxide). The observed glass transition temperature behavior is eludicated

  19. Synergetcs - a field beyond irreversible thermodynamics

    International Nuclear Information System (INIS)

    Haken, H.

    1978-01-01

    This lecture introduces the reader to synergetics, a very young field of interdisciplinary research, which is devoted to the question of self-organization and, quite generally, to the birth of new qualities. After comparing the role of thermodynamics, irreversible thermodynamics and synergetics in the description of phenomena we give a few examples for self-oragnizing systems. Next we outline the mathematical approach and consider the generalized Ginzburg-Landau equations for non equilibrium phase transitions. We continue by applying these equations to the problem of morphogenesis in biology. We close our lecture by extending the formalism to spatially inhomogeneous or oscillating systems and arrive at order-parameter equations which are capable of describing new large classes of higher bifurcation schemes. (HJ)

  20. Chemical kinetics, stochastic processes, and irreversible thermodynamics

    CERN Document Server

    Santillán, Moisés

    2014-01-01

    This book brings theories in nonlinear dynamics, stochastic processes, irreversible thermodynamics, physical chemistry, and biochemistry together in an introductory but formal and comprehensive manner.  Coupled with examples, the theories are developed stepwise, starting with the simplest concepts and building upon them into a more general framework.  Furthermore, each new mathematical derivation is immediately applied to one or more biological systems.  The last chapters focus on applying mathematical and physical techniques to study systems such as: gene regulatory networks and ion channels. The target audience of this book are mainly final year undergraduate and graduate students with a solid mathematical background (physicists, mathematicians, and engineers), as well as with basic notions of biochemistry and cellular biology.  This book can also be useful to students with a biological background who are interested in mathematical modeling, and have a working knowledge of calculus, differential equatio...

  1. Entropy, Extropy and the Physical Driver of Irreversibility

    Directory of Open Access Journals (Sweden)

    Attila Grandpierre

    2012-06-01

    Full Text Available We point out that the fundamental irreversibility of Nature requires the introduction of a suitable measure for the distance from equilibrium. We show that entropy, which is widely held to be such a measure, suffers from the problem that it does not have a physical meaning, since it is introduced on the basis of mathematical arguments. As a consequence, the basic physics beyond irreversibility has remained obscure. We present here a simple but transparent physical approach for solving the problem of irreversibility. This approach shows that extropy, the fundamental thermodynamic variable introduced by Katalin Martinás, is the suitable measure for the distance from equilibrium, since it corresponds to the actual driver of irreversible processes. Since extropy explicitly contains in its definition all the general thermodynamic forces that drive irreversible processes, extropy is the suitable physical measure of irreversibility.

  2. Dificuldades na comunicação em normo-ouvintes: estudo comportamental e eletrofisiológico Communication disorders in subjects with normal hearing: a behavioral and electrophysiological study

    Directory of Open Access Journals (Sweden)

    Marta Regueira Dias Prestes

    2013-02-01

    Full Text Available Olimiar auditivo nem sempre prediz o desempenho em ambientes com redundância extrínseca reduzida. OBJETIVO: Investigar o relato de dificuldades de comunicação de adultos com audiograma normal e verificar o quadro subjacente por meio de avaliações comportamental e eletrofisiológica. MÉTODO: Estudo caso-controle de indivíduos com limiares normais, distribuídos em dois grupos: grupo estudo, 10 adultos com queixas auditivas de comunicação e grupo controle, 10 adultos, sem queixas. Foi medida a frequência em que os participantes apresentam dificuldades de comunicação e realizados testes de fala no silêncio e no ruído, audiometria e potencial evocado auditivo de tronco encefálico. RESULTADOS: O grupo estudo se diferenciou estatisticamente do grupo controle apenas nos escores de dificuldades de comunicação. Foi constatada uma correlação positiva entre os limiares tonais e os escores no autorrelato de dificuldade. CONCLUSÃO: A presença de queixa auditiva na ausência de alterações no audiograma não esteve associada a diferença no desempenho no reconhecimento de fala no ruído, nem nas demais avaliações. Com base na análise de correlação, observou-se que, quanto mais elevados os limiares auditivos, maiores os escores no relato de dificuldades auditivas relacionadas às situações de comunicação, mesmo os limiares variando de 0 a 25 dB.Hearing thresholds are not always predictive of performance in environments with reduced extrinsic redundancy. OBJECTIVE: To investigate the communication disorders reported by adults with normal hearing, and to assess their underlying conditions through behavioral and electrophysiological testing. METHOD: This case control study enrolled 20 adults with normal hearing thresholds and divided them into two groups: a case group with 10 adults with hearing impairment-related communication disorders and a control group with 10 adults with normal hearing. The frequency of occurrence of

  3. Measurements on Hearing

    DEFF Research Database (Denmark)

    Poulsen, Torben

    1996-01-01

    Background material for measurements of hearing for grammar school pupils. The note gives the necessary background for the exercise 'Measurement on Hearing'. The topics comprise sound and decibel, the ear, basic psychoacoustics, hearing threshold, audiometric measurement methods, speech and speech...

  4. Speech and Communication Disorders

    Science.gov (United States)

    ... to being completely unable to speak or understand speech. Causes include Hearing disorders and deafness Voice problems, ... or those caused by cleft lip or palate Speech problems like stuttering Developmental disabilities Learning disorders Autism ...

  5. Formation of Irreversible H-bonds in Cellulose Materials

    Science.gov (United States)

    Umesh P. Agarwal; Sally A. Ralph; Rick S. Reiner; Nicole M. Stark

    2015-01-01

    Understanding of formation of irreversible Hbonds in cellulose is important in a number of fields. For example, fields as diverse as pulp and paper and enzymatic saccharification of cellulose are affected. In the present investigation, the phenomenon of formation of irreversible H-bonds is studied in a variety of celluloses and under two different drying conditions....

  6. Exergetic efficiency optimization for an irreversible heat pump ...

    Indian Academy of Sciences (India)

    side ... For irreversible cycle, the internal irreversibility, i.e., non-isentropic losses in the ... constant thermal capacitance rate (the product of mass flow rate and specific heat), .... reversed Brayton cycle is dependent on the external heat transfer ...

  7. Guinea pig ductus arteriosus. II - Irreversible closure after birth.

    Science.gov (United States)

    Fay, F. S.; Cooke, P. H.

    1972-01-01

    To investigate the mechanism underlying irreversibility of ductal closure after birth, studies were undertaken to determine the exact time course for the onset of irreversible closure of the guinea pig ductus arteriosus. Parallel studies of the reactivity of ductal smooth muscle to oxygen and studies of the postpartum cellular changes within the vessel were also carried out.

  8. Transition to Clean Capital, Irreversible Investment and Stranded Assets

    OpenAIRE

    Rozenberg, Julie; Vogt-Schilb, Adrien; Hallegatte, Stephane

    2014-01-01

    This paper uses a Ramsey model with two types of capital to analyze the optimal transition to clean capital when polluting investment is irreversible. The cost of climate mitigation decomposes as a technical cost of using clean instead of polluting capital and a transition cost from the irreversibility of pre-existing polluting capital. With a carbon price, the transition cost can be limit...

  9. Irreversible energy flow in forced Vlasov dynamics

    KAUST Repository

    Plunk, Gabriel G.

    2014-10-01

    © EDP Sciences, Società Italiana di Fisica, Springer-Verlag. The recent paper of Plunk [G.G. Plunk, Phys. Plasmas 20, 032304 (2013)] considered the forced linear Vlasov equation as a model for the quasi-steady state of a single stable plasma wavenumber interacting with a bath of turbulent fluctuations. This approach gives some insight into possible energy flows without solving for nonlinear dynamics. The central result of the present work is that the forced linear Vlasov equation exhibits asymptotically zero (irreversible) dissipation to all orders under a detuning of the forcing frequency and the characteristic frequency associated with particle streaming. We first prove this by direct calculation, tracking energy flow in terms of certain exact conservation laws of the linear (collisionless) Vlasov equation. Then we analyze the steady-state solutions in detail using a weakly collisional Hermite-moment formulation, and compare with numerical solution. This leads to a detailed description of the Hermite energy spectrum, and a proof of no dissipation at all orders, complementing the collisionless Vlasov result.

  10. Irreversible energy flow in forced Vlasov dynamics

    KAUST Repository

    Plunk, Gabriel G.; Parker, Joseph T.

    2014-01-01

    © EDP Sciences, Società Italiana di Fisica, Springer-Verlag. The recent paper of Plunk [G.G. Plunk, Phys. Plasmas 20, 032304 (2013)] considered the forced linear Vlasov equation as a model for the quasi-steady state of a single stable plasma wavenumber interacting with a bath of turbulent fluctuations. This approach gives some insight into possible energy flows without solving for nonlinear dynamics. The central result of the present work is that the forced linear Vlasov equation exhibits asymptotically zero (irreversible) dissipation to all orders under a detuning of the forcing frequency and the characteristic frequency associated with particle streaming. We first prove this by direct calculation, tracking energy flow in terms of certain exact conservation laws of the linear (collisionless) Vlasov equation. Then we analyze the steady-state solutions in detail using a weakly collisional Hermite-moment formulation, and compare with numerical solution. This leads to a detailed description of the Hermite energy spectrum, and a proof of no dissipation at all orders, complementing the collisionless Vlasov result.

  11. Hearing disorders in multiple sclerosis.

    Science.gov (United States)

    Furst, Miriam; Levine, Robert A

    2015-01-01

    Multiple sclerosis (MS) is a disease that is both a focal inflammatory and a chronic neurodegenerative disease. The focal inflammatory component is characterized by destruction of central nervous system myelin, including the spinal cord; as such it can impair any central neural system, including the auditory system. While on the one hand auditory complaints in MS patients are rare compared to other senses, such as vision and proprioception, on the other hand auditory tests of precise neural timing are never "silent." Whenever focal MS lesions are detected involving the pontine auditory pathway, auditory tests requiring precise neural timing are always abnormal, while auditory functions not requiring such precise timing are often normal. Azimuth sound localization is accomplished by comparing the timing and loudness of the sound at the two ears. Hence tests of azimuth sound localization must obligatorily involve the central nervous system and particularly the brainstem. Whenever a focal lesion was localized to the pontine auditory pathway, timing tests were always abnormal, but loudness tests were not. Moreover, a timing test that included only high-frequency sounds was very often abnormal, even when there was no detectable focal MS lesion involving the pontine auditory pathway. This test may be a marker for the chronic neurodegenerative aspect of MS, and, as such could be used to complement the magnetic resonance imaging scan in monitoring the neurodegenerative aspect of MS. Studies of MS brainstem lesion location and auditory function have led to advances in understanding how the human brain processes sound. The brain processes binaural sounds independently for time and level in a two-stage process. The first stage is at the level of the superior olivary complex (SOC) and the second at a level rostral to the SOC. © 2015 Elsevier B.V. All rights reserved.

  12. Scaling Law for Irreversible Entropy Production in Critical Systems.

    Science.gov (United States)

    Hoang, Danh-Tai; Prasanna Venkatesh, B; Han, Seungju; Jo, Junghyo; Watanabe, Gentaro; Choi, Mahn-Soo

    2016-06-09

    We examine the Jarzynski equality for a quenching process across the critical point of second-order phase transitions, where absolute irreversibility and the effect of finite-sampling of the initial equilibrium distribution arise in a single setup with equal significance. We consider the Ising model as a prototypical example for spontaneous symmetry breaking and take into account the finite sampling issue by introducing a tolerance parameter. The initially ordered spins become disordered by quenching the ferromagnetic coupling constant. For a sudden quench, the deviation from the Jarzynski equality evaluated from the ideal ensemble average could, in principle, depend on the reduced coupling constant ε0 of the initial state and the system size L. We find that, instead of depending on ε0 and L separately, this deviation exhibits a scaling behavior through a universal combination of ε0 and L for a given tolerance parameter, inherited from the critical scaling laws of second-order phase transitions. A similar scaling law can be obtained for the finite-speed quench as well within the Kibble-Zurek mechanism.

  13. Irreversible work in a thermal medium with colored noise

    Science.gov (United States)

    Ohkuma, Takahiro

    2009-10-01

    Irreversible work and its fluctuations in a classical system governed by non-Markovian stochastic dynamics are investigated. The production of irreversible work depends not only on the protocol of an operation but also on the details of the non-Markovian memory. We consider a generalized Langevin equation with a memory kernel and derive an expression for the irreversible work in the case of slow operations by carrying out an expansion of this memory kernel in the parameter representing the length of the memory. We apply our formulation to a harmonically trapped system and demonstrate the efficiency of a cycle by evaluating the irreversible work. It is found that a decrease in the irreversible work due to the memory effect can occur for an operation through which the trap is squeezed. The results for this harmonic system are verified exactly in the case that the memory kernel has exponential decay.

  14. Irreversible work in a thermal medium with colored noise

    International Nuclear Information System (INIS)

    Ohkuma, Takahiro

    2009-01-01

    Irreversible work and its fluctuations in a classical system governed by non-Markovian stochastic dynamics are investigated. The production of irreversible work depends not only on the protocol of an operation but also on the details of the non-Markovian memory. We consider a generalized Langevin equation with a memory kernel and derive an expression for the irreversible work in the case of slow operations by carrying out an expansion of this memory kernel in the parameter representing the length of the memory. We apply our formulation to a harmonically trapped system and demonstrate the efficiency of a cycle by evaluating the irreversible work. It is found that a decrease in the irreversible work due to the memory effect can occur for an operation through which the trap is squeezed. The results for this harmonic system are verified exactly in the case that the memory kernel has exponential decay

  15. Irreversible thermodynamic analysis and application for molecular heat engines

    Science.gov (United States)

    Lucia, Umberto; Açıkkalp, Emin

    2017-09-01

    Is there a link between the macroscopic approach to irreversibility and microscopic behaviour of the systems? Consumption of free energy keeps the system away from a stable equilibrium. Entropy generation results from the redistribution of energy, momentum, mass and charge. This concept represents the essence of the thermodynamic approach to irreversibility. Irreversibility is the result of the interaction between systems and their environment. The aim of this paper is to determine lost works in a molecular engine and compare results with macro (classical) heat engines. Firstly, irreversible thermodynamics are reviewed for macro and molecular cycles. Secondly, irreversible thermodynamics approaches are applied for a quantum heat engine with -1/2 spin system. Finally, lost works are determined for considered system and results show that macro and molecular heat engines obey same limitations. Moreover, a quantum thermodynamic approach is suggested in order to explain the results previously obtained from an atomic viewpoint.

  16. Hearing: Noise-Induced Hearing Loss

    Science.gov (United States)

    ... reduce your exposure to noise by choosing quiet leisure activities rather than noisy ones. Develop the habit ... the degree of your hearing loss, you may benefit from using a hearing aid (a device you ...

  17. Infant hearing screening in India: Current status and way forward

    Directory of Open Access Journals (Sweden)

    Suneela Garg

    2015-01-01

    Full Text Available Loss or impairment of auditory sense is the most prevalent deficit of all the sensory organs. With virtually no mortality, hearing impairment causes huge impact on one′s social, educational and economic well-being. There are 5-6 infants who are hard of hearing out of 1000 neonates. They will not be identified till they attain 2 or more years of age, by then irreversible damage would have been done. Universal screening for hearing of new-borns is the only way to decrease the burden of deafness in our society. There are tools available which can be administered by health workers after initial training for screening the infants for hearing impairment. Under the aegis of National Programme for Prevention and Control of Deafness (NPPCD of India universal screening can and should be applied. The programme would entail additional financial burden for the initial purchase of screening machines and rehabilitating the identified children.

  18. Alzheimer's Disease and Related Disorders: The Government's Response. Hearing before the Select Committee on Aging. House of Representatives, Ninety-Ninth Congress, Second Session (Cold Spring Harbor, NY).

    Science.gov (United States)

    Congress of the U.S., Washington, DC. House Select Committee on Aging.

    This document presents witness testimonies and prepared statements from the Congressional hearing called to examine questions surrounding Alzheimer's disease, its treatment, funding for research, legal aspects, and support for families of Alzheimer's victims. Opening statements are included from Congressmen Downey, Mrazek, and Manton. Testimonies…

  19. Irreversible Electroporation in a Swine Lung Model

    International Nuclear Information System (INIS)

    Dupuy, Damian E.; Aswad, Bassam; Ng, Thomas

    2011-01-01

    Purpose: This study was designed to evaluate the safety and tissue effects of IRE in a swine lung model. Methods: This study was approved by the institutional animal care committee. Nine anesthetized domestic swine underwent 15 percutaneous irreversible electroporation (IRE) lesion creations (6 with bipolar and 3 with 3–4 monopolar electrodes) under fluoroscopic guidance and with pancuronium neuromuscular blockade and EKG gating. IRE electrodes were placed into the central and middle third of the right mid and lower lobes in all animals. Postprocedure PA and lateral chest radiographs were obtained to evaluate for pneumothorax. Three animals were sacrificed at 2 weeks and six at 4 weeks. Animals underwent high-resolution CT scanning and PA and lateral radiographs 1 h before sacrifice. The treated lungs were removed en bloc, perfused with formalin, and sectioned. Gross pathologic and microscopic changes after standard hematoxylin and eosin staining were analyzed within the areas of IRE lesion creation. Results: No significant adverse events were identified. CT showed focal areas of spiculated high density ranging in greatest diameter from 1.1–2.2 cm. On gross inspection of the sectioned lung, focal areas of tan discoloration and increased density were palpated in the areas of IRE. Histological analysis revealed focal areas of diffuse alveolar damage with fibrosis and inflammatory infiltration that respected the boundaries of the interlobular septae. No pathological difference could be discerned between the 2- and 4-week time points. The bronchioles and blood vessels within the areas of IRE were intact and did not show signs of tissue injury. Conclusion: IRE creates focal areas of diffuse alveolar damage without creating damage to the bronchioles or blood vessels. Short-term safety in a swine model appears to be satisfactory.

  20. Irreversible Sorption of Contaminants During Ferrihydrite Transformation

    International Nuclear Information System (INIS)

    Anderson, H.L.; Arthur, S.E.; Brady, P.V.; Cygan, R.T.; Nagy, K.L.; Westrich, H.R.

    1999-01-01

    A better understanding of the fraction of contaminants irreversibly sorbed by minerals is necessary to effectively quantify bioavailability. Ferrihydrite, a poorly crystalline iron oxide, is a natural sink for sorbed contaminants. Contaminants may be sorbed/occluded as ferrihydrite precipitates in natural waters or as it ages and transforms to more crystalline iron oxides such as goethite or hematite. Laboratory studies indicate that Cd, Co, Cr, Cu, Ni, Np, Pb, Sr, U, and Zn are irreversibly sorbed to some extent during the aging and transformation of synthetic ferrihydrite. Barium, Ra and Sr are known to sorb on ferrihydrite in the pH range of 6 to 10 and sorb more strongly at pH values above its zero point of charge (pH> 8). We will review recent literature on metal retardation, including our laboratory and modeling investigation of Ba (as an analogue for Ra) and Sr adsorption/resorption, during ferrihydrite transformation to more crystalline iron oxides. Four ferrihydrite suspensions were aged at pH 12 and 50 C with or without Ba in 0.01 M KN03 for 68 h or in 0.17 M KN03 for 3424 h. Two ferrihydrite suspensions were aged with and without Sr at pH 8 in 0.1 M KN03 at 70C. Barium or Sr sorption, or resorption, was measured by periodically centrifuging suspension subsamples, filtering, and analyzing the filtrate for Ba or Sr. Solid subsamples were extracted with 0.2 M ammonium oxalate (pH 3 in the dark) and with 6 M HCl to determine the Fe and Ba or Sr attributed to ferrihydrite (or adsorbed on the goethite/hematite stiace) and the total Fe and Ba or Sr content, respectively. Barium or Sr occluded in goethite/hematite was determined by the difference between the total Ba or Sr and the oxalate extractable Ba or Sr. The percent transformation of ferrihydrite to goethite/hematite was estimated from the ratio of oxalate and HC1 extractable Fe. All Ba was retained in the precipitates for at least 20 h. Resorption of Ba reached a maximum of 7 to 8% of the Ba2+ added for

  1. Hearing impairment and language delay in infants: Diagnostics and genetics

    Science.gov (United States)

    Lang-Roth, Ruth

    2014-01-01

    This overview study provides information on important phoniatric and audiological aspects of early childhood hearing and language development with the aim of presenting diagnostic and therapeutic approaches. The article first addresses the universal newborn hearing screening that has been implemented in Germany for all infants since January 2009. The process of newborn hearing screening from the maternity ward to confirmation diagnostics is presented in accordance with a decision by the Federal Joint Committee (G-BA). The second topic is pediatric audiology diagnostics. Following confirmation of a permanent early childhood hearing disorder, the search for the cause plays an important role. Hereditary hearing disorders and intrauterine cytomegalovirus (CMV) infection, probably the most common cause of an acquired hearing disorder, are discussed and compared with the most common temporary hearing disorder, otitis media with effusion, which in some cases is severe enough to be relevant for hearing and language development and therefore requires treatment. The third topic covered in this article is speech and language development in the first 3 years of life, which is known today to be crucial for later language development and learning to read and write. There is a short overview and introduction to modern terminology, followed by the abnormalities and diagnostics of early speech and language development. Only some aspects of early hearing and language development are addressed here. Important areas such as the indication for a cochlear implant in the first year of life or because of unilateral deafness are not included due to their complexity. PMID:25587365

  2. Can Baby Hear?

    Science.gov (United States)

    ... born in the United States are deaf or hard-of-hearing. Research shows that early intervention with hearing devices and educational services can help children with hearing loss to develop language skills at the same rate as their hearing peers. ...

  3. Hard of Hearing?

    DEFF Research Database (Denmark)

    T Christensen, Vibeke

    This summary presents the results of a study of the impact of reduced hearing in relation to labour-market attachment and working life. Reduced hearing contributes to early retirement. Many people with impaired hearing are not aware of the impact of their hearing problems on their working life an...

  4. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on the CERN site to participate in the NATIONAL HEARING DAY on: Thursday 10th March 2005 From 9am to 4pm The Infirmary, Blg. 57, Ground Floor We will be offering hearing tests (audiograms), as well as information and advice on hearing loss, tinnitus, etc. Deafness does not just affect the elderly: in Europe, 50% of the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing problems but PREVENTION IS POSSIBLE. For example, hearing protection devices can prevent 80% of tinnitus cases.

  5. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on CERN premises to participate in the National Hearing Day on: Thursday 10th March From 9am to 4pm The Infirmary, Blg. 57, Gr.Fl. We will be offering hearing tests (audiogram); information, advice on hearing loss, tinnitus and more. Deafness does not just affect the elderly: in Europe, 50% the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing loss. But PREVENTION IS POSSIBLE AND EFFECTIVE: for example, Hearing protection devices could reduce tinnitus cases by 80%.

  6. CERN hearing day

    CERN Document Server

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on CERN premises to participate in the National Hearing Day on: Thursday 10th March From 9am to 4pm The Infirmary, Blg. 57, Gr.Fl. We will be offering hearing tests (audiogram); information, advice on hearing loss, tinnitus and more. Deafness does not just affect the elderly: in Europe, 50% the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing loss. But prevention is possible and effective: for example, Hearing protection devices could reduce tinnitus cases by 80%.

  7. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss ? do you? The Medical Service invites everyone working on the CERN site to participate in the NATIONAL HEARING DAY on: Thursday 10th March 2005 From 9am to 4pm The Infirmary, Blg. 57, Ground Floor We will be offering hearing tests (audiograms), as well as information and advice on hearing loss, tinnitus, etc. Deafness does not just affect the elderly: in Europe, 50% of the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing problems but prevention is possible. For example, hearing protection devices can prevent 80% of tinnitus cases.

  8. The Master Hearing Aid

    Science.gov (United States)

    Curran, James R.

    2013-01-01

    As early as the 1930s the term Master Hearing Aid (MHA) described a device used in the fitting of hearing aids. In their original form, the MHA was a desktop system that allowed for simulated or actual adjustment of hearing aid components that resulted in a changed hearing aid response. Over the years the MHA saw many embodiments and contributed to a number of rationales for the fitting of hearing aids. During these same years, the MHA was viewed by many as an inappropriate means of demonstrating hearing aids; the audio quality of the desktop systems was often superior to the hearing aids themselves. These opinions and the evolution of the MHA have molded the modern perception of hearing aids and the techniques used in the fitting of hearing aids. This article reports on a history of the MHA and its influence on the fitting of hearing aids. PMID:23686682

  9. Irreversible adsorption of particles on heterogeneous surfaces.

    Science.gov (United States)

    Adamczyk, Zbigniew; Jaszczółt, Katarzyna; Michna, Aneta; Siwek, Barbara; Szyk-Warszyńska, Lilianna; Zembala, Maria

    2005-12-30

    Methods of theoretical and experimental evaluation of irreversible adsorption of particles, e.g., colloids and globular proteins at heterogeneous surfaces were reviewed. The theoretical models were based on the generalized random sequential adsorption (RSA) approach. Within the scope of these models, localized adsorption of particles occurring as a result of short-ranged attractive interactions with discrete adsorption sites was analyzed. Monte-Carlo type simulations performed according to this model enabled one to determine the initial flux, adsorption kinetics, jamming coverage and the structure of the particle monolayer as a function of the site coverage and the particle/site size ratio, denoted by lambda. It was revealed that the initial flux increased significantly with the site coverage theta(s) and the lambda parameter. This behavior was quantitatively interpreted in terms of the scaled particle theory. It also was demonstrated that particle adsorption kinetics and the jamming coverage increased significantly, at fixed site coverage, when the lambda parameter increased. Practically, for alpha = lambda2theta(s) > 1 the jamming coverage at the heterogeneous surfaces attained the value pertinent to continuous surfaces. The results obtained prove unequivocally that spherically shaped sites were more efficient in binding particles in comparison with disk-shaped sites. It also was predicted that for particle size ratio lambda charge. Particle deposition occurred under diffusion-controlled transport conditions and their coverage was evaluated by direct particle counting using the optical and electron microscopy. Adsorption kinetics was quantitatively interpreted in terms of numerical solutions of the governing diffusion equation with the non-linear boundary condition derived from Monte-Carlo simulations. It was proven that for site coverage as low as a few percent the initial flux at heterogeneous surfaces attained the maximum value pertinent to homogeneous

  10. Asymmetric hearing loss in a random population of patients with mild to moderate sensorineural hearing loss.

    Science.gov (United States)

    Segal, Nili; Shkolnik, Mark; Kochba, Anat; Segal, Avichai; Kraus, Mordechai

    2007-01-01

    We evaluated the correlation of asymmetric hearing loss, in a random population of patients with mild to moderate sensorineural hearing loss, to several clinical factors such as age, sex, handedness, and noise exposure. We randomly selected, from 8 hearing institutes in Israel, 429 patients with sensorineural hearing loss of at least 30 dB at one frequency and a speech reception threshold not exceeding 30 dB. Patients with middle ear disease or retrocochlear disorders were excluded. The results of audiometric examinations were compared binaurally and in relation to the selected factors. The left ear's hearing threshold level was significantly higher than that of the right ear at all frequencies except 1.0 kHz (p < .05). One hundred fifty patients (35%) had asymmetric hearing loss (more than 10 dB difference between ears). In most of the patients (85%) the binaural difference in hearing threshold level, at any frequency, was less than 20 dB. Age, handedness, and sex were not found to be correlated to asymmetric hearing loss. Noise exposure was found to be correlated to asymmetric hearing loss.

  11. Hearing loss in Usher syndrome type II is nonprogressive.

    Science.gov (United States)

    Reisser, Christoph F V; Kimberling, William J; Otterstedde, Christian R

    2002-12-01

    Usher syndrome is an autosomal recessive disorder characterized by sensorineural hearing loss and progressive visual loss secondary to retinitis pigmentosa. In the literature, a possible progression of the moderate to severe hearing loss in Usher syndrome type II (Usher II) is controversial. We studied the development of the hearing loss of 125 patients with a clinical diagnosis of Usher syndrome type II intraindividually and interindividually by repeatedly performing complete audiological and neuro-otologic examinations. Our data show a very characteristic slope of the hearing curve in all Usher II patients and no clinically relevant progression of the hearing loss over up to 17 years. The subjective impression of a deterioration of the communicative abilities of Usher II patients must therefore be attributed to the progressive visual loss. The patients should be reassured that changes in their hearing abilities are unlikely and should be provided with optimally fitted modern hearing aids.

  12. Occupational hearing loss of market mill workers in the city of Accra, Ghana.

    Science.gov (United States)

    Kitcher, Emmanuel D; Ocansey, Grace; Abaidoo, Benjamin; Atule, Alidu

    2014-01-01

    Noise induced hearing loss (NIHL) is an irreversible sensorineural hearing loss associated with exposure to high levels of excessive noise. Prevention measures are not well established in developing countries. This comparative cross sectional study aims to determine the prevalence of hearing loss in both a group of high risk workers and a control group and to assess their knowledge of the effects of noise on hearing health. A total of 101 market mill workers and 103 controls employed within markets in the city of Accra, Ghana, were evaluated using a structured questionnaire and pure tone audiometry. The questionnaire assessed factors including self-reported hearing loss, tinnitus, knowledge on the effects of noise on hearing health and the use of hearing protective devices. Pure tone audiometric testing was conducted for both mill workers and controls. Noise levels at the work premises of the mill workers and controls were measured. Symptoms of hearing loss were reported by 24 (23.76%) and 8 (7.7%) mill workers and controls respectively. Fifty-five (54.5%) and fifty-four (52.37%) mill workers and controls exhibited knowledge of the effects of noise on hearing health. Five (5.0%) mill workers used hearing protective devices. There was significant sensorineural hearing loss and the presence of a 4 kHz audiometric notch among mill workers when compared with controls for the mean thresholds of 2 kHz, 3 kHz and 4 kHz (P = 0. 001). The prevalence of hearing loss in the better hearing ears of the mill workers and controls was 24.8% and 4.8% respectively (P hearing loss, which may be characteristic of NIHL in the better hearing ears of the mill workers and controls was 24.8% and 4.8% respectively. The majority of mill workers did not use hearing protection.

  13. Occupational hearing loss of market mill workers in the city of Accra, Ghana

    Directory of Open Access Journals (Sweden)

    Emmanuel D Kitcher

    2014-01-01

    Full Text Available Noise induced hearing loss (NIHL is an irreversible sensorineural hearing loss associated with exposure to high levels of excessive noise. Prevention measures are not well established in developing countries. This comparative cross sectional study aims to determine the prevalence of hearing loss in both a group of high risk workers and a control group and to assess their knowledge of the effects of noise on hearing health. A total of 101 market mill workers and 103 controls employed within markets in the city of Accra, Ghana, were evaluated using a structured questionnaire and pure tone audiometry. The questionnaire assessed factors including self-reported hearing loss, tinnitus, knowledge on the effects of noise on hearing health and the use of hearing protective devices. Pure tone audiometric testing was conducted for both mill workers and controls. Noise levels at the work premises of the mill workers and controls were measured. Symptoms of hearing loss were reported by 24 (23.76% and 8 (7.7% mill workers and controls respectively. Fifty-five (54.5% and fifty-four (52.37% mill workers and controls exhibited knowledge of the effects of noise on hearing health. Five (5.0% mill workers used hearing protective devices. There was significant sensorineural hearing loss and the presence of a 4 kHz audiometric notch among mill workers when compared with controls for the mean thresholds of 2 kHz, 3 kHz and 4 kHz (P = 0. 001. The prevalence of hearing loss in the better hearing ears of the mill workers and controls was 24.8% and 4.8% respectively (P < 0.5. The prevalence of hearing loss, which may be characteristic of NIHL in the better hearing ears of the mill workers and controls was 24.8% and 4.8% respectively. The majority of mill workers did not use hearing protection.

  14. Thermodynamic Analysis of an Irreversible Maisotsenko Reciprocating Brayton Cycle

    Directory of Open Access Journals (Sweden)

    Fuli Zhu

    2018-03-01

    Full Text Available An irreversible Maisotsenko reciprocating Brayton cycle (MRBC model is established using the finite time thermodynamic (FTT theory and taking the heat transfer loss (HTL, piston friction loss (PFL, and internal irreversible losses (IILs into consideration in this paper. A calculation flowchart of the power output (P and efficiency (η of the cycle is provided, and the effects of the mass flow rate (MFR of the injection of water to the cycle and some other design parameters on the performance of cycle are analyzed by detailed numerical examples. Furthermore, the superiority of irreversible MRBC is verified as the cycle and is compared with the traditional irreversible reciprocating Brayton cycle (RBC. The results can provide certain theoretical guiding significance for the optimal design of practical Maisotsenko reciprocating gas turbine plants.

  15. Performance Optimization of Irreversible Air Heat Pumps Considering Size Effect

    Science.gov (United States)

    Bi, Yuehong; Chen, Lingen; Ding, Zemin; Sun, Fengrui

    2018-06-01

    Considering the size of an irreversible air heat pump (AHP), heating load density (HLD) is taken as thermodynamic optimization objective by using finite-time thermodynamics. Based on an irreversible AHP with infinite reservoir thermal-capacitance rate model, the expression of HLD of AHP is put forward. The HLD optimization processes are studied analytically and numerically, which consist of two aspects: (1) to choose pressure ratio; (2) to distribute heat-exchanger inventory. Heat reservoir temperatures, heat transfer performance of heat exchangers as well as irreversibility during compression and expansion processes are important factors influencing on the performance of an irreversible AHP, which are characterized with temperature ratio, heat exchanger inventory as well as isentropic efficiencies, respectively. Those impacts of parameters on the maximum HLD are thoroughly studied. The research results show that HLD optimization can make the size of the AHP system smaller and improve the compactness of system.

  16. General thermodynamic performance of irreversible absorption heat pump

    International Nuclear Information System (INIS)

    Zhao Xiling; Fu Lin; Zhang Shigang

    2011-01-01

    The absorption heat pump (AHP) was studied with thermodynamics. A four reservoirs model of absorption heat pump was established considering the heat resistance, heat leak and the internal irreversibility. The reasonable working regions, the performance effects of irreversibility, heat leak and the correlation of four components were studied. When studying the effects of internal irreversibility, two internal irreversibility parameters (I he for generator-absorber assembly and I re for evaporator-condenser assembly) were introduced to distinguish the different effects. When studying the heat transfer relations of four components, a universal relationship between the main parameters were deduced. The results which have more realized meaning show that, the reduction of the friction, heat loss, and internal dissipations of the evaporator-condenser assembly are more important than its reduction of generator-absorber assembly, and lessening the heat leak of generator are more important than its reduction of other components to improve the AHP performance.

  17. Irreversibility and dissipation in finite-state automata

    International Nuclear Information System (INIS)

    Ganesh, Natesh; Anderson, Neal G.

    2013-01-01

    Irreversibility and dissipation in finite-state automata (FSA) are considered from a physical-information-theoretic perspective. A quantitative measure for the computational irreversibility of finite automata is introduced, and a fundamental lower bound on the average energy dissipated per state transition is obtained and expressed in terms of FSA irreversibility. The irreversibility measure and energy bound are germane to any realization of a deterministic automaton that faithfully registers abstract FSA states in distinguishable states of a physical system coupled to a thermal environment, and that evolves via a sequence of interactions with an external system holding a physical instantiation of a random input string. The central result, which is shown to follow from quantum dynamics and entropic inequalities alone, can be regarded as a generalization of Landauer's Principle applicable to FSAs and tailorable to specified automata. Application to a simple FSA is illustrated.

  18. Kinetic theory of nonequilibrium ensembles, irreversible thermodynamics, and generalized hydrodynamics

    CERN Document Server

    Eu, Byung Chan

    2016-01-01

    This book presents the fundamentals of irreversible thermodynamics for nonlinear transport processes in gases and liquids, as well as for generalized hydrodynamics extending the classical hydrodynamics of Navier, Stokes, Fourier, and Fick. Together with its companion volume on relativistic theories, it provides a comprehensive picture of the kinetic theory formulated from the viewpoint of nonequilibrium ensembles in both nonrelativistic and, in Vol. 2, relativistic contexts. Theories of macroscopic irreversible processes must strictly conform to the thermodynamic laws at every step and in all approximations that enter their derivation from the mechanical principles. Upholding this as the inviolable tenet, the author develops theories of irreversible transport processes in fluids (gases or liquids) on the basis of irreversible kinetic equations satisfying the H theorem. They apply regardless of whether the processes are near to or far removed from equilibrium, or whether they are linear or nonlinear with respe...

  19. Noise Induced Hearing Loss in Iran: (1997–2012): Systematic Review Article

    Science.gov (United States)

    SOLTANZADEH, Ahmad; EBRAHIMI, Hossein; FALLAHI, Majid; KAMALINIA, Mojtaba; GHASSEMI, Shadi; GOLMOHAMMADI, Rostam

    2014-01-01

    Noise-induced hearing loss, which is one of the 10 leading occupational diseases, is a debilitating and irreversible disease. During the recent 15-years period (1997–2012), several studies have investigated the association between noise, hearing damage and other side effects of noise in Iran. The aim of this study was to review systematically the relevant literature related to noise-induced hearing loss, lead to developing noise exposure limits. In this systematic review, two researchers independently extracted the data from 31 past studies that had considered noise-induced hearing loss (including hearing loss, temporary and permanent hearing threshold shift and auditory trauma). The data were then recorded in a modified form and Statistical analyses were performed using SPSS, version 16.0. In analyzed studies the weighted average equivalent sound pressure level [L Aeq ] was 90.29 dB(A) and average hearing loss was 26.44 dB(A). The Highest degree of hearing loss in the right ear was associated at 4000 Hz, and the highest degree of hearing loss in the left ear was associated to 1000 and 4000 Hz. The majority of the reviewed studies have confirmed that exposure to a noise level above 85 dB (A) can lead to an increased chance of hearing loss. Furthermore, the results of the present review indicated that as L Aeq increased up to 85 dB(A), so did the severity of the hearing loss. PMID:26171352

  20. Anisotropic shift of the irreversibility line by neutron irradiation

    International Nuclear Information System (INIS)

    Sauerzopf, F.M.; Wiesinger, H.P.; Weber, H.W.; Crabtree, G.W.; Frischherz, M.C.; Kirk, M.A.

    1991-09-01

    The irreversibility line of high-T c superconductors is shifted considerably by irradiating the material with fast neutrons. The anisotropic and non-monotonous shift is qualitatively explained by a simple model based on an interaction between three pinning mechanisms, the intrinsic pinning by the ab-planes, the weak pinning by the pre-irradiation defect structure, and strong pinning by neutron induced defect cascades. A correlation between the cascade density and the position of the irreversibility line is observed

  1. Prevalence of noise-induced hearing loss in drivers

    Directory of Open Access Journals (Sweden)

    Andréa Cintra Lopes1, , , ,

    2012-01-01

    Full Text Available Introduction: Work-related hearing loss is one of the most common occupational illness progresses over the years of noise exposure associated with the work environment, may cause damage to undertake physical activity, the individual's physiological and mental besides causing hearing damage irreversible interfering with communication and quality of life. With high prevalence of male evaluates which is the second leading cause of hearing loss. Since there is no medical treatment for this type of hearing loss, it is evident the importance of preventive and conferences aimed at preserving hearing and health as a whole. Objective: To assess the prevalence of hearing loss in audiometry admission of drivers. Methods: Retrospective study. By 76 charts of professional drivers in leased transport companies. We analyzed data from specific interview and pure tone audiometry. Results: The prevalence of abnormal tests was 22.36% with the lowest thresholds for tritonal average of 3,000, 4,000 and 6,000 Hz. The higher the age, the higher thresholds. Conclusion: This study has highlighted the occurrence of hearing in the absence of complaints. Considering that PAIR is preventable, justifies the importance of coordinated and multidisciplinary involving not only health teams and safety, but also the institutions involved in preserving the health of workers, as the team SESMET, unions or prosecutors.

  2. Negotiating hearing disability and hearing disabled identities

    DEFF Research Database (Denmark)

    Lykke Hindhede, Anette

    2012-01-01

        Using disability theory as a framework and social science theories of identity to strengthen the arguments, this paper explores empirically how working-age adults confront the medical diagnosis of hearing impairment. For most participants hearing impairment threatens the stability of social...... interaction and the construction of hearing disabled identities is seen as shaped in the interaction with the hearing impaired person‟s surroundings. In order to overcome the potential stigmatisation the „passing‟ as normal becomes predominant. For many the diagnosis provokes radical redefinitions of the self....... The discursively produced categorisation and subjectivity of senescence mean that rehabilitation technologies such as hearing aids identify a particular life-style (disabled) which determines their social significance. Thus wearing a hearing aid works against the contemporary attempt to create socially ideal...

  3. Hearing Aid and children

    Directory of Open Access Journals (Sweden)

    Jamileh Fatahi

    2002-07-01

    Full Text Available In order to develop oral communication, hearing impaired infants and young children must be able to hear speech comfortably and consistently. To day children with all degrees of hearing loss may be condidates for some kinds of amlification. As children differ from adults, many Factors should be consider in hearing aid selection, evaluation and fitting. For example the child age when he or she is candidate for custom instruments? Do we consider programmable Hearing aid? Are multi memory instruments appropriate for them? What about directional microphones? What style of hearing aid do we select? In this paper such questions are Answered.

  4. Congenital hearing impairment

    Energy Technology Data Exchange (ETDEWEB)

    Robson, Caroline D. [Children' s Hospital and Harvard Medical School, Division of Neuroradiology, Department of Radiology, Boston, MA (United States)

    2006-04-15

    Establishing the etiology of congenital hearing impairment can significantly improve treatment for certain causes of hearing loss and facilitates genetic counseling. High-resolution CT and MRI have contributed to the evaluation and management of hearing impairment. In addition, with the identification of innumerable genetic loci and genetic defects involved in hearing loss, genetic testing has emerged as an invaluable tool in the assessment of hearing impairment. Some of the common forms of congenital hearing loss are reviewed and their imaging features illustrated. (orig.)

  5. Congenital hearing impairment

    International Nuclear Information System (INIS)

    Robson, Caroline D.

    2006-01-01

    Establishing the etiology of congenital hearing impairment can significantly improve treatment for certain causes of hearing loss and facilitates genetic counseling. High-resolution CT and MRI have contributed to the evaluation and management of hearing impairment. In addition, with the identification of innumerable genetic loci and genetic defects involved in hearing loss, genetic testing has emerged as an invaluable tool in the assessment of hearing impairment. Some of the common forms of congenital hearing loss are reviewed and their imaging features illustrated. (orig.)

  6. Pathophysiology of Age-Related Hearing Loss (Peripheral and Central)

    OpenAIRE

    Lee, Kyu-Yup

    2013-01-01

    Age-related hearing loss (presbycusis) refers to bilaterally symmetrical hearing loss resulting from aging process. Presbycusis is a complex phenomenon characterized by audiometric threshold shift, deterioration in speech-understanding and speech-perception difficulties in noisy environments. Factors contributing to presbycusis include mitochondria DNA mutation, genetic disorders including Ahl, hypertension, diabetes, metabolic disease and other systemic diseases in the intrinsic aspects. Ext...

  7. Interventions to prevent occupational noise-induced hearing loss

    NARCIS (Netherlands)

    Tikka, Christina; Verbeek, Jos H.; Kateman, Erik; Morata, Thais C.; Dreschler, Wouter A.; Ferrite, Silvia

    2017-01-01

    This is the second update of a Cochrane Review originally published in 2009. Millions of workers worldwide are exposed to noise levels that increase their risk of hearing disorders. There is uncertainty about the effectiveness of hearing loss prevention interventions. To assess the effectiveness of

  8. Attribution of irreversible loss to anthropogenic climate change

    Science.gov (United States)

    Huggel, Christian; Bresch, David; Hansen, Gerrit; James, Rachel; Mechler, Reinhard; Stone, Dáithí; Wallimann-Helmer, Ivo

    2016-04-01

    The Paris Agreement (2015) under the UNFCCC has anchored loss and damage in a separate article which specifies that understanding and support should be enhanced in areas addressing loss and damage such as early warning, preparedness, insurance and resilience. Irreversible loss is a special category under loss and damage but there is still missing clarity over what irreversible loss actually includes. Many negative impacts of climate change may be handled or mitigated by existing risk management, reduction and absorption approaches. Irreversible loss, however, is thought to be insufficiently addressed by risk management. Therefore, countries potentially or actually affected by irreversible loss are calling for other measures such as compensation, which however is highly contested in international climate policy. In Paris (2015) a decision was adopted that loss and damage as defined in the respective article of the agreement does not involve compensation and liability. Nevertheless, it is likely that some sort of mechanism will eventually need to come into play for irreversible loss due to anthropogenic climate change, which might involve compensation, other forms of non-monetary reparation, or transformation. Furthermore, climate litigation has increasingly been attempted to address negative effects of climate change. In this context, attribution is important to understand the drivers of change, what counts as irreversible loss due to climate change, and, possibly, who or what is responsible. Here we approach this issue by applying a detection and attribution perspective on irreversible loss. We first analyze detected climate change impacts as assessed in the IPCC Fifth Assessment Report. We distinguish between irreversible loss in physical, biological and human systems, and accordingly identify the following candidates of irreversible loss in these systems: loss of glaciers and ice sheets, loss of subsurface ice (permafrost) and related loss of lake systems; loss

  9. Auditory Temporal-Organization Abilities in School-Age Children with Peripheral Hearing Loss

    Science.gov (United States)

    Koravand, Amineh; Jutras, Benoit

    2013-01-01

    Purpose: The objective was to assess auditory sequential organization (ASO) ability in children with and without hearing loss. Method: Forty children 9 to 12 years old participated in the study: 12 with sensory hearing loss (HL), 12 with central auditory processing disorder (CAPD), and 16 with normal hearing. They performed an ASO task in which…

  10. Noise and Hearing Protection

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Noise and Hearing Protection Noise and Hearing Protection Patient ... it is. How can I tell if a noise is dangerous? People differ in their sensitivity to ...

  11. Genes and Hearing Loss

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Genes and Hearing Loss Genes and Hearing Loss Patient ... mutation may only have dystopia canthorum. How Do Genes Work? Genes are a road map for the ...

  12. Buying a Hearing Aid

    Science.gov (United States)

    ... the aids? Start using your hearing aids in quiet surroundings, gradually building up to noisier environments. Then eventually work up to wearing your hearing aids all waking hours. Keep a diary to help you remember your ...

  13. OI Issues: Hearing Loss

    Science.gov (United States)

    ... signals normally to the brain. In addition, hearing losses are classified according to the degree of severity: • Mild, • Moderate, • Severe, • Profound. Hearing losses are also classified according to the sound frequency ...

  14. Hearing Loss: Screening Newborns

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Hearing Loss Screening Newborns Past Issues / Spring 2015 Table ... deafness, which account for most cases. Screening Newborns' Hearing Now Standard In 1993, children born in the ...

  15. Hearing and the cochlea

    Science.gov (United States)

    ... like structure that contains the receptor organ for hearing. The cochlea contains the spiral organ of Corti, which is the receptor organ for hearing. It consists of tiny hair cells that translate ...

  16. Occupational hearing loss

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001048.htm Occupational hearing loss To use the sharing features on this page, please enable JavaScript. Occupational hearing loss is damage to the inner ear from noise ...

  17. Irreversible climate change due to carbon dioxide emissions

    Science.gov (United States)

    Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

    2009-01-01

    The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450–600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the “dust bowl” era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4–1.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.6–1.9 m for peak CO2 concentrations exceeding ≈1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281

  18. International hearing protector standardization

    DEFF Research Database (Denmark)

    Poulsen, Torben

    2002-01-01

    Hearing protectors shall fulfill some minimum requirements to their performance. As hearing protector manufacturers sell the products all over the world, the testing and certification of hearing protectors has become an international issue. The ISO working group WG17 under the headlines Acoustics...

  19. Hearing Aids Communication

    DEFF Research Database (Denmark)

    Globally, hearing loss is the second most frequent disability. About 80% of the persons affected by hearing loss do not use hearing aids. The goal of this edited volume is to present a theoretically founded, interdisciplinary approach geared at understanding and improving social interaction...

  20. Deafness and Hearing Loss.

    Science.gov (United States)

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This brief overview provides information on the definition, incidence, and characteristics of children with hearing impairments and deafness. The federal definitions of hearing impairment and deafness are provided. The different types of hearing loss are noted, including: (1) conductive (caused by diseases or obstructions in the outer or middle…

  1. Hearing poorly with skill

    DEFF Research Database (Denmark)

    Day, Dennis

    2012-01-01

    This paper offers an account of ongoing research into hearing. I offer a characterization of 'skil- led practitioners' from an Ethnomethodological perspective. The skilled practitioner in question is a generic 'hard of hearing' person. The ambition is that such a characterization, both in its...... making and its final state, may be an intrinsic part of design practices concerning the development of hearing aids....

  2. Reversible and Irreversible Binding of Nanoparticles to Polymeric Surfaces

    Directory of Open Access Journals (Sweden)

    Wolfgang H. Binder

    2009-01-01

    Full Text Available Reversible and irreversible binding of CdSe-nanoparticles and nanorods to polymeric surfaces via a strong, multiple hydrogen bond (= Hamilton-receptor/barbituric acid is described. Based on ROMP-copolymers, the supramolecular interaction on a thin polymer film is controlled by living polymerization methods, attaching the Hamilton-receptor in various architectures, and concentrations. Strong binding is observed with CdSe-nanoparticles and CdSe-nanorods, whose surfaces are equipped with matching barbituric acid-moieties. Addition of polar solvents, able to break the hydrogen bonds leads to the detachment of the nanoparticles from the polymeric film. Irreversible binding is observed if an azide/alkine-“click”-reaction is conducted after supramolecular recognition of the nanoparticles on the polymeric surface. Thus reversible or irreversible attachment of the nanosized objects can be achieved.

  3. Spectral line intensity irreversibility in circulatory plasma magnetization processes

    Science.gov (United States)

    Qu, Z. Q.; Dun, G. T.

    2012-01-01

    Spectral line intensity variation is found to be irreversible in circulatory plasma magnetization process by experiments described in this paper, i.e., the curves illustrating spectral line photon fluxes irradiated from a light source immerged in a magnetic field by increasing the magnetic induction cannot be reproduced by decreasing the magnetic induction within the errors. There are two plasma magnetization patterns found. One shows that the intensities are greater at the same magnetic inductions during the magnetic induction decreasing process after the increasing, and the other gives the opposite effect. This reveals that the magneto-induced excitation and de-excitation process is irreversible like ferromagnetic magnetization. But the two irreversible processes are very different in many aspects stated in the text.

  4. Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

    KAUST Repository

    Shang, Ran

    2015-05-06

    The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

  5. Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

    KAUST Repository

    Shang, Ran; Vuong, Francois; Hu, Jingyi; Li, Sheng; Kemperman, Antoine J.B.; Nijmeijer, Kitty; Cornelissen, Emile R.; Heijman, Sebastiaan G.J.; Rietveld, Luuk C.

    2015-01-01

    The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

  6. Noise-Induced Hearing Loss (NIHL: literature review with a focus on occupational medicine

    Directory of Open Access Journals (Sweden)

    Metidieri, Mirella Melo

    2013-04-01

    Full Text Available According to the Ministry of Health (2006, Noise-Induced Hearing Loss (NIHL is hearing loss caused by prolonged exposure to noise. It is characterized as sensorineural hearing loss and is usually bilateral, irreversible, and progressive while the exposure to noise continues. A NIHL is a predictable and preventable disease with an epidemiologically relevant prevalence in urban communities. The hearing loss begins and predominates in the frequencies of 3, 4, and 6 kHz and eventually progresses to 8, 2, 1, 0.5, and 0.25 kHz. In Brazil, regulatory standard 15 limits the exposure to continuous noise to no more than 4 hours' exposure to 90 dBA and a maximum level of 85 dB for a full 8-hour working period. As NIHL is a preventable and predictable disease, preventive action by professionals may be able to change the prevalence of hearing loss in noisy environments.

  7. Noise-Induced Hearing Loss (NIHL): literature review with a focus on occupational medicine.

    Science.gov (United States)

    Metidieri, Mirella Melo; Rodrigues, Hugo Fernandes Santos; Filho, Francisco José Motta Barros de Oliveira; Ferraz, Daniela Pereira; Neto, Antonio Fausto de Almeida; Torres, Sandro

    2013-04-01

    According to the Ministry of Health (2006), Noise-Induced Hearing Loss (NIHL) is hearing loss caused by prolonged exposure to noise. It is characterized as sensorineural hearing loss and is usually bilateral, irreversible, and progressive while the exposure to noise continues. A NIHL is a predictable and preventable disease with an epidemiologically relevant prevalence in urban communities. The hearing loss begins and predominates in the frequencies of 3, 4, and 6 kHz and eventually progresses to 8, 2, 1, 0.5, and 0.25 kHz. In Brazil, regulatory standard 15 limits the exposure to continuous noise to no more than 4 hours' exposure to 90 dBA and a maximum level of 85 dB for a full 8-hour working period. As NIHL is a preventable and predictable disease, preventive action by professionals may be able to change the prevalence of hearing loss in noisy environments.

  8. A new approach to irreversibility in deep inelastic collisions

    International Nuclear Information System (INIS)

    Nemes, M.C.

    1982-01-01

    We use concepts of statistical mechanics to discuss the irreversible character of the experimental data in deep inelastic collisions. A definition of irreversibility proposed by Ruch permits a unified overview on current theories which describe these reactions. An information theoretical analysis of the data leads to a Fokker-Planck equation for the collective variables (excitation energy, charge and mass). The concept of mixing distance can serve as a quantitative measure to characterize the 'approach to equilibrium'. We apply it to the brownian motion as an illustration and also to the phenomenological analysis of deep inelastic scattering data with interesting results. (orig.)

  9. The thermomechanics of nonlinear irreversible behaviors an introduction

    CERN Document Server

    Maugin, Gérard A

    1999-01-01

    In this invaluable book, macroscopic irreversible thermodynamics is presented in its realm and its splendor by appealing to the notion of internal variables of state. This applies to both fluids and solids with or without microstructures of mechanical or electromagnetic origin. This unmatched richness of essentially nonlinear behaviors is the result of the use of modern mathematical techniques such as convex analysis in a clear-cut framework which allows one to put under the umbrella of "irreversible thermodynamics" behaviors which until now have been commonly considered either not easily cove

  10. [Transcultural adaptation of an instrument to evaluate hearing handicap in workers with noise-induced hearing loss].

    Science.gov (United States)

    Holanda, Wanessa Tenório Gonçalves; de Lima, Maria Luiza Carvalho; Figueiroa, José Natal

    2011-01-01

    The noise-induced hearing loss (NIHL) is a chronic and irreversible disease resulting of the exposure to noise in high levels at work. Even in the beginning, this hearing loss can damage in many degrees the worker's quality of life. Before this study, there wasn't an instrument, in Portuguese, to evaluate the psychosocial disadvantages of workers with NIHL. The aim of this research was to make a transcultural adaptation of an especific instrument to evaluate the hearing handicap from the original language to Portuguese, and check the reliability and legitimacy. The selected instrument passed by a process of semantic equivalence that was conducted in five stages: translation, back translation, critical appraisal of the versions, pre-test and a final review by a multi-professional group to develop a consensual version of the instrument for current use in Brazil. The instrument called "Inabilities Scale and Hearing Handicap" had, in general, acceptable psychometric measures, considering the little size of the sample and the fact that workers' hearing loss weren't too significant. Therefore, the Portuguese version of this instrument needs to be further tested in a representative sample of Brazilian workers with NIHL to ratify its utility in order to evaluate hearing handicap in this population.

  11. Hearing impairment caused by mutations in two different genes responsible for nonsyndromic and syndromic hearing loss within a single family.

    Science.gov (United States)

    Niepokój, Katarzyna; Rygiel, Agnieszka M; Jurczak, Piotr; Kujko, Aleksandra A; Śniegórska, Dominika; Sawicka, Justyna; Grabarczyk, Alicja; Bal, Jerzy; Wertheim-Tysarowska, Katarzyna

    2018-02-01

    Usher syndrome is rare genetic disorder impairing two human senses, hearing and vision, with the characteristic late onset of vision loss. This syndrome is divided into three types. In all cases, the vision loss is postlingual, while loss of hearing is usually prelingual. The vestibular functions may also be disturbed in Usher type 1 and sometimes in type 3. Vestibular areflexia is helpful in making a proper diagnosis of the syndrome, but, often, the syndrome is misdiagnosed as a nonsyndromic hearing loss. Here, we present a Polish family with hearing loss, which was clinically classified as nonsyndromic. After excluding mutations in the DFNB1 locus, we implemented the next-generation sequencing method and revealed that hearing loss was syndromic and mutations in the USH2A gene indicate Usher syndrome. This research highlights the importance of molecular analysis in establishing a clinical diagnosis of congenital hearing loss.

  12. Hearing Loss, Dizziness, and Carbohydrate Metabolism

    OpenAIRE

    Albernaz, Pedro L. Mangabeira

    2015-01-01

    Abstract Introduction Metabolic activity of the inner ear is very intense, and makes it sensitive to changes in the body homeostasis. This study involves a group of patients with inner ear disorders related to carbohydrate metabolism disturbances, including hearing loss, tinnitus, dizziness, and episodes of vertigo. Objectives To describe the symptoms of metabolic inner ear disorders and the examinations required to establish diagnoses. These symptoms are often the first to allow for an e...

  13. Demographic and audiological factors as predictors of hearing handicap

    Directory of Open Access Journals (Sweden)

    Leposavić Ljubica

    2006-01-01

    Full Text Available INTRODUCTION Currently available evidence reveals comparatively few studies of psychological effects of hearing impairments, in spite of the fact that clinicians have for a long time been aware of a connection between the acquired hearing impairment and mental disorders. They are focused on the investigation of dysfunction in general. Thus, three domains of the auditory imbalance may be distinguished: disorder, disability and handicap. 'Handicap', according to the definition of the World Health Organization, is a hindrance in an individual that results from an impairment or disability and represents psychological response of the individual to the impairment. OBJECTIVE Validation of acquired hearing impairment as a risk factor of psychical disorders as well as an analysis of relation of some demographic factors (sex, age, education and audiological factors (degree and duration of the impairment with the frequency of hearing handicap. METHOD MMPI-201 has been applied in 60 subjects affected with otosclerosis, potential candidates for stapedectomy, before and after the surgery. RESULTS Individuals with acquired hearing impairment manifest more frequent disorders of psychical functioning in comparison with general population, while demographic and audiometric parameters did not correlate with acquired hearing handicap. CONCLUSION It may be assumed that the very recognition of demographic and audio-logical factors can not help much in the understanding of the psychological stress associated with hearing impairment.

  14. Extended irreversible thermodynamics and the Jeffreys type constitutive equations

    International Nuclear Information System (INIS)

    Serdyukov, S.I.

    2003-01-01

    A postulate of extended irreversible thermodynamics is considered, according to which the entropy density is a function of the internal energy, the specific volume, and their material time derivatives. On the basis of this postulate, entropy balance equations and phenomenological equations are obtained, which directly lead to the Jeffreys type constitutive equations

  15. Investment Irreversibility and Precautionary Savings in General Equilibrium

    DEFF Research Database (Denmark)

    Ejarque, João

    than irreversibility effects. If shocks are idiosyncratic and affect a cross section of agents over capital, an increase in their variance may induce an increase in aggregate investment even if all agents have an incentive to invest less, because zero investment is now an active lower bound for part...

  16. The degree of irreversibility in deterministic finite automata

    DEFF Research Database (Denmark)

    Axelsen, Holger Bock; Holzer, Markus; Kutrib, Martin

    2016-01-01

    the language, and show that the degree induces a strict infinite hierarchy of languages. We examine how the degree of irreversibility behaves under the usual language operations union, intersection, complement, concatenation, and Kleene star, showing tight bounds (some asymptotically) on the degree....

  17. Optimization at different loads by minimization of irreversibilities

    International Nuclear Information System (INIS)

    Wong, K.F.V.; Niu, Z.

    1991-01-01

    This paper reports that the irreversibility of the power cycle was chosen as the objective function as this function can successfully measure both the quality and quantity of energy flow in the cycle. Minimization of the irreversibility ensures that the power cycle will operate more efficiently. One feature of the present work is that the boiler, turbine, condenser and heaters are treated as one system for the purpose of optimization. In the optimization model, nine regression formulae are used, which are obtained from the measured test data. From the results of the present work, it can be seen that the optimization model developed can represent the effect of operational parameters on the power plant first and second law efficiency. Some of the results can be used to provide guidance for the optimal operation of the power plant. When the power cycle works at full load, the main steam temperature and pressure should be at the upper limit for minimal irreversibility of the system. If the load is less than 65% of its design capacity, the steam temperature and pressure should be decreased for a lower irreversibility of the system

  18. Profit rate performance optimization for a generalized irreversible ...

    Indian Academy of Sciences (India)

    fer law system generalized irreversible combined refrigeration cycle model with finite-rate heat ...... Chen L, Sun F, Wu C 2004b Optimum allocation of heat exchanger area for refrigeration and air conditioning plants. Appl. Energy 77(3): 339– ...

  19. Exergetic efficiency optimization for an irreversible heat pump ...

    Indian Academy of Sciences (India)

    This paper deals with the performance analysis and optimization for irreversible heat pumps working on reversed Brayton cycle with constant-temperature heat reservoirs by taking exergetic efficiency as the optimization objective combining exergy concept with finite-time thermodynamics (FTT). Exergetic efficiency is ...

  20. Reversible and irreversible heat engine and refrigerator cycles

    Science.gov (United States)

    Leff, Harvey S.

    2018-05-01

    Although no reversible thermodynamic cycles exist in nature, nearly all cycles covered in textbooks are reversible. This is a review, clarification, and extension of results and concepts for quasistatic, reversible and irreversible processes and cycles, intended primarily for teachers and students. Distinctions between the latter process types are explained, with emphasis on clockwise (CW) and counterclockwise (CCW) cycles. Specific examples of each are examined, including Carnot, Kelvin and Stirling cycles. For the Stirling cycle, potentially useful task-specific efficiency measures are proposed and illustrated. Whether a cycle behaves as a traditional refrigerator or heat engine can depend on whether it is reversible or irreversible. Reversible and irreversible-quasistatic CW cycles both satisfy Carnot's inequality for thermal efficiency, η ≤ η C a r n o t . Irreversible CCW cycles with two reservoirs satisfy the coefficient of performance inequality K ≤ K C a r n o t . However, an arbitrary reversible cycle satisfies K ≥ K C a r n o t when compared with a reversible Carnot cycle operating between its maximum and minimum temperatures, a potentially counterintuitive result.

  1. Challenges in management of childhood sensorineural hearing loss in sub-Saharan Africa, Nigeria.

    Science.gov (United States)

    Lasisi, O A; Ayodele, J K; Ijaduola, G T A

    2006-04-01

    The evaluation of a hearing-impaired child attempts to determine the aetiology, the degree of hearing loss and intervention to aid speech and language. This remains a challenge to practising otolaryngologists, especially in the developing countries as 85-90% of causes of hearing losses were never discovered leading to delayed intervention and irreversible effects. In a review of children presenting at the otolaryngology outpatient in the University College Hospital, Ibadan, Nigeria, sensorineural hearing loss was found in 103, giving a hospital prevalence rate of 14%, we still perceived this figure to be unrepresentatively and low, probably due to poor access to medicare, poverty and other factors. Genetic factor accounted for 25%, followed by measles infections 13% and meningitis 8%. About 60% of them had educationally significant hearing loss at presentation. Access to hearing aid was poor as only 12.5% of the patients could afford it and the rest were managed by deaf training. We conclude by suggesting an audiologic programme which has the comprehensive function of neonatal and infant hearing screening, subsidized hearing aid services and hearing rehabilitation surgery.

  2. Measures of thermodynamic irreversibility in deterministic and stochastic dynamics

    International Nuclear Information System (INIS)

    Ford, Ian J

    2015-01-01

    It is generally observed that if a dynamical system is sufficiently complex, then as time progresses it will share out energy and other properties amongst its component parts to eliminate any initial imbalances, retaining only fluctuations. This is known as energy dissipation and it is closely associated with the concept of thermodynamic irreversibility, measured by the increase in entropy according to the second law. It is of interest to quantify such behaviour from a dynamical rather than a thermodynamic perspective and to this end stochastic entropy production and the time-integrated dissipation function have been introduced as analogous measures of irreversibility, principally for stochastic and deterministic dynamics, respectively. We seek to compare these measures. First we modify the dissipation function to allow it to measure irreversibility in situations where the initial probability density function (pdf) of the system is asymmetric as well as symmetric in velocity. We propose that it tests for failure of what we call the obversibility of the system, to be contrasted with reversibility, the failure of which is assessed by stochastic entropy production. We note that the essential difference between stochastic entropy production and the time-integrated modified dissipation function lies in the sequence of procedures undertaken in the associated tests of irreversibility. We argue that an assumed symmetry of the initial pdf with respect to velocity inversion (within a framework of deterministic dynamics) can be incompatible with the Past Hypothesis, according to which there should be a statistical distinction between the behaviour of certain properties of an isolated system as it evolves into the far future and the remote past. Imposing symmetry on a velocity distribution is acceptable for many applications of statistical physics, but can introduce difficulties when discussing irreversible behaviour. (paper)

  3. Music and hearing aids.

    Science.gov (United States)

    Madsen, Sara M K; Moore, Brian C J

    2014-10-31

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems. © The Author(s) 2014.

  4. Music and Hearing Aids

    Directory of Open Access Journals (Sweden)

    Sara M. K. Madsen

    2014-10-01

    Full Text Available The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems.

  5. Hearing aid adjustment

    DEFF Research Database (Denmark)

    Heinemann, Trine; Matthews, Ben; Raudaskoski, Pirkko Liisa

    2012-01-01

    to the interaction during hearing aid fitting. This report of a Danish pilot study describes two such problems. The first problem arises from the requirement that the audiologist needs to ‘translate’ the patient’s subjective hearing description for making technological decisions. The second problem is the way...... in which the hearing aid user’s implicit and often unrealistic expectations are handled. This kind of research has potential application for developing a model of best practices....

  6. BNNT-mediated irreversible electroporatio: its potential on cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Vittoria Raffa, Cristina Riggio, Michael W. Smith, Kevin C. Jordan, Wei Cao, Alfred Cuschieri

    2012-10-01

    Tissue ablation, i.e., the destruction of undesirable tissues, has become an important minimally invasive technique alternative to resection surgery for the treatment of tumours. Several methods for tissue ablation are based on thermal techniques using cold, e.g. cryosurgery [1] or heat, e.g. radiofrequency [2] or high-intensity focused ultrasound [3] or nanoparticle-mediated irradiation [4]. Alternatively, irreversible electroporation (IRE) has been proposed as non thermal technique for minimally invasive tissue ablation based on the use of electrical pulses. When the electric field is applied to a cell, a change in transmembrane potential is induced, which can cause biochemical and physiological changes of the cell. When the threshold value of the transmembrane potential is exceeded, the cell membrane becomes permeable, thus allowing entrance of molecules that otherwise cannot cross the membrane [5]. A further increase in the electric field intensity may cause irreversible membrane permeabilization and cell death. These pulses create irreversible defects (pores) in the cell membrane lipid bilayer, causing cell death through loss of cell homeostasis [6]. This is desirable in tumour ablation in order to produce large cell death, without the use of cytostatic drugs. A study of Davalos, Mir and Rubinsky showed that IRE can ablate substantial volumes of tissue without inducing a thermal effect and therefore serve as an independent and new tissue ablation modality; this opened the way to the use of IRE in surgery [7]. Their finding was subsequently confirmed in studies on cells [8], small animal models [9] and in large animal models in the liver [10] and the heart [11]. The most important finding in these papers is that irreversible electroporation produces precisely delineated ablation zones with cell scale resolution between ablated and non-ablated areas, without zones in which the extent of damage changes gradually as during thermal ablation. Furthermore, it is

  7. Noise-Induced Hearing Loss

    Science.gov (United States)

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Noise-Induced Hearing Loss On this page: What is ... I find additional information about NIHL? What is noise-induced hearing loss? Every day, we experience sound ...

  8. Hearing Conservation Live #2430

    Energy Technology Data Exchange (ETDEWEB)

    Chochoms, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-09

    Occupational hearing loss is one of the most common work-related illnesses in the United States (US). From 22 to 30 million US workers are exposed to hazardous noise levels at work, and 25% of these workers will develop permanent hearing loss. Hearing loss from noise is slow and painless, and you can have a disability before you notice it. This course presents the hazards associated with workplace noise, the purpose and elements of the Los Alamos National Laboratory (LANL) Hearing Conservation Program (HCP), and controls that are available to reduce your exposure to hazardous levels of noise.

  9. Features of alpha-synuclein that could explain the progression and irreversibility of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Scarlet eGallegos

    2015-03-01

    Full Text Available Alpha-synuclein is a presynaptic protein expressed throughout the central nervous system, and it is the main component of Lewy bodies, one of the histopathological features of Parkinson’s disease (PD which is a progressive and irreversible neurodegenerative disorder. The conformational flexibility of α-synuclein allows it to adopt different conformations, i.e. bound to membranes or form aggregates, the oligomers are believed to be the more toxic species. In this review, we will focus on two major features of α-synuclein, transmission and toxicity that could help to understand the pathological characteristics of PD. One important feature of α-synuclein is its ability to be transmitted from neuron to neuron using mechanisms such as endocytosis, plasma membrane penetration or through exosomes, thus propagating the Lewy body pathology to different brain regions thereby contributing to the progressiveness of PD. The second feature of α-synuclein is that it confers cytotoxicity to recipient cells, principally when it is in an oligomeric state. This form causes mitochondrial dysfunction, endoplasmic reticulum stress, oxidative stress, proteasome impairment, disruption of plasma membrane and pore formation, and lead to apoptosis pathway activation and consequent cell death. The complexity of α-synuclein oligomerization and formation of toxic species could be a major factor for the irreversibility of PD and could also explain the lack of successful therapies to halt the disease.

  10. Irreversible adsorption of phenolic compounds by activated carbons

    International Nuclear Information System (INIS)

    Grant, T.M.; King, C.J.

    1988-12-01

    Studies were undertaken to determine the reasons why phenolic sorbates can be difficult to remove and recover from activated carbons. The chemical properties of the sorbate and the adsorbent surface, and the influences of changes in the adsorption and desorption conditions were investigated. Comparison of isotherms established after different contact times or at different temperatures indicated that phenolic compounds react on carbon surfaces. The reaction rate is a strong function of temperature. Regeneration of carbons by leaching with acetone recovered at least as much phenol as did regeneration with other solvents or with displacers. The physiochemical properties of adsorbents influences irreversible uptakes. Sorbates differed markedly in their tendencies to undergo irreversible adsorption. 64 refs., 47 figs., 32 tabs

  11. Prostaglandin E2 to diagnose between reversible and irreversible pulpitis.

    Science.gov (United States)

    Petrini, M; Ferrante, M; Ciavarelli, L; Brunetti, L; Vacca, M; Spoto, G

    2012-01-01

    The aim of this work is to verify a correlation between the grade of inflammation and the concentration of PGE2 in human dental pulp. A total of 25 human dental pulps were examined by histological analysis and radioimmunologic dosage of PGE2. The pulps used in this experiment were from healthy and symptomatic teeth; the first ones were collected from teeth destined to be extracted for orthodontic reasons. An increase was observed of PGE2 in reversible pulpitis compared with healthy pulps and with the irreversible pulpitis and the clear decrease of these when NSAIDs are taken. This study demonstrates that PGE2 level is correlated to histological analysis thus allowing to distinguish symptomatic teeth in reversible and irreversible pulpitis.

  12. Irreversible adsorption of phenolic compounds by activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Grant, T.M.; King, C.J.

    1988-12-01

    Studies were undertaken to determine the reasons why phenolic sorbates can be difficult to remove and recover from activated carbons. The chemical properties of the sorbate and the adsorbent surface, and the influences of changes in the adsorption and desorption conditions were investigated. Comparison of isotherms established after different contact times or at different temperatures indicated that phenolic compounds react on carbon surfaces. The reaction rate is a strong function of temperature. Regeneration of carbons by leaching with acetone recovered at least as much phenol as did regeneration with other solvents or with displacers. The physiochemical properties of adsorbents influences irreversible uptakes. Sorbates differed markedly in their tendencies to undergo irreversible adsorption. 64 refs., 47 figs., 32 tabs.

  13. Ecological optimization for an irreversible magnetic Ericsson refrigeration cycle

    International Nuclear Information System (INIS)

    Wang Hao; Wu Guo-Xing

    2013-01-01

    An irreversible Ericsson refrigeration cycle model is established, in which multi-irreversibilities such as finite-rate heat transfer, regenerative loss, heat leakage, and the efficiency of the regenerator are taken into account. Expressions for several important performance parameters, such as the cooling rate, coefficient of performance (COP), power input, exergy output rate, entropy generation rate, and ecological function are derived. The influences of the heat leakage and the time of the regenerative processes on the ecological performance of the refrigerator are analyzed. The optimal regions of the ecological function, cooling rate, and COP are determined and evaluated. Furthermore, some important parameter relations of the refrigerator are revealed and discussed in detail. The results obtained here have general significance and will be helpful in gaining a deep understanding of the magnetic Ericsson refrigeration cycle. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  14. Reversing the irreversible: From limit cycles to emergent time symmetry

    Science.gov (United States)

    Cortês, Marina; Smolin, Lee

    2018-01-01

    In 1979 Penrose hypothesized that the arrows of time are explained by the hypothesis that the fundamental laws are time irreversible [R. Penrose, in General Relativity: An Einstein Centenary Survey (1979)]. That is, our reversible laws, such as the standard model and general relativity are effective, and emerge from an underlying fundamental theory which is time irreversible. In [M. Cortês and L. Smolin, Phys. Rev. D 90, 084007 (2014), 10.1103/PhysRevD.90.084007; 90, 044035 (2014), 10.1103/PhysRevD.90.044035; 93, 084039 (2016), 10.1103/PhysRevD.93.084039] we put forward a research program aiming at realizing just this. The aim is to find a fundamental description of physics above the Planck scale, based on irreversible laws, from which will emerge the apparently reversible dynamics we observe on intermediate scales. Here we continue that program and note that a class of discrete dynamical systems are known to exhibit this very property: they have an underlying discrete irreversible evolution, but in the long term exhibit the properties of a time reversible system, in the form of limit cycles. We connect this to our original model proposal in [M. Cortês and L. Smolin, Phys. Rev. D 90, 084007 (2014), 10.1103/PhysRevD.90.084007], and show that the behaviors obtained there can be explained in terms of the same phenomenon: the attraction of the system to a basin of limit cycles, where the dynamics appears to be time reversible. Further than that, we show that our original models exhibit the very same feature: the emergence of quasiparticle excitations obtained in the earlier work in the space-time description is an expression of the system's convergence to limit cycles when seen in the causal set description.

  15. Irreversible pulpitis and achieving profound anesthesia: Complexities and managements

    OpenAIRE

    Modaresi, Jalil; Davoudi, Amin; Badrian, Hamid; Sabzian, Roya

    2016-01-01

    Dental pain management is one of the most critical aspects of modern dentistry. Irreversible pulpitis and further root canal therapy might cause an untolerated pain to the patients. The improvements in anesthetic agents and techniques were one of the advantages of studying nerve biology and stimulation. This article tried to overview of the nerve activities in inflammatory environments or induced pain. Furthermore, the proper advises, and supplementary techniques were reviewed for better pain...

  16. β-characterization by irreversibility analysis: A thermoeconomic diagnosis method

    International Nuclear Information System (INIS)

    Zaleta-Aguilar, Alejandro; Olivares-Arriaga, Abraham; Cano-Andrade, Sergio; Rodriguez-Alejandro, David A.

    2016-01-01

    This paper presents a reconciliation methodology for the diagnosis of energy systems. The methodology is based on the characterization of irreversibilities in the components of an energy system. These irreversibilities can be attributed to malfunctions or dysfunctions. The characterization of irreversibilities as presented here makes possible to reconcile the Actual Operating Condition (AOC) versus the Reference Operating Condition (ROC) of the energy system in a real-time manner. The diagnosis methodology introduces a parameter β, which represents the total exergy or useful work of a component in terms of its inlet and output streams at either design (full-load) or off-design (partial-load) conditions. The methodology is applied to the diagnosis of an actual Natural Gas Combined Cycle (NGCC) power plant. Data for the model is obtained directly from the plant by monitoring its performance at every time; thus, a real-time thermodynamic diagnosis for the system is obtained. Results show that the methodology presented here is able to detect and quantify the deviations on the performance of the NGCC power plant during its real-time operation. Based on the detection and quantification of these deviations, the user is able to make recommendations to schedule maintenance on the components where the irreversibilities are present. - Highlights: • A new methodology for thermoeconomic diagnosis of energy systems is presented. • A parameter β is defined for characterization of the components of an energy system. • The β characterization methodology is tested in a real 420 MW NGCC power plant. • Results show that the complexity of a diagnosis analysis is reduced substantially.

  17. Variability of Irreversible Poleward Transport in the Lower Stratosphere

    Science.gov (United States)

    Olsen, Mark; Douglass, Anne; Newman, Paul; Nash, Eric; Witte, Jacquelyn; Ziemke, Jerry

    2011-01-01

    The ascent and descent of the Brewer-Dobson circulation plays a large role in determining the distributions of many constituents in the extratropical lower stratosphere. However, relatively fast, quasi-horizontal transport out of the tropics and polar regions also significantly contribute to determining these distributions. The tropical tape recorder signal assures that there must be outflow from the tropics into the extratropical lower stratosphere. The phase of the quasi-biennial oscillation (QBO) and state of the polar vortex are known to modulate the transport from the tropical and polar regions, respectively. In this study we examine multiple years of ozone distributions in the extratropical lower stratosphere observed by the Aura Microwave Limb Sounder (MLS) and the Aura High Resolution Dynamic Limb Sounder (HIRDLS). The distributions are compared with analyses of irreversible, meridional isentropic transport. We show that there is considerable year-to-year seasonal variability in the amount of irreversible transport from the tropics, which is related to both the phase of the QBO and the state of the polar vortex. The reversibility of the transport is consistent with the number of observed breaking waves. The variability of the atmospheric index of refraction in the lower stratosphere is shown to be significantly correlated with the wave breaking and amount of irreversible transport. Finally, we will show that the seasonal extratropical stratosphere to troposphere transport of ozone can be substantially modulated by the amount of irreversible meridional transport in the lower stratosphere and we investigate how observable these differences are in data of tropospheric ozone.

  18. Magnetic irreversibility in granular superconductors: ac susceptibility study

    International Nuclear Information System (INIS)

    Perez, F.; Obradors, X.; Fontcuberta, J.; Vallet, M.; Gonzalez-Calbet, J.

    1991-01-01

    Ac susceptibility measurements of a ceramic weak-coupled superconductor in very low ac fields (2mG, 111Hz) are reported. We present evidence for the observation of the magnetic irreversibility following a ZFC-FC thermal cycling by means of ac susceptibilty measurements. It is shown that this technique also reflect local magnetic field effects in granular superconductors, as previously suggested in microwave surface resistance and I-V characteristics. (orig.)

  19. Irreversibility analysis in the process of solar distillation

    International Nuclear Information System (INIS)

    Chávez, S; Terres, H; Lizardi, A; López, R; Lara, A

    2017-01-01

    In this work an irreversibility analysis for the thermal process of solar distillation of three different substances is presented, for which it employs a solar still of a slope where three experimental tests with 5.5 L of brine, river water and MgCl 2 were performed. Temperature data principally in the glass cover, absorber plate, fluid, environment and the incident solar radiation on the device were obtained. With measurements of temperature, solar radiation and exergetic balance, irreversibilities are found on the device. The results show that the highest values of irreversibilities are concentrated in the absorber plate with an average of 321 W, 342 W and 276 W, followed by the cover glass with an average of 75.8 W, 80.4 W and 86.7 W and finally the fluid with 15.3 W, 15.9 W and 16 W, for 5.5 L of brine, river water and MgCl 2 . (paper)

  20. Irreversibility and Action of the Heat Conduction Process

    Directory of Open Access Journals (Sweden)

    Yu-Chao Hua

    2018-03-01

    Full Text Available Irreversibility (that is, the “one-sidedness” of time of a physical process can be characterized by using Lyapunov functions in the modern theory of stability. In this theoretical framework, entropy and its production rate have been generally regarded as Lyapunov functions in order to measure the irreversibility of various physical processes. In fact, the Lyapunov function is not always unique. In the represent work, a rigorous proof is given that the entransy and its dissipation rate can also serve as Lyapunov functions associated with the irreversibility of the heat conduction process without the conversion between heat and work. In addition, the variation of the entransy dissipation rate can lead to Fourier’s heat conduction law, while the entropy production rate cannot. This shows that the entransy dissipation rate, rather than the entropy production rate, is the unique action for the heat conduction process, and can be used to establish the finite element method for the approximate solution of heat conduction problems and the optimization of heat transfer processes.

  1. Anesthetic Efficacy in Irreversible Pulpitis: A Randomized Clinical Trial.

    Science.gov (United States)

    Allegretti, Carlos E; Sampaio, Roberta M; Horliana, Anna C R T; Armonia, Paschoal L; Rocha, Rodney G; Tortamano, Isabel Peixoto

    2016-01-01

    Inferior alveolar nerve block has a high failure rate in the treatment of mandibular posterior teeth with irreversible pulpitis. The aim of this study was to compare the anesthetic efficacy of 4% articaine, 2% lidocaine and 2% mepivacaine, all in combination with 1:100,000 epinephrine, in patients with irreversible pulpitis of permanent mandibular molars during a pulpectomy procedure. Sixty-six volunteers from the Emergency Center of the School of Dentistry, University of São Paulo, randomly received 3.6 mL of local anesthetic as a conventional inferior alveolar nerve block (IANB). The subjective signal of lip numbness, pulpal anesthesia and absence of pain during the pulpectomy procedure were evaluated respectively, by questioning the patient, stimulation using an electric pulp tester and a verbal analogue scale. All patients reported the subjective signal of lip numbness. Regarding pulpal anesthesia success as measured with the pulp tester, the success rate was respectively 68.2% for mepivacaine, 63.6% for articaine and 63.6% for lidocaine. Regarding patients who reported no pain or mild pain during the pulpectomy, the success rate was, respectively 72.7% for mepivacaine, 63.6% for articaine and 54.5% for lidocaine. These differences were not statistically significant. Neither of the solutions resulted in 100% anesthetic success in patients with irreversible pulpitis of mandibular molars.

  2. Irreversible performance of a quantum harmonic heat engine

    Science.gov (United States)

    Rezek, Yair; Kosloff, Ronnie

    2006-05-01

    The unavoidable irreversible loss of power in a heat engine is found to be of quantum origin. Following thermodynamic tradition, a model quantum heat engine operating in an Otto cycle is analysed, where the working medium is composed of an ensemble of harmonic oscillators and changes in volume correspond to changes in the curvature of the potential well. Equations of motion for quantum observables are derived for the complete cycle of operation. These observables are sufficient to determine the state of the system and with it all thermodynamical variables. Once the external controls are set, the engine settles to a limit cycle. Conditions for optimal work, power and entropy production are derived. At high temperatures and quasistatic operating conditions, the efficiency at maximum power coincides with the endoreversible result \\eta_q=1-\\sqrt{{T_c}/{T_h}} . The optimal compression ratio varies from {\\cal C} =\\sqrt{T_h/T_c} in the quasistatic limit where the irreversibility is dominated by heat conductance to {\\cal C} =(T_h/T_c)^{1/4} in the sudden limit when the irreversibility is dominated by friction. When the engine deviates from adiabatic conditions, the performance is subject to friction. The origin of this friction can be traced to the noncommutability of the kinetic and potential energy of the working medium.

  3. Articaine for supplemental intraosseous anesthesia in patients with irreversible pulpitis.

    Science.gov (United States)

    Bigby, Jason; Reader, Al; Nusstein, John; Beck, Mike; Weaver, Joel

    2006-11-01

    The purpose of this study was to determine the anesthetic efficacy and heart rate effect of 4% articaine with 1:100,000 epinephrine for supplemental intraosseous injection in mandibular posterior teeth diagnosed with irreversible pulpitis. Thirty-seven emergency patients, diagnosed with irreversible pulpitis of a mandibular posterior tooth, received an inferior alveolar nerve block and had moderate-to-severe pain upon endodontic access. The Stabident system was used to administer 1.8 ml of 4% articaine with 1:100,000 epinephrine. Success of the intraosseous injection was defined as none or mild pain upon endodontic access or initial instrumentation. The results demonstrated that anesthetic success was obtained in 86% (32 of 37) of the patients. Maximum mean heart rate was increased 32 beats/minute during the intraosseous injection. We can conclude that when the inferior alveolar nerve block fails to provide profound pulpal anesthesia, the intraosseous injection of 4% articaine with 1:100,000 epinephrine would be successful 86% of the time in achieving pulpal anesthesia in mandibular posterior teeth of patients presenting with irreversible pulpitis.

  4. Irreversible Local Markov Chains with Rapid Convergence towards Equilibrium

    Science.gov (United States)

    Kapfer, Sebastian C.; Krauth, Werner

    2017-12-01

    We study the continuous one-dimensional hard-sphere model and present irreversible local Markov chains that mix on faster time scales than the reversible heat bath or Metropolis algorithms. The mixing time scales appear to fall into two distinct universality classes, both faster than for reversible local Markov chains. The event-chain algorithm, the infinitesimal limit of one of these Markov chains, belongs to the class presenting the fastest decay. For the lattice-gas limit of the hard-sphere model, reversible local Markov chains correspond to the symmetric simple exclusion process (SEP) with periodic boundary conditions. The two universality classes for irreversible Markov chains are realized by the totally asymmetric SEP (TASEP), and by a faster variant (lifted TASEP) that we propose here. We discuss how our irreversible hard-sphere Markov chains generalize to arbitrary repulsive pair interactions and carry over to higher dimensions through the concept of lifted Markov chains and the recently introduced factorized Metropolis acceptance rule.

  5. Irreversible dynamics, Onsager-Casimir symmetry, and an application to turbulence.

    Science.gov (United States)

    Ottinger, Hans Christian

    2014-10-01

    Irreversible contributions to the dynamics of nonequilibrium systems can be formulated in terms of dissipative, or irreversible, brackets. We discuss the structure of such irreversible brackets in view of a degeneracy implied by energy conservation, where we consider different types of symmetries of the bracket corresponding to the Onsager and Casimir symmetries of linear irreversible thermodynamics. Slip and turbulence provide important examples of antisymmetric irreversible brackets and offer guidance for the more general modeling of irreversible dynamics without entropy production. Conversely, turbulence modeling could benefit from elucidating thermodynamic structure. The examples suggest constructing antisymmetric irreversible brackets in terms of completely antisymmetric functions of three indices. Irreversible brackets without well-defined symmetry properties can arise for rare events, causing big configurational changes.

  6. The Konrad hearing

    International Nuclear Information System (INIS)

    Thomauske, B.

    1993-01-01

    The paper provides an interim assessment: Attempts to break off early the hearing failed. Neither have significant points be found which would provide a technically motivated reason for reexamination. After the hearing, a positive plan approving decision should be taken as soon as possible. The discussion about the energy-policy consensus will have its effects on this. (orig./HSCH) [de

  7. Individual Hearing Loss

    Directory of Open Access Journals (Sweden)

    Sébastien Santurette

    2016-06-01

    Full Text Available It is well-established that hearing loss does not only lead to a reduction of hearing sensitivity. Large individual differences are typically observed among listeners with hearing impairment in a wide range of suprathreshold auditory measures. In many cases, audiometric thresholds cannot fully account for such individual differences, which make it challenging to find adequate compensation strategies in hearing devices. How to characterize, model, and compensate for individual hearing loss were the main topics of the fifth International Symposium on Auditory and Audiological Research (ISAAR, held in Nyborg, Denmark, in August 2015. The following collection of papers results from some of the work that was presented and discussed at the symposium.

  8. Sentence Writing and Perception of Written Sentences in Hearing-Impaired and Normal-Hearing Primary School Students in Hamadan, Western Iran

    Directory of Open Access Journals (Sweden)

    Afsaneh Yaghobi

    2011-06-01

    Full Text Available Background and Aim: Learning language is acquired in early childhood and gradually developed by new words and new structures. Hearing sense is the most important acquisition for learning this skill. Hearing disorders are barriers for natural language learning. The purpose of this study was to investigate the relationship between writing sentences and perception of written sentences in hearing-impaired and normal-hearing students.Methods: A cross-sectional study was conducted among thirty hearing-impaired students with hearing loss of 70-90 dB and thirty normal hearing students. They were selected from 3rd grade primary school students in Hamadan, a large city in Western Iran. The language skills and non language information was assessed by questionnaire, Action Picture Test, and Sentence Perception Test.Results: Results showed that there was a significant relation between writing sentences and perception of written sentences in hearing impaired students (p<0.001, (r=0.8. This significant relation was seen in normal-hearing students as well (p<0.001, (r=0.7.Conclusion: Disability of hearing-impaired students in verbal communication is not only related to articulation and voice disorders but also is related to their disability to explore and use of language rules. They suffer lack of perception of written sentences, and they are not skilled to convey their feelings and thoughts in order to presenting themselves by using language structures.

  9. Hearing Loss Associated with US Military Combat Deployment

    Science.gov (United States)

    2015-02-01

    Jason M. Jones Tomoko I. Hooper Isabel G. Jacobson Edward J. Boyko Report No. 13-59 The views expressed in this article are those of the...limited. A study of US Army soldiers who visited audiology clinics noted that hearing loss was identifi ed in 68.6% of post-deployment diagnoses and...disorders, hearing loss, military personnel Access this article online Quick Response Code: Website: www.noiseandhealth.org DOI: 10.4103/1463

  10. 78 FR 5556 - Public Hearing

    Science.gov (United States)

    2013-01-25

    ... SUSQUEHANNA RIVER BASIN COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on February 14, 2013, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the...

  11. 77 FR 64576 - Public Hearing

    Science.gov (United States)

    2012-10-22

    ... SUSQUEHANNA RIVER BASIN COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on November 15, 2012, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the...

  12. 78 FR 43961 - Public Hearing

    Science.gov (United States)

    2013-07-22

    ... SUSQUEHANNA RIVER BASIN COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on August 15, 2013, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the...

  13. 77 FR 44703 - Public Hearing

    Science.gov (United States)

    2012-07-30

    ... SUSQUEHANNA RIVER BASIN COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on August 23, 2012, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the...

  14. 78 FR 64260 - Public Hearing

    Science.gov (United States)

    2013-10-28

    ... SUSQUEHANNA RIVER BASIN COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on November 13, 2013, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the...

  15. Efficient evaluation of hearing ability

    NARCIS (Netherlands)

    2009-01-01

    A system for establishing a hearing ability model of a hearing ability of a person, includes a data storage configured to store a representation of a distribution of a hearing ability of a population of individuals, and a processor configured to establish a hearing ability model representing a

  16. Anderson localized state as a predissipative state: irreversible emission of thermalized quanta from a dynamically delocalized state.

    Science.gov (United States)

    Yamada, Hiroaki; Ikeda, Kensuke S

    2002-04-01

    It was shown that localization in one-dimensional disordered (quantum) electronic system is destroyed against coherent harmonic perturbations and the delocalized electron exhibits an unlimited diffusive motion [Yamada and Ikeda, Phys. Rev. E 59, 5214 (1999)]. The appearance of diffusion implies that the system has potential for irreversibility and dissipation. In the present paper, we investigate dissipative property of the dynamically delocalized state, and we show that an irreversible quasistationary energy flow indeed appears in the form of a "heat" flow when we couple the system with another dynamical degree of freedom. In the concrete we numerically investigate dissipative properties of a one-dimensional tight-binding electronic system perturbed by time-dependent harmonic forces, by coupling it with a quantum harmonic oscillator or a quantum anharmonic oscillator. It is demonstrated that if the on-site potential is spatially irregular an irreversible energy transfer from the scattered electron to the test oscillator occurs. Moreover, the test oscillator promptly approaches a thermalized state characterized by a well-defined time-dependent temperature. On the contrary, such a relaxation process cannot be observed at all for periodic potential systems. Our system is one of the minimal quantum systems in which a distinct nonequilibrium statistical behavior is self-induced.

  17. Determining the complex modulus of alginate irreversible hydrocolloid dental material.

    Science.gov (United States)

    King, Shalinie; See, Howard; Thomas, Graham; Swain, Michael

    2008-11-01

    The aim of the study is to investigate the visco-elastic response of an alginate irreversible hydrocolloid dental impression material during setting. A novel squeeze film Micro-Fourier Rheometer (MFR, GBC Scientific Equipment, Australia) was used to determine the complex modulus of an alginate irreversible hydrocolloid dental impression material (Algident, ISO 1563 Class A Type 1, Dentalfarm Australia Pty. Ltd.) during setting after mixing. Data was collected every 30s for 10 min in one study and every 10 min for a total of 60 min in another study. A high level of repeatability was observed. The results indicate that the MFR is capable of recording the complex shear modulus of alginate irreversible hydrocolloid for 60 min from the start of mixing and to simultaneously report the changing visco-elastic parameters at all frequencies between 1 Hz and 100 Hz. The storage modulus shows a dramatic increase to 370% of its starting value after 6 min and then reduces to 55% after 60 min. The loss modulus increases to a maximum of 175% of its starting value after 10 min and then reduces to 94% after 60 min. The MFR enables the changes in the complex modulus through the complete setting process to be followed. It is anticipated this approach may provide a better method to compare the visco-elastic properties of impression materials and assist with identification of optimum types for different clinical requirements. The high stiffness of the instrument and the use of band-limited pseudo-random noise as the input signal are the main advantages of this technique over conventional rheometers for determining the changes in alginate visco-elasticity.

  18. Dimensional Stability of Color-Changing Irreversible Hydrocolloids after Disinfection

    Directory of Open Access Journals (Sweden)

    Khaledi AAR

    2015-03-01

    Full Text Available Statement of Problem: Disinfection of dental impressions is a weak point in the dental hygiene chain. In addition, dental office personnel and dental technicians are endangered by cross-contamination. Objectives: This study aimed to investigate the dimensional stability of two color-changing irreversible hydrocolloid materials (IH after disinfection with glutaraldehyde. Materials and Methods: In this in vitro study, impressions were made of a master maxillary arch containing three reference inserts on the occlucal surface of the left and right maxillary second molars and in the incisal surface of the maxillary central incisors. Two types of color-changing irreversible hydrocolloid (tetrachrom, cavex were used. Glutaraldehyde 2% was used in two methods of spraying and immersion to disinfect the impressions. The control group was not disinfected. Casts were made of type IV gypsum. The linear dimensional change of the stone casts was measured with a profile projector. For statistical analysis, Kruskall-Wallis and Mann-Witney tests were used (α=0.05. Results: By immersion method, the casts fabricated from tetrachrom were 0.36% larger in the anteroposterior (AP and 0.05% smaller in cross arch (CA dimensions; however, the casts prepared after spraying of tetrachrom were 0.44% larger in the AP and 0.10% smaller in CA dimensions. The casts made from Cavex were 0.05% smaller in the AP and 0.02% smaller in CA dimensions after spraying and 0.01% smaller in the AP and 0.003% smaller in CA dimensions after immersion. Generally there were not significant differences in AP and CA dimensions of the experimental groups compared to the control (p > 0.05. Conclusions: Disinfection of the tested color-changing irreversible hydrocolloids by glutaraldahyde 2% did not compromise the accuracy of the obtained casts.

  19. ‘Mom—I don’t want to hear it’: Brain response to maternal praise and criticism in adolescents with major depressive disorder

    Science.gov (United States)

    Lee, Kyung Hwa; Elliott, Rosalind D.; Hooley, Jill M.; Dahl, Ronald E.; Barber, Anita; Siegle, Greg J.

    2017-01-01

    Abstract Recent research has implicated altered neural response to interpersonal feedback as an important factor in adolescent depression, with existing studies focusing on responses to feedback from virtual peers. We investigated whether depressed adolescents differed from healthy youth in neural response to social evaluative feedback from mothers. During neuroimaging, twenty adolescents in a current episode of major depressive disorder (MDD) and 28 healthy controls listened to previously recorded audio clips of their own mothers’ praise, criticism and neutral comments. Whole-brain voxelwise analyses revealed that MDD youth, unlike controls, exhibited increased neural response to critical relative to neutral clips in the parahippocampal gyrus, an area involved in episodic memory encoding and retrieval. Depressed adolescents also showed a blunted response to maternal praise clips relative to neutral clips in the parahippocampal gyrus, as well as areas involved in reward and self-referential processing (i.e. ventromedial prefrontal cortex, precuneus, and thalamus/caudate). Findings suggest that maternal criticism may be more strongly encoded or more strongly activated during memory retrieval related to previous autobiographical instances of negative feedback from mothers in depressed youth compared to healthy youth. Furthermore, depressed adolescents may fail to process the reward value and self-relevance of maternal praise. PMID:28338795

  20. 'Mom-I don't want to hear it': Brain response to maternal praise and criticism in adolescents with major depressive disorder.

    Science.gov (United States)

    Silk, Jennifer S; Lee, Kyung Hwa; Elliott, Rosalind D; Hooley, Jill M; Dahl, Ronald E; Barber, Anita; Siegle, Greg J

    2017-05-01

    Recent research has implicated altered neural response to interpersonal feedback as an important factor in adolescent depression, with existing studies focusing on responses to feedback from virtual peers. We investigated whether depressed adolescents differed from healthy youth in neural response to social evaluative feedback from mothers. During neuroimaging, twenty adolescents in a current episode of major depressive disorder (MDD) and 28 healthy controls listened to previously recorded audio clips of their own mothers' praise, criticism and neutral comments. Whole-brain voxelwise analyses revealed that MDD youth, unlike controls, exhibited increased neural response to critical relative to neutral clips in the parahippocampal gyrus, an area involved in episodic memory encoding and retrieval. Depressed adolescents also showed a blunted response to maternal praise clips relative to neutral clips in the parahippocampal gyrus, as well as areas involved in reward and self-referential processing (i.e. ventromedial prefrontal cortex, precuneus, and thalamus/caudate). Findings suggest that maternal criticism may be more strongly encoded or more strongly activated during memory retrieval related to previous autobiographical instances of negative feedback from mothers in depressed youth compared to healthy youth. Furthermore, depressed adolescents may fail to process the reward value and self-relevance of maternal praise. © The Author (2017). Published by Oxford University Press.

  1. Estimation of the frequency of occult mutations for an autosomal recessive disease in the presence of genetic heterogeneity: application to genetic hearing loss disorders.

    Science.gov (United States)

    Kimberling, William J

    2005-11-01

    The routine testing for pathologic mutation(s) in a patient's DNA has become the foundation of modern molecular genetic diagnosis. It is especially valuable when the phenotype shows genetic heterogeneity, and its importance will grow as treatments become genotype specific. However, the technology of mutation detection is imperfect and mutations are often missed. This can be especially troublesome when dealing with a recessive disorder where the combination of genetic heterogeneity and missed mutation creates an imprecision in the genotypic assessment of individuals who do not appear to have the expected complement of two pathologic mutations. This article describes a statistical approach to the estimation of the likelihood of a genetic diagnosis under these conditions. In addition to providing a means of testing for missed mutations, it also provides a method of estimating and testing for the presence of genetic heterogeneity in the absence of linkage data. Gene frequencies as well as estimates of sensitivity and specificity can be obtained as well. The test is applied to GJB2 recessive nonsyndromic deafness, Usher syndrome types Ib and IIa, and Pendred-enlarged vestibular aqueduct syndrome. Copyright 2005 Wiley-Liss, Inc.

  2. Extended irreversible thermodynamics and non-equilibrium temperature

    Directory of Open Access Journals (Sweden)

    Casas-Vazquez, Jose'

    2008-02-01

    Full Text Available We briefly review the concept of non-equilibrium temperature from the perspectives of extended irreversible thermodynamics, fluctuation theory, and statistical mechanics. The relations between different proposals are explicitly examined in two especially simple systems: an ideal gas in steady shear flow and a forced harmonic oscillator in a thermal bath. We examine with special detail temperatures related to the average molecular kinetic energy along different spatial directions, to the average configurational energy, to the derivative of the entropy with respect to internal energy, to fluctuation-dissipation relation and discuss their measurement.

  3. Exactly solvable irreversible processes on one-dimensional lattices

    International Nuclear Information System (INIS)

    Wolf, N.O.; Evans, J.W.; Hoffman, D.K.

    1984-01-01

    We consider the kinetics of a process where the sites of an infinite 1-D lattice are filled irreversibly and, in general, cooperatively by N-mers (taking N consecutive sites at a time). We extend the previously available exact solution for nearest neighbor cooperative effects to range N cooperative effects. Connection with the continuous ''cooperative car parking problem'' is indicated. Both uniform and periodic lattices, and empty and certain partially filled lattice initial conditions are considered. We also treat monomer ''filling in stages'' for certain highly autoinhibitory cooperative effects of arbitrary range

  4. Hearing Aid Personalization

    DEFF Research Database (Denmark)

    Nielsen, Jens Brehm; Nielsen, Jakob; Jensen, Bjørn Sand

    2013-01-01

    Modern digital hearing aids require and offer a great level of personalization. Today, this personalization is not performed based directly on what the user actually perceives, but on a hearing-care professional’s interpretation of what the user explains about what is perceived. In this paper......, an interactive personalization system based on Gaussian process regression and active learning is proposed, which personalize the hearing aids based directly on what the user perceives. Preliminary results demonstrate a significant difference between a truly personalized setting obtained with the proposed system...

  5. Introduction to audiology: Some basics about hearing loss, hearing technologies and barriers to hearing aid use

    DEFF Research Database (Denmark)

    Mourtou, Eleni; Meis, Markus

    2012-01-01

    This chapter provides background information for researchers who wish to become familiar with some basic medical and audiological aspects of hearing loss and the technology of hearing aids. It introduces (1) the disciplines involved in research on hearing loss, (2) the medical categories of hearing...... loss and their various effects on communication, (3) the different degrees of hearing loss as defined by different national and international organizations, (4) statistics on the preva- lence of hearing loss worldwide, (5) some technological aspects of hearing instruments, (6) sta- tistics on non...

  6. Hearing Conservation Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Hearing Conservation Team focuses on ways to identify the early stages of noise-induced damage to the human ear.Our current research involves the evaluation of...

  7. Living with Hearing Loss

    Science.gov (United States)

    ... version of this page please turn Javascript on. Nora Woodruff and her family, including dad Bob, have ... hearing, balance, smell, taste, voice, speech, and language. Nora Woodruff, daughter of ABC newsman Bob Woodruff and ...

  8. Hearing loss - infants

    Science.gov (United States)

    ... can allow many infants to develop normal language skills without delay. In infants born with hearing loss, ... therapy allow many children to develop normal language skills at the same age as their peers with ...

  9. Types of Hearing Aids

    Science.gov (United States)

    ... aids : Most parts are contained in a small plastic case that rests behind the ear; the case ... certain situations (for example, background noise and whistle reduction). They also have greater flexibility in hearing aid ...

  10. Buying a Hearing Aid

    Science.gov (United States)

    ... in price according to style, features, and local market prices. Price can range from hundreds of dollars to more than $2,500 for a programmable, digital hearing aid. Purchase price should not be the ...

  11. Hearing regulates Drosophila aggression.

    Science.gov (United States)

    Versteven, Marijke; Vanden Broeck, Lies; Geurten, Bart; Zwarts, Liesbeth; Decraecker, Lisse; Beelen, Melissa; Göpfert, Martin C; Heinrich, Ralf; Callaerts, Patrick

    2017-02-21

    Aggression is a universal social behavior important for the acquisition of food, mates, territory, and social status. Aggression in Drosophila is context-dependent and can thus be expected to involve inputs from multiple sensory modalities. Here, we use mechanical disruption and genetic approaches in Drosophila melanogaster to identify hearing as an important sensory modality in the context of intermale aggressive behavior. We demonstrate that neuronal silencing and targeted knockdown of hearing genes in the fly's auditory organ elicit abnormal aggression. Further, we show that exposure to courtship or aggression song has opposite effects on aggression. Our data define the importance of hearing in the control of Drosophila intermale aggression and open perspectives to decipher how hearing and other sensory modalities are integrated at the neural circuit level.

  12. Devices for hearing loss

    Science.gov (United States)

    ... the sounds you want to hear. Assistive listening devices bring certain sounds directly to your ears. This can ... a small room or on a stage. Other devices can bring the sound from your TV, radio, or music ...

  13. Regional Hearing Clerk

    Science.gov (United States)

    The Regional Hearing Clerk receives filings for proceedings under the Consolidated Rules of Practice Governing the Administrative Assessment of Civil Penalties and the Revocation/Termination or Suspension of Permits, 40 Code of Federal Regulations Part 22

  14. Adaptive Processes in Hearing

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Christensen-Dalsgaard, Jakob; Tranebjærg, Lisbeth

    2018-01-01

    , and is essential to achieve successful speech communication, correct orientation in our full environment, and eventually survival. These adaptive processes may differ in individuals with hearing loss, whose auditory system may cope via ‘‘readapting’’ itself over a longer time scale to the changes in sensory input...... induced by hearing impairment and the compensation provided by hearing devices. These devices themselves are now able to adapt to the listener’s individual environment, attentional state, and behavior. These topics related to auditory adaptation, in the broad sense of the term, were central to the 6th...... International Symposium on Auditory and Audiological Research held in Nyborg, Denmark, in August 2017. The symposium addressed adaptive processes in hearing from different angles, together with a wide variety of other auditory and audiological topics. The papers in this special issue result from some...

  15. Genes and Hearing Loss

    Science.gov (United States)

    ... expressivity is seen in families transmitting autosomal dominant Waardenburg syndrome. Within the same family, some affected members may ... risk of having a child with hearing problems. Patient Health Home Copyright © 2018 American Academy of Otolaryngology– ...

  16. Linear Dimensional Stability of Irreversible Hydrocolloid Materials Over Time.

    Science.gov (United States)

    Garrofé, Analía B; Ferrari, Beatriz A; Picca, Mariana; Kaplan, Andrea E

    2015-12-01

    The aim of this study was to evaluate the linear dimensional stability of different irreversible hydrocolloid materials over time. A metal mold was designed with custom trays made of thermoplastic sheets (Sabilex, sheets 0.125 mm thick). Perforations were made in order to improve retention of the material. Five impressions were taken with each of the following: Kromopan 100 (LASCOD) [AlKr], which has dimensional stability of 100 hours, and Phase Plus (ZHERMACK) [AlPh], which has dimensional stability of 48 hours. Standardized digital photographs were taken at different time intervals (0, 15, 30, 45, 60, 120 minutes; 12, 24 and 96 hours), using an "ad-hoc" device. The images were analyzed with software (UTHSCSA Image Tool) by measuring the distance between intersection of the lines previously made at the top of the mold. The results were analyzed by ANOVA for repeated measures. Initial and final values were (mean and standard deviation): AlKr: 16.44 (0.22) and 16.34 (0.11), AlPh: 16.40 (0.06) and 16.18 (0.06). Statistical evaluation showed significant effect of material and time factors. Under the conditions in this study, time significantly affects the linear dimensional stability of irreversible hydrocolloid materials. Sociedad Argentina de Investigación Odontológica.

  17. Irreversible entropy model for damage diagnosis in resistors

    Energy Technology Data Exchange (ETDEWEB)

    Cuadras, Angel, E-mail: angel.cuadras@upc.edu; Crisóstomo, Javier; Ovejas, Victoria J.; Quilez, Marcos [Instrumentation, Sensor and Interfaces Group, Electronic Engineering Department, Escola d' Enginyeria de Telecomunicació i Aeronàutica de Castelldefels EETAC, Universitat Politècnica de Catalunya, Barcelona Tech (UPC), Castelldefels-Barcelona (Spain)

    2015-10-28

    We propose a method to characterize electrical resistor damage based on entropy measurements. Irreversible entropy and the rate at which it is generated are more convenient parameters than resistance for describing damage because they are essentially positive in virtue of the second law of thermodynamics, whereas resistance may increase or decrease depending on the degradation mechanism. Commercial resistors were tested in order to characterize the damage induced by power surges. Resistors were biased with constant and pulsed voltage signals, leading to power dissipation in the range of 4–8 W, which is well above the 0.25 W nominal power to initiate failure. Entropy was inferred from the added power and temperature evolution. A model is proposed to understand the relationship among resistance, entropy, and damage. The power surge dissipates into heat (Joule effect) and damages the resistor. The results show a correlation between entropy generation rate and resistor failure. We conclude that damage can be conveniently assessed from irreversible entropy generation. Our results for resistors can be easily extrapolated to other systems or machines that can be modeled based on their resistance.

  18. Influence of delayed pouring on irreversible hydrocolloid properties

    Directory of Open Access Journals (Sweden)

    Stéfani Becker Rodrigues

    2012-10-01

    Full Text Available The aim of this study was to evaluate the physical properties of irreversible hydrocolloid materials poured immediately and after different storage periods. Four alginates were tested: Color Change (Cavex; Hydrogum (Zhermack; Hydrogum 5 (Zhermack; and Hydro Print Premium (Coltene. Their physical properties, including the recovery from deformation (n = 3, compressive strength (n = 3, and detail reproduction and gypsum compatibility (n = 3, were analyzed according to ANSI/ADA specification no. 18. Specimens were stored at 23ºC and humidity and were then poured with gypsum immediately and after 1, 2, 3, 4, and 5 days. The data were analyzed by two-way analysis of variance (ANOVA and Tukey's test at p < 0.05. All of the alginate impression materials tested exhibited detail reproduction and gypsum compatibility at all times. Hydro Print Premium and Hydrogum 5 showed recovery from deformation, as established by ANSI/ADA specification no. 18, after 5 days of storage. As the storage time increased, the compressive strength values also increased. Considering the properties of compounds' recovery from deformation, compressive strength, and detail reproduction and gypsum compatibility, irreversible hydrocolloids should be poured immediately.

  19. Voter model with arbitrary degree dependence: clout, confidence and irreversibility

    Science.gov (United States)

    Fotouhi, Babak; Rabbat, Michael G.

    2014-03-01

    The voter model is widely used to model opinion dynamics in society. In this paper, we propose three modifications to incorporate heterogeneity into the model. We address the corresponding oversimplifications of the conventional voter model which are unrealistic. We first consider the voter model with popularity bias. The influence of each node on its neighbors depends on its degree. We find the consensus probabilities and expected consensus times for each of the states. We also find the fixation probability, which is the probability that a single node whose state differs from every other node imposes its state on the entire system. In addition, we find the expected fixation time. Then two other extensions to the model are proposed and the motivations behind them are discussed. The first one is confidence, where in addition to the states of neighbors, nodes take their own state into account at each update. We repeat the calculations for the augmented model and investigate the effects of adding confidence to the model. The second proposed extension is irreversibility, where one of the states is given the property that once nodes adopt it, they cannot switch back. This is motivated by applications where, agents take an irreversible action such as seeing a movie, purchasing a music album online, or buying a new product. The dynamics of densities, fixation times and consensus times are obtained.

  20. Irreversibility in physics stemming from unpredictable symbol-handling agents

    Science.gov (United States)

    Myers, John M.; Madjid, F. Hadi

    2016-05-01

    The basic equations of physics involve a time variable t and are invariant under the transformation t --> -t. This invariance at first sight appears to impose time reversibility as a principle of physics, in conflict with thermodynamics. But equations written on the blackboard are not the whole story in physics. In prior work we sharpened a distinction obscured in today's theoretical physics, the distinction between obtaining evidence from experiments on the laboratory bench and explaining that evidence in mathematical symbols on the blackboard. The sharp distinction rests on a proof within the mathematics of quantum theory that no amount of evidence, represented in quantum theory in terms of probabilities, can uniquely determine its explanation in terms of wave functions and linear operators. Building on the proof we show here a role in physics for unpredictable symbol-handling agents acting both at the blackboard and at the workbench, communicating back and forth by means of transmitted symbols. Because of their unpredictability, symbol-handling agents introduce a heretofore overlooked source of irreversibility into physics, even when the equations they write on the blackboard are invariant under t --> -t. Widening the scope of descriptions admissible to physics to include the agents and the symbols that link theory to experiments opens up a new source of time-irreversibility in physics.

  1. Advanced Caries Microbiota in Teeth with Irreversible Pulpitis.

    Science.gov (United States)

    Rôças, Isabela N; Lima, Kenio C; Assunção, Isauremi V; Gomes, Patrícia N; Bracks, Igor V; Siqueira, José F

    2015-09-01

    Bacterial taxa in the forefront of caries biofilms are candidate pathogens for irreversible pulpitis and are possibly the first ones to invade the pulp and initiate endodontic infection. This study examined the microbiota of the most advanced layers of dentinal caries in teeth with irreversible pulpitis. DNA extracted from samples taken from deep dentinal caries associated with pulp exposures was analyzed for the presence and relative levels of 33 oral bacterial taxa by using reverse-capture checkerboard hybridization assay. Quantification of total bacteria, streptococci, and lactobacilli was also performed by using real-time quantitative polymerase chain reaction. Associations between the target bacterial taxa and clinical signs/symptoms were also evaluated. The most frequently detected taxa in the checkerboard assay were Atopobium genomospecies C1 (53%), Pseudoramibacter alactolyticus (37%), Streptococcus species (33%), Streptococcus mutans (33%), Parvimonas micra (13%), Fusobacterium nucleatum (13%), and Veillonella species (13%). Streptococcus species, Dialister invisus, and P. micra were significantly associated with throbbing pain, S. mutans with pain to percussion, and Lactobacillus with continuous pain (P pulpitis is suspected. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Irreversible entropy model for damage diagnosis in resistors

    International Nuclear Information System (INIS)

    Cuadras, Angel; Crisóstomo, Javier; Ovejas, Victoria J.; Quilez, Marcos

    2015-01-01

    We propose a method to characterize electrical resistor damage based on entropy measurements. Irreversible entropy and the rate at which it is generated are more convenient parameters than resistance for describing damage because they are essentially positive in virtue of the second law of thermodynamics, whereas resistance may increase or decrease depending on the degradation mechanism. Commercial resistors were tested in order to characterize the damage induced by power surges. Resistors were biased with constant and pulsed voltage signals, leading to power dissipation in the range of 4–8 W, which is well above the 0.25 W nominal power to initiate failure. Entropy was inferred from the added power and temperature evolution. A model is proposed to understand the relationship among resistance, entropy, and damage. The power surge dissipates into heat (Joule effect) and damages the resistor. The results show a correlation between entropy generation rate and resistor failure. We conclude that damage can be conveniently assessed from irreversible entropy generation. Our results for resistors can be easily extrapolated to other systems or machines that can be modeled based on their resistance

  3. Irreversible absorption heat-pump and its optimal performance

    International Nuclear Information System (INIS)

    Chen Lingen; Qin Xiaoyong; Sun Fengrui; Wu Chih

    2005-01-01

    On the basis of an endoreversible absorption heat-pump cycle, a generalized irreversible four-heat-reservoir absorption heat-pump cycle model is established by taking account of the heat resistances, heat leak and irreversibilities due to the internal dissipation of the working substance. The heat transfer between the heat reservoir and the working substance is assumed to obey the linear (Newtonian) heat-transfer law, and the overall heat-transfer surface area of the four heat-exchangers is assumed to be constant. The fundamental optimal relations between the coefficient of performance (COP) and the heating-load, the maximum COP and the corresponding heating-load, the maximum heating load and the corresponding COP, as well as the optimal temperatures of the working substance and the optimal heat-transfer surface areas of the four heat-exchangers are derived by using finite-time thermodynamics. Moreover, the effects of the cycle parameters on the characteristics of the cycle are studied by numerical examples

  4. IRREVERSIBILITY GENERATION IN SUGAR, ALCOHOL AND BIOGAS INTEGRATED PRODUCTIONS

    Directory of Open Access Journals (Sweden)

    Meilyn González Cortés

    2017-01-01

    Full Text Available In this work, the stages of losses and lower exergetic efficiency are determined when the sugar production process is integrated with others for the production of products such as biogas, torula yeast and electricity. The study is carried out in three scenarios of integrated processes for obtaining the indicated products. A sugar factory in which sugar and electricity are produced is considered as the base scenario and from this; a second scenario is inferred in which alcohol is produced from the molasses of the sugar process and biogas from the vinasse of the alcohol distillation process. Finally, a third scenario is exergetically evaluated in which sugar, electricity, biogas and alcohol are produced, but this last one from juices and molasses of the sugar process. For the exergetic analysis the integrated scheme was divided into 8 subsystems. From the analysis of results, the major subsystems that generate irreversibilities are: cogeneration (64.36-65.98%, juice extraction (8.85-9.85%, crystallization and cooking, (8.48 -9.02%, fermentation (4.12-4.94% and distillation (2.74-3.2%. Improvements are proposed to minimize irreversibilities, including the thermal integration of processes, technological modifications in the fermentation process and the introduction of more efficient equipment for the generation of electricity. The exergetic efficiency is between 78.95-81.10%, obtaining greater exergetic efficiency in the scheme of joint operation to produce sugar, alcohol and biogas.

  5. Expression levels of the BAK1 and BCL2 genes highlight the role of apoptosis in age-related hearing impairment

    Directory of Open Access Journals (Sweden)

    Falah M

    2016-07-01

    Full Text Available Masoumeh Falah,1,2 Mohammad Najafi,2 Massoud Houshmand,3 Mohammad Farhadi1 1ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences, Tehran, Iran; 2Cellular and Molecular Research Center, Biochemistry Department, Iran University of Medical Sciences, Tehran, Iran; 3Department of Medical Genetics, National Institute for Genetic Engineering and Biotechnology, Tehran, Iran Abstract: Age-related hearing impairment (ARHI is a progressive and a common sensory disorder in the elderly and will become an increasingly important clinical problem given the growing elderly population. Apoptosis of cochlear cells is an important factor in animal models of ARHI. As these cells cannot regenerate, their loss leads to irreversible hearing impairment. Identification of molecular mechanisms can facilitate disease prevention and effective treatment. In this study, we compared the expression of the genes BAK1 and BCL2 as two arms of the intrinsic apoptosis pathway between patients with ARHI and healthy subjects. ARHI and healthy subjects were selected after an ear nose throat examination, otoscopic investigation, and pure tone audiometry. RNA was extracted from peripheral blood samples, and relative gene expression levels were measured using quantitative real-time polymerase chain reaction. BAK1 and the BAK1/BCL2 ratio were statistically significantly upregulated in the ARHI subjects. The BAK1/BCL2 ratio was positively correlated with the results of the audiometric tests. Our results indicate that BAK-mediated apoptosis may be a core mechanism in the progression of ARHI in humans, similar to finding in animal models. Moreover, the gene expression changes in peripheral blood samples could be used as a rapid and simple biomarker for early detection of ARHI. Keywords: age-related hearing impairment (ARHI, presbycusis, biomarker, treatment

  6. [Hearing voices does not always constitute a psychosis].

    Science.gov (United States)

    Sommer, I E C; van der Spek, D W

    2016-01-01

    Hearing voices (i.e. auditory verbal hallucinations) is mainly known as part of schizophrenia and other psychotic disorders. However, hearing voices is a symptom that can occur in many psychiatric, neurological and general medical conditions. We present three cases of non-psychotic patients with auditory verbal hallucinations caused by different disorders. The first patient is a 74-year-old male with voices due to hearing loss, the second is a 20-year-old woman with voices due to traumatisation. The third patient is a 27-year-old woman with voices caused by temporal lobe epilepsy. Hearing voices is a phenomenon that occurs in a variety of disorders. Therefore, identification of the underlying disorder is essential to indicate treatment. Improvement of coping with the voices can reduce their impact on a patient. Antipsychotic drugs are especially effective when hearing voices is accompanied by delusions or disorganization. When this is not the case, the efficacy of antipsychotic drugs will probably not outweigh the side-effects.

  7. Smartphone App for Voice Disorders

    Science.gov (United States)

    ... on. Feature: Taste, Smell, Hearing, Language, Voice, Balance Smartphone App for Voice Disorders Past Issues / Fall 2013 ... developed a mobile monitoring device that relies on smartphone technology to gather a week's worth of talking, ...

  8. Autism and peripheral hearing loss: a systematic review.

    Science.gov (United States)

    Beers, Alison N; McBoyle, Melanie; Kakande, Emily; Dar Santos, Rachelle C; Kozak, Frederick K

    2014-01-01

    To systematically review the literature describing the relationship between autism spectrum disorder (ASD) and peripheral hearing loss including literature recommendations for audiological assessment and auditory habilitation in cases where peripheral hearing loss and ASD coexist. Published studies indexed in MEDLINE (1948-2011). The search strategy identified 595 potential studies. After a review of the titles, 115 abstracts were reviewed and 39 articles were retrieved and assessed independently by at least two authors for possible inclusion. 22 articles pertained to children with ASD and peripheral hearing loss, hearing assessment in children with ASD, audiological habilitation for children with ASD or hyper-responsiveness in children with ASD. 17 further studies were garnered from the reference section of the 22 papers. Controversy exists in the literature regarding prevalence of hearing impairment among individuals with ASD. In cases where ASD and hearing impairment co-exist, diagnosis of one condition often leads to a delay in diagnosing the other. Audiological assessment can be difficult in children with ASD and test-retest reliability of behavioural thresholds can be poor. In cases where hearing impairment exists and hearing aids or cochlear implantation are recommended, devices are often fit with special considerations for the child with ASD. Hyper-responsiveness to auditory stimuli may be displayed by individuals with ASD. Evidence or the suspicion of hyper-responsiveness may be taken into consideration when fitting amplification and planning behavioural intervention. Prevalence rates of hearing impairment among individuals with ASD continue to be debated. At present there is no conclusive evidence that children with ASD are at increased risk of peripheral hearing loss. A complete audiological assessment is recommended in all cases where ASD is suspected so as not to delay the diagnosis of hearing impairment in the event that hearing loss and ASD co

  9. Do You Need a Hearing Test?

    Science.gov (United States)

    ... hearing them? Yes No Do you have difficulty hearing or understanding co-workers, clients, or customers? Yes No Do you feel restricted or limited by a hearing problem? Yes No Do you have difficulty hearing ...

  10. Acoustic Trauma - Hearing Loss in Teenagers

    Science.gov (United States)

    ... I Can Hear It, It's Too Loud: Earbuds & Teen Hearing Loss Page Content ​Many parents will agree ... hearing loss." Recommended Hearing Screenings for Older Children & Teens Kids should be screened at three ages: 11- ...

  11. Age-related hearing loss in dogs and treatment with Vibrant Soundbridge middle ear implant

    NARCIS (Netherlands)

    Haar, Gert ter

    Hearing loss is a common disorder in many breeds of dogs and auditory dysfunction and its clinical consequences can vary from mild to severe. Dogs with bilateral hearing loss are unable to anticipate dangers such as motor vehicles and they may consequently fall victim to serious or fatal injury. It

  12. Traumatization in Deaf and Hard-of-Hearing Adult Psychiatric Outpatients

    Science.gov (United States)

    Øhre, Beate; Uthus, Mette Perly; von Tetzchner, Stephen; Falkum, Erik

    2015-01-01

    Deaf and hard-of-hearing persons are at risk for experiencing traumatic events and such experiences are associated with symptoms of mental disorder. We investigated the prevalence of traumatic events and subsequent traumatization in adults referred to specialized psychiatric outpatient units for deaf and hard-of-hearing patients. Sixty-two…

  13. Hearing loss among patients with Turner's syndrome: literature review

    Directory of Open Access Journals (Sweden)

    Cresio Alves

    2014-06-01

    Full Text Available INTRODUCTION: Turner's syndrome (TS is caused by a partial or total deletion of an X chromosome, occurring in 1:2,000 to 1:5,000 live born females. Hearing loss is one of its major clinical manifestations. However, there are few studies investigating this problem. OBJECTIVES: To review the current knowledge regarding the epidemiology, etiology, clinical manifestations and diagnosis of hearing impairment in patients with TS. METHODS: A bibliographic search was performed in the Medline and Lilacs databanks (1980-2012 to identify the main papers associating Turner's syndrome, hearing impairment and its clinical outcomes. CONCLUSIONS: Recurrent otitis media, dysfunction of the Eustachian tube, conductive hearing loss during infancy and sensorineural hearing loss in adolescence are the audiologic disorders more common in ST. The karyotype appears to be important in the hearing loss, with studies demonstrating an increased prevalence in patients with monosomy 45,X or isochromosome 46,i(Xq. Morphologic studies of the cochlea are necessary to help out in the clarifying the etiology of the sensorineural hearing loss.

  14. Irreversible Thermodynamics of the Universe: Constraints from Planck Data

    International Nuclear Information System (INIS)

    Saha, Subhajit; Chakraborty, Subenoy; Biswas, Atreyee

    2014-01-01

    The present work deals with irreversible universal thermodynamics. The homogenous and isotropic flat model of the universe is chosen as open thermodynamical system and nonequilibrium thermodynamics comes into picture. For simplicity, entropy flow is considered only due to heat conduction. Further, due to Maxwell-Cattaneo modified Fourier law for nonequilibrium phenomenon, the temperature satisfies damped wave equation instead of heat conduction equation. Validity of generalized second law of thermodynamics (GSLT) has been investigated for universe bounded by apparent or event horizon with cosmic substratum as perfect fluid with constant or variable equation of state or interacting dark species. Finally, we have used three Planck data sets to constrain the thermal conductivity λ and the coupling parameter b 2 . These constraints must be satisfied in order for GSLT to hold for universe bounded by apparent or event horizons

  15. Ac irreversibility line of bismuth-based high temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Mehdaoui, A. [Laboratoire de Physique et de Spectroscopie Electronique, URA 1435 Faculte des Sciences, Universite de Haute Alsace 4, rue des Freres Lumiere, 68093 Mulhouse Cedex (France); Beille, J. [Laboratoire Louis Neel, CNRS, BP 166, 38042 Grenoble Cedex 9 (France); Berling, D.; Loegel, B. [Laboratoire de Physique et de Spectroscopie Electronique, URA 1435 Faculte des Sciences, Universite de Haute Alsace 4, rue des Freres Lumiere, 68093 Mulhouse Cedex (France); Noudem, J.G.; Tournier, R. [EPM-MATFORMAG, Laboratoire dElaboration par Procede Magnetique, CNRS, BP 166, 38042 Grenoble Cedex 9 (France)

    1997-09-01

    We discuss the magnetic properties of lead doped Bi-2223 bulk samples obtained through combined magnetic melt texturing and hot pressing (MMTHP). The ac complex susceptibility measurements are achieved over a broad ac field range (1 Oe{lt}h{sub ac}{lt}100 Oe) and show highly anisotropic properties. The intergranular coupling is improved in the direction perpendicular to the applied stress and magnetic field direction, and an intragranular loss peak is observed for the first time. A comparison is made with other bismuth-based compounds and it is shown that the MMTHP process shifts the ac irreversibility line (ac IL) toward higher fields. It is also shown that all the ac IL{close_quote}s for quasi 2D bismuth-based compounds show a nearly quadratic temperature dependence and deviate therefore strongly from the linear behavior observed in quasi 3D compounds and expected from a critical state model.{copyright} {ital 1997 Materials Research Society.}

  16. Ac irreversibility line of bismuth-based high temperature superconductors

    International Nuclear Information System (INIS)

    Mehdaoui, A.; Beille, J.; Berling, D.; Loegel, B.; Noudem, J.G.; Tournier, R.

    1997-01-01

    We discuss the magnetic properties of lead doped Bi-2223 bulk samples obtained through combined magnetic melt texturing and hot pressing (MMTHP). The ac complex susceptibility measurements are achieved over a broad ac field range (1 Oe ac <100 Oe) and show highly anisotropic properties. The intergranular coupling is improved in the direction perpendicular to the applied stress and magnetic field direction, and an intragranular loss peak is observed for the first time. A comparison is made with other bismuth-based compounds and it is shown that the MMTHP process shifts the ac irreversibility line (ac IL) toward higher fields. It is also shown that all the ac IL close-quote s for quasi 2D bismuth-based compounds show a nearly quadratic temperature dependence and deviate therefore strongly from the linear behavior observed in quasi 3D compounds and expected from a critical state model.copyright 1997 Materials Research Society

  17. Thermodynamic Optimality criteria for biological systems in linear irreversible thermodynamics

    International Nuclear Information System (INIS)

    Chimal, J C; Sánchez, N; Ramírez, PR

    2017-01-01

    In this paper the methodology of the so-called Linear Irreversible Thermodynamics (LIT) is applied; although traditionally used locally to study general systems in non-equilibrium states in which it is consider both internal and external contributions to the entropy increments in order to analyze the efficiency of two coupled processes with generalized fluxes J 1 , J 2 and their corresponding forces X 1 , X 2 . We extend the former analysis to takes into account two different operating regimes namely: Omega Function and Efficient Power criterion, respectively. Results show analogies in the optimal performance between and we can say that there exist a criteria of optimization which can be used specially for biological systems where a good design of the biological parameters made by nature at maximum efficient power conditions lead to more efficient engines than those at the maximum power conditions or ecological conditions. (paper)

  18. A quantum analogy for the linear thermodynamics of irreversible processes

    International Nuclear Information System (INIS)

    Ibanez-Mengual, J.A.; Tejerina-Garcia, A.F.

    1981-01-01

    In this paper, a model for the transport through a liquid junction of two solutions of the same components, based on quantum-mechanical considerations, is established. A small energy difference, compared with the molecules' energy, among the molecules placed at both sides of the junction is assumed to exist. The liquid junction is assimilated to a potential barrier, getting the material flow from the transmission coefficient of the barrier, when the energy difference is caused by a temperature gradient, a concentration gradient, or both gradients acting together. In all cases, equations formally identical to those of the thermodynamics of irreversible processes are obtained. In the last case, the heat flow is also determined. (author)

  19. Study suggests Arctic sea ice loss not irreversible

    Science.gov (United States)

    Balcerak, Ernie

    2011-10-01

    The Arctic has been losing sea ice as Earth's climate warms, and some studies have suggested that the Arctic could reach a tipping point, beyond which ice would not recover even if global temperatures cooled down again. However, a new study by Armour et al. that uses a state-of-the-art atmosphere-ocean global climate model found no evidence of such irreversibility. In their simulations, the researchers increased atmospheric carbon dioxide levels until Arctic sea ice disappeared year-round and then watched what happened as global temperatures were then decreased. They found that sea ice steadily recovered as global temperatures dropped. An implication of this result is that future sea ice loss will occur only as long as global temperatures continue to rise. (Geophysical Research Letters, doi:10.1029/2011GL048739, 2011)

  20. Irreversibility of world-sheet renormalization group flow

    International Nuclear Information System (INIS)

    Oliynyk, T.; Suneeta, V.; Woolgar, E.

    2005-01-01

    We demonstrate the irreversibility of a wide class of world-sheet renormalization group (RG) flows to first order in α ' in string theory. Our techniques draw on the mathematics of Ricci flows, adapted to asymptotically flat target manifolds. In the case of somewhere-negative scalar curvature (of the target space), we give a proof by constructing an entropy that increases monotonically along the flow, based on Perelman's Ricci flow entropy. One consequence is the absence of periodic solutions, and we are able to give a second, direct proof of this. If the scalar curvature is everywhere positive, we instead construct a regularized volume to provide an entropy for the flow. Our results are, in a sense, the analogue of Zamolodchikov's c-theorem for world-sheet RG flows on noncompact spacetimes (though our entropy is not the Zamolodchikov C-function)

  1. Irreversibility of entanglement distillation for a class of symmetric states

    International Nuclear Information System (INIS)

    Vollbrecht, Karl Gerd H.; Wolf, Michael M.; Werner, Reinhard F.

    2004-01-01

    We investigate the irreversibility of entanglement distillation for a symmetric (d+1)-parameter family of mixed bipartite quantum states acting on Hilbert spaces of arbitrary dimension dxd. We prove that in this family the entanglement cost is generically strictly larger than the distillable entanglement, so that the set of states for which the distillation process is asymptotically reversible is of measure zero. This remains true even if the distillation process is catalytically assisted by pure-state entanglement and every operation is allowed, which preserves the positivity of the partial transpose. It is shown that reversibility occurs only in cases where the state is a tagged mixture. The reversible cases are shown to be completely characterized by minimal uncertainty vectors for entropic uncertainty relations

  2. Structural transition models for a class or irreversible aggregates

    International Nuclear Information System (INIS)

    Canessa, E.

    1995-02-01

    A progress report on two recent theoretical approaches proposed to understand the physics of irreversible fractal aggregates showing up a structural transition from a rather dense to a more multibranched growth is presented. In the first approach the transition is understood by solving the Poisson equation on a squared lattice. The second approach is based on the discretization of the Biharmonic equation. Within these models the transition appears when the growth velocity at the fractal surface presents a minimum. The effects of the surrounding medium and geometrical constraints for the seed particles are considered. By using the optical diffraction method, the structural transition is further characterized by a decrease in the fractal dimension for this peculiar class of aggregates. (author). 17 refs, 4 figs

  3. The Social Cost of Stochastic and Irreversible Climate Change

    Science.gov (United States)

    Cai, Y.; Judd, K. L.; Lontzek, T.

    2013-12-01

    Many scientists are worried about climate change triggering abrupt and irreversible events leading to significant and long-lasting damages. For example, a rapid release of methane from permafrost may lead to amplified global warming, and global warming may increase the frequency and severity of heavy rainfall or typhoon, destroying large cities and killing numerous people. Some elements of the climate system which might exhibit such a triggering effect are called tipping elements. There is great uncertainty about the impact of anthropogenic carbon and tipping elements on future economic wellbeing. Any rational policy choice must consider the great uncertainty about the magnitude and timing of global warming's impact on economic productivity. While the likelihood of tipping points may be a function of contemporaneous temperature, their effects are long lasting and might be independent of future temperatures. It is assumed that some of these tipping points might occur even in this century, but also that their duration and post-tipping impact are uncertain. A faithful representation of the possibility of tipping points for the calculation of social cost of carbon would require a fully stochastic formulation of irreversibility, and accounting for the deep layer of uncertainties regarding the duration of the tipping process and also its economic impact. We use DSICE, a DSGE extension of the DICE2007 model of William Nordhaus, which incorporates beliefs about the uncertain economic impact of possible climate tipping events and uses empirically plausible parameterizations of Epstein-Zin preferences to represent attitudes towards risk. We find that the uncertainty associated with anthropogenic climate change imply carbon taxes much higher than implied by deterministic models. This analysis indicates that the absence of uncertainty in DICE2007 and similar IAM models may result in substantial understatement of the potential benefits of policies to reduce GHG emissions.

  4. Constructal theory through thermodynamics of irreversible processes framework

    International Nuclear Information System (INIS)

    Tescari, S.; Mazet, N.; Neveu, P.

    2011-01-01

    Highlights: → Point to area flow problem is solved through Thermodynamics of irreversible processes. → A new optimisation criterion is defined: the exergy or entropy impedance. → Optimisation is performed following two different routes, constructal or global. → Global optimisation is more efficient than constructal optimisation. → Global optimisation enhances the domain of construct benefits. - Abstract: Point to volume flow problem is revisited on a thermodynamics of irreversible processes (TIP) basis. The first step consists in evaluating the local entropy production of the system, and deducing from this expression the phenomenological laws. Then, the total entropy production can be simply evaluated. It is demonstrated that total entropy production can be written in a remarkable form: the product of the so-called entropy impedance with the square of the heat flux. As the heat flux is given, optimisation consists in minimising the entropy impedance. It is also shown that minimising entropy impedance minimises the maximum temperature difference. Applied to the elemental volume, this optimisation process leads to a shape factor close to the one already published. For the first construction, the equivalent system is defined as stated by Prigogine: when subjected to the same constraints, two systems are thermodynamically equivalent if their entropy production is equal. Two optimisation routes are then investigated: a global optimisation where all scales are taken into account and the constructal optimisation where the system is optimised scale by scale. In this second case, results are close to Ghodossi's work. When global optimisation is performed, it is demonstrated that conductive paths have to be spread uniformly in the active material (i.e. the number of elemental volumes must go to infinite). Comparing the two routes, global optimisation leads to better performance than constructal optimisation. Moreover, global optimisation enlarges the domain of

  5. The detection of local irreversibility in time series based on segmentation

    Science.gov (United States)

    Teng, Yue; Shang, Pengjian

    2018-06-01

    We propose a strategy for the detection of local irreversibility in stationary time series based on multiple scale. The detection is beneficial to evaluate the displacement of irreversibility toward local skewness. By means of this method, we can availably discuss the local irreversible fluctuations of time series as the scale changes. The method was applied to simulated nonlinear signals generated by the ARFIMA process and logistic map to show how the irreversibility functions react to the increasing of the multiple scale. The method was applied also to series of financial markets i.e., American, Chinese and European markets. The local irreversibility for different markets demonstrate distinct characteristics. Simulations and real data support the need of exploring local irreversibility.

  6. Improving regional universal newborn hearing screening programmes in Italy.

    Science.gov (United States)

    Molini, E; Cristi, M C; Lapenna, R; Calzolaro, L; Muzzi, E; Ciciriello, E; Della Volpe, A; Orzan, E; Ricci, G

    2016-02-01

    The Universal Newborn Hearing Screening (UNHS) programme aims at achieving early detection of hearing impairment. Subsequent diagnosis and intervention should follow promptly. Within the framework of the Ministry of Health project CCM 2013 "Preventing Communication Disorders: a Regional Program for early Identification, Intervention and Care of Hearing Impaired Children", the limitations and strengths of current UNHS programs in Italy have been analysed by a group of professionals working in tertiary centres involved in regional UNHS programmes, using SWOT analysis and a subsequent TOWS matrix. Coverage and lost-to-follow up rates are issues related to UNHS programmes. Recommendations to improve the effectiveness of the UNHS programme have been identified. The need for homogeneous policies, high-quality information and dissemination of knowledge for operators and families of hearing-impaired children emerged from the discussion. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale.

  7. Hearing aid controlled by binaural source localizer

    NARCIS (Netherlands)

    2009-01-01

    An adaptive directional hearing aid system comprising a left hearing aid and a right hearing aid, wherein a binaural acoustic source localizer is located in the left hearing aid or in the right hearing aid or in a separate body- worn device connected wirelessly to the left hearing aid and the right

  8. Newborn hearing screening.

    Science.gov (United States)

    Stewart, D L; Pearlman, A

    1994-11-01

    Congenital deafness is a relatively common problem with an incidence of 1/300 to 1/1000. Most states have no mass screening program for hearing loss, but the state of Kentucky compiles a High Risk Registry which is a historical survey of parents relating to risk factors for hearing loss. Unfortunately this survey can miss 50% of those who have a hearing deficit. If not detected prior to discharge, there is often a delay in diagnosis of deafness which prevents early intervention. We report 2 years' experience at Kosair Children's Hospital where 1,987 infants admitted to well baby, intermediate, or intensive care nurseries were screened using the ALGO-1 screener (Natus Medical Inc, Foster City, CA) which is a modified auditory brain stem evoked response (ABR). Our screening of this population led to an 11% incidence of referral for complete audiological evaluation. There were no significant complications. Forty-eight infants were found to have nonspecified, sensorineural, or conductive hearing loss. The positive predictive value of the test was 96%. Therefore, we feel that the use of the modified ABR in the newborn is a timely, cost efficient method of screening for hearing loss and should be used for mass screening of all newborns.

  9. Geological disposal concept hearings

    International Nuclear Information System (INIS)

    1996-01-01

    The article outlines the progress to date on AECL spent-nuclear fuel geological disposal concept. Hearings for discussion, organised by the federal Environmental Assessment Review Panel, of issues related to this type of disposal method occur in three phases, phase I focuses on broad societal issues related to long term management of nuclear fuel waste; phase II will focus on the technical aspects of this method of disposal; and phase III will consist of community visits in New Brunswick, Quebec, Ontario, Manitoba and Saskatchewan. This article provides the events surrounding the first two weeks of phase I hearings (extracted from UNECAN NEWS). In the first week of hearings, where submissions on general societal issues was the focus, there were 50 presentations including those by Natural Resources Canada, Energy Probe, Ontario Hydro, AECL, Canadian Nuclear Society, Aboriginal groups, environmental activist organizations (Northwatch, Saskatchewan Environmental Society, the Inter-Church Uranium Committee, and the Canadian Coalition for Nuclear responsibility). In the second week of hearings there was 33 presentations in which issues related to siting and implementation of a disposal facility was the focus. Phase II hearings dates are June 10-14, 17-21 and 27-28 in Toronto

  10. Hearing speech in music

    Directory of Open Access Journals (Sweden)

    Seth-Reino Ekström

    2011-01-01

    Full Text Available The masking effect of a piano composition, played at different speeds and in different octaves, on speech-perception thresholds was investigated in 15 normal-hearing and 14 moderately-hearing-impaired subjects. Running speech (just follow conversation, JFC testing and use of hearing aids increased the everyday validity of the findings. A comparison was made with standard audiometric noises [International Collegium of Rehabilitative Audiology (ICRA noise and speech spectrum-filtered noise (SPN]. All masking sounds, music or noise, were presented at the same equivalent sound level (50 dBA. The results showed a significant effect of piano performance speed and octave (P<.01. Low octave and fast tempo had the largest effect; and high octave and slow tempo, the smallest. Music had a lower masking effect than did ICRA noise with two or six speakers at normal vocal effort (P<.01 and SPN (P<.05. Subjects with hearing loss had higher masked thresholds than the normal-hearing subjects (P<.01, but there were smaller differences between masking conditions (P<.01. It is pointed out that music offers an interesting opportunity for studying masking under realistic conditions, where spectral and temporal features can be varied independently. The results have implications for composing music with vocal parts, designing acoustic environments and creating a balance between speech perception and privacy in social settings.

  11. Early Hearing Detection and Intervention: Can Your Baby Hear?

    Centers for Disease Control (CDC) Podcasts

    This podcast discusses how important it is that every child receives a hearing screening as soon as possible after birth. It also gives specific ways that parents and health providers can find out if a child has a possible hearing loss and where to get further information. (Created 6/5/2007 by the Early Hearing Detection and Intervention Program, NCBDDD).

  12. Hearing Protection and Hearing Symptoms in Danish Symphony Orchestras

    DEFF Research Database (Denmark)

    Laitinen, Heli; Poulsen, Torben

    2006-01-01

    A study about hearing protectors, problems involving hearing protector usage, hearing problems and working surroundings of classical musicians was made in three Danish symphony orchestras. The questionnaire used in the study was based on a previous study, a study made in Sweden to rock musicians,...

  13. Comparative analysis of endurance of not hearing and hearing students

    Directory of Open Access Journals (Sweden)

    Iwańska Dagmara

    2013-11-01

    Full Text Available Study aim: Sport participation is important for deaf children, as participants experience physical, psychological and social benefits [23]. This study is a summary of four year’s researches on the endurance level of deaf and well hearing girls and boys. The aim of this study was to compare endurance of not hearing and hearing students.

  14. Noise and Hearing Loss Prevention

    Science.gov (United States)

    ... message, please visit this page: About CDC.gov . NOISE AND HEARING LOSS PREVENTION Language: English (US) Español ( ... when hazardous noise levels cannot be adequately reduced. Noise and Hearing Loss on the NIOSH Science Blog ...

  15. Age-related hearing loss

    Science.gov (United States)

    ... grow older. Your genes and loud noise (from rock concerts or music headphones) may play a large role. The following factors contribute to age-related hearing loss: Family history (age-related hearing loss tends to run in ...

  16. How to Get Hearing Aids

    Science.gov (United States)

    ... if desired. What questions should I ask before buying hearing aids? Before you buy a hearing aid, ... the period of warranty? Does the warranty cover future maintenance and repairs? Will loaner aids be provided ...

  17. Hearing Loss: Symptoms, Diagnosis & Treatment

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Hearing Loss Symptoms, Devices, Prevention & Research Past Issues / Spring ... a disease. It can accompany any type of hearing loss. It can be a side effect of ...

  18. Hearing Voices and Seeing Things

    Science.gov (United States)

    ... Facts for Families Guide Facts for Families - Vietnamese Hearing Voices and Seeing Things No. 102; Updated October ... delusions (a fixed, false, and often bizarre belief). Hearing voices or seeing things that are not there ...

  19. Hearing assessment in pre-school children with speech delay.

    Science.gov (United States)

    Psillas, George; Psifidis, Anestis; Antoniadou-Hitoglou, Magda; Kouloulas, Athanasios

    2006-09-01

    The purpose of this study was to detect any underlying hearing loss among the healthy pre-school children with speech delay. 76 children, aged from 1 to 5 years, underwent a thorough audiological examination consisting of tympanometry, free field testing, otoacoustic emission recordings and auditory brainstem responses (ABRs). If hearing was normal, then they were evaluated by a child neurologist-psychiatrist. According to our findings, the children were classified into 3 groups; those with normal hearing levels (group I, 52 children, 68.4%), sensorineural hearing loss (group II, 22 children, 28.9%) and conductive hearing loss (group III, 2 children, 2.6%). In group I, speech delay was attributed to pervasive developmental disorder (PDD), which represents high-functioning autistic children (37 cases). Other causes were specific language impairment (SLI)-expressive (3 cases), bilingualism (2 cases), and unknown etiology (10 cases). More than half (59%) of the children diagnosed with PDD evidenced significant language impairment limited to more than two words. Children with SLI-expressive and bilingualism used a maximum of two words. In group II, 13 children suffered from profound hearing loss in both ears, 3 from severe, 3 had profound hearing loss in one ear and severe in the other, 2 from moderate, and 1 had moderate in one ear and severe in the other. No child had mild sensorineural hearing loss. The children with profound hearing loss in at least one ear had total language impairment using no word at all (10 cases), or a maximum of two words (6 cases). When hearing loss was moderate to severe, then the speech vocabulary was confined to several words (more than two words-6 cases). Only two children suffering from conductive hearing loss both presented with complete lack of speech. A great number of healthy pre-school children with speech delay were found to have normal hearing. In this case, the otolaryngologist should be aware of the possible underlying clinical

  20. Congenital sensorineural hearing loss

    International Nuclear Information System (INIS)

    Mafee, M.F.; Selis, J.E.; Yannias, D.A.; Valvassori, G.E.; Pruzansky, S.; Applebaum, E.L.; Capek, V.

    1984-01-01

    The ears of 47 selected patients with congenital sensorineural hearing loss were examined with complex-motion tomography. The patients were divided into 3 general categories: those with a recognized syndrome, those with sensorineural hearing loss unrelated to any known syndrome, and those with microtia. A great variety of inner ear anomalies was detected, but rarely were these characteristic of a particular clinical entity. The most common finding was the Mondini malformation or one of its variants. Isolated dysplasia of the internal auditory canal or the vestibular aqueduct may be responsible for sensorineural hearing loss in some patients. Patients with microtia may also have severe inner ear abnormalities despite the fact that the outer and inner ears develop embryologically from completely separate systems

  1. Congenital sensorineural hearing loss

    Energy Technology Data Exchange (ETDEWEB)

    Mafee, M.F.; Selis, J.E.; Yannias, D.A.; Valvassori, G.E.; Pruzansky, S.; Applebaum, E.L.; Capek, V.

    1984-02-01

    The ears of 47 selected patients with congenital sensorineural hearing loss were examined with complex-motion tomography. The patients were divided into 3 general categories: those with a recognized syndrome, those with sensorineural hearing loss unrelated to any known syndrome, and those with microtia. A great variety of inner ear anomalies was detected, but rarely were these characteristic of a particular clinical entity. The most common finding was the Mondini malformation or one of its variants. Isolated dysplasia of the internal auditory canal or the vestibular aqueduct may be responsible for sensorineural hearing loss in some patients. Patients with microtia may also have severe inner ear abnormalities despite the fact that the outer and inner ears develop embryologically from completely separate systems.

  2. Deaf/Hearing Research Partnerships

    Science.gov (United States)

    Wolsey, Ju-Lee A.; Misener Dunn, Kim; Gentzke, Scott W.; Joharchi, Hannah A.; Clark, M. Diane

    2017-01-01

    Deaf individuals typically are seen through the lens of the dominant hearing society's perception, i.e., that being deaf is an impairment. Today, a small but growing number of Deaf and hearing researchers are challenging this perception. The authors examined perceptions of what components are necessary for a successful Deaf/hearing research…

  3. 78 FR 11237 - Public Hearing

    Science.gov (United States)

    2013-02-15

    ... NATIONAL TRANSPORTATION SAFETY BOARD Public Hearing On Tuesday, February 26, 2013 the National Transportation Safety Board (NTSB) will convene an Investigative Hearing to gather additional factual information... Union Pacific (UP) intermodal train No. AAMMLX-22 on June 24, 2012 near Goodwell, Oklahoma. The hearing...

  4. Efficient evaluation of hearing ability

    NARCIS (Netherlands)

    2010-01-01

    The present invention relates to a method of establishing a hearing ability model for a person, the method including providing a representation of the distribution of hearing ability for a population of individuals. The method may comprise the steps) performing a hearing evaluation event, comprising

  5. 78 FR 39017 - Investigative Hearing

    Science.gov (United States)

    2013-06-28

    ... NATIONAL TRANSPORTATION SAFETY BOARD Investigative Hearing On November 30, 2012, at 6:59 a.m... exposure. The investigative hearing will discuss Conrail operations and the emergency response to the... in establishing a unified command. The goals of this hearing are to gather additional factual...

  6. 78 FR 21632 - Investigative Hearing

    Science.gov (United States)

    2013-04-11

    ... NATIONAL TRANSPORTATION SAFETY BOARD Investigative Hearing On January 7, 2013, about 1021 eastern... Part 129. The investigative hearing is being held to discuss the Boeing 787 battery and battery charger... goals of this hearing will be to gather additional information on the selection of the lithium ion (Li...

  7. 78 FR 64026 - Investigative Hearing

    Science.gov (United States)

    2013-10-25

    ... NATIONAL TRANSPORTATION SAFETY BOARD Investigative Hearing On Wednesday, November 6, 2013, and... hearing to gather additional factual information for the ongoing investigation into two Metro-North... Investigative Hearing. On Friday, May 17, 2013, at 6:01 p.m. eastern daylight time, eastbound Metro-North...

  8. Assessment of Hearing Impaired Youth.

    Science.gov (United States)

    Hicks, Doin E., Ed.; And Others

    1980-01-01

    The issue of Directions contains 11 articles on assessment of hearing impaired individuals. Entries have the following titles and authors: "Classroom Assessment Techniques for Hearing Impaired Students--A Literature Review" (B. McKee, M. Hausknecht); "Informal Assessment of Hearing Impaired Students In the Classroom" (B. Culhane, R. Hein);…

  9. Comparing Analog and Digital Hearing Aids in Reducing Hearing Disability

    Directory of Open Access Journals (Sweden)

    Ghassem Mohammad Khani

    2004-06-01

    Full Text Available Objective: Comparing analog and digital hearing aids reducing disability caused by hearing deficiency among moderate to severe sensorineural hearing-impaired persons. Method and Material: This descriptive-analytic study was carried out on two groups of subjects participated in this study in some audiology clinics of hearing aid since May 2002 to October 2003. Twenty subjects wore analog hearing aids and twenty one subjects wore digital hearing aids. In this study , no subject had previous middle ear or psychological problems. APHAB questionnaire was completed before using hearing aid and 2 months after to determine benefit of hearing aid use. Results: Total score mean of APHAB inventory before and after use of analoge hearing aids were 52.215+6.420 and 32.300+3.443 respectively. Also total score mean of APHAB inventory before and after use of digital hearing aids were 54.9252+9.028 and 26.321+10.916 respectively. There was no significant difference between total mean score of APHAB inventory before and after using analog and digital hearing aids (P=0.058.While there was significant difference between total mean score of APHAB questionnaire before and after use of analog hearing aids (P<0.001 and also before and after use of digital hearing aids (P<0.001. Moreover age, gender , litracy level , occupation , degree of hearing loss and manner of hearing aid usage did not have significant effect on APHAB results. Configuration of loss had siginficant effect on aversiveness subscale before and after use of analog hearing aids (P=0.008. Previous experience and duration of hearing aid usage had significant effect on aversiveness subscale before and after use of digital hearing aids (P=0.043 and (P=0.024, respectively , while all of these three items did not have significant effect on total mean score of APHAB inventory and also total mean scores of three subscales of ease of communication , reverberation and background noise. Conclusion: Comparing to

  10. Ear, Hearing and Speech

    DEFF Research Database (Denmark)

    Poulsen, Torben

    2000-01-01

    An introduction is given to the the anatomy and the function of the ear, basic psychoacoustic matters (hearing threshold, loudness, masking), the speech signal and speech intelligibility. The lecture note is written for the course: Fundamentals of Acoustics and Noise Control (51001)......An introduction is given to the the anatomy and the function of the ear, basic psychoacoustic matters (hearing threshold, loudness, masking), the speech signal and speech intelligibility. The lecture note is written for the course: Fundamentals of Acoustics and Noise Control (51001)...

  11. How to quantify binaural hearing in patients with unilateral hearing using hearing implants.

    Science.gov (United States)

    Snik, Ad; Agterberg, Martijn; Bosman, Arjan

    2015-01-01

    Application of bilateral hearing devices in bilateral hearing loss and unilateral application in unilateral hearing loss (second ear with normal hearing) does not a priori lead to binaural hearing. An overview is presented on several measures of binaural benefits that have been used in patients with unilateral or bilateral deafness using one or two cochlear implants, respectively, and in patients with unilateral or bilateral conductive/mixed hearing loss using one or two percutaneous bone conduction implants (BCDs), respectively. Overall, according to this overview, the most significant and sensitive measure is the benefit in directional hearing. Measures using speech (viz. binaural summation, binaural squelch or use of the head shadow effect) showed minor benefits, except for patients with bilateral conductive/mixed hearing loss using two BCDs. Although less feasible in daily practise, the binaural masking level difference test seems to be a promising option in the assessment of binaural function. © 2015 S. Karger AG, Basel.

  12. Mitochondrial Sensorineural Hearing Loss: A Retrospective Study and a Description of Cochlear Implantation in a MELAS Patient

    Directory of Open Access Journals (Sweden)

    Mauro Scarpelli

    2012-01-01

    Full Text Available Hearing impairment is common in patients with mitochondrial disorders, affecting over half of all cases at some time in the course of the disease. In some patients, deafness is only part of a multisystem disorder. By contrast, there are also a number of “pure” mitochondrial deafness disorders, the most common probably being maternally inherited. We retrospectively analyzed the last 60 genetically confirmed mitochondrial disorders diagnosed in our Department: 28 had bilateral sensorineural hearing loss, whereas 32 didn't present ear's abnormalities, without difference about sex and age of onset between each single group of diseases. We reported also a case of MELAS patient with sensorineural hearing loss, in which cochlear implantation greatly contributed to the patient's quality of life. Our study suggests that sensorineural hearing loss is an important feature in mitochondrial disorders and indicated that cochlear implantation can be recommended for patients with MELAS syndrome and others mitochondrial disorders.

  13. COMPARISON OF ABILITY OF OPPOSITION WORDS PROCESSING BETWEEN HEARING AND HEARING IMPAIRED STUDENT IN FIFTH GRADE IN TEHRAN

    Directory of Open Access Journals (Sweden)

    B SHAFIEI

    2003-12-01

    Full Text Available Introduction: Hearing impaired Persons have disorders in Communication. Theu are not able to learning many aspects of language Structures in Paroper time; quantity and quality. They can not Process these factors as same as Partners. In this research we going to assess and comparison opposite word in hearing and hearing impaired Student in fifth grade. This is a semantic research.
    Methods: Subjects of this research were hearing impaired students in fifth grade in tehramwohad + 70dbheaing loss in Best Binaural Average and in order to comparison with them, we selected hearing students in fifth grade. In this research four non linguistic factors were investigated (age, sex, words of Farsi language. The subjects must read these words and write an opposite Word in front of it. In this examination the quantity of types: right, false and without answers.
    Findings: The sequence of right answers had significant different in two group. The Sequence of learned words had significant different two groups. The time of processing in hearing students was shorter than hearing impaired students. The female subjects gave right answers more than male subjects. Discussion: The differences between bearing and hearing impaired students were in the quantity of answers specially in right answers and time of doing the test. probably these differences were due to lack of proper lexicon words and/or poor of it. The hearing students had more right answers and were shorter in time of processing.

  14. ESTIMATION OF IRREVERSIBLE DAMAGEABILITY AT FATIGUE OF CARBON STEEL

    Directory of Open Access Journals (Sweden)

    I. O. Vakulenko

    2014-04-01

    Full Text Available Purpose. Damageability estimation of carbon steel in the conditions of cyclic loading. Methodology. The steel fragments of railway wheel rim and rail head served as material for research with chemical composition 0.65 % С, 0.67 % Mn, 0.3 % Si, 0.027 % P, 0.028 % S и 0.7 % C, 0.82 % Mn, 0.56 % Si, 0.025 % P, 0.029 % S accordingly. The microstructure of tested steels corresponded to the state of metal after a hot plastic deformation. The fatigue research was conducted in the conditions of symmetric bend using the proof-of-concept machine of type «Saturn-10». Full Wohler diagrams and the lines corresponding to forming of sub-and micro cracks were constructed. The distribution analysis of internal stresses in the metal under cyclic loading was carried out using the microhardness tester of PMT-3 type.Findings. On the basis of fatigue curves for high-carbon steels analysis the positions of borders dividing the areas of convertible and irreversible damages were determined. The article shows that with the growth of carbon concentration in the steel at invariability of the structural state an increase of fatigue limit is observed. At the same time the acceleration of processes, which determine transition terms from the stage of forming of submicrocracks to the microcracks occurs. The research of microhardness distribution in the metal after destruction confirmed the nature of carbon amount influence on the carbon steel characteristics. Originality. Regardless on the stages of breakdown site forming the carbon steels behavior at a fatigue is determined by the ration between the processes of strengthening and softening. At a cyclic loading the heterogeneity of internal stresses distribution decreases with the increase of distance from the destruction surface. Analysis of metal internal restructuring processes at fatigue loading made it possible to determine that at the stages prior to incubation period in the metal microvolumes the cells are already

  15. A associação entre a suspeita inicial de perda auditiva e a ausência de comunicação verbal em crianças com transtornos do espectro autístico The association between an initial suspicion of hearing loss and the absence of verbal communication in children with autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Elaine Colombo Sousa

    2009-01-01

    Full Text Available OBJETIVO: Averiguar a associação entre a suspeita inicial de deficiência auditiva e a ausência de comunicação verbal em crianças com diagnóstico de transtornos do espectro autístico. MÉTODOS: Por meio de estudo retrospectivo, analisamos 54 anamneses de indivíduos com diagnóstico de transtornos do espectro autístico. Inicialmente, obtivemos o registro da suspeita inicial de perda auditiva, mencionada pela família. O grau de associação entre a presença de suspeita inicial de perda auditiva e o tipo de desempenho comunicativo (não verbal e verbal foi verificado. Posteriormente, as avaliações audiológicas foram rastreadas para confirmarmos a pertinência da queixa auditiva mencionada. Para tratamento estatístico dos resultados utilizamos os Testes Qui-quadrado e Exato de Fisher. Estabeleceu-se nível de significância de 0,05. RESULTADOS: Verificamos que 62,96% dos pais de crianças autistas (verbais ou não apresentaram a suspeita inicial de perda auditiva como primeira etiologia. A avaliação audiológica mostrou que somente 11,11% dos indivíduos com comunicação não verbal e nenhum com comunicação verbal apresentaram algum tipo de deficiência auditiva. CONCLUSÕES: O número de crianças com suspeita inicial de perda auditiva mostrou-se significativo, independente destas serem verbais ou não. Na análise da associação entre desempenho comunicativo e suspeita de prejuízos na audição, os resultados foram estatisticamente significante maiores em crianças não verbais. Esses dados nos fazem refletir sobre a importância da sensibilização dos profissionais que atuam em clínica infantil quanto à busca pelo diagnóstico diferencial entre a deficiência auditiva e os transtornos do espectro autístico.PURPOSE: To determine the association between the initial suspicion of hearing loss and the absence of verbal communication in children with diagnosis of autistic spectrum disorders. METHODS: A retrospective study was

  16. [Hearing loss and idoneity--the segnalation of noise-induced hearing loss hearing Loss].

    Science.gov (United States)

    Albera, Roberto; Dagna, Federico; Cassandro, Claudia; Canale, Andrea

    2011-01-01

    Work idoneity in hearing loss must be related to working ability and evolution risks. Working ability is referred to the difficulties found in speech comprehension and in signals perception. As regards hearing loss evolution it is necessary to define if the subject is affected by conductive or neurosensorial hearing loss. In conductive hearing loss it is necessary to evaluate entity and frequential distribution of the deficit. In neurosensorial hearing loss it is necessary to distinguish between noise-induced hearing loss and extraprofessional hearing loss. In noise-induced hearing loss the evolution risk is high if the noise exposure is less than 10-15 years or the actual noise exposure is louder than the former. In case of extraprofessional hearing loss the evolution risk is higher in presbycusis, endolymphatic hydrops and toxic hearing loss. The necessity to report the presence on professionale noise-induced hearing loss arises if audiometric threshold is more than 25 dB at 0.5-1-2-3-4 kHz and if it is verified the professional origine of hearing loss.

  17. Ear Nose Throat (ENT disorders in Government Schools of Far-Western Nepal

    Directory of Open Access Journals (Sweden)

    Anup Acharya

    2013-12-01

    Full Text Available Background: ENT disorders specially hearing impairment negatively impacts students’ development of academic, language and social skills. If left undiagnosed, these conditions may result in significant irreversible damage such as varying degree of hearing loss that can affect the social or professional performance of the individuals in later stages of life. Students going to government school in our country generally come from under privileged society. We investigated the occurrence of ENT diseases among various government school students in Kailali district. Methods: Nine government school of Kailai district were chosen at random. All students of those school present on the day of examination went routine ENT examinations. Brief history, if any, was recorded and findings were noted. The study was done throughout the month of September, 2013. Results: There were a total of 2256 students enrolled in the study. There were 1126 male and 1130 female students. Mean age of the students was 9.88 years. Forty One percent of students had ENT problems. Ear wax was the most common (17% findings followed by suppurative ear diseases, otittis media with effusion as so on in decreasing frequency. Conclusions: ENT diseases and specially ear diseases are important health problems among school children of Nepal. Regular school health services, screening program, public awareness, improvement of socioeconomic status, timely referral to a specialist doctor can help to reduce the disease-related burden.

  18. Learning Disabilities and Conductive Hearing Loss Involving Otitis Media.

    Science.gov (United States)

    Reichman, Julie; Healey, William C.

    1983-01-01

    A review of research on the relationship of otitis media (ear infection) and learning/language/hearing disorders revealed that incidence of otitis media was twice as common in learning disabled as nonLD students; and that, in general, otitis-prone children scored below controls with frequent evidence of performance deficits. (CL)

  19. Considerations in Diagnosing Usher's Syndrome: RP and Hearing Loss.

    Science.gov (United States)

    Vernon, McCay

    1982-01-01

    The association of hearing loss and retinitis pigmentosa has been generally recognized as the genetic disorder of Usher's syndrome. The article reviews findings of this syndrome and suggests strategies for dealing with the clinical and psychological problems displayed by Usher's syndrome patients. (Author/SW)

  20. Auditory Deprivation and Early Conductive Hearing Loss from Otitis Media.

    Science.gov (United States)

    Gunnarson, Adele D.; And Others

    1990-01-01

    This article reviews auditory deprivation effects on anatomy, physiology, and behavior in animals and discusses the sequelae of otitis media with effusion (OME) in children. Focused on are central auditory processing disorders associated with early fluctuating hearing loss from OME. (DB)

  1. Hearings on nuclear deterrence

    International Nuclear Information System (INIS)

    Adam, Patricia; Tertrais, Bruno; Niquet, Valerie; Vilboux, Nicole; Kalika, Arnaud; Ravel, Luc; Korsia, Haim; Remy, Stephane; Arbi, Abdelkader; Bentegeat, Henri; Villiers, Pierre de; Norlain, Bernard; Mercier, Denis; Charaix, Patrick; Rogel, Bernard; Coriolis, Charles-edouard de; Boissier, Patrick; Bouvier, Antoine; Charmeau, Alain; Collet-Billon, Laurent; Ricketts, Peter; Collin, Jean-Marie; Bouveret, Patrice; Bigot, Bernard; Verwaerde, Daniel

    2014-01-01

    This report contains hearings of various French actors and experts (researchers, military chaplains, high-ranking officers, industrial executives, members of public military agencies, members of associations promoting non proliferation) on the issue of nuclear deterrence. Each of them states its point of view on nuclear deterrence, on strategic issues, on military issues, on philosophical issues, depending on their positions

  2. NATIONAL HEARING DAY

    CERN Multimedia

    2003-01-01

    The 12th of June 2003 Is the French National Hearing Day. The Medical Service invites everyone working at CERN to come and have an ear test at the infirmary. Bld. 57, ground floor, between 9h00 and 16h00 Tel. 73802

  3. National hearing day

    CERN Multimedia

    2003-01-01

    The 12th of June 2003 Is the French National Hearing Day. The Medical Service invites everyone working at CERN to come and have an ear test at the infirmary. Bld. 57, ground floor, between 9h00 and 16h00 Tel. 73802

  4. Overview of a public health approach to pediatric hearing impairment in the Pacific Islands.

    Science.gov (United States)

    Kaspar, Annette; Kei, Joseph; Driscoll, Carlie; Swanepoel, De Wet; Goulios, Helen

    2016-07-01

    Childhood hearing impairment is a significant cause of disability in developing countries. Otitis media and meningitis are leading infectious causes of preventable hearing loss in children. It is estimated that the Pacific Islands have among the greatest global burden of childhood hearing impairment due to infectious causes, and yet there is currently very little in the research literature on pediatric hearing disorders in this region. (1) To review existing research literature on pediatric hearing impairment in the Pacific Islands, and (2) to present a public health approach to the development and improvement of childhood hearing services in the Pacific Islands. The primary tool was a comprehensive literature review. MEDLINE and ScienceDirect databases were searched for relevant journal articles. There was no limit on the date of publication. Any article reporting on hearing impairment in the Pacific Region was included. A total of 23 journal articles were found that satisfied the above inclusion criteria. The limited information available in the literature suggests that otitis media and vaccine-preventable infections are a significant cause of avoidable childhood hearing impairment in the Pacific Islands. Pediatric audiology services are limited in this region. Further research is required to develop effective public health programs that should reduce the burden of preventable childhood hearing loss in the Pacific Islands. There is limited information in the research literature on pediatric hearing impairment and audiology services in the Pacific Islands. Epidemiological data based on the WHO Ear and Hearing Disorders Survey Protocol are urgently needed, and the development of audiology services within the existing public and primary health care framework should reduce the burden of preventable hearing loss in the Pacific Islands. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Fundamental economic irreversibilities influence policies for enhancing international forest phytosanitary security

    Science.gov (United States)

    Thomas P. Holmes; Will Allen; Robert G. Haight; E. Carina H. Keskitalo; Mariella Marzano; Maria Pettersson; Christopher P. Quine; E. R. Langer

    2017-01-01

    National and international efforts to manage forest biosecurity create tension between opposing sources of ecological and economic irreversibility. Phytosanitary policies designed to protect national borders from biological invasions incur sunk costs deriving from economic and political irreversibilities that incentivizes wait-and-see decision-making. However, the...

  6. A minimal dissipation type-based classification in irreversible thermodynamics and microeconomics

    Science.gov (United States)

    Tsirlin, A. M.; Kazakov, V.; Kolinko, N. A.

    2003-10-01

    We formulate the problem of finding classes of kinetic dependencies in irreversible thermodynamic and microeconomic systems for which minimal dissipation processes belong to the same type. We show that this problem is an inverse optimal control problem and solve it. The commonality of this problem in irreversible thermodynamics and microeconomics is emphasized.

  7. Multiscale Analysis of Time Irreversibility Based on Phase-Space Reconstruction and Horizontal Visibility Graph Approach

    Science.gov (United States)

    Zhang, Yongping; Shang, Pengjian; Xiong, Hui; Xia, Jianan

    Time irreversibility is an important property of nonequilibrium dynamic systems. A visibility graph approach was recently proposed, and this approach is generally effective to measure time irreversibility of time series. However, its result may be unreliable when dealing with high-dimensional systems. In this work, we consider the joint concept of time irreversibility and adopt the phase-space reconstruction technique to improve this visibility graph approach. Compared with the previous approach, the improved approach gives a more accurate estimate for the irreversibility of time series, and is more effective to distinguish irreversible and reversible stochastic processes. We also use this approach to extract the multiscale irreversibility to account for the multiple inherent dynamics of time series. Finally, we apply the approach to detect the multiscale irreversibility of financial time series, and succeed to distinguish the time of financial crisis and the plateau. In addition, Asian stock indexes away from other indexes are clearly visible in higher time scales. Simulations and real data support the effectiveness of the improved approach when detecting time irreversibility.

  8. Spectral deformation techniques applied to the study of quantum statistical irreversible processes

    International Nuclear Information System (INIS)

    Courbage, M.

    1978-01-01

    A procedure of analytic continuation of the resolvent of Liouville operators for quantum statistical systems is discussed. When applied to the theory of irreversible processes of the Brussels School, this method supports the idea that the restriction to a class of initial conditions is necessary to obtain an irreversible behaviour. The general results are tested on the Friedrichs model. (Auth.)

  9. Phase control of light amplification with dynamically irreversible pathways of population transfer in a Λ system

    International Nuclear Information System (INIS)

    Yuan Shi; Wu Jinhui; Gao Jinyue; Pan Chunliu

    2002-01-01

    We use the relative phase of two coherent fields for the control of light amplification with dynamically irreversible pathways of population transfer in a Λ system. The population inversion and gain with dynamically irreversible pathways of population transfer are shown as the relative phase is varied. We support our results by numerical calculation and analytical explanation

  10. Sensorineural hearing loss in children.

    LENUS (Irish Health Repository)

    Wormald, R

    2010-02-01

    The objective of the study was to examine the aetiology of sensorineural hearing loss (SNHL) in a paediatric population presenting to the National Centre of Medical Genetics. A retrospective chart review from 1998 to 2006. One hundred and twenty nine children were investigated for SNHL. The average age of diagnosis of hearing loss was 36 months. The degree of hearing loss was mild in 8 children, moderate in 33 children, severe in 31 children and profound in 57 children. Eighty-five children (66%) were diagnosed with a hereditary hearing loss, 11 (8%) children had an acquired hearing loss and no cause found in 33 (26%) children. This is the first report of the causes of hearing loss in Irish children. The mean age of diagnosis in our cohort is high and emphasises the need for a neonatal screening programme. There remains a number of children for whom the cause of hearing loss remains unknown.

  11. Irreversibility and higher-spin conformal field theory

    CERN Document Server

    Anselmi, D

    2000-01-01

    I discuss the idea that quantum irreversibility is a general principle of nature and a related "conformal hypothesis", stating that all fundamental quantum field theories should be renormalization-group (RG) interpolations between ultraviolet and infrared conformal fixed points. In particular, the Newton constant should be viewed as a low-energy effect of the RG scale. This approach leads naturally to consider higher-spin conformal field theories, which are here classified, as candidate high-energy theories. Bosonic conformal tensors have a positive-definite action, equal to the square of a field strength, and a higher-derivative gauge invariance. The central charges c and a are well defined and positive. I calculate their values and study the operator-product structure. Fermionic theories have no gauge invariance and can be coupled to Abelian and non-Abelian gauge fields in a renormalizable way. At the quantum level, they contribute to the one-loop beta function with the same sign as ordinary matter, admit a...

  12. Road deicing salt irreversibly disrupts osmoregulation of salamander egg clutches

    International Nuclear Information System (INIS)

    Karraker, Nancy E.; Gibbs, James P.

    2011-01-01

    It has been postulated that road deicing salts are sufficiently diluted by spring rains to ameliorate any physiological impacts to amphibians breeding in wetlands near roads. We tested this conjecture by exposing clutches of the spotted salamander (Ambystoma maculatum) to three chloride concentrations (1 mg/L, 145 mg/L, 945 mg/L) for nine days, then transferred clutches to control water for nine days, and measured change in mass at three-day intervals. We measured mass change because water uptake by clutches reduces risks to embryos associated with freezing, predation, and disease. Clutches in controls sequestered water asymptotically. Those in the moderate concentrations lost 18% mass initially and regained 14% after transfer to control water. Clutches in high concentration lost 33% mass and then lost an additional 8% after transfer. Our results suggest that spring rains do not ameliorate the effects of deicing salts in wetlands with extremely high chloride concentrations. - Road deicing salts irreversibly disrupts osmoregulation of salamander egg clutches.

  13. Fuel starvation. Irreversible degradation mechanisms in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, Carmen M.; Silva, R.A.; Travassos, M.A.; Paiva, T.I.; Fernandes, V.R. [LNEG, National Laboratory for Energy and Geology, Lisboa (Portugal). UPCH Fuel Cells and Hydrogen Unit

    2010-07-01

    PEM fuel cell operates under very aggressive conditions in both anode and cathode. Failure modes and mechanism in PEM fuel cells include those related to thermal, chemical or mechanical issues that may constrain stability, power and lifetime. In this work, the case of fuel starvation is examined. The anode potential may rise to levels compatible with the oxidization of water. If water is not available, oxidation of the carbon support will accelerate catalyst sintering. Diagnostics methods used for in-situ and ex-situ analysis of PEM fuel cells are selected in order to better categorize irreversible changes of the cell. Electrochemical Impedance Spectroscopy (EIS) is found instrumental in the identification of fuel cell flooding conditions and membrane dehydration associated to mass transport limitations / reactant starvation and protonic conductivity decrease, respectively. Furthermore, it indicates that water electrolysis might happen at the anode. Cross sections of the membrane catalyst and gas diffusion layers examined by scanning electron microscopy indicate electrode thickness reduction as a result of reactions taking place during hydrogen starvation. Catalyst particles are found to migrate outwards and located on carbon backings. Membrane degradation in fuel cell environment is analyzed in terms of the mechanism for fluoride release which is considered an early predictor of membrane degradation. (orig.)

  14. Road deicing salt irreversibly disrupts osmoregulation of salamander egg clutches

    Energy Technology Data Exchange (ETDEWEB)

    Karraker, Nancy E., E-mail: karraker@hku.hk [Department of Environmental and Forest Biology, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210 (United States); Gibbs, James P [Department of Environmental and Forest Biology, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210 (United States)

    2011-03-15

    It has been postulated that road deicing salts are sufficiently diluted by spring rains to ameliorate any physiological impacts to amphibians breeding in wetlands near roads. We tested this conjecture by exposing clutches of the spotted salamander (Ambystoma maculatum) to three chloride concentrations (1 mg/L, 145 mg/L, 945 mg/L) for nine days, then transferred clutches to control water for nine days, and measured change in mass at three-day intervals. We measured mass change because water uptake by clutches reduces risks to embryos associated with freezing, predation, and disease. Clutches in controls sequestered water asymptotically. Those in the moderate concentrations lost 18% mass initially and regained 14% after transfer to control water. Clutches in high concentration lost 33% mass and then lost an additional 8% after transfer. Our results suggest that spring rains do not ameliorate the effects of deicing salts in wetlands with extremely high chloride concentrations. - Road deicing salts irreversibly disrupts osmoregulation of salamander egg clutches.

  15. Irreversible Markov chains in spin models: Topological excitations

    Science.gov (United States)

    Lei, Ze; Krauth, Werner

    2018-01-01

    We analyze the convergence of the irreversible event-chain Monte Carlo algorithm for continuous spin models in the presence of topological excitations. In the two-dimensional XY model, we show that the local nature of the Markov-chain dynamics leads to slow decay of vortex-antivortex correlations while spin waves decorrelate very quickly. Using a Fréchet description of the maximum vortex-antivortex distance, we quantify the contributions of topological excitations to the equilibrium correlations, and show that they vary from a dynamical critical exponent z∼ 2 at the critical temperature to z∼ 0 in the limit of zero temperature. We confirm the event-chain algorithm's fast relaxation (corresponding to z = 0) of spin waves in the harmonic approximation to the XY model. Mixing times (describing the approach towards equilibrium from the least favorable initial state) however remain much larger than equilibrium correlation times at low temperatures. We also describe the respective influence of topological monopole-antimonopole excitations and of spin waves on the event-chain dynamics in the three-dimensional Heisenberg model.

  16. Reversibility and irreversibility from an initial value formulation

    International Nuclear Information System (INIS)

    Muriel, A.

    2013-01-01

    From a time evolution equation for the single particle distribution function derived from the N-particle distribution function (A. Muriel, M. Dresden, Physica D 101 (1997) 297), an exact solution for the 3D Navier–Stokes equation – an old problem – has been found (A. Muriel, Results Phys. 1 (2011) 2). In this Letter, a second exact conclusion from the above-mentioned work is presented. We analyze the time symmetry properties of a formal, exact solution for the single-particle distribution function contracted from the many-body Liouville equation. This analysis must be done because group theoretic results on time reversal symmetry of the full Liouville equation (E.C.G. Sudarshan, N. Mukunda, Classical Mechanics: A Modern Perspective, Wiley, 1974). no longer applies automatically to the single particle distribution function contracted from the formal solution of the N-body Liouville equation. We find the following result: if the initial momentum distribution is even in the momentum, the single particle distribution is reversible. If there is any asymmetry in the initial momentum distribution, no matter how small, the system is irreversible.

  17. General performance characteristics of an irreversible ferromagnetic Stirling refrigeration cycle

    International Nuclear Information System (INIS)

    Lin, G.; Tegus, O.; Zhang, L.; Brueck, E.

    2004-01-01

    A new magnetic-refrigeration-cycle model using ferromagnetic materials as a cyclic working substance is set up, in which finite-rate heat transfer, heat leak and regeneration time are taken into account. On the basis of the thermodynamic properties of a ferromagnetic material, the general performance characteristics of the ferromagnetic Stirling refrigeration cycle are investigated and the effects of some key irreversibilities on the performance of the cycle are revealed. By using the optimal-control theory, the optimal relation between the coefficient of performance and the cooling rate is derived and some important performance bounds, e.g., the maximum cooling rate, the maximum coefficient of performance, are determined. Moreover, the optimal operating regions for cooling rate, coefficient of performance and the optimal operating temperatures of a cyclic working substance in the two heat-transfer processes are obtained. Furthermore, the influences of magnetization and magnetic field on the performance characteristics of the cycle are discussed. The results obtained here have general significance and can be deduced to the related ones of the Stirling refrigeration cycle using paramagnetic salt as a cyclic working substance

  18. The effects of irreversible electroporation (IRE on nerves.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available BACKGROUND: If a critical nerve is circumferentially involved with tumor, radical surgery intended to cure the cancer must sacrifice the nerve. Loss of critical nerves may lead to serious consequences. In spite of the impressive technical advancements in nerve reconstruction, complete recovery and normalization of nerve function is difficult to achieve. Though irreversible electroporation (IRE might be a promising choice to treat tumors near or involved critical nerve, the pathophysiology of the nerve after IRE treatment has not be clearly defined. METHODS: We applied IRE directly to a rat sciatic nerve to study the long term effects of IRE on the nerve. A sequence of 10 square pulses of 3800 V/cm, each 100 µs long was applied directly to rat sciatic nerves. In each animal of group I (IRE the procedure was applied to produce a treated length of about 10 mm. In each animal of group II (Control the electrodes were only applied directly on the sciatic nerve for the same time. Electrophysiological, histological, and functional studies were performed on immediately after and 3 days, 1 week, 3, 5, 7 and 10 weeks following surgery. FINDINGS: Electrophysiological, histological, and functional results show the nerve treated with IRE can attain full recovery after 7 weeks. CONCLUSION: This finding is indicative of the preservation of nerve involving malignant tumors with respect to the application of IRE pulses to ablate tumors completely. In summary, IRE may be a promising treatment tool for any tumor involving nerves.

  19. Nitric oxide-related species-induced protein oxidation: reversible, irreversible, and protective effects on enzyme function of papain.

    Science.gov (United States)

    Väänänen, Antti J; Kankuri, Esko; Rauhala, Pekka

    2005-04-15

    Protein oxidation, irreversible modification, and inactivation may play key roles in various neurodegenerative disorders. Therefore, we studied the effects of the potentially in vivo occurring nitric oxide-related species on two different markers of protein oxidation: protein carbonyl generation on bovine serum albumine (BSA) and loss of activity of a cysteine-dependent protease, papain, in vitro by using Angeli's salt, papanonoate, SIN-1, and S-nitrosoglutathione (GSNO) as donors of nitroxyl, nitric oxide, peroxynitrite, and nitrosonium ions, respectively. Angeli's salt, SIN-1, and papanonoate (0-1000 microM) all generated a concentration-dependent increase in carbonyl formation on BSA (107, 60, and 45%, respectively). GSNO did not affect carbonyl formation. Papain was inhibited by Angeli's salt, SIN-1, papanonoate, and GSNO with IC50 values of 0.62, 2.3, 54, and 80 microM, respectively. Angeli's salt (3.16 microM)-induced papain inactivation was only partially reversible, while the effects of GSNO (316 microM) and papanonoate (316 microM) were reversible upon addition of excess DTT. The Angeli's salt-mediated DTT-irreversible inhibition of papain was prevented by GSNO or papanonoate pretreatment, hypothetically through mixed disulfide formation or S-nitrosylation of the catalytically critical thiol group of papain. These results, for the first time, compare the generation of carbonyls in proteins by Angeli's salt, papanonoate, and SIN-1. Furthermore, these results suggest that S-nitrosothiols may have a novel function in protecting critical thiols from irreversible oxidative damage.

  20. Ecological optimization and parametric study of irreversible Stirling and Ericsson heat pumps

    International Nuclear Information System (INIS)

    Tyagi, S.K.; Kaushik, S.C.; Salohtra, R.

    2002-01-01

    This communication presents the ecological optimization and parametric study of irreversible Stirling and Ericsson heat pump cycles, in which the external irreversibility is due to finite temperature difference between working fluid and external reservoirs while the internal irreversibilities are due to regenerative heat loss and other entropy generations within the cycle. The ecological function is defined as the heating load minus the irreversibility (power loss) which is ambient temperature times the entropy generation. The ecological function is optimized with respect to working fluid temperatures, and the expressions for various parameters at the optimal operating condition are obtained. The effects of different operating parameters on the performance of these cycles have been studied. It is found that the effect of internal irreversibility parameter is more pronounced than the other parameters on the performance of these cycles. (author)

  1. Generalized irreversible heat-engine experiencing a complex heat-transfer law

    International Nuclear Information System (INIS)

    Chen Lingen; Li Jun; Sun Fengrui

    2008-01-01

    The fundamental optimal relation between optimal power-output and efficiency of a generalized irreversible Carnot heat-engine is derived based on a generalized heat-transfer law, including a generalized convective heat-transfer law and a generalized radiative heat-transfer law, q ∝ (ΔT n ) m . The generalized irreversible Carnot-engine model incorporates several internal and external irreversibilities, such as heat resistance, bypass heat-leak, friction, turbulence and other undesirable irreversibility factors. The added irreversibilities, besides heat resistance, are characterized by a constant parameter and a constant coefficient. The effects of heat-transfer laws and various loss terms are analyzed. The results obtained corroborate those in the literature

  2. P300 in individuals with sensorineural hearing loss

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Mirandola Barbosa Reis

    2015-04-01

    Full Text Available INTRODUCTION: Behavioral and electrophysiological auditory evaluations contribute to the understanding of the auditory system and of the process of intervention.OBJECTIVE: To study P300 in subjects with severe or profound sensorineural hearing loss.METHODS: This was a descriptive cross-sectional prospective study. It included 29 individuals of both genders with severe or profound sensorineural hearing loss without other type of disorders, aged 11 to 42 years; all were assessed by behavioral audiological evaluation and auditory evoked potentials.RESULTS: A recording of the P3 wave was obtained in 17 individuals, with a mean latency of 326.97 ms and mean amplitude of 3.76 V. There were significant differences in latency in relation to age and in amplitude according to degree of hearing loss. There was a statistically significant association of the P300 results with the degrees of hearing loss (p = 0.04, with the predominant auditory communication channels (p < 0.0001, and with time of hearing loss.CONCLUSIONS: P300 can be recorded in individuals with severe and profound congenital sensorineural hearing loss; it may contribute to the understanding of cortical development and is a good predictor of the early intervention outcome.

  3. P300 in individuals with sensorineural hearing loss.

    Science.gov (United States)

    Reis, Ana Cláudia Mirandola Barbosa; Frizzo, Ana Claudia Figueiredo; Isaac, Myriam de Lima; Garcia, Cristiane Fregonesi Dutra; Funayama, Carolina Araújo Rodrigues; Iório, Maria Cecília Martinelli

    2015-01-01

    Behavioral and electrophysiological auditory evaluations contribute to the understanding of the auditory system and of the process of intervention. To study P300 in subjects with severe or profound sensorineural hearing loss. This was a descriptive cross-sectional prospective study. It included 29 individuals of both genders with severe or profound sensorineural hearing loss without other type of disorders, aged 11 to 42 years; all were assessed by behavioral audiological evaluation and auditory evoked potentials. A recording of the P3 wave was obtained in 17 individuals, with a mean latency of 326.97ms and mean amplitude of 3.76V. There were significant differences in latency in relation to age and in amplitude according to degree of hearing loss. There was a statistically significant association of the P300 results with the degrees of hearing loss (p=0.04), with the predominant auditory communication channels (p<0.0001), and with time of hearing loss. P300 can be recorded in individuals with severe and profound congenital sensorineural hearing loss; it may contribute to the understanding of cortical development and is a good predictor of the early intervention outcome. Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  4. Achieving effective hearing aid fitting within one month after identification of childhood permanent hearing impairment.

    Science.gov (United States)

    Bastanza, G; Gallus, R; De Carlini, M; Picciotti, P M; Muzzi, E; Ciciriello, E; Orzan, E; Conti, G

    2016-02-01

    Diagnosis of child permanent hearing impairment (PHI) can be made with extreme timeliness compared to the past thanks to improvements in PHI identification through newborn hearing screening programmes. It now becomes essential to provide an effective amplification as quickly as possible in order to restore auditory function and favour speech and language development. The early fitting of hearing aids and possible later cochlear implantation indeed prompts the development of central auditory pathways, connections with secondary sensory brain areas, as well as with motor and articulatory cortex. The aim of this paper is to report the results of a strategic analysis that involves identification of strengths, weaknesses, opportunities and threats regarding the process of achieving early amplification in all cases of significant childhood PHI. The analysis is focused on the Italian situation and is part of the Italian Ministry of Health project CCM 2013 "Preventing Communication Disorders: a Regional Program for Early Identification, Intervention and Care of Hearing Impaired Children". © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale.

  5. Biaxially mechanical tuning of 2-D reversible and irreversible surface topologies through simultaneous and sequential wrinkling.

    Science.gov (United States)

    Yin, Jie; Yagüe, Jose Luis; Boyce, Mary C; Gleason, Karen K

    2014-02-26

    Controlled buckling is a facile means of structuring surfaces. The resulting ordered wrinkling topologies provide surface properties and features desired for multifunctional applications. Here, we study the biaxially dynamic tuning of two-dimensional wrinkled micropatterns under cyclic mechanical stretching/releasing/restretching simultaneously or sequentially. A biaxially prestretched PDMS substrate is coated with a stiff polymer deposited by initiated chemical vapor deposition (iCVD). Applying a mechanical release/restretch cycle in two directions loaded simultaneously or sequentially to the wrinkled system results in a variety of dynamic and tunable wrinkled geometries, the evolution of which is investigated using in situ optical profilometry, numerical simulations, and theoretical modeling. Results show that restretching ordered herringbone micropatterns, created through sequential release of biaxial prestrain, leads to reversible and repeatable surface topography. The initial flat surface and the same wrinkled herringbone pattern are obtained alternatively after cyclic release/restretch processes, owing to the highly ordered structure leaving no avenue for trapping irregular topological regions during cycling as further evidenced by the uniformity of strains distributions and negligible residual strain. Conversely, restretching disordered labyrinth micropatterns created through simultaneous release shows an irreversible surface topology whether after sequential or simultaneous restretching due to creation of irregular surface topologies with regions of highly concentrated strain upon formation of the labyrinth which then lead to residual strains and trapped topologies upon cycling; furthermore, these trapped topologies depend upon the subsequent strain histories as well as the cycle. The disordered labyrinth pattern varies after each cyclic release/restretch process, presenting residual shallow patterns instead of achieving a flat state. The ability to

  6. Magnetic resonance in hearing loss and vertigo

    Directory of Open Access Journals (Sweden)

    Manuel Ángel MARTÍN-PÉREZ

    2017-03-01

    Full Text Available Introduction and objective: Hearing loss and vertiginous syndrome represent an important part of the otorhinolaryngology clinic. The role of the radiologist plays in their workup become fundamental. Studies using magnetic resonance imaging (MRI are essential to guide or give the diagnosis in these cases. Method: After performing a retrospective analysis of 456 MRI studies of patients with these symptoms, we conducted a review of the main pathologies recorded that can cause these symptoms. Results: We classify into vascular disorders and other variants, tumor pathology, malformations and inflammatory pathology; We also describe the most relevant findings on MRI and illustrated with examples of our center.

  7. 9 CFR 124.42 - Hearing procedure.

    Science.gov (United States)

    2010-01-01

    ... Diligence Hearing § 124.42 Hearing procedure. (a) The presiding officer shall be appointed by the... hearing. (g) The due diligence hearing will be conducted in accordance with rules of practice adopted for... opportunity to participate as a party in the hearing. The standard of due diligence set forth in § 124.33 will...

  8. 34 CFR 300.181 - Hearing procedures.

    Science.gov (United States)

    2010-07-01

    ... evidentiary hearing and estimation of time for each presentation; or (E) Completion of the review and the... of the parties during the proceedings. The Hearing Official or Hearing Panel takes all steps... disposition of the case. (2) The Hearing Official or Hearing Panel may schedule a prehearing conference with...

  9. 12 CFR 308.155 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Hearing. 308.155 Section 308.155 Banks and... Pursuant to Section 32 of the FDIA § 308.155 Hearing. (a) Hearing dates. The Executive Secretary shall order a hearing to be commenced within 30 days after receipt of a request for a hearing filed pursuant...

  10. 19 CFR 111.67 - Hearing.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Hearing. 111.67 Section 111.67 Customs Duties U.S... Revocation § 111.67 Hearing. (a) Hearing officer. The hearing officer must be an administrative law judge... right to examine all exhibits offered at the hearing and will have the right to cross-examine witnesses...

  11. 49 CFR 209.115 - Hearing.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Hearing. 209.115 Section 209.115 Transportation... Hearing. (a) When a hearing is requested and scheduled under § 209.113, a hearing officer designated by the Chief Counsel convenes and presides over the hearing. If requested by respondent and if...

  12. 5 CFR 1215.5 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Hearing. 1215.5 Section 1215.5... § 1215.5 Hearing. (a) Request for hearing. (1) An employee must file a petition for a hearing in accordance with the instructions outlined in the agency's notice to offset. (2) A hearing may be requested by...

  13. 34 CFR 668.116 - Hearing.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Hearing. 668.116 Section 668.116 Education Regulations... Program Review Determinations § 668.116 Hearing. (a) A hearing is a process conducted by the hearing official whereby an orderly presentation of arguments and evidence is made by the parties. (b) The hearing...

  14. 14 CFR 13.79 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hearing. 13.79 Section 13.79 Aeronautics....79 Hearing. If an alleged violator requests a hearing in accordance with § 13.75, the procedure of Subpart D of this part applies. At the close of the hearing, the Hearing Officer, on the record or...

  15. 40 CFR 57.807 - Hearing.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Hearing. 57.807 Section 57.807... § 57.807 Hearing. (a) Composition of hearing panel. The Presiding Officer shall preside at the hearing held under this subpart. An EPA panel shall also take part in the hearing. In general, the membership...

  16. 34 CFR 668.88 - Hearing.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Hearing. 668.88 Section 668.88 Education Regulations of... Proceedings § 668.88 Hearing. (a) A hearing is an orderly presentation of arguments and evidence conducted by a hearing official. (b) If the hearing official, the designated department official who brought a...

  17. 10 CFR 16.9 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Hearing. 16.9 Section 16.9 Energy NUCLEAR REGULATORY... § 16.9 Hearing. (a) Request for hearing. (1) An employee shall file a petition for a hearing in... creditor agency, a hearing may be requested by filing a written petition stating why the employee disputes...

  18. 45 CFR 16.11 - Hearing.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Hearing. 16.11 Section 16.11 Public Welfare... BOARD § 16.11 Hearing. (a) Electing a hearing. If the appellant believes a hearing is appropriate, the... appeal file). The Board will approve a request (and may schedule a hearing on its own or in response to a...

  19. 19 CFR 356.23 - Hearing.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Hearing. 356.23 Section 356.23 Customs Duties... § 356.23 Hearing. (a) Scheduling of hearing. The administrative law judge will schedule the hearing at a... parties adequately to prepare for the hearing and the importance of expeditiously resolving the matter. (b...

  20. Irreversibility and higher-spin conformal field theory

    Science.gov (United States)

    Anselmi, Damiano

    2000-08-01

    I discuss the properties of the central charges c and a for higher-derivative and higher-spin theories (spin 2 included). Ordinary gravity does not admit a straightforward identification of c and a in the trace anomaly, because it is not conformal. On the other hand, higher-derivative theories can be conformal, but have negative c and a. A third possibility is to consider higher-spin conformal field theories. They are not unitary, but have a variety of interesting properties. Bosonic conformal tensors have a positive-definite action, equal to the square of a field strength, and a higher-derivative gauge invariance. There exists a conserved spin-2 current (not the canonical stress tensor) defining positive central charges c and a. I calculate the values of c and a and study the operator-product structure. Higher-spin conformal spinors have no gauge invariance, admit a standard definition of c and a and can be coupled to Abelian and non-Abelian gauge fields in a renormalizable way. At the quantum level, they contribute to the one-loop beta function with the same sign as ordinary matter, admit a conformal window and non-trivial interacting fixed points. There are composite operators of high spin and low dimension, which violate the Ferrara-Gatto-Grillo theorem. Finally, other theories, such as conformal antisymmetric tensors, exhibit more severe internal problems. This research is motivated by the idea that fundamental quantum field theories should be renormalization-group (RG) interpolations between ultraviolet and infrared conformal fixed points, and quantum irreversibility should be a general principle of nature.

  1. A model of irreversible jam formation in dense traffic

    Science.gov (United States)

    Brankov, J. G.; Bunzarova, N. Zh.; Pesheva, N. C.; Priezzhev, V. B.

    2018-03-01

    We study an one-dimensional stochastic model of vehicular traffic on open segments of a single-lane road of finite size L. The vehicles obey a stochastic discrete-time dynamics which is a limiting case of the generalized Totally Asymmetric Simple Exclusion Process. This dynamics has been previously used by Bunzarova and Pesheva (2017) for an one-dimensional model of irreversible aggregation. The model was shown to have three stationary phases: a many-particle one, MP, a phase with completely filled configuration, CF, and a boundary perturbed MP+CF phase, depending on the values of the particle injection (α), ejection (β) and hopping (p) probabilities. Here we extend the results for the stationary properties of the MP+CF phase, by deriving exact expressions for the local density at the first site of the chain and the probability P(1) of a completely jammed configuration. The unusual phase transition, characterized by jumps in both the bulk density and the current (in the thermodynamic limit), as α crosses the boundary α = p from the MP to the CF phase, is explained by the finite-size behavior of P(1). By using a random walk theory, we find that, when α approaches from below the boundary α = p, three different regimes appear, as the size L → ∞: (i) the lifetime of the gap between the rightmost clusters is of the order O(L) in the MP phase; (ii) small jams, separated by gaps with lifetime O(1) , exist in the MP+CF phase close to the left chain boundary; and (iii) when β = p, the jams are divided by gaps with lifetime of the order O(L 1 / 2) . These results are supported by extensive Monte Carlo calculations.

  2. 45 CFR 81.51 - Notice of hearing or opportunity for hearing.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Notice of hearing or opportunity for hearing. 81.51 Section 81.51 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PRACTICE AND PROCEDURE FOR HEARINGS UNDER PART 80 OF THIS TITLE Proceedings Prior to Hearing § 81.51 Notice of hearing or opportunity for hearing....

  3. Mathematics Motivation, Anxiety, and Performance in Female Deaf/Hard-of-Hearing and Hearing Students

    Science.gov (United States)

    Ariapooran, Saeed

    2017-01-01

    Hearing loss can be a major detriment to academic achievement among students. The present comparative study examines the differences in mathematics motivation, anxiety, and performance in female students with hearing loss and their hearing peers. A total of 63 female students with hearing loss (deaf and hard-of-hearing) and 63 hearing female…

  4. Conductive hearing loss and bone conduction devices: restored binaural hearing?

    Science.gov (United States)

    Agterberg, Martijn J H; Hol, Myrthe K S; Cremers, Cor W R J; Mylanus, Emmanuel A M; van Opstal, John; Snik, Ad F M

    2011-01-01

    An important aspect of binaural hearing is the proper detection of interaural sound level differences and interaural timing differences. Assessments of binaural hearing were made in patients with acquired unilateral conductive hearing loss (UCHL, n = 11) or congenital UCHL (n = 10) after unilateral application of a bone conduction device (BCD), and in patients with bilateral conductive or mixed hearing loss after bilateral BCD application. Benefit (bilateral versus unilateral listening) was assessed by measuring directional hearing, compensation of the acoustic head shadow, binaural summation and binaural squelch. Measurements were performed after an acclimatization time of at least 10 weeks. Unilateral BCD application was beneficial, but there was less benefit in the patients with congenital UCHL as compared to patients with acquired UCHL. In adults with bilateral hearing loss, bilateral BCD application was clearly beneficial as compared to unilateral BCD application. Binaural summation was present, but binaural squelch could not be proven. To explain the poor results in the patients with congenital UCHL, two factors seemed to be important. First, a critical period in the development of binaural hearing might affect the binaural hearing abilities. Second, crossover stimulation, referring to additional stimulation of the cochlea contralateral to the BCD side, might deteriorate binaural hearing in patients with UCHL. Copyright © 2011 S. Karger AG, Basel.

  5. Can You Hear Architecture

    DEFF Research Database (Denmark)

    Ryhl, Camilla

    2016-01-01

    Taking an off set in the understanding of architectural quality being based on multisensory architecture, the paper aims to discuss the current acoustic discourse in inclusive design and its implications to the integration of inclusive design in architectural discourse and practice as well...... as the understanding of user needs. The paper further points to the need to elaborate and nuance the discourse much more, in order to assure inclusion to the many users living with a hearing impairment or, for other reasons, with a high degree of auditory sensitivity. Using the authors’ own research on inclusive...... design and architectural quality for people with a hearing disability and a newly conducted qualitative evaluation research in Denmark as well as architectural theories on multisensory aspects of architectural experiences, the paper uses examples of existing Nordic building cases to discuss the role...

  6. Hearing loss and speech perception in noise difficulties in Fanconi anemia.

    Science.gov (United States)

    Verheij, Emmy; Oomen, Karin P Q; Smetsers, Stephanie E; van Zanten, Gijsbert A; Speleman, Lucienne

    2017-10-01

    Fanconi anemia is a hereditary chromosomal instability disorder. Hearing loss and ear abnormalities are among the many manifestations reported in this disorder. In addition, Fanconi anemia patients often complain about hearing difficulties in situations with background noise (speech perception in noise difficulties). Our study aimed to describe the prevalence of hearing loss and speech perception in noise difficulties in Dutch Fanconi anemia patients. Retrospective chart review. A retrospective chart review was conducted at a Dutch tertiary care center. All patients with Fanconi anemia at clinical follow-up in our hospital were included. Medical files were reviewed to collect data on hearing loss and speech perception in noise difficulties. In total, 49 Fanconi anemia patients were included. Audiograms were available in 29 patients and showed hearing loss in 16 patients (55%). Conductive hearing loss was present in 24.1%, sensorineural in 20.7%, and mixed in 10.3%. A speech in noise test was performed in 17 patients; speech perception in noise was subnormal in nine patients (52.9%) and abnormal in two patients (11.7%). Hearing loss and speech perception in noise abnormalities are common in Fanconi anemia. Therefore, pure tone audiograms and speech in noise tests should be performed, preferably already at a young age, because hearing aids or assistive listening devices could be very valuable in developing language and communication skills. 4. Laryngoscope, 127:2358-2361, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  7. Ictal time-irreversible intracranial EEG signals as markers of the epileptogenic zone.

    Science.gov (United States)

    Schindler, Kaspar; Rummel, Christian; Andrzejak, Ralph G; Goodfellow, Marc; Zubler, Frédéric; Abela, Eugenio; Wiest, Roland; Pollo, Claudio; Steimer, Andreas; Gast, Heidemarie

    2016-09-01

    To show that time-irreversible EEG signals recorded with intracranial electrodes during seizures can serve as markers of the epileptogenic zone. We use the recently developed method of mapping time series into directed horizontal graphs (dHVG). Each node of the dHVG represents a time point in the original intracranial EEG (iEEG) signal. Statistically significant differences between the distributions of the nodes' number of input and output connections are used to detect time-irreversible iEEG signals. In 31 of 32 seizure recordings we found time-irreversible iEEG signals. The maximally time-irreversible signals always occurred during seizures, with highest probability in the middle of the first seizure half. These signals spanned a large range of frequencies and amplitudes but were all characterized by saw-tooth like shaped components. Brain regions removed from patients who became post-surgically seizure-free generated significantly larger time-irreversibilities than regions removed from patients who still had seizures after surgery. Our results corroborate that ictal time-irreversible iEEG signals can indeed serve as markers of the epileptogenic zone and can be efficiently detected and quantified in a time-resolved manner by dHVG based methods. Ictal time-irreversible EEG signals can help to improve pre-surgical evaluation in patients suffering from pharmaco-resistant epilepsies. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Multiscale time irreversibility of heart rate and blood pressure variability during orthostasis

    International Nuclear Information System (INIS)

    Chladekova, L; Czippelova, B; Turianikova, Z; Tonhajzerova, I; Calkovska, A; Javorka, M; Baumert, M

    2012-01-01

    Time irreversibility is a characteristic feature of non-equilibrium, complex systems such as the cardiovascular control mediated by the autonomic nervous system (ANS). Time irreversibility analysis of heart rate variability (HRV) and blood pressure variability (BPV) represents a new approach to assess cardiovascular regulatory mechanisms. The aim of this paper was to assess the changes in HRV and BPV irreversibility during the active orthostatic test (a balance of ANS shifted towards sympathetic predominance) in 28 healthy young subjects. We used three different time irreversibility indices—Porta’s, Guzik's and Ehler's indices (P%, G% and E, respectively) derived from data segments containing 1000 beat-to-beat intervals on four timescales. We observed an increase in the HRV and a decrease in the BPV irreversibility during standing compared to the supine position. The postural change in irreversibility was confirmed by surrogate data analysis. The differences were more evident in G% and E than P% and for higher scale factors. Statistical analysis showed a close relationship between G% and E. Contrary to this, the association between P% and G% and P% and E was not proven. We conclude that time irreversibility of beat-to-beat HRV and BPV is significantly altered during orthostasis, implicating involvement of the autonomous nervous system in its generation. (paper)

  9. Hearing speech in music.

    Science.gov (United States)

    Ekström, Seth-Reino; Borg, Erik

    2011-01-01

    The masking effect of a piano composition, played at different speeds and in different octaves, on speech-perception thresholds was investigated in 15 normal-hearing and 14 moderately-hearing-impaired subjects. Running speech (just follow conversation, JFC) testing and use of hearing aids increased the everyday validity of the findings. A comparison was made with standard audiometric noises [International Collegium of Rehabilitative Audiology (ICRA) noise and speech spectrum-filtered noise (SPN)]. All masking sounds, music or noise, were presented at the same equivalent sound level (50 dBA). The results showed a significant effect of piano performance speed and octave (Ptempo had the largest effect; and high octave and slow tempo, the smallest. Music had a lower masking effect than did ICRA noise with two or six speakers at normal vocal effort (Pmusic offers an interesting opportunity for studying masking under realistic conditions, where spectral and temporal features can be varied independently. The results have implications for composing music with vocal parts, designing acoustic environments and creating a balance between speech perception and privacy in social settings.

  10. Everyday trajectories of hearing correction

    DEFF Research Database (Denmark)

    Lykke Hindhede, Anette

    2010-01-01

    wearers in order to rehabilitate them back to ‘normal'. However, within audiological research, noncompliance has attracted much attention as investigations have shown that more than 20 percent of hearing aids are very seldom, if ever, in use and 19 percent are used only occasionally. As shown in the paper...... are complex and epistemologically contested and can help explain why noncompliance is dominant when it comes to hearing rehabilitation for hearing impaired adults....

  11. A Fingerprint Encryption Scheme Based on Irreversible Function and Secure Authentication

    Directory of Open Access Journals (Sweden)

    Yijun Yang

    2015-01-01

    Full Text Available A fingerprint encryption scheme based on irreversible function has been designed in this paper. Since the fingerprint template includes almost the entire information of users’ fingerprints, the personal authentication can be determined only by the fingerprint features. This paper proposes an irreversible transforming function (using the improved SHA1 algorithm to transform the original minutiae which are extracted from the thinned fingerprint image. Then, Chinese remainder theorem is used to obtain the biokey from the integration of the transformed minutiae and the private key. The result shows that the scheme has better performance on security and efficiency comparing with other irreversible function schemes.

  12. Classical many-body theory with retarded interactions: Dynamical irreversibility and determinism without probabilities

    Energy Technology Data Exchange (ETDEWEB)

    Zakharov, A.Yu., E-mail: Anatoly.Zakharov@novsu.ru; Zakharov, M.A., E-mail: ma_zakharov@list.ru

    2016-01-28

    The exact equations of motion for microscopic density of classical many-body system with account of inter-particle retarded interactions is derived. It is shown that interactions retardation leads to irreversible behavior of many-body systems. - Highlights: • A new form of equation of motion of classical many-body system is proposed. • Interactions retardation as one of the mechanisms of many-body system irreversibility. • Irreversibility and determinism without probabilities. • The possible way to microscopic foundation of thermodynamics.

  13. Performance of an irreversible quantum Ericsson cooler at low temperature limit

    International Nuclear Information System (INIS)

    Wu Feng; Chen Lingen; Wu Shuang; Sun Fengrui

    2006-01-01

    The purpose of this paper is to investigate the effect of quantum properties of the working medium on the performance of an irreversible quantum Ericsson cooler with spin-1/2. The cooler is studied with the losses of heat resistance, heat leakage and internal irreversibility. The optimal relationship between the dimensionless cooling load R * versus the coefficient of performance ε for the irreversible quantum Ericsson cooler is derived. In particular, the performance characteristics of the cooler at the low temperature limit are discussed

  14. Optimization of the performance characteristics in an irreversible magnetic Brayton refrigeration cycle

    International Nuclear Information System (INIS)

    Wang Hao; Liu Sanqiu

    2008-01-01

    An irreversible cycle model of magnetic Brayton refrigerators is established, in which the thermal resistance and irreversibility in the two adiabatic processes are taken into account. Expressions for several important performance parameters, such as the coefficient of performance, cooling rate and power input are derived. Moreover, the optimal performance parameters are obtained at the maximum coefficient of performance. The optimization region (or criteria) for an irreversible magnetic Brayton refrigerator is obtained. The results obtained here have general significance and will be helpful to understand deeply the performance of a magnetic Brayton refrigeration cycle

  15. Consequences of Early Conductive Hearing Loss on Long-Term Binaural Processing.

    Science.gov (United States)

    Graydon, Kelley; Rance, Gary; Dowell, Richard; Van Dun, Bram

    The aim of the study was to investigate the long-term effects of early conductive hearing loss on binaural processing in school-age children. One hundred and eighteen children participated in the study, 82 children with a documented history of conductive hearing loss associated with otitis media and 36 controls who had documented histories showing no evidence of otitis media or conductive hearing loss. All children were demonstrated to have normal-hearing acuity and middle ear function at the time of assessment. The Listening in Spatialized Noise Sentence (LiSN-S) task and the masking level difference (MLD) task were used as the two different measures of binaural interaction ability. Children with a history of conductive hearing loss performed significantly poorer than controls on all LiSN-S conditions relying on binaural cues (DV90, p = binaural cues. Fifteen children with a conductive hearing loss history (18%) showed results consistent with a spatial processing disorder. No significant difference was observed between the conductive hearing loss group and the controls on the MLD task. Furthermore, no correlations were found between LiSN-S and MLD. Results show a relationship between early conductive hearing loss and listening deficits that persist once hearing has returned to normal. Results also suggest that the two binaural interaction tasks (LiSN-S and MLD) may be measuring binaural processing at different levels. Findings highlight the need for a screening measure of functional listening ability in children with a history of early otitis media.

  16. Grade repetition and parents' perception of hearing loss: An analysis of data from children in the United States.

    Science.gov (United States)

    Gilani, Sapideh; Roditi, Rachel; Bhattacharyya, Neil

    2017-03-01

    To determine whether parent-perceived hearing problems are associated with grade repetition among children in the United States. Retrospective cohort analysis of a contemporary national database. The National Survey of Children's Health 2011 to 2012 was analyzed. Hearing loss, as perceived and reported by parents, was categorized as: no hearing problem, history of a hearing problem, or current hearing problem. Children never repeating a grade versus repeating one or more grades (kindergarten-high school) were identified. Univariate statistics and multivariate logistic regression analyzed the association of hearing problems with grade repetition. Patients with mental retardation, autism, and attention-deficit/hyperactivity disorder were excluded from the analysis. After adjusting for race, sex, and poverty level, odds ratios for grade repetition were computed. Among 66.1 million (average age, 8.3 years, 49.0% male) children, 97.3% never had a hearing problem, 1.7% had a history of a hearing problem, and 1.0% had a current hearing problem. Overall, 7.1% repeated a grade. Grade repetition was reported in 6.9% of children without a hearing problem versus 9.4% with a history of a hearing problem and 19.3% with a current hearing problem (P hearing problem demonstrated an odds ratio of 1.9 (95% confidence interval 0.82-4.13) for grade repetition, whereas a current hearing problem demonstrated an odds ratio of 3.0 (1.90-4.80). Parents' perception of children's hearing problems is strongly associated with grade repetition. This trend is noticed in elementary school more than in high school. 4. Laryngoscope, 127:741-745, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  17. Serving and Supporting Young Children with a Dual Diagnosis of Hearing Loss and Autism: The Stories of Four Families

    Science.gov (United States)

    Myck-Wayne, Janice; Robinson, Suzanne; Henson, Erica

    2011-01-01

    The research on young children with a dual diagnosis of hearing loss and autism spectrum disorder (ASD) is meager and scattered. Pockets of research on this population of children suggest that it is difficult to make the diagnosis of ASD in children with hearing loss. A case study design was used to examine the diagnostic process for young…

  18. Cochlear Homocysteine Metabolism at the Crossroad of Nutrition and Sensorineural Hearing Loss

    Directory of Open Access Journals (Sweden)

    Isabel Varela-Nieto

    2017-04-01

    Full Text Available Hearing loss (HL is one of the most common causes of disability, affecting 360 million people according to the World Health Organization (WHO. HL is most frequently of sensorineural origin, being caused by the irreversible loss of hair cells and/or spiral ganglion neurons. The etiology of sensorineural HL (SNHL is multifactorial, with genetic and environmental factors such as noise, ototoxic substances and aging playing a role. The nutritional status is central in aging disability, but the interplay between nutrition and SNHL has only recently gained attention. Dietary supplementation could therefore constitute the first step for the prevention and potential repair of hearing damage before it reaches irreversibility. In this context, different epidemiological studies have shown correlations among the nutritional condition, increased total plasma homocysteine (tHcy and SNHL. Several human genetic rare diseases are also associated with homocysteine (Hcy metabolism and SNHL confirming this potential link. Accordingly, rodent experimental models have provided the molecular basis to understand the observed effects. Thus, increased tHcy levels and vitamin deficiencies, such as folic acid (FA, have been linked with SNHL, whereas long-term dietary supplementation with omega-3 fatty acids improved Hcy metabolism, cell survival and hearing acuity. Furthermore, pharmacological supplementations with the anti-oxidant fumaric acid that targets Hcy metabolism also improved SNHL. Overall these results strongly suggest that cochlear Hcy metabolism is a key player in the onset and progression of SNHL, opening the way for the design of prospective nutritional therapies.

  19. Interventions to promote the wearing of hearing protection.

    Science.gov (United States)

    El Dib, R P; Verbeek, J; Atallah, A N; Andriolo, R B; Soares, B G O

    2006-04-19

    Noise induced hearing loss can only be prevented by eliminating or lowering noise exposure levels. Where the source of the noise can not be eliminated workers have to rely on hearing protective equipment. Several trials have been conducted to study the effectiveness of interventions to influence the wearing of hearing protection and to decrease noise exposure. We aimed to establish whether interventions to increase the wearing of hearing protection are effective. To summarise the evidence for the effectiveness of interventions to enhance the wearing of hearing protection among workers exposed to noise in the workplace. We searched the Cochrane Ear, Nose and Throat Disorders Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2 2005), MEDLINE (1966 to June 2005), EMBASE (1980 to June 2005), NIOSHTIC, CISDOC, CINAHL, LILACS (1982 to June 2005) and Scientific Electronic Library Online. The date of the last search was June 2005. Studies were included if they had a randomised design, if they were among noise exposed (> 80 dB(A)) workers or pupils, if there was some kind of intervention to promote the wearing of hearing protection (compared to another intervention or no intervention), and if the outcome measured was the amount of use of hearing protection or a proxy measure thereof. Two reviewers selected relevant trials, assessed methodological quality and extracted data. There were no cases where the pooling of data was appropriate. Two studies were found. One study was a two-phased randomised controlled trial. A computer-based intervention tailored to the risk of an individual worker lasting 30 minutes was not found to be more effective than a video providing general information among workers, around 80% of whom already used hearing protection. The second phase of the trial involved sending a reminder to the home address of participants at 30 days, 90 days or at both 30 and 90 days after the intervention

  20. Interaction between diabetes mellitus and hypertension on risk of hearing loss in highly endogamous population.

    Science.gov (United States)

    Bener, Abdulbari; Al-Hamaq, Abdulla O A A; Abdulhadi, Khalid; Salahaldin, Ahmed H; Gansan, Loida

    2017-11-01

    The aim of this study was to determine the prevalence of hearing loss and its association with type 2 diabetes mellitus (T2DM) in a highly endogamous population. This is a cross-sectional study. The present study is carried out in Ear Nose Throat (ENT) and Endocrinology outpatient clinics of the Hamad General and Rumeilah Hospitals, Hamad Medical Corporation. All subjects aged between 20 and 59 years who visited the Endocrinology and ENT outpatient clinics of the Hamad Medical Corporation with hearing difficulty were included in this study during the period from January 2013 to July 2014. During the study period, prevalence, hearing, audiological test, family history and medical problems associated with hearing impairment in middle aged patients were recorded. Two audiometers Grason Stadler GSI 61 and Madsen Orbiter 922 were used to evaluate the hearing loss. Majority of the hearing loss observed at the age above 45 years old, (44.8% vs 51.7%, p=0.05). The prevalence of hearing impairment was higher in Qataris than in non-Qataris (59.7% vs 46.6%, pdiabetes onset duration (7.8±4.12years), sleeping disorder (5.81±1.29h), obese subjects (38% vs 27.4%); family history of diabetes (30.6 vs 23.1%) were higher among hearing impairment. The associated risk factors were significantly higher in T2DM with hearing loss, hypoglycemia (32.8% vs 27.4%), retinopathy (313% vs 18.5%), Nephropathy (17.9% vs 9.8%), Neuropathy (17.9% vs 10.2%), macro-vascular disease (11.9% vs 6.2%), diabetic foot ulcer (20.9% vs 12.6%), Tinnitus (68.7% vs 51.3%), and Vertigo (25.4% vs 16.9%) than in normal hearing diabetes. There was a statistically significant differences between hearing impairment and normal hearing among T2DM regarding hearing assessment frequency (p=0.041). There were statistically significant differences between hearing impairment versus normal hearing for vitamin D [18.91±7.65ng/mL vs 22.85±9.00ng/mL; pdiabetic patients. The current study results confirm previous reports

  1. Behavioral training promotes multiple adaptive processes following acute hearing loss.

    Science.gov (United States)

    Keating, Peter; Rosenior-Patten, Onayomi; Dahmen, Johannes C; Bell, Olivia; King, Andrew J

    2016-03-23

    The brain possesses a remarkable capacity to compensate for changes in inputs resulting from a range of sensory impairments. Developmental studies of sound localization have shown that adaptation to asymmetric hearing loss can be achieved either by reinterpreting altered spatial cues or by relying more on those cues that remain intact. Adaptation to monaural deprivation in adulthood is also possible, but appears to lack such flexibility. Here we show, however, that appropriate behavioral training enables monaurally-deprived adult humans to exploit both of these adaptive processes. Moreover, cortical recordings in ferrets reared with asymmetric hearing loss suggest that these forms of plasticity have distinct neural substrates. An ability to adapt to asymmetric hearing loss using multiple adaptive processes is therefore shared by different species and may persist throughout the lifespan. This highlights the fundamental flexibility of neural systems, and may also point toward novel therapeutic strategies for treating sensory disorders.

  2. Hearing loss at work? Hearing loss from leisure activities?

    CERN Multimedia

    2006-01-01

    The nurses of the Medical Service would like invite all persons working on the CERN site to take part in a: HEARING LOSS DETECTION WEEK From 28 August to 1st September 2006 At the Infirmary, Building 57 from 9 a.m. to 4 p.m. Hearing tests - advice - information - documentation - protective equipment

  3. 45 CFR 400.23 - Hearings.

    Science.gov (United States)

    2010-10-01

    ... under the Act with an opportunity for a hearing to contest adverse determinations using hearing... issue by inspection of the individual's documentation issued by the Immigration and Naturalization...

  4. Sample size effect on the determination of the irreversibility line of high-Tc superconductors

    International Nuclear Information System (INIS)

    Li, Q.; Suenaga, M.; Li, Q.; Freltoft, T.

    1994-01-01

    The irreversibility lines of a high-J c superconducting Bi 2 Sr 2 Ca 2 Cu 3 O x /Ag tape were systematically measured upon a sequence of subdivisions of the sample. The irreversibility field H r (T) (parallel to the c axis) was found to change approximately as L 0.13 , where L is the effective dimension of the superconducting tape. Furthermore, it was found that the irreversibility line for a grain-aligned Bi 2 Sr 2 Ca 2 Cu 3 O x specimen can be approximately reproduced by the extrapolation of this relation down to a grain size of a few tens of micrometers. The observed size effect could significantly obscure the real physical meaning of the irreversibility lines. In addition, this finding surprisingly indicated that the Bi 2 Sr 2 Ca 2 Cu 2 O x /Ag tape and grain-aligned specimen may have similar flux line pinning strength

  5. Treatise on irreversible and statistical thermodynamics an introduction to nonclassical thermodynamics

    CERN Document Server

    Yourgrau, Wolfgang; Raw, Gough

    2002-01-01

    Extensively revised edition of a much-respected work examines thermodynamics of irreversible processes, general principles of statistical thermodynamics, assemblies of noninteracting structureless particles, and statistical theory. 1966 edition.

  6. Irreversible membrane fouling abatement through pre-deposited layer of hierarchical porous carbons

    KAUST Repository

    Hamad, Juma; Dua, Rubal; Kurniasari, Novita; Kennedy, Maria Dolores; Wang, Peng; Amy, Gary L.

    2014-01-01

    In this work, dual-templated hierarchical porous carbons (HPCs), produced from a coupled ice-hard templating approach, are shown to be a highly effective solution to the commonly occurring problem of irreversible fouling of low-pressure membranes

  7. Evaluation of properties of irreversible hydrocolloid impression materials mixed with disinfectant liquids

    Directory of Open Access Journals (Sweden)

    Arul Amalan

    2013-01-01

    Conclusion: Chlorhexidine solution can be used to mix irreversible hydrocolloid impression materials in regular dental practice as it did not significantly alter the properties. This may ensure effective disinfection of impressions.

  8. Ecological optimization of an irreversible quantum Carnot heat engine with spin-1/2 systems

    International Nuclear Information System (INIS)

    Liu Xiaowei; Chen Lingen; Wu Feng; Sun Fengrui

    2010-01-01

    A model of a quantum heat engine with heat resistance, internal irreversibility and heat leakage and many non-interacting spin-1/2 systems is established in this paper. The quantum heat engine cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot heat engine. Based on the quantum master equation and the semi-group approach, equations of some important performance parameters, such as power output, efficiency, entropy generation rate and ecological function (a criterion representing the optimal compromise between exergy output rate and exergy loss rate), for the irreversible spin quantum Carnot heat engine are derived. The optimal ecological performance of the heat engine in the classical limit is analyzed with numerical examples. The effects of internal irreversibility and heat leakage on ecological performance are discussed in detail.

  9. Irreversibility analysis for gravity driven non-Newtonian liquid film along an inclined isothermal plate

    International Nuclear Information System (INIS)

    Makinde, O.D.

    2005-10-01

    In this paper, the first and second law of thermodynamics are employed in order to study the inherent irreversibility for a gravity driven non-Newtonian Ostwald-de Waele power law liquid film along an inclined isothermal plate. Based on some simplified assumptions, the governing equations are obtained and solved analytically. Expressions for fluid velocity, temperature, volumetric entropy generation numbers, irreversibility distribution ratio and the Bejan number are also determined. (author)

  10. Effectiveness of Group Training of Assertiveness on Social Anxiety among Deaf and Hard of Hearing Adolescents.

    Science.gov (United States)

    Ahmadi, Hamed; Daramadi, Parviz Sharifi; Asadi-Samani, Majid; Givtaj, Hamed; Sani, Mohammad Reza Mahmoudian

    2017-06-01

    The present study was conducted to compare the effectiveness of assertiveness group training on social anxiety (SAD) between deaf and hearing impaired adolescents. Forty eight (24 deaf and 24 hearing impaired) people participated in this study. First, participants with SAD, i.e. attaining the scores above 40 for Connor's Social Inventory Scale 2000 (SPIN), were selected according to convenience sampling and randomly assigned to two groups, i.e. intervention and control. Then, assertiveness group training was conducted for intervention group within 10 sessions, and immediately after completion of the training sessions, SPIN was re-administered to the two groups. ANCOVA showed that the effectiveness of assertiveness group training on SAD is different between deaf and hearing impaired participants, i.e. assertiveness group training was effective on improvement of SAD in hearing impaired participants but not deaf ones. Therefore, it is recommended to incorporate assertiveness group training in the educational programs developed for adolescents with ear disorders especially hearing impairment.

  11. Hearing symptoms personal stereos.

    Science.gov (United States)

    da Luz, Tiara Santos; Borja, Ana Lúcia Vieira de Freitas

    2012-04-01

     Practical and portable the personal stereos if had become almost indispensable accessories in the day the day. Studies disclose that the portable players of music can cause auditory damages in the long run for who hear music in high volume for a drawn out time.  to verify the prevalence of auditory symptoms in users of amplified players and to know its habits of use  Observational prospective study of transversal cut carried through in three institutions of education of the city of Salvador BA, being two of public net and one of the private net. 400 students had answered to the questionnaire, of both the sex, between 14 and 30 years that had related the habit to use personal stereos.  The symptoms most prevalent had been hyperacusis (43.5%), auricular fullness (30.5%) and humming (27.5), being that the humming is the symptom most present in the population youngest. How much to the daily habits: 62.3% frequent use, 57% in raised intensities, 34% in drawn out periods. An inverse relation between exposition time was verified and the band of age (p = 0,000) and direct with the prevalence of the humming.  Although to admit to have knowledge on the damages that the exposition the sound of high intensity can cause the hearing, the daily habits of the young evidence the inadequate use of the portable stereos characterized by long periods of exposition, raised intensities, frequent use and preference for the insertion phones. The high prevalence of symptoms after the use suggests a bigger risk for the hearing of these young.

  12. Hearing symptoms personal stereos

    Directory of Open Access Journals (Sweden)

    Tiara Santos da Luz1

    2012-01-01

    Full Text Available Introduction: Practical and portable the personal stereos if had become almost indispensable accessories in the day the day. Studies disclose that the portable players of music can cause auditory damages in the long run for who hear music in high volume for a drawn out time. Objective: to verify the prevalence of auditory symptoms in users of amplified players and to know its habits of use. Method: Observational prospective study of transversal cut carried through in three institutions of education of the city of Salvador BA, being two of public net and one of the private net. 400 students had answered to the questionnaire, of both the sex, between 14 and 30 years that had related the habit to use personal stereos. Results: The symptoms most prevalent had been hyperacusis (43.5%, auricular fullness (30.5% and humming (27.5, being that the humming is the symptom most present in the population youngest. How much to the daily habits: 62.3% frequent use, 57% in raised intensities, 34% in drawn out periods. An inverse relation between exposition time was verified and the band of age (p=0,000 and direct with the prevalence of the humming. Conclusion: Although to admit to have knowledge on the damages that the exposition the sound of high intensity can cause the hearing, the daily habits of the young evidence the inadequate use of the portable stereos characterized by long periods of exposition, raised intensities, frequent use and preference for the insertion phones. The high prevalence of symptoms after the use suggests a bigger risk for the hearing of these young.

  13. Psychotic reactions to daily life stress and dopamine function in people with severe hearing impairment

    NARCIS (Netherlands)

    Gevonden, M. J.; Myin-Germeys, I.; van den Brink, W.; van Os, J.; Selten, J. P.; Booij, J.

    2015-01-01

    Minor stresses measured in daily life have repeatedly been associated with increased momentary psychotic experiences, both in individuals with psychotic disorders and in persons who are genetically at an increased risk for these disorders. Severe hearing impairment (SHI) is an environmental risk

  14. Hearing thresholds at high frequency in patients with cystic fibrosis: a systematic review

    Directory of Open Access Journals (Sweden)

    Debora T.M. Caumo

    Full Text Available Abstract Introduction: High-frequency audiometry may contribute to the early detection of hearing loss caused by ototoxic medications. Many ototoxic drugs are widely used in the treatment of patients with cystic fibrosis. Early detection of hearing loss should allow known harmful drugs to be identified before the damage affects speech frequencies. The damage caused by ototoxicity is irreversible, resulting in important social and psychological consequences. In children, hearing loss, even when restricted to high frequencies, can affect the development of language. Objective: To investigate the efficacy and effectiveness of hearing monitoring through high-frequency audiometry in pediatric patients with cystic fibrosis. Methods: Electronic databases PubMed, MedLine, Web of Science and LILACS were searched, from January to November 2015. The selected studies included those in which high-frequency audiometry was performed in patients with cystic fibrosis, undergoing treatment with ototoxic drugs and published in Portuguese, English and Spanish. The GRADE system was chosen for the evaluation of the methodological quality of the articles. Results: During the search process carried out from January 2015 to November 2015, 512 publications were identified, of which 250 were found in PubMed, 118 in MedLine, 142 in Web of Science and 2 in LILACS. Of these, nine articles were selected. Conclusion: The incidence of hearing loss was identified at high frequencies in cystic fibrosis patients without hearing complaints. It is assumed that high-frequency audiometry can be an early diagnostic method to be recommended for hearing investigation of patients at risk of ototoxicity.

  15. Protect Your Hearing at Work

    Centers for Disease Control (CDC) Podcasts

    Noise-induced hearing loss is one of the most common work-related illnesses. This podcast features information from CDC’s National Institute for Occupational Safety and Health on how to protect yourself from work-related noise-induced hearing loss.

  16. Genes and Syndromic Hearing Loss.

    Science.gov (United States)

    Keats, Bronya J. B.

    2002-01-01

    This article provides a description of the human genome and patterns of inheritance and discusses genes that are associated with some of the syndromes for which hearing loss is a common finding, including: Waardenburg, Stickler, Jervell and Lange-Neilsen, Usher, Alport, mitochondrial encephalomyopathy, and sensorineural hearing loss. (Contains…

  17. The Stigma of Hearing Loss

    Science.gov (United States)

    Wallhagen, Margaret I.

    2010-01-01

    Purpose: To explore dimensions of stigma experienced by older adults with hearing loss and those with whom they frequently communicate to target interventions promoting engagement and positive aging. Design and Methods: This longitudinal qualitative study conducted interviews over 1 year with dyads where one partner had hearing loss. Participants…

  18. Age-Related Hearing Loss

    Science.gov (United States)

    ... 29, 2017 Granicus - Health Topics Languages Español Download PDF version Order free publications Find organizations Syndicate content Related Topics Do You Need a Hearing Test? Hearing Loss and Older Adults News Spatial organization of cells in the inner ear enables the sense and ...

  19. A Hearing Aid Primer 1

    Science.gov (United States)

    Yetter, Carol J.

    2009-01-01

    This hearing aid primer is designed to define the differences among the three levels of hearing instrument technology: conventional analog circuit technology (most basic), digitally programmable/analog circuit technology (moderately advanced), and fully digital technology (most advanced). Both moderate and advanced technologies mean that hearing…

  20. Gait performance of children and adolescents with sensorineural hearing loss.

    Science.gov (United States)

    Melo, Renato de Souza

    2017-09-01

    Several studies have demonstrated that children with sensorineural hearing loss (SNHL) may exhibit balance disorders, which can compromise the gait performance of this population. Compare the gait performance of normal hearing (NH) children and those with SNHL, considering the sex and age range of the sample, and analyze gait performance according to degrees of hearing loss and etiological factors in the latter group. This is a cross-sectional study that assessed 96 students, 48 NH and 48 with SNHL, aged between 7 and 18 years. The Brazilian version of the Dynamic Gait Index (DGI) was used to analyze gait and the Mann-Whitney test for statistical analysis. The group with SNHL obtained lower average gait performance compared to NH subjects (p=0.000). This was also observed when the children were grouped by sex female and male (p=0.000). The same difference occurred when the children were stratified by age group: 7-18 years (p=0.000). The group with severe and profound hearing loss exhibited worse gait performance than those with mild and moderate loss (p=0.048) and children with prematurity as an etiological factor demonstrated the worst gait performance. The children with SNHL showed worse gait performance compared to NH of the same sex and age group. Those with severe and profound hearing loss and prematurity as an etiological factor demonstrated the worst gait performances. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Sensorineural hearing loss and celiac disease: a coincidental finding.

    Science.gov (United States)

    Volta, Umberto; Ferri, Gian Gaetano; De Giorgio, Roberto; Fabbri, Angela; Parisi, Claudia; Sciajno, Laura; Castellari, Alessandra; Fiorini, Erica; Piscaglia, Maria; Barbara, Giovanni; Granito, Alessandro; Pirodda, Antonio

    2009-08-01

    Celiac disease (CD) can be associated with a variety of extraintestinal manifestations, including neurological diseases. A new neurological correlation has been found between CD and sensorineural hearing loss (SNHL). To verify the association between SNHL and CD, and to establish whether the neurological hearing impairment in CD is related to nonorgan-specific and antineuronal antibodies, as well as the presence of autoimmune disorders. A sample of 59 consecutive biopsy- and serologically proven CD patients were studied. Among CD patients, 11 were newly diagnosed and 48 were on a gluten-free diet. Hearing function was assessed by audiometric analysis in all CD patients as well as in 59 age- and sex-matched controls. Patients were tested for a panel of immune markers including nonorgan-specific autoantibodies and antineuronal antibodies. SNHL was detected in five CD patients (8.5%) and in two controls (3.4%). In one patient, the SNHL was bilateral, whereas the remaining four had a monolateral impairment. The prevalence of SNHL was not significantly different between CD patients and controls. At least one of the antibodies tested for was positive in two of the five CD patients with SNHL and in 12 of the 54 CD patients without SNHL. Antineuronal antibodies to central nervous system antigens were consistently negative in the five CD patients with SNHL. Only one of the five CD patients with SNHL had Hashimoto thyroiditis. SNHL and CD occur coincidentally. Hearing function should be assessed only in CD patients with clinical signs of hearing deficiency.

  2. Follow-up of permanent hearing impairment in childhood.

    Science.gov (United States)

    Della Volpe, A; De Lucia, A; Pastore, V; Bracci Laudiero, L; Buonissimo, I; Ricci, G

    2016-02-01

    Programmes for early childhood childhood hearing impairment identification allows to quickly start the appropriate hearing aid fitting and rehabilitation process; nevertheless, a large number of patients do not join the treatment program. The goal of this article is to present the results of a strategic review of the strengths, weaknesses, opportunities and threats connected with the audiologic/prosthetic/language follow-up process of children with bilateral permanent hearing impairment. Involving small children, the follow-up includes the involvement of specialised professionals of a multidisciplinary team and a complex and prolonged multi-faced management. Within the framework of the Italian Ministry of Health project CCM 2013 "Preventing Communication Disorders: a Regional Program for Early Identification, Intervention and Care of Hearing Impaired Children", the purpose of this analysis was to propose recommendations that can harmonise criteria for outcome evaluation and provide guidance on the most appropriate assessment methods to be used in the follow-up course of children with permanent hearing impairment. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale.

  3. Hearing Loss in Osteogenesis Imperfecta: Characteristics and Treatment Considerations

    Science.gov (United States)

    Pillion, Joseph P.; Vernick, David; Shapiro, Jay

    2011-01-01

    Osteogenesis imperfecta (OI) is the most common heritable disorder of connective tissue. It is associated with fractures following relatively minor injury, blue sclerae, dentinogenesis imperfecta, increased joint mobility, short stature, and hearing loss. Structures in the otic capsule and inner ear share in the histologic features common to other skeletal tissues. OI is due to mutations involving several genes, the most commonly involved are the COL1A1 or COL1A2 genes which are responsible for the synthesis of the proalpha-1 and proalpha-2 polypeptide chains that form the type I collagen triple helix. A genotype/phenotype relationship to hearing loss has not been established in OI. Hearing loss is commonly found in OI with prevalence rates ranging from 50 to 92% in some studies. Hearing loss in OI may be conductive, mixed, or sensorineural and is more common by the second or third decade. Treatment options such as hearing aids, stapes surgery, and cochlear implants are discussed. PMID:22567374

  4. Characterization of hearing loss in aged type II diabetics

    Science.gov (United States)

    Frisina, Susan T.; Mapes, Frances; Kim, SungHee; Frisina, D. Robert; Frisina, Robert D.

    2009-01-01

    Presbycusis – age-related hearing loss – is the number one communicative disorder and a significant chronic medical condition of the aged. Little is known about how type II diabetes, another prevalent age-related medical condition, and presbycusis interact. The present investigation aimed to comprehensively characterize the nature of hearing impairment in aged type II diabetics. Hearing tests measuring both peripheral (cochlea) and central (brainstem and cortex) auditory processing were utilized. The majority of differences between the hearing abilities of the aged diabetics and their age-matched controls were found in measures of inner ear function. For example, large differences were found in pure-tone audiograms, wideband noise and speech reception thresholds, and otoacoustic emissions. The greatest deficits tended to be at low frequencies. In addition, there was a strong tendency for diabetes to affect the right ear more than the left. One possible interpretation is that as one develops presbycusis, the right ear advantage is lost, and this decline is accelerated by diabetes. In contrast, auditory processing tests that measure both peripheral and central processing showed fewer declines between the elderly diabetics and the control group. Consequences of elevated blood sugar levels as possible underlying physiological mechanisms for the hearing loss are discussed. PMID:16309862

  5. Epileptiform electroencephalogram abnormality in children with congenital sensorineural hearing loss.

    Science.gov (United States)

    El-Badry, Mohamed Mohamed; Hamdy, Nermin Aly; Sobhy, Sayed; Gamal, Reham

    2014-04-01

    This work was designed to study electroencephalogram findings in children with congenital sensorineural hearing loss and correlate these findings with the SNHL parameters as duration, etiology, severity, and type. Ninety children with bilateral congenital sensorineural hearing loss served as the study group. They were free from any neurological disorders or symptoms that are commonly associated with abnormal electroencephalogram as convulsions or loss of consciousness. Twenty children having normal hearing with no history of otological or neurological disorders served as the control group. All children participating in the study were subjected to full medical and audiological history, otological examination, neurological examination, audiological evaluation and electroencephalogram recording. Mean age of the children in the control group was 3.56 ± 2.1 years and mean age of the children in the study group was 3.8 ± 2.2 years. While none of the control children had abnormal electroencephalogram, 38 (42.2%) of children with congenital SNHL had epileptiform electroencephalogram abnormality. The epileptiform abnormality was generalized in 14 children (36.8%), focal temporal in 17 children (44.7%) and focal other than temporal in 7 children (18.4%). According to the hemispheric side affected, the abnormality was right in 14 children (36.8%), left in 10 children (26.3%) and bilateral in 14 children (36.8%). No statistically significant predominance of specific site or side of the epileptiform abnormality was found. Similarly, no statistical significant prevalent of the epileptiform abnormality was found in relation to the age or sex of children, duration of hearing loss or etiology of hearing loss (i.e., genetic vs. neonatal insults). On the other hand, the epileptiform abnormality was statistically prevalent in children with moderate degree of hearing loss, and in children with auditory neuropathy spectrum disorder. The epileptiform electroencephalogram abnormality is

  6. Otolithic organ function in patients with profound sensorineural hearing loss

    Directory of Open Access Journals (Sweden)

    Yujuan Zhou

    2016-06-01

    Full Text Available Profound sensorineural hearing loss (PSHL is not uncommonly encountered in otology. In clinics, there is a high incidence of otolithic damage in patients with PSHL, but relevant reports are few. Sharing a continuous membranous structure and similar receptor cell ultrastructures, the cochlea and vestibule may be susceptible to the same harmful factors. Disorders of the inner ear may result in a variety of manifestations, including vertigo, spatial disorientation, blurred vision, impaired articulation, and hearing impairment. Considering the diversity of clinical symptoms associated with PSHL with otolithic dysfunction, it may be frequently misdiagnosed, and objective means of testing the function of otolithic organs should be recommended for hearing-impaired patients. Vestibular-evoked myogenic potentials (VEMPs via air-conducted sound are of great importance for the diagnosis of otolithic function. Hearing devices such as cochlear implants are commonly accepted treatments for PSHL, and early identification and treatment of vestibular disorders may increase the success rate of cochlear implantation. Therefore, it is necessary to increase awareness of otolithic functional states in patients with PSHL.

  7. Relationship between hearing complaint and hearing loss among older people

    Directory of Open Access Journals (Sweden)

    Teixeira, Adriane Ribeiro

    2009-03-01

    Full Text Available Introduction: Presbycusis is a public health problem. Despite its high prevalence, many elders do not have their hearing ability investigated periodically, because they do not have a specific complaint. Objective: To check whether there is a relationship between the complaint and the presence of hearing loss in elder people. Method: Transversal study in elders from a neighborhood in the city of Canoas, Rio Grande do Sul. After the definition of the neighborhood's geographic boundaries, all houses were visited, the older people's addresses were ascertained and the invitations to take part in the research were provided. A questionnaire survey was applied which had a question about hearing loss complaint and air-conducted hearing thresholds were obtained and studied. Out of the 72 identified elders 50 elders agreed to participate, 35 (70% women, and 15 (30% men. Results: It was confirmed that only 12 (24% elders showed a specific complaint of hearing loss, although 33 (66% elders showed slight, moderate, severe and profound hearing losses. Conclusion: Data analysis confirmed there was no relationship between the complaint and the presence of hearing loss in the assessed group, and demonstrated the need to forward the elders for audiological evaluation even without any specific complaint.

  8. [The occupational risk of hearing impairment associated with cardiovascular pathologies in the subjects engaged in 'noisy' industries].

    Science.gov (United States)

    Pankova, V B; Preobrazhenskaya, E A; Fedina, I N

    The objective of the present study was to analyze the structure of concomitant somatic pathology in the subjects experiencing the occupational hearing problems. The study demonstrated the increase in the frequency of concomitant chronic diseases and the prevalence of polynosological conditions with the increasing severity of hearing impairment. It was shown that cardiovascular pathologies tend to enhance the risk of hearing loss in the employees engaged in «noisy» occupations. The cause-and-effect relationships were elucidated as the contribution of the "vascular" factor to the formation of occupational pathology of the organs of hearing. The clinical audilogical features of co-morbid occupational hearing impairment associated with vascular pathology were characterized by the accelerated development and progression of the hearing disorders with the gradual disappearance of the audiological signs characteristic of noise-induced lesions.

  9. Problems among childrens with impaired hearing. The impact of noise on the work of teachers

    Directory of Open Access Journals (Sweden)

    Ewelina Karolina Kucharska

    2017-09-01

    Full Text Available Introduction and Aim In the life of every human senses, including the sense of hearing, they play an important role in the harmonious development. Each hearing loss in childhood influences, depending on the depth, nature and time of its inception, in a negative way on the development of many mental activities, intellectual, behavior, cognitive, causing significant impairment in the child's position the hearing impaired, deaf and especially in the world of the hearing. The aim of this study is to assess the parents' awareness of hearing loss in children with hearing loss as a result of a survey of parents of children from the first classes of primary schools in the Lublin province. Material and Methods Analysis was performed on 31 results of parents of children with hearing impairment made in children aged 6 and 7 years, pupils and primary schools in the Lublin province. Parents were asked the question: 'Do you think your child has hearing problems?' The analysis indicated the assessment of awareness of parents of children with hearing disorders.   Results In the study group, as many as 77% of parents stated that the child does not have problems with hearing, only 3% of parents noted the problem, while 20% of parents did not answer the question. Conclusions Based on the research it can be stated with a high percentage of parents still do not notice hearing loss in their children. Early notice of the problem, the correct procedure and the cooperation with the parent group of specialists are often the way to success. It is crucial to support the child in difficult situations, which often is exposed to contact with all sorts of obstacles. An important issue is the numerous health programs, shaping the attitude of parents and society as a whole.

  10. Curing hearing loss: Patient expectations, health care practitioners, and basic science.

    Science.gov (United States)

    Oshima, Kazuo; Suchert, Steffen; Blevins, Nikolas H; Heller, Stefan

    2010-01-01

    Millions of patients are debilitated by hearing loss, mainly caused by degeneration of sensory hair cells in the cochlea. The underlying reasons for hair cell loss are highly diverse, ranging from genetic disposition, drug side effects, traumatic noise exposure, to the effects of aging. Whereas modern hearing aids offer some relief of the symptoms of mild hearing loss, the only viable option for patients suffering from profound hearing loss is the cochlear implant. Despite their successes, hearing aids and cochlear implants are not perfect. Particularly frequency discrimination and performance in noisy environments and general efficacy of the devises vary among individual patients. The advent of regenerative medicine, the publicity of stem cells and gene therapy, and recent scientific achievements in inner ear cell regeneration have generated an emerging spirit of optimism among scientists, health care practitioners, and patients. In this review, we place the different points of view of these three groups in perspective with the goal of providing an assessment of patient expectations, health care reality, and potential future treatment options for hearing disorders. (1) Readers will be encouraged to put themselves in the position of a hearing impaired patient or family member of a hearing impaired person. (2) Readers will be able to explain why diagnosis of the underlying pathology of hearing loss is difficult. (3) Readers will be able to list the main directions of current research aimed to cure hearing loss. (4) Readers will be able to understand the different viewpoints of patients and their relatives, health care providers, and scientists with respect to finding novel treatments for hearing loss. Copyright 2010 Elsevier Inc. All rights reserved.

  11. Treatment Efficacy: Hearing Aids in the Management of Hearing Loss in Adults.

    Science.gov (United States)

    Weinstein, Barbara E.

    1996-01-01

    This article reviews the efficacy of hearing aids in adults with hearing impairments. Information is provided on the prevalence of hearing impairments; the daily effects of a hearing impairment; and the role of the audiologist. The effectiveness and benefits of hearing aids are reviewed, and a case study is provided. (CR)

  12. Early Hearing Detection and Intervention: Can Your Baby Hear?

    Centers for Disease Control (CDC) Podcasts

    2007-06-15

    This podcast discusses how important it is that every child receives a hearing screening as soon as possible after birth. It also gives specific ways that parents and health providers can find out if a child has a possible hearing loss and where to get further information. (Created 6/5/2007 by the Early Hearing Detection and Intervention Program, NCBDDD).  Created: 6/15/2007 by National Center on Birth Defects and Developmental Disabilities.   Date Released: 6/25/2007.

  13. Hearing aid fitting in older persons with hearing impairment: the influence of cognitive function, age, and hearing loss on hearing aid benefit.

    Science.gov (United States)

    Meister, Hartmut; Rählmann, Sebastian; Walger, Martin; Margolf-Hackl, Sabine; Kießling, Jürgen

    2015-01-01

    To examine the association of cognitive function, age, and hearing loss with clinically assessed hearing aid benefit in older hearing-impaired persons. Hearing aid benefit was assessed using objective measures regarding speech recognition in quiet and noisy environments as well as a subjective measure reflecting everyday situations captured using a standardized questionnaire. A broad range of general cognitive functions such as attention, memory, and intelligence were determined using different neuropsychological tests. Linear regression analyses were conducted with the outcome of the neuropsychological tests as well as age and hearing loss as independent variables and the benefit measures as dependent variables. Thirty experienced older hearing aid users with typical age-related hearing impairment participated. Most of the benefit measures revealed that the participants obtained significant improvement with their hearing aids. Regression models showed a significant relationship between a fluid intelligence measure and objective hearing aid benefit. When individual hearing thresholds were considered as an additional independent variable, hearing loss was the only significant contributor to the benefit models. Lower cognitive capacity - as determined by the fluid intelligence measure - was significantly associated with greater hearing loss. Subjective benefit could not be predicted by any of the variables considered. The present study does not give evidence that hearing aid benefit is critically associated with cognitive function in experienced hearing aid users. However, it was found that lower fluid intelligence scores were related to higher hearing thresholds. Since greater hearing loss was associated with a greater objective benefit, these results strongly support the advice of using hearing aids regardless of age and cognitive function to counter hearing loss and the adverse effects of age-related hearing impairment. Still, individual cognitive capacity might

  14. The impact of hyperacusis and hearing loss on tinnitus perception in German teachers

    Directory of Open Access Journals (Sweden)

    Sandra P Meuer

    2015-01-01

    Full Text Available Recent research indicates that a notable number of teachers are concerned with conditions of auditory impairment such as tinnitus, hyperacusis, and hearing loss. Studies focussing on characteristics and interdependencies of single hearing disorders (HD are rare. This explorative study examines tinnitus, hyperacusis, hearing loss, and all possible combinations (tinnitus + hyperacusis; tinnitus + hearing loss; hyperacusis + hearing loss; tinnitus, hyperacusis + hearing loss in German teachers. The impact of single HD on perceived distress, depending on the number and kind of comorbid HD, was of special interest. Information was collected via online survey and includes self-reported data as well as data from the Mini-Tinnitus Questionnaire (Mini-TQ. Results show that most of the 1468 participants (45% suffered from two HD in different combinations, and the fewest (25% were afflicted with only one HD. Considering the seven HD groups, most teachers (30% suffered from all three HD. Across all groups, tinnitus was present in 1096, hyperacusis in 988, and hearing loss in 937 teachers. Multiple intergroup comparisons revealed that self-rated tinnitus-related distress rose significantly with the increasing number of HD. No significant differences were found for distress ratings of hyperacusis between the four groups including hyperacusis and between the four groups with hearing loss. In the Mini-TQ, groups including hyperacusis scored considerably higher than those excluding hyperacusis. The frequent prevalence of HD in German teachers points to a need of better noise prevention in German schools as one priority of occupational safety.

  15. 40 CFR 791.30 - Hearing procedures.

    Science.gov (United States)

    2010-07-01

    ... officer may deem necessary to an understanding and determination of the dispute. The hearing officer shall... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Hearing procedures. 791.30 Section 791... (CONTINUED) DATA REIMBURSEMENT Hearing Procedures § 791.30 Hearing procedures. (a) Representation by counsel...

  16. 21 CFR 60.44 - Hearing procedures.

    Science.gov (United States)

    2010-04-01

    ... RESTORATION Due Diligence Hearings § 60.44 Hearing procedures. The due diligence hearing shall be conducted in accordance with this part, supplemented by the nonconflicting procedures in part 16. During the due diligence... requesting a hearing under part 16. The standard of due diligence set forth in § 60.36 will apply in the due...

  17. 45 CFR 33.6 - Hearings.

    Science.gov (United States)

    2010-10-01

    ... adjudication and need not take the form of an evidentiary hearing, i.e., the rules of evidence need not apply... information developed at the hearing, as soon as practicable after the hearing, but not later than sixty (60) days after the date on which the hearing petition was received by the creditor agency, unless the...

  18. 45 CFR 1179.5 - Hearing.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Hearing. 1179.5 Section 1179.5 Public Welfare... ENDOWMENT FOR THE HUMANITIES SALARY OFFSET § 1179.5 Hearing. (a) Request for hearing. (1) An employee must file a petition for a hearing in accordance with the instructions outlined in the agency's notice to...

  19. 78 FR 56951 - Notice of Hearing

    Science.gov (United States)

    2013-09-16

    ... No. 6] Notice of Hearing ACTION: Notice of a hearing. SUMMARY: The Privacy and Civil Liberties Oversight Board (PCLOB) will conduct a public hearing with current and former government officials and... federal government regarding the government's counterterrorism surveillance programs. This hearing will...

  20. 45 CFR 1606.8 - Hearing.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Hearing. 1606.8 Section 1606.8 Public Welfare... PROCEDURES; RECOMPETITION § 1606.8 Hearing. (a) The recipient may make written request for a hearing within... days after receipt of a request for a hearing, the Corporation shall notify the recipient in writing of...

  1. 19 CFR 207.66 - Hearing.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Hearing. 207.66 Section 207.66 Customs Duties... EXPORTS TO THE UNITED STATES Five-Year Reviews § 207.66 Hearing. (a) In general. The Commission shall hold a hearing in each full review. The date of the hearing shall be specified in the scheduling notice...

  2. 29 CFR 2200.209 - Hearing.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Hearing. 2200.209 Section 2200.209 Labor Regulations... Simplified Proceedings § 2200.209 Hearing. (a) Procedures. As soon as practicable after the conclusion of the pre-hearing conference, the Judge will hold a hearing on any issue that remains in dispute. The...

  3. 10 CFR 2.1405 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Hearing. 2.1405 Section 2.1405 Energy NUCLEAR REGULATORY... with Oral Hearings § 2.1405 Hearing. (a) No later than twenty (20) days after the conclusion of the prehearing conference, the presiding officer shall hold a hearing on any contention that remains in dispute...

  4. 5 CFR 831.1106 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Hearing. 831.1106 Section 831.1106...) RETIREMENT Prohibition on Payments of Annuities § 831.1106 Hearing. (a) OPM's hearing examiner shall preside at any hearing held pursuant to this subpart, unless OPM designates another presiding officer. The...

  5. 15 CFR 90.14 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Hearing. 90.14 Section 90.14 Commerce... OF COMMERCE PROCEDURE FOR CHALLENGING CERTAIN POPULATION AND INCOME ESTIMATES § 90.14 Hearing. (a) The hearing shall be conducted by the same hearing officer who collected the documentary evidence, if...

  6. 5 CFR 1639.23 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Hearing. 1639.23 Section 1639.23... Hearing. (a) Request for hearing. Except as provided in paragraph (b) of this section, an employee who desires a hearing concerning the existence or amount of the debt or the proposed offset schedule must send...

  7. 29 CFR 101.34 - Hearing.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 2 2010-07-01 2010-07-01 false Hearing. 101.34 Section 101.34 Labor Regulations Relating... Section 10(k) of the Act § 101.34 Hearing. If the parties have not adjusted the dispute or agreed upon methods of voluntary adjustment, a hearing, usually open to the public, is held before a hearing officer...

  8. 45 CFR 607.5 - Hearing.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Hearing. 607.5 Section 607.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION SALARY OFFSET § 607.5 Hearing. (a) Request for hearing. (1) An employee may file a petition for an oral or paper hearing in...

  9. 7 CFR 900.115 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Hearing. 900.115 Section 900.115 Agriculture... Hearing. (a) The arbitrator shall have full discretion to conduct the hearing in such manner as will, in..., and other experts. (h) When more than two arbitrators are designated to hear a dispute, and they...

  10. 75 FR 67145 - Sunshine Act: Public Hearing

    Science.gov (United States)

    2010-11-01

    ... OVERSEAS PRIVATE INVESTMENT CORPORATION Sunshine Act: Public Hearing TIME AND DATE: 2 p.m... Avenue, NW., Washington, DC. STATUS: Hearing open to the Public at 2 p.m. PURPOSE: Public Hearing in... hearing orally must provide advance notice to OPIC's Corporate Secretary no later than 5 p.m. Thursday...

  11. 47 CFR 1.1928 - Hearing.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Hearing. 1.1928 Section 1.1928... United States Salary Offset-Individual Debt § 1.1928 Hearing. (a) Petition for hearing. (1) An employee may request a hearing by filing a written petition with the Managing Director of the Commission, or...

  12. 12 CFR 308.142 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Hearing. 308.142 Section 308.142 Banks and... Exchange Act of 1934 § 308.142 Hearing. (a) Proceedings are informal. Formal rules of evidence, the... Local Rules shall not apply to hearings under this subpart. (b) Hearing Procedure. (1) Parties to the...

  13. 19 CFR 354.12 - Hearing.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Hearing. 354.12 Section 354.12 Customs Duties... ANTIDUMPING OR COUNTERVAILING DUTY ADMINISTRATIVE PROTECTIVE ORDER § 354.12 Hearing. (a) Scheduling of hearing. The presiding official will schedule the hearing at a reasonable time, date, and place, which will be...

  14. 75 FR 16422 - Notice of Public Hearing

    Science.gov (United States)

    2010-04-01

    ... documents other than rules #0;or proposed rules that are applicable to the public. Notices of hearings #0... Hearing AGENCY: Financial Crisis Inquiry Commission. ACTION: Notice. SUMMARY: The Financial Crisis Inquiry Commission (FCIC) announces that it will hear from public and private sector entities in a hearing titled...

  15. 76 FR 68260 - Notice of Public Hearing

    Science.gov (United States)

    2011-11-03

    ... of Public Hearing The Marquette Rail, LLC (MQT), by a May 23, 2011, document, has petitioned the... Railroad Signalmen; and Railsoft Systems, Inc., FRA has determined that a public hearing is necessary... participate in a public hearing on December 13, 2011. The hearing will be conducted at the Holiday Inn Express...

  16. 29 CFR 4221.6 - Hearing.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Hearing. 4221.6 Section 4221.6 Labor Regulations Relating... PLANS ARBITRATION OF DISPUTES IN MULTIEMPLOYER PLANS § 4221.6 Hearing. (a) Time and place of hearing established. Unless the parties agree to proceed without a hearing as provided in § 4221.5(c), the parties and...

  17. 49 CFR 209.321 - Hearing.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Hearing. 209.321 Section 209.321 Transportation... TRANSPORTATION RAILROAD SAFETY ENFORCEMENT PROCEDURES Disqualification Procedures § 209.321 Hearing. (a) Upon receipt of a hearing request complying with § 209.311, an administrative hearing for review of a notice of...

  18. Fluctuation theorems in feedback-controlled open quantum systems: Quantum coherence and absolute irreversibility

    Science.gov (United States)

    Murashita, Yûto; Gong, Zongping; Ashida, Yuto; Ueda, Masahito

    2017-10-01

    The thermodynamics of quantum coherence has attracted growing attention recently, where the thermodynamic advantage of quantum superposition is characterized in terms of quantum thermodynamics. We investigate the thermodynamic effects of quantum coherent driving in the context of the fluctuation theorem. We adopt a quantum-trajectory approach to investigate open quantum systems under feedback control. In these systems, the measurement backaction in the forward process plays a key role, and therefore the corresponding time-reversed quantum measurement and postselection must be considered in the backward process, in sharp contrast to the classical case. The state reduction associated with quantum measurement, in general, creates a zero-probability region in the space of quantum trajectories of the forward process, which causes singularly strong irreversibility with divergent entropy production (i.e., absolute irreversibility) and hence makes the ordinary fluctuation theorem break down. In the classical case, the error-free measurement ordinarily leads to absolute irreversibility, because the measurement restricts classical paths to the region compatible with the measurement outcome. In contrast, in open quantum systems, absolute irreversibility is suppressed even in the presence of the projective measurement due to those quantum rare events that go through the classically forbidden region with the aid of quantum coherent driving. This suppression of absolute irreversibility exemplifies the thermodynamic advantage of quantum coherent driving. Absolute irreversibility is shown to emerge in the absence of coherent driving after the measurement, especially in systems under time-delayed feedback control. We show that absolute irreversibility is mitigated by increasing the duration of quantum coherent driving or decreasing the delay time of feedback control.

  19. Irreversible denaturation of maltodextrin glucosidase studied by differential scanning calorimetry, circular dichroism, and turbidity measurements.

    Science.gov (United States)

    Goyal, Megha; Chaudhuri, Tapan K; Kuwajima, Kunihiro

    2014-01-01

    Thermal denaturation of Escherichia coli maltodextrin glucosidase was studied by differential scanning calorimetry, circular dichroism (230 nm), and UV-absorption measurements (340 nm), which were respectively used to monitor heat absorption, conformational unfolding, and the production of solution turbidity. The denaturation was irreversible, and the thermal transition recorded at scan rates of 0.5-1.5 K/min was significantly scan-rate dependent, indicating that the thermal denaturation was kinetically controlled. The absence of a protein-concentration effect on the thermal transition indicated that the denaturation was rate-limited by a mono-molecular process. From the analysis of the calorimetric thermograms, a one-step irreversible model well represented the thermal denaturation of the protein. The calorimetrically observed thermal transitions showed excellent coincidence with the turbidity transitions monitored by UV-absorption as well as with the unfolding transitions monitored by circular dichroism. The thermal denaturation of the protein was thus rate-limited by conformational unfolding, which was followed by a rapid irreversible formation of aggregates that produced the solution turbidity. It is thus important to note that the absence of the protein-concentration effect on the irreversible thermal denaturation does not necessarily means the absence of protein aggregation itself. The turbidity measurements together with differential scanning calorimetry in the irreversible thermal denaturation of the protein provided a very effective approach for understanding the mechanisms of the irreversible denaturation. The Arrhenius-equation parameters obtained from analysis of the thermal denaturation were compared with those of other proteins that have been reported to show the one-step irreversible thermal denaturation. Maltodextrin glucosidase had sufficiently high kinetic stability with a half-life of 68 days at a physiological temperature (37°C).

  20. The use of TiO2 nanoparticles to reduce refrigerator ir-reversibility

    International Nuclear Information System (INIS)

    Padmanabhan, Venkataramana Murthy V.; Palanisamy, Senthilkumar

    2012-01-01

    Highlights: ► COP of hydrocarbons mixture VCRSs increases less when compared to R134a. ► Compressor ir-reversibility of VCRSs decreases by 33% (R134a), 14% (R436A and R436B). ► Total ir-reversibility of selected VCRSs decreases. ► Exergy efficiency of R134a is exceptionally low at lower reference temperature. ► Exergy efficiency of selected VCRSs increases. - Abstract: The ir-reversibility at the process of a vapour-compression refrigeration system (VCRS) with nanoparticles in the working fluid was investigated experimentally. Mineral oil (MO) with 0.1 g L −1 TiO 2 nanoparticles mixture were used as the lubricant instead of Polyol-ester (POE) oil in the R134a, R436A (R290/R600a-56/44-wt.%) and R436B (R290/R600a-52/48-wt.%)VCRSs. The VCRS ir-reversibility at the process with the nanoparticles was investigated using second law of thermodynamics. The results indicate that R134a, R436A and R436B and MO with TiO 2 nanoparticles work normally and safely in the VCRS. The VCRSs total ir-reversibility (529, 588 and 570 W) at different process was better than the R134a, R436A and R436B and POE oil system (777, 697 and 683 W). The same tests with Al 2 O 3 nanoparticles showed that the different nanoparticles properties have little effect on the VCRS ir-reversibility. Thus, TiO 2 nanoparticles can be used in VCRS with reciprocating compressor to considerably reduce ir-reversibility at the process.

  1. [Hearing capacity and speech production in 417 children with facial cleft abnormalities].

    Science.gov (United States)

    Schönweiler, R; Schönweiler, B; Schmelzeisen, R

    1994-11-01

    Children with cleft palates often suffer from chronic conductive hearing losses, delayed language acquisition and speech disorders. This study presents results of speech and language outcomes in relation to hearing function and types of palatal malformations found. 417 children with cleft palates were examined during followup evaluations that extended over several years. Disorders were studied as they affected the ears, nose and throat, audiometry and speech and language pathology. Children with isolated cleft lips were excluded. Among the total group, 8% had normal speech and language development while 92% had speech or language disorders. 80% of these latter children had hearing problems that predominantly consisted of fluctuating conductive hearing losses caused by otitis media with effusion. 5% had sensorineural hearing losses. Fifty-eight children (14%) with rhinolalia aperta were not improved by speech therapy and required velopharyngoplasties, using a cranial-based pharyngeal flap. Language skills did not depend on the type of cleft palate presents but on the frequency and amount of hearing loss found. Otomicroscopy and audiometric follow-ups with insertions of ventilation tubes were considered to be most important for language development in those children with repeated middle ear infections. Speech or language therapy was necessary in 49% of the children.

  2. Neonatal Hearing screening in tafila

    International Nuclear Information System (INIS)

    Rashed, K.A.

    2007-01-01

    To measure the true prevalence of hearing impairment in neonates in Tafila, Jordan. This retrospective study was carried out at Prince Zeid Hospital, Taflia, Jordan through analysis of data of all births from January 2005 and January 2006. Transient evoked otoacoustic emissions (TEOAE) were measured via the application of echoprobe to both ears. There were two groups of births that were analysed statistically. Hearing impaired neonates were those with two fails or more in each ear. Normal ones were those with 3 pass or more. Of the 1788 babies in the study group, 1622 (90.7%) were enrolled in the study with 9.3% loss rate. 1512 babies were examined on the 2 day of birth, 2 of them had hearing impairment with a rate of 1.2/1000. 110 babies were screened on the day of discharge from the nursery, one of them with hearing defect with a rate of 5.9/1000. Thus, true prevalence of hearing impaiment or failure was 1.7/1000. We conclude that screening for hearing impairment in the neonatal period is easy, informative and the true prevalence of hearing impairment in Tafila is similar to that in different parts of the world. (author)

  3. Pairing transition, coherence transition, and the irreversibility line in granular GdBa2Cu3O7-δ

    Science.gov (United States)

    Roa-Rojas, J.; Menegotto Costa, R.; Pureur, P.; Prieto, P.

    2000-05-01

    We report on electrical magnetoconductivity experiments near the superconducting transition of a granular sample of GdBa2Cu3O7-δ. The measurements were performed in magnetic fields ranging from 0 to 500 Oe applied parallel to the current orientation. The results show that the transition proceeds in two steps. When the temperature is decreased we first observe the pairing transition, which stabilizes superconductivity within the grains at a temperature practically coincident with the bulk critical temperature Tc. Analysis of the fluctuation contributions to the conductivity shows that the universality class for this transition is that of the three dimensional (3D)-XY model in the ordered case, with dynamic critical exponent z=3/2. Close to the zero-resistance state, the measurements reveal the occurrence of a coherence transition, where the phases of the order parameter in individual grains become long-range ordered. The critical temperature Tco for this transition is close to the point where the resistivity vanishes. A strong enlargement of the fluctuation interval preceding the coherence transition is caused by the applied magnetic field. In this region, a 3D-Gaussian regime and an asymptotic critical regime were clearly identified. The critical conductivity behavior for the coherence transition is interpreted within a 3D-XY model where disorder and frustration are relevant. The irreversibility line is determined from magnetoconductivity measurements performed according to the zero-field-cooled (ZFC) and field-cooled data collected on cooling (FCC) recipes. The locus of this line coincides with the upper temperature limit for the fluctuation region above the coherence transition. The irreversibility line is interpreted as an effect of the formation of small clusters with closed loops of Josephson-coupled grains.

  4. [Evolution of speech and hearing].

    Science.gov (United States)

    Pitkäranta, Anne

    2009-01-01

    Actual spoken language of man developed only approximately 200,000 to 100,000 years ago. As a result of natural selection, man has developed hearing, which is most sensitive in the frequency regions of 200 to 4000 Hz, corresponding to those of spoken sounds. Functional hearing has been one of the prerequisites for the development of speech, although according to current opinion the language itself may have evolved by mimicking gestures with the so-called mirror neurons. Due to hearing, gesticulation was no longer necessary, and the hands became available for other purposes.

  5. Health Technology Assessment of CEM Pulpotomy in Permanent Molars with Irreversible Pulpitis

    Science.gov (United States)

    Yazdani, Shahram; Jadidfard, Mohammad-Pooyan; Tahani, Bahareh; Kazemian, Ali; Dianat, Omid; Alim Marvasti, Laleh

    2014-01-01

    Introduction: Teeth with irreversible pulpitis usually undergo root canal therapy (RCT). This treatment modality is often considered disadvantageous as it removes vital pulp tissue and weakens the tooth structure. A relatively new concept has risen which suggests vital pulp therapy (VPT) for irreversible pulpitis. VPT with calcium enriched mixture (VPT/CEM) has demonstrated favorable treatment outcomes when treating permanent molars with irreversible pulpitis. This study aims to compare patient related factors, safety and organizational consideration as parts of health technology assessment (HTA) of the new VPT/CEM biotechnology when compared with RCT. Materials and Methods: Patient related factors were assessed by looking at short- and long-term clinical success; safety related factors were evaluated by a specialist committee and discussion board involved in formulating healthcare policies. Organizational evaluation was performed and the social implications were assessed by estimating the costs, availability, accessibility and acceptability. The impact of VPT/CEM biotechnology was assessed by investigating the incidence of irreversible pulpitis and the effect of this treatment on reducing the burden of disease. Results: VPT/CEM biotechnology was deemed feasible and acceptable like RCT; however, it was more successful, accessible, affordable, available and also safer than RCT. Conclusion: When considering socioeconomic implications on oral health status and oral health-related quality of life of VPT/CEM, the novel biotechnology can be more effective and more efficient than RCT in mature permanent molars with irreversible pulpitis. PMID:24396372

  6. Substance P and CGRP expression in dental pulps with irreversible pulpitis.

    Science.gov (United States)

    Sattari, Mandana; Mozayeni, Mohammad Ali; Matloob, Arash; Mozayeni, Maryam; Javaheri, Homan H

    2010-08-01

    The purpose of this study was to compare substance P (SP) and calcitonin gene-related peptide (CGRP) expression in pulp tissue with clinically diagnosed symptomatic and asymptomatic irreversible pulpitis. Healthy pulps acted as controls. Five normal pulps and 40 with irreversible pulpitis (20 symptomatic and 20 asymptomatic) were obtained from 45 different patients. SP and CGRP expression was determined by competition binding assays using enzyme immunoassay. anova and Mann-Whitney tests were used to ascertain if there were statistically significant differences between the groups. The results showed that neuropeptides were found in all pulp samples. The highest and the lowest expressions for SP and CGRP were found in symptomatic irreversible pulpitis and healthy pulps groups, respectively. The differences between healthy pulps and the groups of pulps having irreversible pulpitis were significant (P pulpitis groups (P pulpitis groups were not significant. This study demonstrated that the expression of CGRP and SP is significantly higher in pulps with irreversible pulpitis compared with healthy pulps.

  7. Irreversible JPEG 2000 compression of abdominal CT for primary interpretation: assessment of visually lossless threshold

    International Nuclear Information System (INIS)

    Lee, Kyoung Ho; Kim, Young Hoon; Kim, Bo Hyoung; Kim, Kil Joong; Kim, Tae Jung; Kim, Hyuk Jung; Hahn, Seokyung

    2007-01-01

    To estimate the visually lossless threshold for Joint Photographic Experts Group (JPEG) 2000 compression of contrast-enhanced abdominal computed tomography (CT) images, 100 images were compressed to four different levels: a reversible (as negative control) and irreversible 5:1, 10:1, and 15:1. By alternately displaying the original and the compressed image on the same monitor, six radiologists independently determined if the compressed image was distinguishable from the original image. For each reader, we compared the proportion of the compressed images being rated distinguishable from the original images between the reversible compression and each of the three irreversible compressions using the exact test for paired proportions. For each reader, the proportion was not significantly different between the reversible (0-1%, 0/100 to 1/100) and irreversible 5:1 compression (0-3%). However, the proportion significantly increased with the irreversible 10:1 (95-99%) and 15:1 compressions (100%) versus reversible compression in all readers (P < 0.001); 100 and 95% of the 5:1 compressed images were rated indistinguishable from the original images by at least five of the six readers and all readers, respectively. Irreversibly 5:1 compressed abdominal CT images are visually lossless and, therefore, potentially acceptable for primary interpretation. (orig.)

  8. Living with hearing loss

    Science.gov (United States)

    ... background sounds, such as heat and air conditioning, traffic noises, or the radio or TV. In order ... voice, speech, or language disorders. Nidcd.nih.gov website. www.nidcd.nih.gov/health/assistive-devices-people- ...

  9. 10 CFR 710.25 - Appointment of Hearing Officer; prehearing conference; commencement of hearings.

    Science.gov (United States)

    2010-01-01

    ... papers, issuing subpoenas for witnesses to attend the hearing or for the production of specific documents... extension of the hearing date past 90 calendar days from the date the request for hearing is received by the...

  10. An Investigation of the Effect of Graphite Degradation on the Irreversible Capacity in Lithium-ion Cells

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, Cynthia; Hardwick, Laurence J.; Marcinek, Marek; Beer, Leanne; Kerr, John B.; Kostecki, Robert

    2008-03-03

    The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) measurements confirmed that Ar-ion sputtered Mag-10 electrodes display similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle, compared to fresh un-altered anodes. Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy on surface modified graphite anodes indicated the formation of a thicker and slightly more resistive SEI layer. Gas chromatography/mass spectroscopy (GC/MS) analysis of solvent extracts from the electrodes detected the presence of new compounds with M{sub w} on the order of 1600 g mol{sup -1} for the surface modified electrode with no evidence of elevated M{sub w} species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling maybe responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells.

  11. Feasibility and acceptability of training community health workers in ear and hearing care in Malawi: a cluster randomised controlled trial.

    Science.gov (United States)

    Mulwafu, Wakisa; Kuper, Hannah; Viste, Asgaut; Goplen, Frederik K

    2017-10-11

    To assess the feasibility and acceptability of training community health workers (CHWs) in ear and hearing care, and their ability to identify patients with ear and hearing disorders. Cluster randomised controlled trial (RCT). Health centres in Thyolo district, Malawi. Ten health centres participated, 5 intervention (29 CHWs) and 5 control (28 CHWs). Intervention CHWs received 3 days of training in primary ear and hearing care, while among control CHWs, training was delayed for 6 months. Both groups were given a pretest that assessed knowledge about ear and hearing care, only the intervention group was given the posttest on the third day of training. The intervention group was given 1 month to identify patients with ear and hearing disorders in their communities, and these people were screened for hearing disorders by ear, nose and throat clinical specialists. Primary outcome measure was improvement in knowledge of ear and hearing care among CHWs after the training. Secondary outcome measures were number of patients with ear or hearing disorders identified by CHWs and number recorded at health centres during routine activities, and the perceived feasibility and acceptability of the intervention. The average overall correct answers increased from 55% to 68% (95% CI 65 to 71) in the intervention group (phearing disorders were identified by CHWs and 860 patients attended the screening camps, of whom 400 had hearing loss (73 patients determined through bilateral fail on otoacoustic emissions, 327 patients through audiometry). Where cause could be determined, the most common cause of ear and hearing disorders was chronic suppurative otitis media followed by impacted wax. The intervention was perceived as feasible and acceptable to implement. Training was effective in improving the knowledge of CHW in ear and hearing care in Malawi and allowing them to identify patients with ear and hearing disorders. This intervention could be scaled up to other CHWs in low-income and

  12. Noise pollution effect in flour factory on workers' hearing in Lamerd City.

    Science.gov (United States)

    Mohammadizadeh, M; Ahmadi, S H; Sekhavati, E; Ahani-Jegar, K

    2015-01-01

    Introduction: Noise pollution is one of the most important problems in industry that has an effect on the auditory system and other physiological parameters, as well as persons in noise exposure situations. While noise-induced hearing loss is preventable, once acquired, hearing loss is permanent and irreversible. Methodology: In the current study, noise in various sections of Flour Company in Lamerd estimated via the audio recorder, which revealed that the operators' expression remained larger than the state criterion; hence, the perception experiment (audio recorder) was performed on the operators and its outcomes were examined via utilizing SPSS 16 of version. Findings: Overall, Pearson relationship r = 0.453 discovered among job reports and the performance decline between all operators by significant stage p≤0.05. Moreover, T-test applied to examine noise impact on operators included in boisterous rooms (mean more than 85 dB) also average=26. 71 and regular deviation=11.72 got (p≤0.05) that was greater than 25db (as the standard hearing threshold). Conclusion: The outcomes of audio measuring and T-test revealed that the noise corruption has an impact on the hearing of bodies operating in noisy rooms.

  13. Hearing Screening and Diagnostic Evaluation of Children With Unilateral and Mild Bilateral Hearing Loss

    OpenAIRE

    Ross, Danielle S.; Holstrum, W. June; Gaffney, Marcus; Green, Denise; Oyler, Robert F.; Gravel, Judith S.

    2008-01-01

    More than 90% of newborns in the United States are now being screened for hearing loss. A large fraction of cases of unilateral hearing loss and mild bilateral hearing loss are not currently identified through newborn hearing screening. This is of concern because a preponderance of research has demonstrated that unilateral hearing loss and mild bilateral hearing loss can lead to developmental delays and educational problems for some children. To help address this probable underidentification ...

  14. Psychopathology among a sample of hearing impaired adolescents.

    Science.gov (United States)

    Mosaku, Kolawole; Akinpelu, Victoria; Ogunniyi, Grace

    2015-12-01

    Hearing impairment is a recognized cause of emotional and psychological disturbances worldwide, however little is known about this condition in Nigeria. The aim of this study is to compare the prevalence of psychopathology between hearing impaired adolescents and healthy adolescents. Students attending two special schools for the hearing impaired were assessed for psychopathology with the help of a trained signer and their teacher, using the International Classification of Diseases Diagnostic Criteria (ICD 10). Fifty two hearing impaired students and 52 age and sex matched controls from the same school were also interviewed using the same instrument. The mean age of the hearing impaired students was 16 (sd=3.8), while for the controls the mean age was 16 (sd=2.5). Psychopathology was present in 10 (19%) of the hearing impaired adolescents compared to 2 (4%) among the control group, this difference was statistically significant (χ(2)=4.62 p=0.03). The most common diagnosis was generalized anxiety disorder 4 (8%), followed by depression 2 (4%). Years spent in school (t=4.81, p=0.001), primary guardian (χ(2)=18.3, p=0.001) and mean income of guardian (t=7.10, p=0.001) were all significantly different between the two groups. Psychopathology is relatively common in this population. Proper assessment and treatment should be made available for this population group. A limitation to this study is communication difficulty which made only a third party assessment possible; this may affect the generalizability of the findings. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Apparent third patient with cutaneous mastocytosis, microcephaly, conductive hearing loss, and microtia.

    Science.gov (United States)

    Salpietro, Carmelo Damiano; Briuglia, Silvana; Cutrupi, Maria Concetta; Gallizzi, Romina; Rigoli, Luciana; Dallapiccola, Bruno

    2009-10-01

    Mastocytosis refers to a heterogeneous group of rare disorders characterized by an abnormal accumulation of mast cells in one or more organ systems. Cutaneous mastocytosis (CM) is the most frequent form in children and is characterized by hyperpigmented macules or papules symmetrically distributed over the trunk, and less so over the limbs, neck, and scalp. Two published articles have reported on unrelated girls presenting with mastocytosis, microcephaly, hearing loss, and hypotonia. Based on the original observation, this disorder was defined as CM with short stature, conductive hearing loss, and microtia (OMIM 248910). Here we report on a girl with similar manifestations who corroborates the existence of this rare disorder. CM, microcephaly, microtia, and/or hearing loss are the minimal diagnostic criteria. All the known patients were sporadic, but parental consanguinity in the first case argues for a possible autosomal-recessive inheritance.

  16. Eldercare at Home: Hearing Problems

    Science.gov (United States)

    ... harder to hear what is being said. Talk face-to-face. The older person needs to see your face ... members and friends to comment on how much communication has improved when your mother is wearing the ...

  17. Hearing Aid with Visual Indicator

    DEFF Research Database (Denmark)

    2004-01-01

    The invention comprises a hearing aid, which has a casing containing a signal receiving part for receiving an audio signal, an audio transducer for providing an audio signal to the user, a signal transmission path between the signal receiving part and the audio transducer, whereby a battery...... is provided for powering the signal receiving part, the signal path and the audio transducer, and where further means are provided for assessing the function of the hearing aid and for generating an electrical indication signal which indicates the function of the hearing aid and where further means...... are provided for intermittently generating a power signal in response to the electrical indication signal and where means are provided for converting the power signal into a light signal, such that the light signal is visible from outside the hearing aid....

  18. Exploring reasons for late identification of children with early-onset hearing loss.

    Science.gov (United States)

    Fitzpatrick, Elizabeth M; Dos Santos, Johnny Cesconetto; Grandpierre, Viviane; Whittingham, JoAnne

    2017-09-01

    Several studies have shown that early identification of childhood hearing loss leads to better language outcomes. However, delays in the confirmation of hearing loss persist even in the presence of well-established universal newborn hearing screening programs (UNHS). The objective of this population-based study was to document the proportion of children who experienced delayed confirmation of congenital and early onset hearing loss in a UNHS program in one region of Canada. The study also sought to determine the reasons for delayed confirmation of hearing loss in children. Population level data related to age of first assessment, age of identification and clinical characteristics were collected prospectively for all children identified through the UNHS program. We documented the number of children who experienced delay (defined as more than 3 months) from initial audiologic assessment to confirmation of hearing loss. A detailed chart review was subsequently performed to examine the reasons for delay to confirmation. Of 418 children identified from 2003 to 2013, 182 (43.5%) presented with congenital or early onset hearing loss, of whom 30 (16.5%) experienced more than 3 months delay from initial audiologic assessment to confirmation of their hearing disorder. The median age of first assessment and confirmation of hearing loss for these 30 children was 3.7 months (IQR: 2.0, 7.6) and 13.8 months (IQR: 9.7, 26.1) respectively. Close examination of the factors related to delay to confirmation revealed that for the overwhelming majority of children, a constellation of factors contributed to late diagnosis. Several children (n = 22; 73.3%) presented with developmental/medical issues, 15 of whom also had middle ear dysfunction at assessment, and 9 of whom had documented family follow-up concerns. For the remaining eight children, additional reasons included ongoing middle ear dysfunction for five children, complicated by family follow-up concerns (n = 3) and mild

  19. Interaction of smoking and occupational noise exposure on hearing loss: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Mohammadi Saber

    2007-07-01

    Full Text Available Abstract Background Noise is the most common hazardous agent at workplaces. Noise induced hearing loss (NIHL has been known since the industrial revolution. Although NIHL is permanent, irreversible and frequent, it is preventable. The economic costs of NIHL have been estimated to be about billions of dollars. Besides, cigarette smoking is a common habit worldwide, and according to some recent studies smoking and noise may act in common causal pathways for hearing loss. Methods A cross-sectional study was designed to study the effect of smoking on NIHL in 206 male smoker workers and 206 male non-smoker workers in a large food-producing factory, in which workers were exposed to noise levels exceeding 85dBA. To determine noise exposure level, we used sound level measurements reported by industrial hygienists. A qualified audiologist assessed hearing acuity by using standardized audiometric procedures assuring at least 14 h of noise avoidance. Results We observed that the percentage of workers with hearing threshold differences of greater than or equal to 30 dB between 4000 Hz and 1000 Hz in both ears were 49.5% and 11.2% in smoker and non smoker groups, respectively (Odds ratio = 7.8, 95% CI = 4.7 – 13, and the percentage of workers with a hearing threshold of greater than 25dB at 4000 Hz in the better ear were 63.6% and 18.4% in smoker and non smoker groups, respectively. This difference was statistically significant after adjustment for age and exposure duration. Conclusion It can be concluded that smoking can accelerate noise induced hearing loss, but more research is needed to understand the underlying mechanisms. Accurate follow up of smoker workers who are exposed to noise levels exceeding 85 dBA is suggested. Smokers should periodically attend educational courses on "smoking cessation", especially in noisy workplaces.

  20. Interaction of smoking and occupational noise exposure on hearing loss: a cross-sectional study.

    Science.gov (United States)

    Pouryaghoub, Gholamreza; Mehrdad, Ramin; Mohammadi, Saber

    2007-07-03

    Noise is the most common hazardous agent at workplaces. Noise induced hearing loss (NIHL) has been known since the industrial revolution. Although NIHL is permanent, irreversible and frequent, it is preventable. The economic costs of NIHL have been estimated to be about billions of dollars. Besides, cigarette smoking is a common habit worldwide, and according to some recent studies smoking and noise may act in common causal pathways for hearing loss. A cross-sectional study was designed to study the effect of smoking on NIHL in 206 male smoker workers and 206 male non-smoker workers in a large food-producing factory, in which workers were exposed to noise levels exceeding 85 dBA. To determine noise exposure level, we used sound level measurements reported by industrial hygienists.A qualified audiologist assessed hearing acuity by using standardized audiometric procedures assuring at least 14 h of noise avoidance. We observed that the percentage of workers with hearing threshold differences of greater than or equal to 30 dB between 4000 Hz and 1000 Hz in both ears were 49.5% and 11.2% in smoker and non smoker groups, respectively (Odds ratio = 7.8, 95% CI = 4.7-13), and the percentage of workers with a hearing threshold of greater than 25 dB at 4000 Hz in the better ear were 63.6% and 18.4% in smoker and non smoker groups, respectively. This difference was statistically significant after adjustment for age and exposure duration. It can be concluded that smoking can accelerate noise induced hearing loss, but more research is needed to understand the underlying mechanisms. Accurate follow up of smoker workers who are exposed to noise levels exceeding 85 dBA is suggested. Smokers should periodically attend educational courses on "smoking cessation", especially in noisy workplaces.

  1. Peptide Drug Release Behavior from Biodegradable Temperature-Responsive Injectable Hydrogels Exhibiting Irreversible Gelation

    Directory of Open Access Journals (Sweden)

    Kazuyuki Takata

    2017-10-01

    Full Text Available We investigated the release behavior of glucagon-like peptide-1 (GLP-1 from a biodegradable injectable polymer (IP hydrogel. This hydrogel shows temperature-responsive irreversible gelation due to the covalent bond formation through a thiol-ene reaction. In vitro sustained release of GLP-1 from an irreversible IP formulation (F(P1/D+PA40 was observed compared with a reversible (physical gelation IP formulation (F(P1. Moreover, pharmaceutically active levels of GLP-1 were maintained in blood after subcutaneous injection of the irreversible IP formulation into rats. This system should be useful for the minimally invasive sustained drug release of peptide drugs and other water-soluble bioactive reagents.

  2. FINITE TIME THERMODYNAMIC MODELING AND ANALYSIS FOR AN IRREVERSIBLE ATKINSON CYCLE

    Directory of Open Access Journals (Sweden)

    Yanlin Ge

    2010-01-01

    Full Text Available Performance of an air-standard Atkinson cycle is analyzed by using finite-time thermodynamics. The irreversible cycle model which is more close to practice is founded. In this model, the non-linear relation between the specific heats of working fluid and its temperature, the friction loss computed according to the mean velocity of the piston, the internal irreversibility described by using the compression and expansion efficiencies, and heat transfer loss are considered. The relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, as well as the optimal relation between power output and the efficiency of the cycle are derived by detailed numerical examples. Moreover, the effects of internal irreversibility, heat transfer loss and friction loss on the cycle performance are analyzed. The results obtained in this paper may provide guidelines for the design of practical internal combustion engines.

  3. Protect Your Hearing at Work

    Centers for Disease Control (CDC) Podcasts

    2015-11-09

    Noise-induced hearing loss is one of the most common work-related illnesses. This podcast features information from CDC’s National Institute for Occupational Safety and Health on how to protect yourself from work-related noise-induced hearing loss.  Created: 11/9/2015 by National Institute for Occupational Safety and Health (NIOSH).   Date Released: 11/9/2015.

  4. How well can centenarians hear?

    Directory of Open Access Journals (Sweden)

    Zhongping Mao

    Full Text Available With advancements in modern medicine and significant improvements in life conditions in the past four decades, the elderly population is rapidly expanding. There is a growing number of those aged 100 years and older. While many changes in the human body occur with physiological aging, as many as 35% to 50% of the population aged 65 to 75 years have presbycusis. Presbycusis is a progressive sensorineural hearing loss that occurs as people get older. There are many studies of the prevalence of age-related hearing loss in the United States, Europe, and Asia. However, no audiological assessment of the population aged 100 years and older has been done. Therefore, it is not clear how well centenarians can hear. We measured middle ear impedance, pure-tone behavioral thresholds, and distortion-product otoacoustic emission from 74 centenarians living in the city of Shaoxing, China, to evaluate their middle and inner ear functions. We show that most centenarian listeners had an "As" type tympanogram, suggesting reduced static compliance of the tympanic membrane. Hearing threshold tests using pure-tone audiometry show that all centenarian subjects had varying degrees of hearing loss. More than 90% suffered from moderate to severe (41 to 80 dB hearing loss below 2,000 Hz, and profound (>81 dB hearing loss at 4,000 and 8,000 Hz. Otoacoustic emission, which is generated by the active process of cochlear outer hair cells, was undetectable in the majority of listeners. Our study shows the extent and severity of hearing loss in the centenarian population and represents the first audiological assessment of their middle and inner ear functions.

  5. How Well Can Centenarians Hear?

    Science.gov (United States)

    Mao, Zhongping; Zhao, Lijun; Pu, Lichun; Wang, Mingxiao; Zhang, Qian; He, David Z. Z.

    2013-01-01

    With advancements in modern medicine and significant improvements in life conditions in the past four decades, the elderly population is rapidly expanding. There is a growing number of those aged 100 years and older. While many changes in the human body occur with physiological aging, as many as 35% to 50% of the population aged 65 to 75 years have presbycusis. Presbycusis is a progressive sensorineural hearing loss that occurs as people get older. There are many studies of the prevalence of age-related hearing loss in the United States, Europe, and Asia. However, no audiological assessment of the population aged 100 years and older has been done. Therefore, it is not clear how well centenarians can hear. We measured middle ear impedance, pure-tone behavioral thresholds, and distortion-product otoacoustic emission from 74 centenarians living in the city of Shaoxing, China, to evaluate their middle and inner ear functions. We show that most centenarian listeners had an “As” type tympanogram, suggesting reduced static compliance of the tympanic membrane. Hearing threshold tests using pure-tone audiometry show that all centenarian subjects had varying degrees of hearing loss. More than 90% suffered from moderate to severe (41 to 80 dB) hearing loss below 2,000 Hz, and profound (>81 dB) hearing loss at 4,000 and 8,000 Hz. Otoacoustic emission, which is generated by the active process of cochlear outer hair cells, was undetectable in the majority of listeners. Our study shows the extent and severity of hearing loss in the centenarian population and represents the first audiological assessment of their middle and inner ear functions. PMID:23755251

  6. Occupational hearing loss in farmers.

    OpenAIRE

    Plakke, B L; Dare, E

    1992-01-01

    Studies have shown that there is a great deal of high-frequency sensorineural hearing loss among farmers. The studies have failed, however, to differentiate farmers who have occupational noise exposure only from other potential hearing loss etiologies. This study, through extensive case history information, has isolated a farm noise-exposure group and matched its members by age with persons with no significant noise exposure. Results indicate that farmers exposed only to noise from farming ha...

  7. Detailed Modeling and Irreversible Transfer Process Analysis of a Multi-Element Thermoelectric Generator System

    Science.gov (United States)

    Xiao, Heng; Gou, Xiaolong; Yang, Suwen

    2011-05-01

    Thermoelectric (TE) power generation technology, due to its several advantages, is becoming a noteworthy research direction. Many researchers conduct their performance analysis and optimization of TE devices and related applications based on the generalized thermoelectric energy balance equations. These generalized TE equations involve the internal irreversibility of Joule heating inside the thermoelectric device and heat leakage through the thermoelectric couple leg. However, it is assumed that the thermoelectric generator (TEG) is thermally isolated from the surroundings except for the heat flows at the cold and hot junctions. Since the thermoelectric generator is a multi-element device in practice, being composed of many fundamental TE couple legs, the effect of heat transfer between the TE couple leg and the ambient environment is not negligible. In this paper, based on basic theories of thermoelectric power generation and thermal science, detailed modeling of a thermoelectric generator taking account of the phenomenon of energy loss from the TE couple leg is reported. The revised generalized thermoelectric energy balance equations considering the effect of heat transfer between the TE couple leg and the ambient environment have been derived. Furthermore, characteristics of a multi-element thermoelectric generator with irreversibility have been investigated on the basis of the new derived TE equations. In the present investigation, second-law-based thermodynamic analysis (exergy analysis) has been applied to the irreversible heat transfer process in particular. It is found that the existence of the irreversible heat convection process causes a large loss of heat exergy in the TEG system, and using thermoelectric generators for low-grade waste heat recovery has promising potential. The results of irreversibility analysis, especially irreversible effects on generator system performance, based on the system model established in detail have guiding significance for

  8. Inequalities for trace anomalies, length of the RG flow, distance between the fixed points and irreversibility

    International Nuclear Information System (INIS)

    Anselmi, Damiano

    2004-01-01

    I discuss several issues about the irreversibility of the RG flow and the trace anomalies c, a and a'. First I argue that in quantum field theory: (i) the scheme-invariant area Δ a' of the graph of the effective beta function between the fixed points defines the length of the RG flow; (ii) the minimum of Δ a' in the space of flows connecting the same UV and IR fixed points defines the (oriented) distance between the fixed points and (iii) in even dimensions, the distance between the fixed points is equal to Δ a = a UV - a IR . In even dimensions, these statements imply the inequalities 0 ≤ Δ a ≤ Δ a' and therefore the irreversibility of the RG flow. Another consequence is the inequality a ≤ c for free scalars and fermions (but not vectors), which can be checked explicitly. Secondly, I elaborate a more general axiomatic set-up where irreversibility is defined as the statement that there exist no pairs of non-trivial flows connecting interchanged UV and IR fixed points. The axioms, based on the notions of length of the flow, oriented distance between the fixed points and certain 'oriented-triangle inequalities', imply the irreversibility of the RG flow without a global a function. I conjecture that the RG flow is also irreversible in odd dimensions (without a global a function). In support of this, I check the axioms of irreversibility in a class of d = 3 theories where the RG flow is integrable at each order of the large N expansion

  9. Effect of disinfection on irreversible hydrocolloid and alternative impression materials and the resultant gypsum casts.

    Science.gov (United States)

    Suprono, Montry S; Kattadiyil, Mathew T; Goodacre, Charles J; Winer, Myron S

    2012-10-01

    Many new products have been introduced and marketed as alternatives to traditional irreversible hydrocolloid materials. These alternative materials have the same structural formula as addition reaction silicone, also known as vinyl polysiloxane (VPS), impression materials. Currently, there is limited in vitro and in vivo research on these products, including on the effects of chemical disinfectants on the materials. The purpose of this study was to compare the effects of a spray disinfecting technique on a traditional irreversible hydrocolloid and 3 new alternative impression materials in vitro. The tests were performed in accordance with the American National Standards Institute/American Dental Association (ANSI/ADA) Specification Nos. 18 and 19. Under standardized conditions, 100 impressions were made of a ruled test block with an irreversible hydrocolloid and 3 alternative impression materials. Nondisinfected irreversible hydrocolloid was used as the control. The impressions were examined for surface detail reproduction before and after disinfection with a chloramine-T product. Type III and Type V dental stone casts were evaluated for linear dimensional change and gypsum compatibility. Comparisons of linear dimensional change were analyzed with 2-way ANOVA of mean ranks with the Scheffé post hoc comparisons (α=.05). Data for surface detail reproduction were analyzed with the Wilcoxon Signed-Rank procedure and gypsum compatibility with the Kruskal-Wallis Rank procedure (α=.05). The alternative impression materials demonstrated significantly better outcomes with all 3 parameters tested. Disinfection with chloroamine-T did not have any effect on the 3 alternative impression materials. The irreversible hydrocolloid groups produced the most variability in the measurements of linear dimensional change. All of the tested materials were within the ADA's acceptable limit of 1.0% for linear dimensional change, except for the disinfected irreversible hydrocolloid

  10. Canonical formalism, fundamental equation, and generalized thermomechanics for irreversible fluids with heat transfer

    International Nuclear Information System (INIS)

    Sieniutycz, S.; Berry, R.S.

    1993-01-01

    A Lagrangian with dissipative (e.g., Onsager's) potentials is constructed for the field description of irreversible heat-conducting fluids, off local equilibrium. Extremum conditions of action yield Clebsch representations of temperature, chemical potential, velocities, and generalized momenta, including a thermal momentum introduced recently [R. L. Selinger and F. R. S. Whitham, Proc. R. Soc. London, Ser. A 302, 1 (1968); S. Sieniutycz and R. S. Berry, Phys. Rev. A 40, 348 (1989)]. The basic question asked is ''To what extent may irreversibility, represented by a given form of the entropy source, influence the analytical form of the conservation laws for the energy and momentum?'' Noether's energy for a fluid with heat flow is obtained, which leads to a fundamental equation and extended Hamiltonian dynamics obeying the second law of thermodynamics. While in the case of the Onsager potentials this energy coincides numerically with the classical energy E, it contains an extra term (vanishing along the path) still contributing to an irreversible evolution. Components of the energy-momentum tensor preserve all terms regarded standardly as ''irreversible'' (heat, tangential stresses, etc.) generalized to the case when thermodynamics includes the state gradients and the so-called thermal phase, which we introduce here. This variable, the Lagrange multiplier of the entropy generation balance, is crucial for consistent treatment of irreversible processes via an action formalism. We conclude with the hypothesis that embedding the first and second laws in the context of the extremal behavior of action under irreversible conditions may imply accretion of an additional term to the classical energy

  11. Quantum degeneracy effect on performance of irreversible Otto cycle with ideal Bose gas

    International Nuclear Information System (INIS)

    Wu Feng; Chen Lingen; Sun Fengrui; Wu Chih; Guo Fangzhong; Li Qing

    2006-01-01

    An Otto cycle working with an ideal Bose gas is called a Bose Otto cycle. The internal irreversibility of the cycle is included in the factors of internal irreversibility degree. The quantum degeneracy effect on the performance of the cycle is investigated based on quantum statistical mechanics and thermodynamics. Variations of the maximum work output ratio R W and the efficiency ratio y with temperature ratio τ are examined, which reveal the influence of the quantum degeneracy of the working substance on the performance of a Bose Otto cycle. It is shown that the results obtained herein are valid under both classical and quantum ideal gas conditions

  12. The universal power and efficiency characteristics for irreversible reciprocating heat engine cycles

    CERN Document Server

    Qin Xiao Yong; Sun Feng Rui; Wu Chih

    2003-01-01

    The performance of irreversible reciprocating heat engine cycles with heat transfer loss and friction-like term loss is analysed using finite-time thermodynamics. The universal relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, and the optimal relation between power output and the efficiency of the cycles are derived. Moreover, analysis and optimization of the model were carried out in order to investigate the effect of cycle processes on the performance of the cycle using numerical examples. The results obtained herein include the performance characteristics of irreversible reciprocating Diesel, Otto, Atkinson and Brayton cycles.

  13. Performance analysis of irreversible molten carbonate fuel cell – Braysson heat engine with ecological objective approach

    International Nuclear Information System (INIS)

    Açıkkalp, Emin

    2017-01-01

    Highlights: • An irreversible MCFC - Braysson heat engine is considered. • Its performance is investigated with ecological approach. • A new ecological criteria are presented called as modified ecological function. • Result are obtained numerically and discussed. - Abstract: An irreversible hybrid molten carbonate fuel cell-Braysson heat engine is taken into account. Basic thermodynamics parameters including power output, efficiency and exergy destruction rate are considered. In addition ecological function and new criteria, which is based on ecological function, for heat engines called as modified ecological function is suggested. Optimum conditions for mentioned parameters above are determined. Numerical results are obtained and plotted. Finally, results are discussed.

  14. Effects of irreversibility and economics on the performance of a heat engine

    International Nuclear Information System (INIS)

    Ibrahim, O.M.; Klein, S.A.; Mitchell, J.W.

    1992-01-01

    In this paper, optimization of the power output of an internally irreversible heat engine is considered for finite capacitance rates of the external fluid streams. The method of Lagrange multipliers is used to solve for working fluid temperatures which yield maximum power. Analytical expressions for the maximum power and the cycle efficiency at miximum power are obtained. The effects of irreversibility and economics on the performance of a heat engine are investigated. A relationship between the maximum power point and economically optimum design is identified. It is demonstrated that, with certain reasonable economic assumptions, the maximum power point of a heat engine corresponds to a point of minimum life-cycle costs

  15. A general nonlinear evolution equation for irreversible conservative approach to stable equilibrium

    International Nuclear Information System (INIS)

    Beretta, G.P.

    1986-01-01

    This paper addresses a mathematical problem relevant to the question of nonequilibrium and irreversibility, namely, that of ''designing'' a general evolution equation capable of describing irreversible but conservative relaxtion towards equilibrium. The objective is to present an interesting mathematical solution to this design problem, namely, a new nonlinear evolution equation that satisfies a set of very stringent relevant requirements. Three different frameworks are defined from which the new equation could be adopted, with entirely different interpretations. Some useful well-known mathematics involving Gram determinants are presented and a nonlinear evolution equation is given which meets the stringent design specifications

  16. Antibacterial efficacy and effect of chlorhexidine mixed with irreversible hydrocolloid for dental impressions: a randomized controlled trial.

    Science.gov (United States)

    Cubas, Glória; Valentini, Fernanda; Camacho, Guilherme Brião; Leite, Fábio; Cenci, Maximiliano Sérgio; Pereira-Cenci, Tatiana

    2014-01-01

    This study aimed to evaluate whether chlorhexidine mixed with irreversible hydrocolloid powder decreases microbial contamination during impression taking without affecting the resulting casts. Twenty volunteers were randomly divided into two groups (n = 10) according to the liquid used for impression taking in conjunction with irreversible hydrocolloid: 0.12% chlorhexidine or water. Surface roughness and dimensional stability of the casts were evaluated. Chlorhexidine mixed with irreversible hydrocolloid decreased the percentage of microorganisms when compared with water (P impression quality.

  17. Sensorineural and conductive hearing loss in infants diagnosed in the program of universal newborn hearing screening.

    Science.gov (United States)

    Wroblewska-Seniuk, Katarzyna; Dabrowski, Piotr; Greczka, Grazyna; Szabatowska, Katarzyna; Glowacka, Agata; Szyfter, Witold; Mazela, Jan

    2018-02-01

    The aim of this study was to analyze infants diagnosed with sensorineural or conductive hearing deficit and to identify risk factors associated with these defects. A retrospective analysis of infants diagnosed with hearing deficit based on the database of the universal newborn hearing screening program and medical records of the patients. 27 935 infants were covered by the universal neonatal hearing screening program. 109 (0.39%) were diagnosed with hearing deficit and referred for treatment and rehabilitation. 56 (51.4%) children were diagnosed with conductive, 38 (34.9%) with sensorineural and 15 (13.8%) with mixed type of hearing deficit. Children with sensorineural hearing deficit more frequently suffered from hyperbilirubinemia (p conductive hearing loss were more frequently diagnosed with isolated craniofacial anomalies (p hearing deficit occurred almost 3 times more often bilaterally than unilaterally (p hearing deficit, the difference was not significant. In children with conductive and mixed type of hearing loss the impairment was mainly mild while among those with sensorineural hearing deficit in almost 45% it was severe and profound (p hearing screening test by means of otoacoustic emissions and the final diagnosis of hearing deficit we found that the highest agreement rate was observed in children with sensorineural hearing loss (p hearing deficit was similar in children with sensorineural, conductive and mixed type of hearing loss, only hyperbilirubinemia seemed to predispose to sensorineural hearing deficit and isolated craniofacial malformations seemed to be associated with conductive hearing loss. Sensorineural hearing deficit usually occurred bilaterally and was severe or profound, while conductive and mixed type of hearing deficit were most often of mild degree. Most children with the final diagnosis of sensorineural hearing deficit had positive result of hearing screening by means of otoacoustic emissions. Copyright © 2017 Elsevier B.V. All

  18. Hearing Status in Pediatric Renal Transplant Recipients.

    Science.gov (United States)

    Gulleroglu, Kaan; Baskin, Esra; Aydin, Erdinc; Ozluoglu, Levent; Moray, Gokhan; Haberal, Mehmet

    2015-08-01

    Renal transplant provides a long-term survival. Hearing impairment is a major factor in subjective health status. Status of hearing and the cause of hearing impairment in the pediatric renal transplant group have not been evaluated. Here, we studied to evaluate hearing status in pediatric renal transplant patients and to determine the factors that cause hearing impairment. Twenty-seven pediatric renal transplant recipients were investigated. All patients underwent audiologic assessment by means of pure-tone audiometry. The factors on hearing impairment were performed. Sensorineural hearing impairment was found in 17 patients. There was marked hearing impairment for the higher frequencies between 4000 and 8000 Hz. Sudden hearing loss developed in 2 patients, 1 of them had tinnitus. Decrease of speech understanding was found in 8 patients. The cyclosporine level was significantly high in patients with hearing impairment compared with group without hearing impairment. Cyclosporine levels also were found to be statistically significantly high when compared with the group with decrease of speech understanding and the group without decrease of speech understanding. Similar relations cannot be found between tacrolimus levels and hearing impairment and speech understanding. Sensorineural hearing impairment prevalence was high in pediatric renal transplant recipients when compared with the general population of children. Cyclosporine may be responsible for causing hearing impairment after renal transplant. We suggest that this effect is a dose-dependent toxicity.

  19. Hearing Loss, Dizziness, and Carbohydrate Metabolism.

    Science.gov (United States)

    Albernaz, Pedro L Mangabeira

    2016-07-01

    Metabolic activity of the inner ear is very intense, and makes it sensitive to changes in the body homeostasis. This study involves a group of patients with inner ear disorders related to carbohydrate metabolism disturbances, including hearing loss, tinnitus, dizziness, and episodes of vertigo. To describe the symptoms of metabolic inner ear disorders and the examinations required to establish diagnoses. These symptoms are often the first to allow for an early diagnosis of metabolic disorders and diabetes. Retrospective study of 376 patients with inner ear symptoms suggestive of disturbances of carbohydrate metabolism. The authors present patientś clinical symptoms and clinical evaluations, with emphasis on the glucose and insulin essays. Authors based their conclusions on otolaryngological findings, diagnostic procedures and treatment principles. They found that auditory and vestibular symptoms usually occur prior to other manifestations of metabolic changes, leading to an early diagnosis of hyperinsulinemia, intestinal sugar malabsorption or diabetes. Previously undiagnosed diabetes mellitus type II was found in 39 patients. The identification of carbohydrate metabolism disturbances is important not only to minimize the patients' clinical symptoms, but also to help maintain their general health.

  20. Hearing Loss, Dizziness, and Carbohydrate Metabolism

    Directory of Open Access Journals (Sweden)

    Albernaz, Pedro L. Mangabeira

    2015-07-01

    Full Text Available Introduction Metabolic activity of the inner ear is very intense, and makes it sensitive to changes in the body homeostasis. This study involves a group of patients with inner ear disorders related to carbohydrate metabolism disturbances, including hearing loss, tinnitus, dizziness, and episodes of vertigo. Objectives To describe the symptoms of metabolic inner ear disorders and the examinations required to establish diagnoses. These symptoms are often the first to allow for an early diagnosis of metabolic disorders and diabetes. Methods Retrospective study of 376 patients with inner ear symptoms suggestive of disturbances of carbohydrate metabolism. The authors present patientś clinical symptoms and clinical evaluations, with emphasis on the glucose and insulin essays. Results Authors based their conclusions on otolaryngological findings, diagnostic procedures and treatment principles. They found that auditory and vestibular symptoms usually occur prior to other manifestations of metabolic changes, leading to an early diagnosis of hyperinsulinemia, intestinal sugar malabsorption or diabetes. Previously undiagnosed diabetes mellitus type II was found in 39 patients. Conclusions The identification of carbohydrate metabolism disturbances is important not only to minimize the patients' clinical symptoms, but also to help maintain their general health.

  1. Deterioration of noise-induced hearing loss among bottling factory workers.

    Science.gov (United States)

    Ologe, F E; Olajide, T G; Nwawolo, C C; Oyejola, B A

    2008-08-01

    Repeated exposure to excessive noise will eventually lead to an irreversible increase in hearing thresholds. In theory, the damage reflects both the intensity of the noise and the duration of exposure. This is not linear with respect to duration of exposure; rather, the worker may experience a disproportionate loss in the early years of exposure. A prospective study surveying workers of the production section (i.e. most noise-exposed area) of a bottling factory was carried out in December 2003 and in December 2005. A self-administered questionnaire was used to extract information about worker's demographic characteristics, drug intake, and medical and occupational history, as well as information on the use of hearing protection devices. Noise mapping of the various departments of the factory was carried out. Otological examination, tympanometry and audiometry were also carried out on selected subjects. Eighty-four workers, 76 (90.5 per cent) men and eight (9.5 per cent) women, were studied. Their mean age was 33.0 +/- 7.6 years in 2003 and 35.0 +/- 7.6 years in 2005. The recorded noise levels in the factory production section ranged between 91.5 and 98.7 dBA. The prevalence of sensorineural hearing loss among workers was noted to be 64.9 and 86.9 per cent for test one (2003) and test two (2005), respectively. The degree of hearing deterioration within the two years of this study was 1.0-3.2 dB for the right ear and 1.6-3.4 dB for the left ear. This deterioration was at discrete frequencies. More than half (53.6 per cent) of the workers did not have a hearing protection device. Of the 46.4 per cent who did, only 38.5 per cent claimed to have used it regularly. These findings showed that there was a high prevalence of mild sensorineural hearing loss and significant hearing deterioration among workers, due to exposure to excessive noise over a two-year period. The study demonstrates the practical importance of serial audiometry for noise-exposed workers as a means of

  2. Antibacterial efficacy and effect of Morinda citrifolia L. mixed with irreversible hydrocolloid for dental impressions: A randomized controlled trial.

    Science.gov (United States)

    Ahmed, A Shafath; Charles, P David; Cholan, R; Russia, M; Surya, R; Jailance, L

    2015-08-01

    This study aimed to evaluate whether the extract of Morinda citrifolia L. mixed with irreversible hydrocolloid powder decreases microbial contamination during impression making without affecting the resulting casts. Twenty volunteers were randomly divided into two groups (n = 10). Group A 30 ml extract of M. citrifolia L diluted in 30 ml of water was mixed to make the impression with irreversible hydrocolloid material. Group B 30 ml deionized water was mixed with irreversible hydrocolloid material to make the impressions following which the surface roughness and dimensional stability of casts were evaluated. Extract of M. citrifolia L. mixed with irreversible hydrocolloid decreased the percentage of microorganisms when compared with water (P impression quality.

  3. Psychosocial Aspects of Hearing Loss in Children.

    Science.gov (United States)

    Sorkin, Donna L; Gates-Ulanet, Patricia; Mellon, Nancy K

    2015-12-01

    Pediatric hearing loss changed more in the past two decades than it had in the prior 100 years with children now identified in the first weeks of life and fit early with amplification. Dramatic improvements in hearing technology allow children the opportunity to listen, speak and read on par with typically hearing peers. National laws mandate that public and private schools, workplaces, and anywhere people go must be accessible to individuals with disabilities. In 2015, most children with hearing loss attended mainstream schools with typically hearing peers. Psychosocial skills still present challenges for some children with hearing loss. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Addressing Intersections in HIV/AIDS and Mental Health: The Role of Organizations for d/Deaf and Hard of Hearing Individuals in South Africa

    Science.gov (United States)

    Mall, Sumaya; Swartz, Leslie

    2011-01-01

    Like South Africans generally, d/Deaf and hard of hearing South Africans are at risk of HIV/AIDS and mental disorders resulting from barriers to communication and care. In interviews and a focus group, members of South African organizations for d/Deaf and hard of hearing individuals all gave priority to HIV/AIDS education and prevention, citing…

  5. Acoustics and Hearing

    CERN Document Server

    Damaske, Peter

    2008-01-01

    When one listens to music at home, one would like to have an acoustic impression close to that of being in the concert hall. Until recently this meant elaborate multi-channelled sound systems with 5 or more speakers. But head-related stereophony achieves the surround-sound effect in living rooms with only two loudspeakers. By virtue of their slight directivity as well as an electronic filter the limitations previously common to two-speaker systems can be overcome and this holds for any arbitrary two-channel recording. The book also investigates the question of how a wide and diffuse sound image can arise in concert halls and shows that the quality of concert halls decisively depends on diffuse sound images arising in the onset of reverberation. For this purpose a strong onset of reverberation is modified in an anechoic chamber by electroacoustic means. Acoustics and Hearing proposes ideas concerning signal processing in the auditory system that explain the measured results and the resultant sound effects plea...

  6. Hearing impairment in Estonia

    DEFF Research Database (Denmark)

    Teek, R; Kruustük, K; Zordania, R

    2013-01-01

    Abstract Purpose: The present study was initiated to establish the etiological causes of early onset hearing loss (HL) among Estonian children between 2000-2009. Methods: The study group consisted of 233 probands who were first tested with an arrayed primer extension assay, which covers 199 mutat...... for 115 Estonian patients (49%). This algorithm may be generalized to other populations for clinical application....... performed. Results: In 110 (47%) cases, the etiology of HL was genetic and in 5 (2%) congenital CMV infection was diagnosed. We found mutations with clinical significance in GJB2 (100 children, 43%) and in 2 mitochondrial genes (2 patients, 1%). A single mutation in SLC26A4 gene was detected in 5 probands...... able to conclude that the found abnormalities are definitely pathogenic (12q13.3-q14.2 and 17q22-23.2 microdeletion), but the pathogenity of 2 other findings (3p26.2 and 1p33 microdeletion) remained unknown. Conclusion: This practical diagnostic algorithm confirmed the etiology of early onset HL...

  7. The relation of hearing loss degrees and oral stereognosis in 5-year-old children

    Directory of Open Access Journals (Sweden)

    Seyede Zohre Mousavi

    2012-12-01

    Full Text Available Background and Aim: Oral stereognosis is the ability to recognize the objects placed in the mouth; this plays a significant role in speech sounds production. Since the children with hearing loss have articulation disorders, this study aimed to clear the relation of hearing loss degrees and oral stereognosis in 5-year-old children.Methods: In this cross-sectional non-invasive study, 40 children of 5-year-old (30 children with different degrees of hearing loss and 10 normal children were involved. Oral steriognostic test was done for all of them and the Mann-Whitney U was used for statistical analysis.Results: There were significant differences between the mean of oral stereognostic ability between the normal children and the children with severe (p<0.01 or profound hearing loss (p=0.05. There was no significant difference between the mean of oral stereognostic ability among the children with moderate, severe and profound hearing loss compared with together. Besides, there was no significant difference between the mean of the time of diagnosis among all of hearing loss and normal children.Conclusion: The study shows that the children with moderate, severe and profound hearing loss have inefficient oral stereognosis in comparison with the normal children.

  8. Newborn hearing screening vs later hearing screening and developmental outcomes in children with permanent childhood hearing impairment

    NARCIS (Netherlands)

    Korver, Anna M. H.; Konings, Saskia; Dekker, Friedo W.; Beers, Mieke; Wever, Capi C.; Frijns, Johan H. M.; Oudesluys-Murphy, Anne M.; de Vries, Jutte; Vossen, Ann; Kant, Sarina; van den Akker-van Marle, Elske; le Cessie, Saskia; Rieffe, Carolien; Ens-Dokkum, Martina; van Straaten, Irma; Uilenburg, Noelle; Elvers, Bert; Loeber, Gerard; Meuwese-Jongejeugd, Anneke; Maré, Marcel; van Zanten, Bert; Goedegebure, André; Coster, Francien; van Dijk, Pim; Goverts, Theo; Admiraal, Ronald; Cremers, Cor; Kunst, Dirk; de Leeuw, Marina; Dijkhuizen, Janette; Scharloo, Marleen; Hoeben, Dirk; Rijpma, Gerti; Graef, Wim; Linschoten, Dik; Kuijper, Jessica; Hof, Nanda; Koldewijn, Reinoud; Pans, Donné; Jorritsma, Frank; van Beurden, Maarten; ter Huurne, Christien; Brienesse, Patrick; Seekles, Lisanne; de Jong, Jantine; Thijssen, Andrea; Lievense, Andrea; van Egdom-van der Wind, Marina; Theunissen, Stephanie; Mooij, Sophie

    2010-01-01

    Newborn hearing screening programs have been implemented in many countries because it was thought that the earlier permanent childhood hearing impairment is detected, the less developmentally disadvantaged children would become. To date, however, no strong evidence exists for universal introduction

  9. Ecological optimization and performance study of irreversible Stirling and Ericsson heat engines

    International Nuclear Information System (INIS)

    Tyagi, S K; Kaushik, S C; Salhotra, R

    2002-01-01

    The concept of finite time thermodynamics is used to determine the ecological function of irreversible Stirling and Ericsson heat engine cycles. The ecological function is defined as the power output minus power loss (irreversibility), which is the ambient temperature times, the entropy generation rate. The ecological function is maximized with respect to cycle temperature ratio and the expressions for the corresponding power output and thermal efficiency are derived at the optimal operating conditions. The effect of different operating parameters, the effectiveness on the hot, cold and the regenerative side heat exchangers, the cycle temperature ratio, heat capacitance ratio and the internal irreversibility parameter on the maximum ecological function are studied. It is found that the effect of regenerator effectiveness is more than the hot and cold side heat exchangers and the effect of the effectiveness on cold side heat exchanger is more than the effectiveness on the hot side heat exchanger on the maximum ecological function. It is also found that the effect of internal irreversibility parameter is more than the other parameters not only on the maximum ecological function but also on the corresponding power output and the thermal efficiency

  10. Irreversible thermodynamics of dark energy on the entropy-corrected apparent horizon

    Energy Technology Data Exchange (ETDEWEB)

    Karami, K; Sahraei, N [Department of Physics, University of Kurdistan, Pasdaran Street, Sanandaj (Iran, Islamic Republic of); Jamil, M, E-mail: KKarami@uok.ac.i, E-mail: mjamil@camp.nust.edu.p [Center for Advanced Mathematics and Physics (CAMP), National University of Sciences and Technology (NUST), Islamabad (Pakistan)

    2010-10-15

    We study the irreversible (non-equilibrium) thermodynamics of the Friedmann-Robertson-Walker (FRW) universe containing only dark energy. Using the modified entropy-area relation that is motivated by loop quantum gravity, we calculate the entropy-corrected form of the apparent horizon of the FRW universe.

  11. Revisiting the Glansdorff–Prigogine criterion for stability within irreversible thermodynamics

    Czech Academy of Sciences Publication Activity Database

    Maes, C.; Netočný, Karel

    2015-01-01

    Roč. 159, č. 6 (2015), s. 1286-1299 ISSN 0022-4715 R&D Projects: GA ČR GAP204/12/0897 Institutional support: RVO:68378271 Keywords : irreversible processes * thermodynamic stability * excess entropy production * nonequilibrium free energy * Clausius heat theorem Subject RIV: BE - Theoretical Physics Impact factor: 1.537, year: 2015

  12. Irreversibility and multiplicity: two criteria for the disposal of nuclear wastes

    International Nuclear Information System (INIS)

    Rochlin, G.

    1976-01-01

    Two criteria are suggested for comparing waste management methods: technical irreversibility and site multiplicity. These criteria can be used to reduce future risk in the face of inherent uncertainty and to provide for safe disposal without requiring guaranteed future ability to recognize, detect or repair areas of failure

  13. Wall heat flux influence on the thermodynamic optimisation of irreversibilities of a circulating fluidised bed combustor

    CSIR Research Space (South Africa)

    Baloyi, J

    2016-07-01

    Full Text Available . The irreversibilities generated were arrived at by computing the entropy generation rates due to the combustion and frictional pressure drop processes. For the combustor where the wall condition was changed from adiabatic to negative heat flux (that is heat leaving...

  14. Performance characteristics and parametric optimization of an irreversible magnetic Ericsson heat-pump

    International Nuclear Information System (INIS)

    Wei Fang; Lin Guoxing; Chen Jincan; Brueck, Ekkes

    2011-01-01

    Taking into account the finite-rate heat transfer in the heat-transfer processes, heat leak between the two external heat reservoirs, regenerative loss, regeneration time, and internal irreversibility due to dissipation of the cycle working substance, an irreversible magnetic Ericsson heat-pump cycle is presented. On the basis of the thermodynamic properties of magnetic materials, the performance characteristics of the irreversible magnetic Ericsson heat-pump are investigated and the relationship between the optimal heating load and the coefficient of performance (COP) is derived. Moreover, the maximum heating load and the corresponding COP as well as the maximum COP and the corresponding heating load are obtained. Furthermore, the other optimal performance characteristics are discussed in detail. The results obtained here may provide some new information for the optimal parameter design and the development of real magnetic Ericsson heat-pumps. -- Research Highlights: →The effects of multi-irreversibilities on the performance of a magnetic heat-pump are revealed. →Mathematical expressions of the heating load and the COP are derived and the optimal performance and operating parameters are analyzed and discussed. →Several important performance bounds are determined.

  15. Ecological optimization and performance study of irreversible Stirling and Ericsson heat engines

    Science.gov (United States)

    Tyagi, S. K.; Kaushik, S. C.; Salhotra, R.

    2002-10-01

    The concept of finite time thermodynamics is used to determine the ecological function of irreversible Stirling and Ericsson heat engine cycles. The ecological function is defined as the power output minus power loss (irreversibility), which is the ambient temperature times, the entropy generation rate. The ecological function is maximized with respect to cycle temperature ratio and the expressions for the corresponding power output and thermal efficiency are derived at the optimal operating conditions. The effect of different operating parameters, the effectiveness on the hot, cold and the regenerative side heat exchangers, the cycle temperature ratio, heat capacitance ratio and the internal irreversibility parameter on the maximum ecological function are studied. It is found that the effect of regenerator effectiveness is more than the hot and cold side heat exchangers and the effect of the effectiveness on cold side heat exchanger is more than the effectiveness on the hot side heat exchanger on the maximum ecological function. It is also found that the effect of internal irreversibility parameter is more than the other parameters not only on the maximum ecological function but also on the corresponding power output and the thermal efficiency.

  16. Pulpitis irreversible como forma de presentación de un odontoma

    OpenAIRE

    Berástegui, Esther; Buenechea Imaz, Ramón

    1997-01-01

    Se presenta un caso de odontoma compuesto que provocó pulpitis irreversible en el incisivo central superior derecho (1,1) en una joven de 20 años. El tratamiento fue la biopulpectomía total y extirpación quirúrgica del tumor.

  17. How to account for irreversibility in integrated assessment of climate change?

    International Nuclear Information System (INIS)

    Ha Duong, M.

    1998-04-01

    How to account for irreversibility in integrated assessment of climate change? This Ph. D. thesis in Economics balances discounting, technical progress and the inertia of existing capital stock against uncertainty and the inertia of socio-economic systems to examine the issue of near term limitations of greenhouse gases emissions. After a general overview in chapter 2, and a more historical presentation of the debates in chapter 3, chapter 4 proceeds to review a large number of integrated assessment models. Chapter 5 introduces a Model on the Dynamics of Inertia and Adaptability of energy systems: DIAM, used to discuss how much previous studies might have overestimated the long term costs of CO 2 limitations and underestimated adjustment costs. It shows that, given a target date for atmospheric CO 2 concentration stabilisation, a higher inertia implies a lower optimal concentration trajectory. In a sequential decision framework, chapter 6 shows that current uncertainties about which CO 2 concentration ceiling would not present dangerous interference with the climate system justifies precautionary action. Finally, chapter 7 uses the irreversibility effect theory to define formally situations of decision under controversy and compare the irreversibility of CO 2 accumulation with the irreversibility of investments needed to moderate it. An option value for greenhouse gases emissions limitations is computed. (author)

  18. Irreversible colloidal agglomeration in presence of associative inhibitors: Computer simulation study

    International Nuclear Information System (INIS)

    Barcenas, Mariana; Duda, Yurko

    2007-01-01

    Monte Carlo simulation is employed to study the irreversible particle-cluster agglomeration of valence-limited colloids affected by associative inhibitors. The cluster size distribution and number of connections between colloids are analyzed as a function of density and inhibitor concentration. The influence of colloid functionality on its aggregation is discussed

  19. Which elements are involved in reversible and irreversible cartilage degradation in osteoarthritis?

    DEFF Research Database (Denmark)

    Bay-Jensen, Anne-Christine; Hoegh-Madsen, Suzi; Dam, Erik

    2010-01-01

    -physiology of the joint and whether the joint damage is reversible or irreversible. In this review, we compile emerging data on cellular and pathological aspects of OA, and ask whether these data could give clue to when cartilage degradation is reversible and whether a point-of-no-return exists. We highlight different...

  20. Unifying principles of irreversibility minimization for efficiency maximization in steady-flow chemically-reactive engines

    International Nuclear Information System (INIS)

    Ramakrishnan, Sankaran; Edwards, Christopher F.

    2014-01-01

    Systems research has led to the conception and development of various steady-flow, chemically-reactive, engine cycles for stationary power generation and propulsion. However, the question that remains unanswered is: What is the maximum-efficiency steady-flow chemically-reactive engine architecture permitted by physics? On the one hand the search for higher-efficiency cycles continues, often involving newer processes and devices (fuel cells, carbon separation, etc.); on the other hand the design parameters for existing cycles are continually optimized in response to improvements in device engineering. In this paper we establish that any variation in engine architecture—parametric change or process-sequence change—contributes to an efficiency increase via one of only two possible ways to minimize total irreversibility. These two principles help us unify our understanding from a large number of parametric analyses and cycle-optimization studies for any steady-flow chemically-reactive engine, and set a framework to systematically identify maximum-efficiency engine architectures. - Highlights: • A unified thermodynamic model to study chemically-reactive engine architectures is developed. • All parametric analyses of efficiency are unified by two irreversibility-minimization principles. • Variations in internal energy transfers yield a net work increase that is greater than engine irreversibility reduced. • Variations in external energy transfers yield a net work increase that is lesser than engine irreversibility reduced